Use of bidirectional Mendelian randomization to unveil the association of Helicobacter pylori infection and Pancreatic cancer

Use of bidirectional Mendelian randomization to unveil the association of Helicobacter pylori infection and Pancreatic cancer | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Use of bidirectional Mendelian randomization to unveil the association of Helicobacter pylori infection and Pancreatic cancer Jingping Hu, Lintao Dong, FangWang This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7168408/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Introduction : Helicobacter pylori(H. pylori), a common gram-negative bacterium and known carcinogen, causes chronic infection. Recent studies suggest its link to extra-gastric cancers, including pancreatic cancer, but conflicting findings due to confounding factors hinder clear association. Methods : Using summary-level data from genome-wide association studies, we analyzed the bidirectional causal relationship between H. pylori-related antibody-mediated immune responses and pancreatic cancer. We further validated the results using generalized summary-data-based Mendelian randomization(GSMR). Results : We found that the levels of H. pylori outer membrane protein(OMP) antibody can significantly increase the risk of pancreatic cancer (OR: 1.8122, 95% CI: 1.3192 to 2.4894, P < 0.001). These results were consistent with the weighted median algorithm (OR: 1.9638, 95% CI: 1.2686 to 3.0399, P = 0.002). Furthermore, the results from GSMR were also consistent with the above results (OR: 1.7099, 95% CI: 1.2632 to 2.3144, P < 0.001). Conclusion : Our study found that H. pylori OMP antibody levels significantly increase pancreatic cancer risk. With rising antibiotic resistance, OMP’s adhesive properties and immune-triggering potential make it a promising target for H. pylori vaccine development, offering future prospects for prevention and treatment. Bioinformatics Gastroenterology & Hepatology Pancreatic cancer Helicobacter pylori Antibody-mediated immune response mendelian randomization Genetic Summary-data-based Mendelian Randomization Figures Figure 1 Figure 2 Figure 3 1 Introduction Pancreatic cancer is one of the deadliest cancers, with a median survival period of approximately 4 months and a 5-year survival rate of 13% 1 . Additionally, Pancreatic cancer progresses rapidly and usually worsens within just a few months of diagnosis 2 . The treatment of pancreatic cancer mainly includes surgery, chemotherapy, radiotherapy, and targeted therapy. Surgery is the only possible cure, but it is restricted to early-stage patients. Due to late-stage diagnosis, many patients are no longer eligible for surgical resection at the time of presentation 3 . However, the etiological mechanism of pancreatic cancer is still unclear, and environmental, and lifestyle risk factors and genetic predisposition may contribute to the development of pancreatic cancer. At present, scholars believe that it involves a variety of factors, including gene mutations (such as changes in KRAS, p53, and other genes), chronic inflammation (such as chronic pancreatitis), and changes in the pancreatic microenvironment 4 . Chronic inflammation and immune responses can induce the continuous expression of pro-inflammatory cytokines (such as TNF-α and IL-6), thereby activating signaling pathways such as Hh and Wnt-β-catenin, promoting tumor cell proliferation, anti-apoptosis and immune escape 5 . Epithelial-mesenchymal transformation (EMT) may also be one of the pathogeneses because it contributes to the invasion and metastasis of cancer cells 6 . Therefore, it is urgently necessary to deeply clarify the inflammation-related signaling network, the regulatory mechanism of EMT, and the key molecular interactions between the tumor microenvironment and immune response in pancreatic cancer, so as to provide a solid theoretical basis for the development of targeted therapy and immunotherapy strategies. H. pylori is a spiral-shaped gram-negative bacterium that is the most common chronic bacterial infection worldwide. Recently, in 2021, the National Toxicology Program's 15th Report on Carcinogens listed chronic H. pylori infection as a "substance known or reasonably expected to be carcinogenic to humans" 7 . If H. pylori infection is not eradicated, prolonged infection may lead to disease progression and an increased risk of mucosa-associated lymphoid tissue (MALT) lymphoma, gastric cancer, and other cancers 8 , 9 . In recent years, it has been found that chronic infection of H. pylori may also be associated with a variety of extra-gastric malignant diseases, such as pancreatic cancer, esophageal cancer, and colorectal cancer 10 – 12 . Although the exact mechanism by which H. pylori infection promotes the occurrence and development of pancreatic cancer is still under exploration, some scholars have proposed that it may involve several biological theories. H. pylori infection causes chronic reactions in the gastrointestinal mucosa. The persistent inflammatory state may affect the adjacent pancreatic tissue through paracrine means, leading to persistent oxidative stress and DNA damage 13 , 14 . Inflammation-related cytokines can further promote the proliferation of abnormal cells and immune escape. H. pylori infection may also activate the Wnt/β-catenin signaling pathway, which plays a central role in carcinogenesis by promoting the expansion of cancer stem-like cells 15 , 16 . In addition, H.pylori weakens the body's ability to recognize and eliminate abnormal pancreatic cells by affecting the immune microenvironment 17 . Lifestyle factors, genetic susceptibility, and the virulence factors of the bacterial strain can all act in concert with H. pylori infection to increase the risk of pancreatic cancer 18 . Interestingly, although new studies have continuously appeared in recent years on whether there is an association between pancreatic cancer and H. pylori, their conclusions have been inconsistent. This may be because most studies did not adequately adjust for confounders at the time of data aggregation, making it difficult to draw a definitive conclusion on whether there is an association between H. pylori and pancreatic cancer. In this study, we aimed to analyze the causal relationship between seven antibody immune responses to H. pylori and pancreatic cancer. We chose to use the antibody-mediated immune response data after H.pylori infection because antibodies can reflect the host's long-term immune memory of H.pylori infection, which is helpful for a more comprehensive understanding of the long-term association between infection and pancreatic cancer and its underlying mechanism. Mendelian randomization (MR) infers the potential causal relationship between exposure factors and outcomes by using genetic variations as instrumental variables (IVs) 19 . In this study, we further employed the generalized summary Mendelian Randomization (GSMR) method. GSMR accounts for the linkage disequilibrium (LD) among genetic variations in its analysis and identifies and eliminates pleiotropic single-nucleotide polymorphisms (SNPs) through the Heterogeneity In Dependent Instruments (HEIDI) outlier test, thereby enhancing the reliability and efficiency of causal estimation 20 . Since previous epidemiological studies have failed to establish a causal relationship between H. pylori infection and pancreatic cancer, we use data from the Genome-Wide Association Study (GWAS) to apply bidirectional two-sample MR and GSMR to clarify the complex causal relationship between them. 2 Materials and methods 2.1 Research design The data used in this MR Study were approved by the ethical review committee of the relevant research professional institutions. Therefore, no additional ethical scrutiny was required. All experimental results were described in detail in the text and supplementary materials. In this study, we used 7 antibodies against H. pylori as the exposure database, and European patients with pancreatic cancer as the outcome (In Fig. 1 ). Two-sample bidirectional MR method was used to analyze the causal relationship between H. pylori and pancreatic cancer. Based on MR, we also employed the GSMR method to verify the results obtained by the above method. In this study, SNPs were defined as IVs. 2.2 Data source The exposure data used in our analysis came from aggregated GWAS results for seven antibody immune responses associated with H. pylori infection as proposed by Butler-Laporte et al. These antibody types were used to evaluate the host immune response to various H. pylori components, including overall IgG seropositivity and antibodies targeting specific antigens such as cytotoxin-associated gene A (CagA), catalase, 60-kDa heat shock protein (GroEL), OMP, urease subunit (UREA), and vacuolating cytotoxin A (VacA). The summary statistics were obtained respectively from GWAS analyses of 8735, 985, 1558, 2716, 2640, 2251, and 1571 participants, which were available in the MRC-IEU UK Biobank (UKB) OpenGWAS 21 . We extracted IVs for pancreatic cancer from the GWAS conducted by Jiang et al., which included 232 cases and 456,116 controls, covering a total of 1,701,334 SNPs 22 . Detailed information of all data can be found in Table 1 . Table 1 Details of the genome-wide association studies and datasets used in this study. Exposure or outcome Links for datadownload PMID pancreatic cancer https://www.ebi.ac.uk/gwas/studies/GCST90043861 34737426 Anti-helicobacter pylori IgG seropositivity https://www.ebi.ac.uk/gwas/studies/GCST90006910 33204752 Helicobacter pylori CagA antibody levels https://www.ebi.ac.uk/gwas/studies/GCST90006911 33204752 Helicobacter pylori Catalase antibody levels https://www.ebi.ac.uk/gwas/studies/GCST90006912 33204752 Helicobacter pylori GroEL antibody levels https://www.ebi.ac.uk/gwas/studies/GCST90006913 33204752 Helicobacter pylori OMP antibody levels https://www.ebi.ac.uk/gwas/studies/GCST90006914 33204752 Helicobacter pylori UREA antibody levels https://www.ebi.ac.uk/gwas/studies/GCST90006915 33204752 Helicobacter pylori VacA antibody levels https://www.ebi.ac.uk/gwas/studies/GCST90006916 33204752 2.3 MR analysis We applied five MR analysis methods, including inverse variance weighted (IVW), MR-Egger, Weighted Median, MR-PRESSO, and simple mode and weighted mode to analyze the relationship between all antibody-mediated immune responses and pancreatic cancer 23 – 25 . SNPs that reached a genome-wide significance level (P < 1 × 10^-5) were used as IVs of antibody-mediated immune responses associated with H. pylori. To investigate the reverse causal relationship, we used the following selection criteria to select genetic IVs, setting a GWAS significance threshold of P < 5 × 10^-5 for SNPs associated with pancreatic cancer. Then, we clumped the GWAS significant SNPs from each split’s GWAS with a clumping window of 10,000 kb and an r² threshold of 0.001. All non-matching alleles were aligned, and the signs of the beta estimates were flipped 26 . We calculated the F statistics of the selected SNPs to detect the strength of the IVs at a threshold of F > 10, which is typically recommended in MR analysis. Then, we excluded SNPs associated with confounders that interfere with the pathway between H. pylori infection and pancreatic cancer 27 . We estimated heterogeneity among IVs by using Cochran’s Q statistic 28 . We used the MR-Egger intercept method and the MR-PRESSO to assess bias that might be caused by horizontal pleiotropy. Finally, we conducted a leave-one-out analysis to evaluate the robustness of MR Results. 2.4 GSMR approach In our primary analysis, we adopted GSMR, a flexible approach that tested the causal relationship between risk factors (or phenotypes) and disease by using aggregated GWAS data from independent studies for MR analysis and using multiple near-independent IVs. For the genetic IVs in the exposure, we selected genome-wide significance SNPs (r^2 threshold of 0.05, P-value threshold of 1 × 10^-5) for each feature by using a linkage elimination algorithm and used the "1000 genome (1000G) Phase III European sample as a reference estimates for LD". In the reverse analysis, for GWAS summary statistics for pancreatic cancer, we selected independent SNPs with an LD threshold of r^2 < 0.05 and a P-value threshold of 5 × 10^-5. Then, the HEIDI outlier method was applied to remove IVs with strong predictive pleiotropy effects, and the P-value threshold is set to 0.01 in the HEIDI outlier filtering analysis 29 . All analyses were performed using "TwoSampleMR", "foreach", "gsmr2" and "ggplot2" in R version 4.3.1 for data visualization and analysis. 2.5 Ethical Statement Participants consented to the GWAS as per the original protocols, and all ethical approvals were obtained by the original authors. 3 Results 3.1. Association between H. pylori and pancreatic cancer by MR After removing palindromic and ambiguous SNPs, non-proxy SNPs, and SNPs identified by Steiger filtering as having incorrect causal direction, the number of SNPs used as IVs for each exposure was presented in Supplementary Table S1. This table also provided the variances interpreted as exposure instruments and F statistics. All F-values were greater than 10, indicating that our study provided strong statistical power to detect potential causal effects between H. pylori and pancreatic cancer. We analyzed the levels of several H. pylori-related antibodies, including anti-H. pylori IgG seropositivity and antibodies against specific antigens such as CagA, catalase, GroEL, OMP, UREA, and VacA. In our research, the IVW algorithm was the main method, and viewed other methods as auxiliary. We observed an increased risk of pancreatic cancer for every one standard deviation increase in H. pylori OMP antibody levels (OR: 1.8122, 95% CI: 1.3192 to 2.4894 P <0.001), the results were consistent with the Weighted median algorithm (OR: 1.9638, 95% CI: 1.2686 to 3.0399 P =0.002), and both were statistically significant (Supplementary Table S4). However, other antibody-mediated immune responses associated with H. pylori infection were not found to have a statistically significant causal effect. In addition, to further explore the causal relationship between pancreatic cancer and H. pylori, we also used reverse MR to detect whether there was a reverse causal relationship between them. The results showed that pancreatic cancer did not affect the level of H. pylori antibody-mediated immune response (In Figure 2). 3.2. Association between H. pylori and pancreatic cancer by GSMR After the ordinary bidirectional two-sample MR, we further applied GSMR analysis to ensure the robustness of the analysis. The GSMR method can effectively identify and eliminate multiple groups of genetic variants, thus reducing bias and improving the reliability of causal reasoning. In the GSMR results, each standard deviation increase in H. pylori OMP antibody levels was associated with an increased risk of pancreatic cancer (OR: 1.7099, 95% CI: 1.2632 to 2.3144 P <0.001). The OR of other H. pylori-related antibody-mediated immune responses was greater than 1, but there was no statistical significance. In addition, pancreatic cancer did not affect the level of antibody-mediated immune response to H. pylori in the GSMR (In Figure 3). 3.3. Sensitivity analysis To ensure that the results were accurate and reliable, we assessed the sensitivity of each antibody immune response. Cochran's Q test (Supplementary Table S2) and funnel plot (Supplementary Figure S1-S2) were used to detect heterogeneity. Horizontal pleiotropy was detected by the MR-Egger intercept method and the MRPRESSO method (Supplementary Table S2). The results showed that when pancreatic cancer was the outcome and H. pylori UREA antibody levels were used as the exposure, MR Egger and IVW are found to be heterogeneous (Q=42.91; Q-P value=0.01). No heterogeneity or pleiotropy was found in other results. Leave-one-out analysis did not identify any single SNP with a significant influence on the overall causal estimate (Supplementary Figures S3-S4). 4 Discussion H. pylori is a spiral-shaped gram-negative bacterium known to be associated with gastric and duodenal ulcers and gastric cancer 30 , 31 . With further study, researchers have found that H. pylori is associated with the occurrence and development of some extra-gastric diseases. The association between H. pylori infection and pancreatic cancer has remained inconclusive despite extensive investigation. In bidirectional two-sample MR analysis, our study found that genetically predicted H. pylori OMP antibody levels are causally associated with the development of pancreatic cancer. OMP plays a key role in the attachment and colonization of gastric mucosa by H. pylori, and the presence of antibodies indicates that an infection has occurred or is currently present. Xu et al. evaluated the association between H. pylori infection and pancreatic cancer by conducting a meta-analysis of 17 studies. The results showed a significant association between H. pylori infection and pancreatic cancer, but no significant association was found in CagA and VacA-positive strains 32 . Xiao et al. conducted a meta-analysis of 9 studies from different regions and found a weak association between H. pylori infection and pancreatic cancer 33 . Guo et al. 's meta-analysis also obtained the same result, but due to statistical heterogeneity and publication bias, the conclusion needs to be further verified by basic experiments 34 . It is noteworthy that Huang et al. conducted a case-control study on the pathology of 448 patients with pancreatic cancer and their controls and found that the risk of pancreatic cancer was seropositive with H. pylori in the European population (OR = 0.96; 95% CI: 0.70, 1.31) or CagA seropositive (OR = 1.07; 95% CI: 0.77, 1.48) were not relevant 35 . Interestingly, Schulte et al. collected blood samples from 580 patients and 626 controls and used an Enzyme-Linked Immunosorbent Assay (ELISA) kit to determine the seroprevalence of H. pylori and its virulent protein CagA. No association was observed between positive serum antibodies to H. pylori and the risk of pancreatic cancer. Interestingly, the study also found that CagA-negative H. pylori was associated with an increased risk of pancreatic cancer (OR 1.23; 95% CI 0.83–1.82), suggesting that the association between H. pylori and pancreatic cancer may depend on different strain types of H. pylori 36 . This finding is consistent with our study, which also identified a causal relationship between H.pylori OMP antibody levels and adenocarcinoma, while H.pylori CagA antibody levels showed no causal relationship with pancreatic cancer. This may be because some meta-analyses did not consider whether the included population is smokers 37 , as smokers have a higher incidence of H. pylori and pancreatic cancer than non-smokers 38 . It may also be due to different detection methods that lead to different results 39 . Most existing studies only detect H. pylori IgG or IgM antibodies to determine the infection, once either of the IgG or IgM antibodies is seropositivity, it is identified as H. pylori infection. However, this approach does not adequately consider levels of other key antigens of H. pylori, such as Catalase, GroEL, OMP, UREA, and VacA antibodies, which may also play an important role in the pathogenic mechanism. H. Pylori detection methods include invasive and non-invasive methods. Invasive methods are histological examination, rapid urease test, or bacterial culture by gastroscopy sampling, while non-invasive methods include breath tests, serum antibody testing, and fecal antigen testing. Although invasive tests (such as gastroscopy combined with gastric mucosal biopsy for histopathology of H. pylori) can provide a definitive diagnosis, they are not beneficial for pregnant women. Therefore, non-invasive diagnostic methods such as serum antibody tests, urea breath tests, and fecal antigen tests are the preferred common detections. The detection of H.pylori IgG antibodies in the patient's serum by ELISA can reflect the current or previous infection status. This is because it takes 6 to 12 months for the antibodies to turn negative after the eradication of H.pylori, which leads to different test results 40 . Therefore, our study used serum-based detection of antibody-mediated immune responses to H. pylori, offering a non-invasive approach suitable for vulnerable populations such as pregnant women, children, and the elderly. Secondly, the serum levels of H. pylori IgG antibodies, CagA, Catalase, GroEL, OMP, UREA, and VacA are detected by ELISA. The advantage of this multi-indicator test is that it provides a more comprehensive assessment of H. pylori infection status, especially infection caused by different strains and virulence factors. Scholars have proposed several possible mechanisms to explain how H. pylori increases the risk of pancreatic cancer. After long-term colonization of the gastric mucosa by H.pylori, the gastric mucosa usually undergoes a series of pathological changes, such as chronic superficial gastritis, atrophic gastritis, intestinal metaplasia, and dysplasia. The development of multifocal atrophic gastritis can lead to the loss of parietal cells, which in turn can lead to low or no gastric acid, and it is worth noting that about one-third of gastric cancer occurs in patients with acid deficiency. Too low stomach acid can lead to bacterial overgrowth and an increase in N-nitroso compounds. Through blood circulation, N-nitrosamines may be transported to the pancreas, resulting in the activation of oncogenes in the pancreatic duct epithelium 41 – 43 . Juhua Luo et al. concluded through a large number of cohort studies that they were consistent with the previously proposed hypothesis model that "H. pylori infection promotes the occurrence of pancreatic cancer through gastric body colonization, low gastric acid state and the formation of nitrosamines in the stomach", which also provides some support for us 44 . Another possible mechanism involves H. pylori colonization in the antrum, which may lead to excess gastric acid, which stimulates the duodenum to release uninhibited secretin and induces the basal bicarbonate secretion of the pancreatic duct, thereby causing the proliferation of the pancreatic ductal epithelial cells (PDECs) through increased DNA synthesis. Excessive proliferation of PDECs, accumulation of genetic mutations, and persistent chronic inflammation, leading to the occurrence and development of pancreatic cancer 45 . Our study found that genetically elevated levels of H. pylori OMP antibodies are a risk factor for pancreatic cancer, for which clinical evidence is lacking. H. pylori OMPs play a crucial role in the infection process, especially during bacterial attachment, colonization, and persistent infection. These proteins help H. pylori attach to gastric epithelial cells early in infection, increasing its virulence 46 . We hypothesize that seropositivity for H. pylori OMP antibodies may contribute causally to the development of pancreatic cancer. However, the main function of OMP protein is adhesion, and although it enhances the virulence of H. pylori, in the absence of the combined action of key virulence factors such as CagA and VacA, the promotional effect of single OMP antibody-positive strains in the development of pancreatic cancer may be relatively weak. The rise of antibiotic-resistant H. pylori strains has made vaccine development an urgent research priority. Because of their ability to adhere to and trigger host cell immune responses, OMPs are considered immune antigens. Researchers are also using proteomic approaches to assess whether OMP could be a candidate for vaccine 47 . As the role of H. pylori OMP in adhesion and triggering host immune responses is gradually revealed, OMP shows great prospects as a potential target for vaccine development in the prevention and treatment of pancreatic cancer in the future. Specifically, the OMP vaccine is expected to prevent H. pylori from playing a promoting role in the early development of pancreatic cancer by inhibiting the adhesion process of H. pylori, thereby reducing the persistent colonization of the bacteria in the stomach and other digestive tract tissues. Our research has several advantages. First, the combination of MR and GSMR analysis clarifies the causal direction and minimizes confounding bias. Second, all GWAS data come from participants of European descent, suggesting that population stratification has less impact on our results. Most importantly, the exposure data in our study use antibody-mediated immune responses to a variety of H. pylori-related proteins or factors, which, compared with other studies that directly evaluate H. pylori itself, provide a deeper reflection of the body's immune system's long-term response to H. pylori infection and its potential impact on cancer risk. For example, different virulence factors of H. pylori have different biological functions and may have different effects on cancer risk. By analyzing these specific factors, it is possible to identify specific virulence factors associated with disease risk; different strains of H. pylori may carry different virulence factors and have different effects on the disease. However, some limitations to our study should be noted. First, H.pylori is a highly heterogeneous bacterium, and numerous studies have confirmed that its virulence varies across geographic regions 48 , 49 . For instance, the H. pylori seroprevalence in Germany (defined as positivity for at least three antigens) is 48% 50 . In the study by Meira Epplein et al., it was found that the seropositive rate of H.pylori in African Americans was higher than that in white people 51 . Another study shows that in the Asian region, with the improvement of social and economic levels, the serological positive rate of H. pylori has been gradually decreasing, among which the infection rate in developed countries is significantly lower than that in developing and underdeveloped countries 52 . The seropositivity rates vary among different provinces in China. For instance, it is 58.3% in Guangxi, China 53 , while the IgG seropositivity rate in Beijing is 31.7% 54 . The data samples used in this study were all from European populations. Due to the differences in genetic background among these populations, the generalizability of the research results may be somewhat limited. Secondly, in this study, serum antibodies were used as indicators of H. pylori infection. However, some studies have pointed out that some antigens of H. pylori have molecular mimicry with the host's own proteins, and these antibodies may cross-react with host proteins such as heat shock protein 60 (HSP60), forming non-specific immune signals. For example, H. pylori GroEL has up to 54% sequence homology and 92% coverage with human HSP60, providing a structural basis for cross-reaction, and anti-H. pylori Hsp60 antibodies have been found to cross-bind to human Hsp60. This indicates that the current antibody level may not fully represent the immune response of a specific strain or virulence factor, thereby reducing the specificity of antibody-mediated indicators and the accuracy of infection recognition 55 . Finally, MR is a powerful tool for exploring the potential causal relationship between exposure and disease, but its results cannot replace clinical trials. Meanwhile, we also plan to isolate and purify H. pylori OMP-specific antibodies from the patient's serum for further research on the potential pathogenic mechanism between this strain and pancreatic cancer. Abbreviations Helicobacter pylori (H. pylori) linkage disequilibrium (LD) Generalized Summary Mendelian Randomization (GSMR) Genome-Wide Association Study (GWAS) Heterogeneity in Dependent Instruments (HEIDI) single nucleotide polymorphisms (SNPs) instrumental variables (IVs) outer membrane protein (OMP) inverse variance weighted (IVW) Mendelian Randomization (MR) Enzyme-Linked Immunosorbent Assay (ELISA) Epithelial-mesenchymal transition (EMT) heat shock protein 60 (HSP60) mucosa-associated lymphoid tissue (MALT) pancreatic ductal epithelial cells (PDECs) cytotoxin-associated gene A (CagA) 60-kDa heat shock protein (GroEL) urease subunit (UREA) vacuolating cytotoxin A (VacA). Declarations Data availability statement The datasets used in this study are accessible through online repositories. The article's Table 1 include the repository names and accession numbers. We are deeply appreciative of all participants and researchers who shared these valuable datasets. Author Contributions Jingping Hu:Writing original draft,Methodology,Formal analysis, Conceptualization. Lintao Dong:Writing original draft, Formal analysis, Data curation. Fang Wang*:Writing – review & editing, Conceptualization. Funding This work was supported by the National Natural Science Foundation of China (Grant No. 82460563, project title: The mechanism of PFKFB4 inhibition of SIRT2-mediated ketone body degradation regulating Rela/ZZ modification in promoting chemoresistance in colorectal cancer). Acknowledgments and Ethics approval The data for the exposure and outcome in this study were obtained from the GWAS database, and both have received ethical approval and participant informed consent. We appreciate all the participants and investigators for sharing these data. Conflict of interest The authors declare that they have no competing interests. References Stoop TF, Javed AA, Oba A et al (2025) Pancreatic cancer. Lancet 405(10485):1182–1202. 10.1016/S0140-6736(25)00261-2 Singhi AD, Koay EJ, Chari ST, Maitra A (2019) Early Detection of Pancreatic Cancer: Opportunities and Challenges. Gastroenterology 156(7):2024–2040. 10.1053/j.gastro.2019.01.259 Zhao Z, Liu W (2020) Pancreatic Cancer: A Review of Risk Factors, Diagnosis, and Treatment. Technol Cancer Res T 19:1533033820962117. 10.1177/1533033820962117 Morris JPT, Wang SC, Hebrok MKRAS, Hedgehog (2010) Wnt and the twisted developmental biology of pancreatic ductal adenocarcinoma. Nat Rev Cancer 10(10):683–695. 10.1038/nrc2899 Li L, Yu R, Cai T et al (2020) Effects of immune cells and cytokines on inflammation and immunosuppression in the tumor microenvironment. Int Immunopharmacol 88:106939. 10.1016/j.intimp.2020.106939 Guarino M, Rubino B, Ballabio G (2007) The role of epithelial-mesenchymal transition in cancer pathology. Pathology 39(3):305–318. 10.1080/00313020701329914 Francesco VD, Zullo A, Manta R et al (2022) Culture-based antibiotic susceptibility testing for Helicobacter pylori infection: a systematic review. Ann Gastroenterol 35(2):127–134. 10.20524/aog.2022.0689 Nakamura S, Sugiyama T, Matsumoto T et al (2012) Long-term clinical outcome of gastric MALT lymphoma after eradication of Helicobacter pylori: a multicentre cohort follow-up study of 420 patients in Japan. Gut 61(4):507–513. 10.1136/gutjnl-2011-300495 Fang Z, Zhang W, Wang H et al (2024) Helicobacter pylori promotes gastric cancer progression by activating the TGF-beta/Smad2/EMT pathway through HKDC1. Cell Mol Life Sci 81(1):453. 10.1007/s00018-024-05491-x Liu Q, Sadr-Azodi O, Engstrand L, Fall K, Brusselaers N (2024) Helicobacter pylori Eradication Therapy and the Risk of Colorectal Cancer: A Population-Based Nationwide Cohort Study in Sweden. Helicobacter 29(6):e70001. 10.1111/hel.70001 Maity R, Dhali A, Biswas J (2024) Is Helicobacter pylori infection protective against esophageal cancer? World J Gastroentero 30(38):4168–4174. 10.3748/wjg.v30.i38.4168 Zhou B, Mei Y, Wang J et al (2023) Is Helicobacter pylori infection associated with pancreatic cancer? A systematic review and meta-analysis of observational studies. Ther Adv Chronic Dis 14:20406223231155119. 10.1177/20406223231155119 Posselt G, Backert S, Wessler S (2013) The functional interplay of Helicobacter pylori factors with gastric epithelial cells induces a multi-step process in pathogenesis. Cell Commun Signal 11:77. 10.1186/1478-811X-11-77 Jimenez-Soto LF, Haas R (2016) The CagA toxin of Helicobacter pylori: abundant production but relatively low amount translocated. Sci Rep-Uk 6:23227. 10.1038/srep23227 Liu J, Xiao Q, Xiao J et al (2022) Wnt/beta-catenin signalling: function, biological mechanisms, and therapeutic opportunities. Signal Transduct Tar 7(1):3. 10.1038/s41392-021-00762-6 Yu F, Yu C, Li F et al (2021) Wnt/beta-catenin signaling in cancers and targeted therapies. Signal Transduct Tar 6(1):307. 10.1038/s41392-021-00701-5 Peek RMJ, Blaser MJ (2002) Helicobacter pylori and gastrointestinal tract adenocarcinomas. Nat Rev Cancer 2(1):28–37. 10.1038/nrc703 Klein AP (2021) Pancreatic cancer epidemiology: understanding the role of lifestyle and inherited risk factors. Nat Rev Gastro Hepat 18(7):493–502. 10.1038/s41575-021-00457-x Choi KW, Chen C, Stein MB et al (2019) Assessment of Bidirectional Relationships Between Physical Activity and Depression Among Adults: A 2-Sample Mendelian Randomization Study. Jama Psychiat 76(4):399–408. 10.1001/jamapsychiatry.2018.4175 Lin BD, Alkema A, Peters T et al (2019) Assessing causal links between metabolic traits, inflammation and schizophrenia: a univariable and multivariable, bidirectional Mendelian-randomization study. Int J Epidemiol 48(5):1505–1514. 10.1093/ije/dyz176 Butler-Laporte G, Kreuzer D, Nakanishi T, Harroud A, Forgetta V, Richards JB (2020) Genetic Determinants of Antibody-Mediated Immune Responses to Infectious Diseases Agents: A Genome-Wide and HLA Association Study. Open Forum Infect Di 7(11):ofaa450. 10.1093/ofid/ofaa450 Jiang L, Zheng Z, Fang H, Yang J (2021) A generalized linear mixed model association tool for biobank-scale data. Nat Genet 53(11):1616–1621. 10.1038/s41588-021-00954-4 Hemani G, Zheng J, Elsworth B et al (2018) The MR-Base platform supports systematic causal inference across the human phenome. Elife 7. 10.7554/eLife.34408 Burgess S, Thompson SG (2017) Interpreting findings from Mendelian randomization using the MR-Egger method. Eur J Epidemiol 32(5):377–389. 10.1007/s10654-017-0255-x Bowden J, Davey Smith G, Haycock PC, Burgess S (2016) Consistent Estimation in Mendelian Randomization with Some Invalid Instruments Using a Weighted Median Estimator. Genet Epidemiol 40(4):304–314. 10.1002/gepi.21965 Abecasis GR, Altshuler D, Auton A et al (2010) A map of human genome variation from population-scale sequencing. Nature 467(7319):1061–1073. 10.1038/nature09534 Burgess S, Thompson SG (2011) Avoiding bias from weak instruments in Mendelian randomization studies. Int J Epidemiol 40(3):755–764. 10.1093/ije/dyr036 Tan J, Liu N, Guo T, Hu S, Hua L (2021) Genetically predicted obesity and risk of deep vein thrombosis. Thromb Res 207:16–24. 10.1016/j.thromres.2021.08.026 Zhu Z, Zheng Z, Zhang F et al (2018) Causal associations between risk factors and common diseases inferred from GWAS summary data. Nat Commun 9(1):224. 10.1038/s41467-017-02317-2 Gastric cancer and Helicobacter pylori: a combined analysis of 12 case control studies nested within prospective cohorts. Gut. (2001) ;49(3):347–353. 10.1136/gut.49.3.347 Pormohammad A, Ghotaslou R, Leylabadlo HE, Nasiri MJ, Dabiri H, Hashemi A (2018) Risk of gastric cancer in association with Helicobacter pylori different virulence factors: A systematic review and meta-analysis. Microb Pathogenesis 118:214–219. 10.1016/j.micpath.2018.03.004 Xu W, Zhou X, Yin M, Gao J, Weng Z, Xu C (2022) The relationship between Helicobacter pylori and pancreatic cancer: a meta-analysis. Transl Cancer Res 11(8):2810–2822. 10.21037/tcr-21-2803 Xiao M, Wang Y, Gao Y (2013) Association between Helicobacter pylori infection and pancreatic cancer development: a meta-analysis. PLoS ONE 8(9):e75559. 10.1371/journal.pone.0075559 Guo Y, Liu W, Wu J (2016) Helicobacter pylori infection and pancreatic cancer risk: A meta-analysis. J Cancer Res Ther 12(Supplement):C229–C232. 10.4103/0973-1482.200744 Huang J, Zagai U, Hallmans G et al (2017) Helicobacter pylori infection, chronic corpus atrophic gastritis and pancreatic cancer risk in the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort: A nested case-control study. Int J Cancer 140(8):1727–1735. 10.1002/ijc.30590 Schulte A, Pandeya N, Fawcett J et al (2015) Association between Helicobacter pylori and pancreatic cancer risk: a meta-analysis. Cancer Cause Control 26(7):1027–1035. 10.1007/s10552-015-0595-3 Trikudanathan G, Philip A, Dasanu CA, Baker WL (2011) Association between Helicobacter pylori infection and pancreatic cancer. A cumulative meta-analysis. J Pancreas 12(1):26–31 Butt J, Varga MG, Wang T et al (2019) Smoking, Helicobacter Pylori Serology, and Gastric Cancer Risk in Prospective Studies from China, Japan, and Korea. Cancer Prev Res 12(10):667–674. 10.1158/1940-6207.CAPR-19-0238 Michel A, Waterboer T, Kist M, Pawlita M (2009) Helicobacter pylori multiplex serology. Helicobacter 14(6):525–535. 10.1111/j.1523-5378.2009.00723.x Kosunen TU, Seppala K, Sarna S, Sipponen P (1992) Diagnostic value of decreasing IgG, IgA, and IgM antibody titres after eradication of Helicobacter pylori. Lancet 339(8798):893–895. 10.1016/0140-6736(92)90929-w Schrenk D, Bignami M, Bodin L et al (2023) Risk assessment of N-nitrosamines in food. Efsa J 21(3):e07884. 10.2903/j.efsa.2023.7884 Houben GM, Stockbrugger RW (1995) Bacteria in the aetio-pathogenesis of gastric cancer: a review. Scand J Gastroenterol Suppl 212:13–18. 10.3109/00365529509090296 Correa P (1992) Human gastric carcinogenesis: a multistep and multifactorial process–First American Cancer Society Award Lecture on Cancer Epidemiology and Prevention. Cancer Res 52(24):6735–6740 Luo J, Nordenvall C, Nyren O, Adami H, Permert J, Ye W (2007) The risk of pancreatic cancer in patients with gastric or duodenal ulcer disease. Int J Cancer 120(2):368–372. 10.1002/ijc.22123 Risch HA (2003) Etiology of pancreatic cancer, with a hypothesis concerning the role of N-nitroso compounds and excess gastric acidity. Jnci-J Natl Cancer I 95(13):948–960. 10.1093/jnci/95.13.948 Kao C, Sheu B, Wu J (2016) Helicobacter pylori infection: An overview of bacterial virulence factors and pathogenesis. Biomed J 39(1):14–23. 10.1016/j.bj.2015.06.002 Xu C, Soyfoo DM, Wu Y, Xu S (2020) Virulence of Helicobacter pylori outer membrane proteins: an updated review. Eur J Clin Microbiol 39(10):1821–1830. 10.1007/s10096-020-03948-y Yamaoka Y (2010) Mechanisms of disease: Helicobacter pylori virulence factors. Nat Rev Gastro Hepat 7(11):629–641. 10.1038/nrgastro.2010.154 Crowe SE (2019) Helicobacter pylori Infection. New Engl J Med 380(12):1158–1165. 10.1056/NEJMcp1710945 Michel A, Pawlita M, Boeing H, Gissmann L, Waterboer T (2014) Helicobacter pylori antibody patterns in Germany: a cross-sectional population study. Gut Pathog 6:10. 10.1186/1757-4749-6-10 Epplein M, Signorello LB, Zheng W et al (2011) Race, African ancestry, and Helicobacter pylori infection in a low-income United States population. Cancer Epidem Biomar 20(5):826–834. 10.1158/1055-9965.EPI-10-1258 Fock KM, Ang TL (2010) Epidemiology of Helicobacter pylori infection and gastric cancer in Asia. J Gastroen Hepatol 25(3):479–486. 10.1111/j.1440-1746.2009.06188.x Liu W, Sun Y, Yuan Y (2020) Analysis of serum gastrin-17 and Helicobacter pylori antibody in healthy Chinese population. J Clin Lab Anal 34(12):e23518. 10.1002/jcla.23518 Yu J, Zhao Y, Wang X, Xu Y (2022) Evaluation of Anti-Helicobacter pylori IgG Antibodies for the Detection of Helicobacter pylori Infection in Different Populations. Diagnostics 12(5). 10.3390/diagnostics12051214 Sanchez Caraballo A, Guzman Y, Sanchez J, Munera M, Garcia E, Gonzalez-Devia D (2023) Potential contribution of Helicobacter pylori proteins in the pathogenesis of type 1 gastric neuroendocrine tumor and urticaria. In silico approach. PLoS ONE 18(4):e0281485. 10.1371/journal.pone.0281485 Additional Declarations The authors declare no competing interests. Supplementary Files SupplementaryMaterials.xlsx SupplementaryFigure.docx Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-7168408","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":488009186,"identity":"437c2ca1-274d-459f-a161-7fbb86bc2b55","order_by":0,"name":"Jingping Hu","email":"","orcid":"","institution":"The First Clinical Medical School, Ningxia Medical University, Yinchuan, China","correspondingAuthor":false,"prefix":"","firstName":"Jingping","middleName":"","lastName":"Hu","suffix":""},{"id":488009187,"identity":"03a97e25-ae3b-4bb4-9d4e-46a6d9e7a960","order_by":1,"name":"Lintao Dong","email":"","orcid":"","institution":"The First Clinical Medical School, Ningxia Medical University, Yinchuan, China","correspondingAuthor":false,"prefix":"","firstName":"Lintao","middleName":"","lastName":"Dong","suffix":""},{"id":488009188,"identity":"a5144ddf-2505-4fd5-adc6-876b338a6a33","order_by":2,"name":"FangWang","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA7klEQVRIiWNgGAWjYLCCCiDmZ29sfvDBwMaOOC1ngFiy5/AxwxkFacnEazG4kZYgzfPhEGMDIdUGx88efnGg5o7dhjNnDIxtDA4wM7AfProBr5YzeWkWB449S555vMfgcY7BHT4GnrS0G/i0mB3IMTP+wHY4mQ9kS47BM2YGCR4z/FrOvzEzOPDvcDLDjRwDaQuDw4wNBLXcyDF+cLDtsJ0AyPsMxGixv/HGjOFg3+EEcCD3GKQlsxHyi2R/jvGHA98O24Oj8scfGzt+9sPH8GoBAjYJIJHYAOcSUA4CzB9ADiRC4SgYBaNgFIxUAAAGW1jE3evz7AAAAABJRU5ErkJggg==","orcid":"https://orcid.org/0000-0001-5802-8231","institution":"Department of Gastroenterology, General Hospital, Ningxia Medical University, Yinchuan ,Ningxia, China","correspondingAuthor":true,"prefix":"","firstName":"","middleName":"","lastName":"FangWang","suffix":""}],"badges":[],"createdAt":"2025-07-20 08:23:51","currentVersionCode":1,"declarations":{"humanSubjects":true,"vertebrateSubjects":false,"conflictsOfInterestStatement":false,"humanSubjectEthicalGuidelines":true,"humanSubjectConsent":true,"humanSubjectClinicalTrial":false,"humanSubjectCaseReport":false,"vertebrateSubjectEthicalGuidelines":false},"doi":"10.21203/rs.3.rs-7168408/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-7168408/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":87438168,"identity":"380ddd6d-2f3b-4cfa-8d46-cb8991d0b642","added_by":"auto","created_at":"2025-07-23 19:12:53","extension":"jpg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":804628,"visible":true,"origin":"","legend":"\u003cp\u003eThe schematic flowchart showing the study design of Helicobacter pylori and pancreatic cancer.\u003c/p\u003e","description":"","filename":"Figure1.jpg","url":"https://assets-eu.researchsquare.com/files/rs-7168408/v1/c47fa790dd6cb394628e89fd.jpg"},{"id":87438964,"identity":"1ed67e1c-145d-46e4-9121-4c70d6204215","added_by":"auto","created_at":"2025-07-23 19:20:53","extension":"jpg","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":1007085,"visible":true,"origin":"","legend":"\u003cp\u003eForest plot illustrating the bidirectional two-sample Mendelian Randomization analysis of H. pylori and pancreatic cancer\u003c/p\u003e","description":"","filename":"Figure2.jpg","url":"https://assets-eu.researchsquare.com/files/rs-7168408/v1/0a607fce987bfe7041f6bb81.jpg"},{"id":87438179,"identity":"16acbb0f-65c8-41a5-93fe-ec5df5e0b905","added_by":"auto","created_at":"2025-07-23 19:12:53","extension":"jpg","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":1001829,"visible":true,"origin":"","legend":"\u003cp\u003eThe forest plot depicts the bidirectional GSMR effect of H. pylori and pancreatic cancer.\u003c/p\u003e","description":"","filename":"Figure3.jpg","url":"https://assets-eu.researchsquare.com/files/rs-7168408/v1/5ea944847d2bf11e75fa1a3c.jpg"},{"id":87440088,"identity":"199978ad-4356-41b3-92b4-78fa5022bd6c","added_by":"auto","created_at":"2025-07-23 19:36:58","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":3338272,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7168408/v1/7f9472a8-a23f-4996-b4d2-988322a659c4.pdf"},{"id":87439817,"identity":"1e98cb1e-860b-4721-8986-910d1a2870d1","added_by":"auto","created_at":"2025-07-23 19:28:53","extension":"xlsx","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":218465,"visible":true,"origin":"","legend":"","description":"","filename":"SupplementaryMaterials.xlsx","url":"https://assets-eu.researchsquare.com/files/rs-7168408/v1/8ee39a08d6854c2444a314e1.xlsx"},{"id":87438173,"identity":"5698be6a-6a63-4c39-80f1-341a2c642982","added_by":"auto","created_at":"2025-07-23 19:12:53","extension":"docx","order_by":2,"title":"","display":"","copyAsset":false,"role":"supplement","size":394783,"visible":true,"origin":"","legend":"","description":"","filename":"SupplementaryFigure.docx","url":"https://assets-eu.researchsquare.com/files/rs-7168408/v1/f970dacff0609e9dea6b80a4.docx"}],"financialInterests":"The authors declare no competing interests.","formattedTitle":"\u003cp\u003eUse of bidirectional Mendelian randomization to unveil the association of Helicobacter pylori infection and Pancreatic cancer\u003c/p\u003e","fulltext":[{"header":"1 Introduction","content":"\u003cp\u003ePancreatic cancer is one of the deadliest cancers, with a median survival period of approximately 4 months and a 5-year survival rate of 13%\u003csup\u003e1\u003c/sup\u003e. Additionally, Pancreatic cancer progresses rapidly and usually worsens within just a few months of diagnosis\u003csup\u003e\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e\u003c/sup\u003e. The treatment of pancreatic cancer mainly includes surgery, chemotherapy, radiotherapy, and targeted therapy. Surgery is the only possible cure, but it is restricted to early-stage patients. Due to late-stage diagnosis, many patients are no longer eligible for surgical resection at the time of presentation\u003csup\u003e\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e\u003c/sup\u003e. However, the etiological mechanism of pancreatic cancer is still unclear, and environmental, and lifestyle risk factors and genetic predisposition may contribute to the development of pancreatic cancer. At present, scholars believe that it involves a variety of factors, including gene mutations (such as changes in KRAS, p53, and other genes), chronic inflammation (such as chronic pancreatitis), and changes in the pancreatic microenvironment\u003csup\u003e\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e\u003c/sup\u003e. Chronic inflammation and immune responses can induce the continuous expression of pro-inflammatory cytokines (such as TNF-α and IL-6), thereby activating signaling pathways such as Hh and Wnt-β-catenin, promoting tumor cell proliferation, anti-apoptosis and immune escape\u003csup\u003e\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e\u003c/sup\u003e. Epithelial-mesenchymal transformation (EMT) may also be one of the pathogeneses because it contributes to the invasion and metastasis of cancer cells\u003csup\u003e\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e\u003c/sup\u003e. Therefore, it is urgently necessary to deeply clarify the inflammation-related signaling network, the regulatory mechanism of EMT, and the key molecular interactions between the tumor microenvironment and immune response in pancreatic cancer, so as to provide a solid theoretical basis for the development of targeted therapy and immunotherapy strategies.\u003c/p\u003e\u003cp\u003eH. pylori is a spiral-shaped gram-negative bacterium that is the most common chronic bacterial infection worldwide. Recently, in 2021, the National Toxicology Program's 15th Report on Carcinogens listed chronic H. pylori infection as a \"substance known or reasonably expected to be carcinogenic to humans\"\u003csup\u003e\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e\u003c/sup\u003e. If H. pylori infection is not eradicated, prolonged infection may lead to disease progression and an increased risk of mucosa-associated lymphoid tissue (MALT) lymphoma, gastric cancer, and other cancers\u003csup\u003e\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e,\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e\u003c/sup\u003e. In recent years, it has been found that chronic infection of H. pylori may also be associated with a variety of extra-gastric malignant diseases, such as pancreatic cancer, esophageal cancer, and colorectal cancer\u003csup\u003e\u003cspan additionalcitationids=\"CR11\" citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e\u003c/sup\u003e. Although the exact mechanism by which H. pylori infection promotes the occurrence and development of pancreatic cancer is still under exploration, some scholars have proposed that it may involve several biological theories. H. pylori infection causes chronic reactions in the gastrointestinal mucosa. The persistent inflammatory state may affect the adjacent pancreatic tissue through paracrine means, leading to persistent oxidative stress and DNA damage\u003csup\u003e\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e,\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e\u003c/sup\u003e. Inflammation-related cytokines can further promote the proliferation of abnormal cells and immune escape. H. pylori infection may also activate the Wnt/β-catenin signaling pathway, which plays a central role in carcinogenesis by promoting the expansion of cancer stem-like cells\u003csup\u003e\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e,\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e\u003c/sup\u003e. In addition, H.pylori weakens the body's ability to recognize and eliminate abnormal pancreatic cells by affecting the immune microenvironment\u003csup\u003e\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e\u003c/sup\u003e. Lifestyle factors, genetic susceptibility, and the virulence factors of the bacterial strain can all act in concert with H. pylori infection to increase the risk of pancreatic cancer\u003csup\u003e\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e\u003c/sup\u003e. Interestingly, although new studies have continuously appeared in recent years on whether there is an association between pancreatic cancer and H. pylori, their conclusions have been inconsistent. This may be because most studies did not adequately adjust for confounders at the time of data aggregation, making it difficult to draw a definitive conclusion on whether there is an association between H. pylori and pancreatic cancer.\u003c/p\u003e\u003cp\u003eIn this study, we aimed to analyze the causal relationship between seven antibody immune responses to H. pylori and pancreatic cancer. We chose to use the antibody-mediated immune response data after H.pylori infection because antibodies can reflect the host's long-term immune memory of H.pylori infection, which is helpful for a more comprehensive understanding of the long-term association between infection and pancreatic cancer and its underlying mechanism. Mendelian randomization (MR) infers the potential causal relationship between exposure factors and outcomes by using genetic variations as instrumental variables (IVs)\u003csup\u003e\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e\u003c/sup\u003e. In this study, we further employed the generalized summary Mendelian Randomization (GSMR) method. GSMR accounts for the linkage disequilibrium (LD) among genetic variations in its analysis and identifies and eliminates pleiotropic single-nucleotide polymorphisms (SNPs) through the Heterogeneity In Dependent Instruments (HEIDI) outlier test, thereby enhancing the reliability and efficiency of causal estimation\u003csup\u003e\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e\u003c/sup\u003e. Since previous epidemiological studies have failed to establish a causal relationship between H. pylori infection and pancreatic cancer, we use data from the Genome-Wide Association Study (GWAS) to apply bidirectional two-sample MR and GSMR to clarify the complex causal relationship between them.\u003c/p\u003e"},{"header":"2 Materials and methods","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e\u003ch2\u003e2.1 Research design\u003c/h2\u003e\u003cp\u003eThe data used in this MR Study were approved by the ethical review committee of the relevant research professional institutions. Therefore, no additional ethical scrutiny was required. All experimental results were described in detail in the text and supplementary materials. In this study, we used 7 antibodies against H. pylori as the exposure database, and European patients with pancreatic cancer as the outcome (In Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). Two-sample bidirectional MR method was used to analyze the causal relationship between H. pylori and pancreatic cancer. Based on MR, we also employed the GSMR method to verify the results obtained by the above method. In this study, SNPs were defined as IVs.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec4\" class=\"Section2\"\u003e\u003ch2\u003e2.2 Data source\u003c/h2\u003e\u003cp\u003eThe exposure data used in our analysis came from aggregated GWAS results for seven antibody immune responses associated with H. pylori infection as proposed by Butler-Laporte et al. These antibody types were used to evaluate the host immune response to various H. pylori components, including overall IgG seropositivity and antibodies targeting specific antigens such as cytotoxin-associated gene A (CagA), catalase, 60-kDa heat shock protein (GroEL), OMP, urease subunit (UREA), and vacuolating cytotoxin A (VacA). The summary statistics were obtained respectively from GWAS analyses of 8735, 985, 1558, 2716, 2640, 2251, and 1571 participants, which were available in the MRC-IEU UK Biobank (UKB) OpenGWAS\u003csup\u003e\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e\u003c/sup\u003e. We extracted IVs for pancreatic cancer from the GWAS conducted by Jiang et al., which included 232 cases and 456,116 controls, covering a total of 1,701,334 SNPs\u003csup\u003e\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e\u003c/sup\u003e. Detailed information of all data can be found in Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e.\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eDetails of the genome-wide association studies and datasets used in this study.\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"3\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003eExposure or outcome\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eLinks for datadownload\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003ePMID\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003epancreatic cancer\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://www.ebi.ac.uk/gwas/studies/GCST90043861\u003c/span\u003e\u003cspan address=\"https://www.ebi.ac.uk/gwas/studies/GCST90043861\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e34737426\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eAnti-helicobacter pylori IgG seropositivity\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://www.ebi.ac.uk/gwas/studies/GCST90006910\u003c/span\u003e\u003cspan address=\"https://www.ebi.ac.uk/gwas/studies/GCST90006910\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e33204752\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eHelicobacter pylori CagA antibody levels\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://www.ebi.ac.uk/gwas/studies/GCST90006911\u003c/span\u003e\u003cspan address=\"https://www.ebi.ac.uk/gwas/studies/GCST90006911\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e33204752\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eHelicobacter pylori Catalase antibody levels\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://www.ebi.ac.uk/gwas/studies/GCST90006912\u003c/span\u003e\u003cspan address=\"https://www.ebi.ac.uk/gwas/studies/GCST90006912\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e33204752\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eHelicobacter pylori GroEL antibody levels\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://www.ebi.ac.uk/gwas/studies/GCST90006913\u003c/span\u003e\u003cspan address=\"https://www.ebi.ac.uk/gwas/studies/GCST90006913\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e33204752\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eHelicobacter pylori OMP antibody levels\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://www.ebi.ac.uk/gwas/studies/GCST90006914\u003c/span\u003e\u003cspan address=\"https://www.ebi.ac.uk/gwas/studies/GCST90006914\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e33204752\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eHelicobacter pylori UREA antibody levels\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://www.ebi.ac.uk/gwas/studies/GCST90006915\u003c/span\u003e\u003cspan address=\"https://www.ebi.ac.uk/gwas/studies/GCST90006915\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e33204752\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eHelicobacter pylori VacA antibody levels\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://www.ebi.ac.uk/gwas/studies/GCST90006916\u003c/span\u003e\u003cspan address=\"https://www.ebi.ac.uk/gwas/studies/GCST90006916\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e33204752\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec5\" class=\"Section2\"\u003e\u003ch2\u003e2.3 MR analysis\u003c/h2\u003e\u003cp\u003eWe applied five MR analysis methods, including inverse variance weighted (IVW), MR-Egger, Weighted Median, MR-PRESSO, and simple mode and weighted mode to analyze the relationship between all antibody-mediated immune responses and pancreatic cancer\u003csup\u003e\u003cspan additionalcitationids=\"CR24\" citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e\u003c/sup\u003e. SNPs that reached a genome-wide significance level (P\u0026thinsp;\u0026lt;\u0026thinsp;1 \u0026times; 10^-5) were used as IVs of antibody-mediated immune responses associated with H. pylori. To investigate the reverse causal relationship, we used the following selection criteria to select genetic IVs, setting a GWAS significance threshold of P\u0026thinsp;\u0026lt;\u0026thinsp;5 \u0026times; 10^-5 for SNPs associated with pancreatic cancer. Then, we clumped the GWAS significant SNPs from each split\u0026rsquo;s GWAS with a clumping window of 10,000 kb and an r\u0026sup2; threshold of 0.001. All non-matching alleles were aligned, and the signs of the beta estimates were flipped\u003csup\u003e\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e\u003c/sup\u003e. We calculated the F statistics of the selected SNPs to detect the strength of the IVs at a threshold of F\u0026thinsp;\u0026gt;\u0026thinsp;10, which is typically recommended in MR analysis. Then, we excluded SNPs associated with confounders that interfere with the pathway between H. pylori infection and pancreatic cancer\u003csup\u003e\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e\u003c/sup\u003e. We estimated heterogeneity among IVs by using Cochran\u0026rsquo;s Q statistic\u003csup\u003e\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e\u003c/sup\u003e. We used the MR-Egger intercept method and the MR-PRESSO to assess bias that might be caused by horizontal pleiotropy. Finally, we conducted a leave-one-out analysis to evaluate the robustness of MR Results.\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec6\" class=\"Section2\"\u003e\u003ch2\u003e2.4 GSMR approach\u003c/h2\u003e\u003cp\u003eIn our primary analysis, we adopted GSMR, a flexible approach that tested the causal relationship between risk factors (or phenotypes) and disease by using aggregated GWAS data from independent studies for MR analysis and using multiple near-independent IVs. For the genetic IVs in the exposure, we selected genome-wide significance SNPs (r^2 threshold of 0.05, P-value threshold of 1 \u0026times; 10^-5) for each feature by using a linkage elimination algorithm and used the \"1000 genome (1000G) Phase III European sample as a reference estimates for LD\". In the reverse analysis, for GWAS summary statistics for pancreatic cancer, we selected independent SNPs with an LD threshold of r^2\u0026thinsp;\u0026lt;\u0026thinsp;0.05 and a P-value threshold of 5 \u0026times; 10^-5. Then, the HEIDI outlier method was applied to remove IVs with strong predictive pleiotropy effects, and the P-value threshold is set to 0.01 in the HEIDI outlier filtering analysis\u003csup\u003e\u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e\u003c/sup\u003e. All analyses were performed using \"TwoSampleMR\", \"foreach\", \"gsmr2\" and \"ggplot2\" in R version 4.3.1 for data visualization and analysis.\u003c/p\u003e\u003c/div\u003e\n\u003ch2\u003e2.5 Ethical Statement\u003c/h2\u003e\n\u003cp\u003eParticipants consented to the GWAS as per the original protocols, and all ethical approvals were obtained by the original authors.\u003c/p\u003e"},{"header":"3 Results","content":"\u003cp\u003e3.1. Association between H. pylori and pancreatic cancer by MR\u003c/p\u003e\n\u003cp\u003eAfter removing palindromic and ambiguous SNPs, non-proxy SNPs, and SNPs identified by Steiger filtering as having incorrect causal direction, the number of SNPs used as IVs for each exposure was presented in Supplementary Table S1. This table also provided the variances interpreted as exposure instruments and F statistics. All F-values were greater than 10, indicating that our study provided strong statistical power to detect potential causal effects between H. pylori and pancreatic cancer. We analyzed the levels of several H. pylori-related antibodies, including anti-H. pylori IgG seropositivity and antibodies against specific antigens such as CagA, catalase, GroEL, OMP, UREA, and VacA. In our research, the IVW algorithm was the main method, and viewed other methods as auxiliary. We observed an increased risk of pancreatic cancer for every one standard deviation increase in H. pylori OMP antibody levels (OR: 1.8122, 95% CI: 1.3192 to 2.4894 P \u0026lt;0.001), the results were consistent with the Weighted median algorithm (OR: 1.9638, 95% CI: 1.2686 to 3.0399 P =0.002), and both were statistically significant (Supplementary Table S4). However, other antibody-mediated immune responses associated with H. pylori infection were not found to have a statistically significant causal effect. In addition, to further explore the causal relationship between pancreatic cancer and H. pylori, we also used reverse MR to detect whether there was a reverse causal relationship between them. The results showed that pancreatic cancer did not affect the level of H. pylori antibody-mediated immune response (In Figure 2).\u003c/p\u003e\n\u003cp\u003e3.2. Association between H. pylori and pancreatic cancer by GSMR\u003c/p\u003e\n\u003cp\u003eAfter the ordinary bidirectional two-sample MR, we further applied GSMR analysis to ensure the robustness of the analysis. The GSMR method can effectively identify and eliminate multiple groups of genetic variants, thus reducing bias and improving the reliability of causal reasoning. In the GSMR results, each standard deviation increase in H. pylori OMP antibody levels was associated with an increased risk of pancreatic cancer (OR: 1.7099, 95% CI: 1.2632 to 2.3144 P \u0026lt;0.001). The OR of other H. pylori-related antibody-mediated immune responses was greater than 1, but there was no statistical significance. In addition, pancreatic cancer did not affect the level of antibody-mediated immune response to H. pylori in the GSMR (In Figure 3).\u003c/p\u003e\n\u003cp\u003e3.3. Sensitivity analysis\u003c/p\u003e\n\u003cp\u003eTo ensure that the results were accurate and reliable, we assessed the sensitivity of each antibody immune response. Cochran\u0026apos;s Q test (Supplementary Table S2) and funnel plot (Supplementary Figure S1-S2) were used to detect heterogeneity. Horizontal pleiotropy was detected by the MR-Egger intercept method and the MRPRESSO method (Supplementary Table S2). The results showed that when pancreatic cancer was the outcome and H. pylori UREA antibody levels were used as the exposure, MR Egger and IVW are found to be heterogeneous (Q=42.91; Q-P value=0.01). No heterogeneity or pleiotropy was found in other results. Leave-one-out analysis did not identify any single SNP with a significant influence on the overall causal estimate (Supplementary Figures S3-S4).\u003c/p\u003e"},{"header":"4 Discussion","content":"\u003cp\u003eH. pylori is a spiral-shaped gram-negative bacterium known to be associated with gastric and duodenal ulcers and gastric cancer\u003csup\u003e\u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e,\u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e31\u003c/span\u003e\u003c/sup\u003e. With further study, researchers have found that H. pylori is associated with the occurrence and development of some extra-gastric diseases. The association between H. pylori infection and pancreatic cancer has remained inconclusive despite extensive investigation. In bidirectional two-sample MR analysis, our study found that genetically predicted H. pylori OMP antibody levels are causally associated with the development of pancreatic cancer. OMP plays a key role in the attachment and colonization of gastric mucosa by H. pylori, and the presence of antibodies indicates that an infection has occurred or is currently present. Xu et al. evaluated the association between H. pylori infection and pancreatic cancer by conducting a meta-analysis of 17 studies. The results showed a significant association between H. pylori infection and pancreatic cancer, but no significant association was found in CagA and VacA-positive strains\u003csup\u003e\u003cspan citationid=\"CR32\" class=\"CitationRef\"\u003e32\u003c/span\u003e\u003c/sup\u003e. Xiao et al. conducted a meta-analysis of 9 studies from different regions and found a weak association between H. pylori infection and pancreatic cancer\u003csup\u003e\u003cspan citationid=\"CR33\" class=\"CitationRef\"\u003e33\u003c/span\u003e\u003c/sup\u003e. Guo et al. 's meta-analysis also obtained the same result, but due to statistical heterogeneity and publication bias, the conclusion needs to be further verified by basic experiments\u003csup\u003e\u003cspan citationid=\"CR34\" class=\"CitationRef\"\u003e34\u003c/span\u003e\u003c/sup\u003e. It is noteworthy that Huang et al. conducted a case-control study on the pathology of 448 patients with pancreatic cancer and their controls and found that the risk of pancreatic cancer was seropositive with H. pylori in the European population (OR\u0026thinsp;=\u0026thinsp;0.96; 95% CI: 0.70, 1.31) or CagA seropositive (OR\u0026thinsp;=\u0026thinsp;1.07; 95% CI: 0.77, 1.48) were not relevant\u003csup\u003e\u003cspan citationid=\"CR35\" class=\"CitationRef\"\u003e35\u003c/span\u003e\u003c/sup\u003e. Interestingly, Schulte et al. collected blood samples from 580 patients and 626 controls and used an Enzyme-Linked Immunosorbent Assay (ELISA) kit to determine the seroprevalence of H. pylori and its virulent protein CagA. No association was observed between positive serum antibodies to H. pylori and the risk of pancreatic cancer. Interestingly, the study also found that CagA-negative H. pylori was associated with an increased risk of pancreatic cancer (OR 1.23; 95% CI 0.83\u0026ndash;1.82), suggesting that the association between H. pylori and pancreatic cancer may depend on different strain types of H. pylori\u003csup\u003e\u003cspan citationid=\"CR36\" class=\"CitationRef\"\u003e36\u003c/span\u003e\u003c/sup\u003e. This finding is consistent with our study, which also identified a causal relationship between H.pylori OMP antibody levels and adenocarcinoma, while H.pylori CagA antibody levels showed no causal relationship with pancreatic cancer. This may be because some meta-analyses did not consider whether the included population is smokers\u003csup\u003e\u003cspan citationid=\"CR37\" class=\"CitationRef\"\u003e37\u003c/span\u003e\u003c/sup\u003e, as smokers have a higher incidence of H. pylori and pancreatic cancer than non-smokers\u003csup\u003e\u003cspan citationid=\"CR38\" class=\"CitationRef\"\u003e38\u003c/span\u003e\u003c/sup\u003e. It may also be due to different detection methods that lead to different results\u003csup\u003e\u003cspan citationid=\"CR39\" class=\"CitationRef\"\u003e39\u003c/span\u003e\u003c/sup\u003e. Most existing studies only detect H. pylori IgG or IgM antibodies to determine the infection, once either of the IgG or IgM antibodies is seropositivity, it is identified as H. pylori infection. However, this approach does not adequately consider levels of other key antigens of H. pylori, such as Catalase, GroEL, OMP, UREA, and VacA antibodies, which may also play an important role in the pathogenic mechanism. H. Pylori detection methods include invasive and non-invasive methods. Invasive methods are histological examination, rapid urease test, or bacterial culture by gastroscopy sampling, while non-invasive methods include breath tests, serum antibody testing, and fecal antigen testing. Although invasive tests (such as gastroscopy combined with gastric mucosal biopsy for histopathology of H. pylori) can provide a definitive diagnosis, they are not beneficial for pregnant women. Therefore, non-invasive diagnostic methods such as serum antibody tests, urea breath tests, and fecal antigen tests are the preferred common detections. The detection of H.pylori IgG antibodies in the patient's serum by ELISA can reflect the current or previous infection status. This is because it takes 6 to 12 months for the antibodies to turn negative after the eradication of H.pylori, which leads to different test results\u003csup\u003e\u003cspan citationid=\"CR40\" class=\"CitationRef\"\u003e40\u003c/span\u003e\u003c/sup\u003e. Therefore, our study used serum-based detection of antibody-mediated immune responses to H. pylori, offering a non-invasive approach suitable for vulnerable populations such as pregnant women, children, and the elderly. Secondly, the serum levels of H. pylori IgG antibodies, CagA, Catalase, GroEL, OMP, UREA, and VacA are detected by ELISA. The advantage of this multi-indicator test is that it provides a more comprehensive assessment of H. pylori infection status, especially infection caused by different strains and virulence factors.\u003c/p\u003e\u003cp\u003eScholars have proposed several possible mechanisms to explain how H. pylori increases the risk of pancreatic cancer. After long-term colonization of the gastric mucosa by H.pylori, the gastric mucosa usually undergoes a series of pathological changes, such as chronic superficial gastritis, atrophic gastritis, intestinal metaplasia, and dysplasia. The development of multifocal atrophic gastritis can lead to the loss of parietal cells, which in turn can lead to low or no gastric acid, and it is worth noting that about one-third of gastric cancer occurs in patients with acid deficiency. Too low stomach acid can lead to bacterial overgrowth and an increase in N-nitroso compounds. Through blood circulation, N-nitrosamines may be transported to the pancreas, resulting in the activation of oncogenes in the pancreatic duct epithelium\u003csup\u003e\u003cspan additionalcitationids=\"CR42\" citationid=\"CR41\" class=\"CitationRef\"\u003e41\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR43\" class=\"CitationRef\"\u003e43\u003c/span\u003e\u003c/sup\u003e. Juhua Luo et al. concluded through a large number of cohort studies that they were consistent with the previously proposed hypothesis model that \"H. pylori infection promotes the occurrence of pancreatic cancer through gastric body colonization, low gastric acid state and the formation of nitrosamines in the stomach\", which also provides some support for us\u003csup\u003e\u003cspan citationid=\"CR44\" class=\"CitationRef\"\u003e44\u003c/span\u003e\u003c/sup\u003e. Another possible mechanism involves H. pylori colonization in the antrum, which may lead to excess gastric acid, which stimulates the duodenum to release uninhibited secretin and induces the basal bicarbonate secretion of the pancreatic duct, thereby causing the proliferation of the pancreatic ductal epithelial cells (PDECs) through increased DNA synthesis. Excessive proliferation of PDECs, accumulation of genetic mutations, and persistent chronic inflammation, leading to the occurrence and development of pancreatic cancer\u003csup\u003e\u003cspan citationid=\"CR45\" class=\"CitationRef\"\u003e45\u003c/span\u003e\u003c/sup\u003e. Our study found that genetically elevated levels of H. pylori OMP antibodies are a risk factor for pancreatic cancer, for which clinical evidence is lacking. H. pylori OMPs play a crucial role in the infection process, especially during bacterial attachment, colonization, and persistent infection. These proteins help H. pylori attach to gastric epithelial cells early in infection, increasing its virulence\u003csup\u003e\u003cspan citationid=\"CR46\" class=\"CitationRef\"\u003e46\u003c/span\u003e\u003c/sup\u003e. We hypothesize that seropositivity for H. pylori OMP antibodies may contribute causally to the development of pancreatic cancer. However, the main function of OMP protein is adhesion, and although it enhances the virulence of H. pylori, in the absence of the combined action of key virulence factors such as CagA and VacA, the promotional effect of single OMP antibody-positive strains in the development of pancreatic cancer may be relatively weak. The rise of antibiotic-resistant H. pylori strains has made vaccine development an urgent research priority. Because of their ability to adhere to and trigger host cell immune responses, OMPs are considered immune antigens. Researchers are also using proteomic approaches to assess whether OMP could be a candidate for vaccine\u003csup\u003e\u003cspan citationid=\"CR47\" class=\"CitationRef\"\u003e47\u003c/span\u003e\u003c/sup\u003e. As the role of H. pylori OMP in adhesion and triggering host immune responses is gradually revealed, OMP shows great prospects as a potential target for vaccine development in the prevention and treatment of pancreatic cancer in the future. Specifically, the OMP vaccine is expected to prevent H. pylori from playing a promoting role in the early development of pancreatic cancer by inhibiting the adhesion process of H. pylori, thereby reducing the persistent colonization of the bacteria in the stomach and other digestive tract tissues.\u003c/p\u003e\u003cp\u003eOur research has several advantages. First, the combination of MR and GSMR analysis clarifies the causal direction and minimizes confounding bias. Second, all GWAS data come from participants of European descent, suggesting that population stratification has less impact on our results. Most importantly, the exposure data in our study use antibody-mediated immune responses to a variety of H. pylori-related proteins or factors, which, compared with other studies that directly evaluate H. pylori itself, provide a deeper reflection of the body's immune system's long-term response to H. pylori infection and its potential impact on cancer risk. For example, different virulence factors of H. pylori have different biological functions and may have different effects on cancer risk. By analyzing these specific factors, it is possible to identify specific virulence factors associated with disease risk; different strains of H. pylori may carry different virulence factors and have different effects on the disease. However, some limitations to our study should be noted. First, H.pylori is a highly heterogeneous bacterium, and numerous studies have confirmed that its virulence varies across geographic regions\u003csup\u003e\u003cspan citationid=\"CR48\" class=\"CitationRef\"\u003e48\u003c/span\u003e,\u003cspan citationid=\"CR49\" class=\"CitationRef\"\u003e49\u003c/span\u003e\u003c/sup\u003e. For instance, the H. pylori seroprevalence in Germany (defined as positivity for at least three antigens) is 48%\u003csup\u003e50\u003c/sup\u003e. In the study by Meira Epplein et al., it was found that the seropositive rate of H.pylori in African Americans was higher than that in white people\u003csup\u003e\u003cspan citationid=\"CR51\" class=\"CitationRef\"\u003e51\u003c/span\u003e\u003c/sup\u003e. Another study shows that in the Asian region, with the improvement of social and economic levels, the serological positive rate of H. pylori has been gradually decreasing, among which the infection rate in developed countries is significantly lower than that in developing and underdeveloped countries\u003csup\u003e\u003cspan citationid=\"CR52\" class=\"CitationRef\"\u003e52\u003c/span\u003e\u003c/sup\u003e. The seropositivity rates vary among different provinces in China. For instance, it is 58.3% in Guangxi, China\u003csup\u003e\u003cspan citationid=\"CR53\" class=\"CitationRef\"\u003e53\u003c/span\u003e\u003c/sup\u003e, while the IgG seropositivity rate in Beijing is 31.7%\u003csup\u003e54\u003c/sup\u003e. The data samples used in this study were all from European populations. Due to the differences in genetic background among these populations, the generalizability of the research results may be somewhat limited. Secondly, in this study, serum antibodies were used as indicators of H. pylori infection. However, some studies have pointed out that some antigens of H. pylori have molecular mimicry with the host's own proteins, and these antibodies may cross-react with host proteins such as heat shock protein 60 (HSP60), forming non-specific immune signals. For example, H. pylori GroEL has up to 54% sequence homology and 92% coverage with human HSP60, providing a structural basis for cross-reaction, and anti-H. pylori Hsp60 antibodies have been found to cross-bind to human Hsp60. This indicates that the current antibody level may not fully represent the immune response of a specific strain or virulence factor, thereby reducing the specificity of antibody-mediated indicators and the accuracy of infection recognition\u003csup\u003e\u003cspan citationid=\"CR55\" class=\"CitationRef\"\u003e55\u003c/span\u003e\u003c/sup\u003e. Finally, MR is a powerful tool for exploring the potential causal relationship between exposure and disease, but its results cannot replace clinical trials. Meanwhile, we also plan to isolate and purify H. pylori OMP-specific antibodies from the patient's serum for further research on the potential pathogenic mechanism between this strain and pancreatic cancer.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cp\u003eHelicobacter pylori (H. pylori)\u003c/p\u003e\n\u003cp\u003elinkage disequilibrium (LD)\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eGeneralized Summary Mendelian Randomization (GSMR)\u003c/p\u003e\n\u003cp\u003eGenome-Wide Association Study (GWAS)\u003c/p\u003e\n\u003cp\u003eHeterogeneity in Dependent Instruments (HEIDI)\u003c/p\u003e\n\u003cp\u003esingle nucleotide polymorphisms (SNPs)\u003c/p\u003e\n\u003cp\u003einstrumental variables (IVs)\u003c/p\u003e\n\u003cp\u003eouter membrane protein (OMP)\u003c/p\u003e\n\u003cp\u003einverse variance weighted (IVW)\u003c/p\u003e\n\u003cp\u003eMendelian Randomization (MR)\u003c/p\u003e\n\u003cp\u003eEnzyme-Linked Immunosorbent Assay (ELISA)\u003c/p\u003e\n\u003cp\u003eEpithelial-mesenchymal transition (EMT)\u003c/p\u003e\n\u003cp\u003eheat shock protein 60 (HSP60)\u003c/p\u003e\n\u003cp\u003emucosa-associated lymphoid tissue (MALT)\u003c/p\u003e\n\u003cp\u003epancreatic ductal epithelial cells (PDECs)\u003c/p\u003e\n\u003cp\u003ecytotoxin-associated gene A (CagA)\u003c/p\u003e\n\u003cp\u003e60-kDa heat shock protein (GroEL)\u003c/p\u003e\n\u003cp\u003eurease subunit (UREA)\u003c/p\u003e\n\u003cp\u003evacuolating cytotoxin A (VacA).\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eData availability statement\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe datasets used in this study are accessible through online repositories. The article\u0026apos;s Table 1 include the repository names and accession numbers. We are deeply appreciative of all participants and researchers who shared these valuable datasets.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthor Contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eJingping Hu:Writing original draft,Methodology,Formal analysis, Conceptualization.\u003c/p\u003e\n\u003cp\u003eLintao Dong:Writing original draft, Formal analysis, Data curation.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eFang Wang*:Writing \u0026ndash; review \u0026amp; editing, Conceptualization.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis work was supported by the National Natural Science Foundation of China (Grant No. 82460563, project title: The mechanism of PFKFB4 inhibition of SIRT2-mediated ketone body degradation regulating Rela/ZZ modification in promoting chemoresistance in colorectal cancer).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgments\u003c/strong\u003e \u003cstrong\u003eand\u003c/strong\u003e \u003cstrong\u003eEthics approval\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe data for the exposure and outcome in this study were obtained from the GWAS database, and both have received ethical approval and participant informed consent. We appreciate all the participants and investigators for sharing these data.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConflict of interest\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare that they have no competing interests.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eStoop TF, Javed AA, Oba A et al (2025) Pancreatic cancer. Lancet 405(10485):1182\u0026ndash;1202. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/S0140-6736(25)00261-2\u003c/span\u003e\u003cspan address=\"10.1016/S0140-6736(25)00261-2\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eSinghi AD, Koay EJ, Chari ST, Maitra A (2019) Early Detection of Pancreatic Cancer: Opportunities and Challenges. Gastroenterology 156(7):2024\u0026ndash;2040. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1053/j.gastro.2019.01.259\u003c/span\u003e\u003cspan address=\"10.1053/j.gastro.2019.01.259\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eZhao Z, Liu W (2020) Pancreatic Cancer: A Review of Risk Factors, Diagnosis, and Treatment. Technol Cancer Res T 19:1533033820962117. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1177/1533033820962117\u003c/span\u003e\u003cspan address=\"10.1177/1533033820962117\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eMorris JPT, Wang SC, Hebrok MKRAS, Hedgehog (2010) Wnt and the twisted developmental biology of pancreatic ductal adenocarcinoma. Nat Rev Cancer 10(10):683\u0026ndash;695. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1038/nrc2899\u003c/span\u003e\u003cspan address=\"10.1038/nrc2899\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eLi L, Yu R, Cai T et al (2020) Effects of immune cells and cytokines on inflammation and immunosuppression in the tumor microenvironment. Int Immunopharmacol 88:106939. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/j.intimp.2020.106939\u003c/span\u003e\u003cspan address=\"10.1016/j.intimp.2020.106939\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eGuarino M, Rubino B, Ballabio G (2007) The role of epithelial-mesenchymal transition in cancer pathology. Pathology 39(3):305\u0026ndash;318. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1080/00313020701329914\u003c/span\u003e\u003cspan address=\"10.1080/00313020701329914\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eFrancesco VD, Zullo A, Manta R et al (2022) Culture-based antibiotic susceptibility testing for Helicobacter pylori infection: a systematic review. Ann Gastroenterol 35(2):127\u0026ndash;134. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.20524/aog.2022.0689\u003c/span\u003e\u003cspan address=\"10.20524/aog.2022.0689\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eNakamura S, Sugiyama T, Matsumoto T et al (2012) Long-term clinical outcome of gastric MALT lymphoma after eradication of Helicobacter pylori: a multicentre cohort follow-up study of 420 patients in Japan. Gut 61(4):507\u0026ndash;513. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1136/gutjnl-2011-300495\u003c/span\u003e\u003cspan address=\"10.1136/gutjnl-2011-300495\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eFang Z, Zhang W, Wang H et al (2024) Helicobacter pylori promotes gastric cancer progression by activating the TGF-beta/Smad2/EMT pathway through HKDC1. Cell Mol Life Sci 81(1):453. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1007/s00018-024-05491-x\u003c/span\u003e\u003cspan address=\"10.1007/s00018-024-05491-x\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eLiu Q, Sadr-Azodi O, Engstrand L, Fall K, Brusselaers N (2024) Helicobacter pylori Eradication Therapy and the Risk of Colorectal Cancer: A Population-Based Nationwide Cohort Study in Sweden. Helicobacter 29(6):e70001. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1111/hel.70001\u003c/span\u003e\u003cspan address=\"10.1111/hel.70001\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eMaity R, Dhali A, Biswas J (2024) Is Helicobacter pylori infection protective against esophageal cancer? World J Gastroentero 30(38):4168\u0026ndash;4174. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.3748/wjg.v30.i38.4168\u003c/span\u003e\u003cspan address=\"10.3748/wjg.v30.i38.4168\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eZhou B, Mei Y, Wang J et al (2023) Is Helicobacter pylori infection associated with pancreatic cancer? A systematic review and meta-analysis of observational studies. Ther Adv Chronic Dis 14:20406223231155119. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1177/20406223231155119\u003c/span\u003e\u003cspan address=\"10.1177/20406223231155119\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003ePosselt G, Backert S, Wessler S (2013) The functional interplay of Helicobacter pylori factors with gastric epithelial cells induces a multi-step process in pathogenesis. Cell Commun Signal 11:77. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1186/1478-811X-11-77\u003c/span\u003e\u003cspan address=\"10.1186/1478-811X-11-77\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eJimenez-Soto LF, Haas R (2016) The CagA toxin of Helicobacter pylori: abundant production but relatively low amount translocated. Sci Rep-Uk 6:23227. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1038/srep23227\u003c/span\u003e\u003cspan address=\"10.1038/srep23227\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eLiu J, Xiao Q, Xiao J et al (2022) Wnt/beta-catenin signalling: function, biological mechanisms, and therapeutic opportunities. Signal Transduct Tar 7(1):3. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1038/s41392-021-00762-6\u003c/span\u003e\u003cspan address=\"10.1038/s41392-021-00762-6\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eYu F, Yu C, Li F et al (2021) Wnt/beta-catenin signaling in cancers and targeted therapies. Signal Transduct Tar 6(1):307. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1038/s41392-021-00701-5\u003c/span\u003e\u003cspan address=\"10.1038/s41392-021-00701-5\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003ePeek RMJ, Blaser MJ (2002) Helicobacter pylori and gastrointestinal tract adenocarcinomas. Nat Rev Cancer 2(1):28\u0026ndash;37. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1038/nrc703\u003c/span\u003e\u003cspan address=\"10.1038/nrc703\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eKlein AP (2021) Pancreatic cancer epidemiology: understanding the role of lifestyle and inherited risk factors. Nat Rev Gastro Hepat 18(7):493\u0026ndash;502. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1038/s41575-021-00457-x\u003c/span\u003e\u003cspan address=\"10.1038/s41575-021-00457-x\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eChoi KW, Chen C, Stein MB et al (2019) Assessment of Bidirectional Relationships Between Physical Activity and Depression Among Adults: A 2-Sample Mendelian Randomization Study. Jama Psychiat 76(4):399\u0026ndash;408. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1001/jamapsychiatry.2018.4175\u003c/span\u003e\u003cspan address=\"10.1001/jamapsychiatry.2018.4175\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eLin BD, Alkema A, Peters T et al (2019) Assessing causal links between metabolic traits, inflammation and schizophrenia: a univariable and multivariable, bidirectional Mendelian-randomization study. Int J Epidemiol 48(5):1505\u0026ndash;1514. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1093/ije/dyz176\u003c/span\u003e\u003cspan address=\"10.1093/ije/dyz176\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eButler-Laporte G, Kreuzer D, Nakanishi T, Harroud A, Forgetta V, Richards JB (2020) Genetic Determinants of Antibody-Mediated Immune Responses to Infectious Diseases Agents: A Genome-Wide and HLA Association Study. Open Forum Infect Di 7(11):ofaa450. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1093/ofid/ofaa450\u003c/span\u003e\u003cspan address=\"10.1093/ofid/ofaa450\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eJiang L, Zheng Z, Fang H, Yang J (2021) A generalized linear mixed model association tool for biobank-scale data. Nat Genet 53(11):1616\u0026ndash;1621. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1038/s41588-021-00954-4\u003c/span\u003e\u003cspan address=\"10.1038/s41588-021-00954-4\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eHemani G, Zheng J, Elsworth B et al (2018) The MR-Base platform supports systematic causal inference across the human phenome. Elife 7. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.7554/eLife.34408\u003c/span\u003e\u003cspan address=\"10.7554/eLife.34408\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eBurgess S, Thompson SG (2017) Interpreting findings from Mendelian randomization using the MR-Egger method. Eur J Epidemiol 32(5):377\u0026ndash;389. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1007/s10654-017-0255-x\u003c/span\u003e\u003cspan address=\"10.1007/s10654-017-0255-x\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eBowden J, Davey Smith G, Haycock PC, Burgess S (2016) Consistent Estimation in Mendelian Randomization with Some Invalid Instruments Using a Weighted Median Estimator. Genet Epidemiol 40(4):304\u0026ndash;314. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1002/gepi.21965\u003c/span\u003e\u003cspan address=\"10.1002/gepi.21965\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eAbecasis GR, Altshuler D, Auton A et al (2010) A map of human genome variation from population-scale sequencing. Nature 467(7319):1061\u0026ndash;1073. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1038/nature09534\u003c/span\u003e\u003cspan address=\"10.1038/nature09534\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eBurgess S, Thompson SG (2011) Avoiding bias from weak instruments in Mendelian randomization studies. Int J Epidemiol 40(3):755\u0026ndash;764. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1093/ije/dyr036\u003c/span\u003e\u003cspan address=\"10.1093/ije/dyr036\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eTan J, Liu N, Guo T, Hu S, Hua L (2021) Genetically predicted obesity and risk of deep vein thrombosis. Thromb Res 207:16\u0026ndash;24. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/j.thromres.2021.08.026\u003c/span\u003e\u003cspan address=\"10.1016/j.thromres.2021.08.026\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eZhu Z, Zheng Z, Zhang F et al (2018) Causal associations between risk factors and common diseases inferred from GWAS summary data. Nat Commun 9(1):224. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1038/s41467-017-02317-2\u003c/span\u003e\u003cspan address=\"10.1038/s41467-017-02317-2\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eGastric cancer and Helicobacter pylori: a combined analysis of 12 case control studies nested within prospective cohorts. Gut. (2001) ;49(3):347\u0026ndash;353. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1136/gut.49.3.347\u003c/span\u003e\u003cspan address=\"10.1136/gut.49.3.347\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003ePormohammad A, Ghotaslou R, Leylabadlo HE, Nasiri MJ, Dabiri H, Hashemi A (2018) Risk of gastric cancer in association with Helicobacter pylori different virulence factors: A systematic review and meta-analysis. Microb Pathogenesis 118:214\u0026ndash;219. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/j.micpath.2018.03.004\u003c/span\u003e\u003cspan address=\"10.1016/j.micpath.2018.03.004\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eXu W, Zhou X, Yin M, Gao J, Weng Z, Xu C (2022) The relationship between Helicobacter pylori and pancreatic cancer: a meta-analysis. Transl Cancer Res 11(8):2810\u0026ndash;2822. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.21037/tcr-21-2803\u003c/span\u003e\u003cspan address=\"10.21037/tcr-21-2803\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eXiao M, Wang Y, Gao Y (2013) Association between Helicobacter pylori infection and pancreatic cancer development: a meta-analysis. PLoS ONE 8(9):e75559. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1371/journal.pone.0075559\u003c/span\u003e\u003cspan address=\"10.1371/journal.pone.0075559\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eGuo Y, Liu W, Wu J (2016) Helicobacter pylori infection and pancreatic cancer risk: A meta-analysis. J Cancer Res Ther 12(Supplement):C229\u0026ndash;C232. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.4103/0973-1482.200744\u003c/span\u003e\u003cspan address=\"10.4103/0973-1482.200744\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eHuang J, Zagai U, Hallmans G et al (2017) Helicobacter pylori infection, chronic corpus atrophic gastritis and pancreatic cancer risk in the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort: A nested case-control study. Int J Cancer 140(8):1727\u0026ndash;1735. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1002/ijc.30590\u003c/span\u003e\u003cspan address=\"10.1002/ijc.30590\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eSchulte A, Pandeya N, Fawcett J et al (2015) Association between Helicobacter pylori and pancreatic cancer risk: a meta-analysis. Cancer Cause Control 26(7):1027\u0026ndash;1035. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1007/s10552-015-0595-3\u003c/span\u003e\u003cspan address=\"10.1007/s10552-015-0595-3\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eTrikudanathan G, Philip A, Dasanu CA, Baker WL (2011) Association between Helicobacter pylori infection and pancreatic cancer. A cumulative meta-analysis. J Pancreas 12(1):26\u0026ndash;31\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eButt J, Varga MG, Wang T et al (2019) Smoking, Helicobacter Pylori Serology, and Gastric Cancer Risk in Prospective Studies from China, Japan, and Korea. Cancer Prev Res 12(10):667\u0026ndash;674. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1158/1940-6207.CAPR-19-0238\u003c/span\u003e\u003cspan address=\"10.1158/1940-6207.CAPR-19-0238\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eMichel A, Waterboer T, Kist M, Pawlita M (2009) Helicobacter pylori multiplex serology. Helicobacter 14(6):525\u0026ndash;535. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1111/j.1523-5378.2009.00723.x\u003c/span\u003e\u003cspan address=\"10.1111/j.1523-5378.2009.00723.x\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eKosunen TU, Seppala K, Sarna S, Sipponen P (1992) Diagnostic value of decreasing IgG, IgA, and IgM antibody titres after eradication of Helicobacter pylori. Lancet 339(8798):893\u0026ndash;895. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/0140-6736(92)90929-w\u003c/span\u003e\u003cspan address=\"10.1016/0140-6736(92)90929-w\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eSchrenk D, Bignami M, Bodin L et al (2023) Risk assessment of N-nitrosamines in food. Efsa J 21(3):e07884. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.2903/j.efsa.2023.7884\u003c/span\u003e\u003cspan address=\"10.2903/j.efsa.2023.7884\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eHouben GM, Stockbrugger RW (1995) Bacteria in the aetio-pathogenesis of gastric cancer: a review. Scand J Gastroenterol Suppl 212:13\u0026ndash;18. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.3109/00365529509090296\u003c/span\u003e\u003cspan address=\"10.3109/00365529509090296\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eCorrea P (1992) Human gastric carcinogenesis: a multistep and multifactorial process\u0026ndash;First American Cancer Society Award Lecture on Cancer Epidemiology and Prevention. Cancer Res 52(24):6735\u0026ndash;6740\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eLuo J, Nordenvall C, Nyren O, Adami H, Permert J, Ye W (2007) The risk of pancreatic cancer in patients with gastric or duodenal ulcer disease. Int J Cancer 120(2):368\u0026ndash;372. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1002/ijc.22123\u003c/span\u003e\u003cspan address=\"10.1002/ijc.22123\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eRisch HA (2003) Etiology of pancreatic cancer, with a hypothesis concerning the role of N-nitroso compounds and excess gastric acidity. Jnci-J Natl Cancer I 95(13):948\u0026ndash;960. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1093/jnci/95.13.948\u003c/span\u003e\u003cspan address=\"10.1093/jnci/95.13.948\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eKao C, Sheu B, Wu J (2016) Helicobacter pylori infection: An overview of bacterial virulence factors and pathogenesis. Biomed J 39(1):14\u0026ndash;23. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/j.bj.2015.06.002\u003c/span\u003e\u003cspan address=\"10.1016/j.bj.2015.06.002\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eXu C, Soyfoo DM, Wu Y, Xu S (2020) Virulence of Helicobacter pylori outer membrane proteins: an updated review. Eur J Clin Microbiol 39(10):1821\u0026ndash;1830. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1007/s10096-020-03948-y\u003c/span\u003e\u003cspan address=\"10.1007/s10096-020-03948-y\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eYamaoka Y (2010) Mechanisms of disease: Helicobacter pylori virulence factors. Nat Rev Gastro Hepat 7(11):629\u0026ndash;641. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1038/nrgastro.2010.154\u003c/span\u003e\u003cspan address=\"10.1038/nrgastro.2010.154\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eCrowe SE (2019) Helicobacter pylori Infection. New Engl J Med 380(12):1158\u0026ndash;1165. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1056/NEJMcp1710945\u003c/span\u003e\u003cspan address=\"10.1056/NEJMcp1710945\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eMichel A, Pawlita M, Boeing H, Gissmann L, Waterboer T (2014) Helicobacter pylori antibody patterns in Germany: a cross-sectional population study. Gut Pathog 6:10. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1186/1757-4749-6-10\u003c/span\u003e\u003cspan address=\"10.1186/1757-4749-6-10\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eEpplein M, Signorello LB, Zheng W et al (2011) Race, African ancestry, and Helicobacter pylori infection in a low-income United States population. Cancer Epidem Biomar 20(5):826\u0026ndash;834. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1158/1055-9965.EPI-10-1258\u003c/span\u003e\u003cspan address=\"10.1158/1055-9965.EPI-10-1258\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eFock KM, Ang TL (2010) Epidemiology of Helicobacter pylori infection and gastric cancer in Asia. J Gastroen Hepatol 25(3):479\u0026ndash;486. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1111/j.1440-1746.2009.06188.x\u003c/span\u003e\u003cspan address=\"10.1111/j.1440-1746.2009.06188.x\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eLiu W, Sun Y, Yuan Y (2020) Analysis of serum gastrin-17 and Helicobacter pylori antibody in healthy Chinese population. J Clin Lab Anal 34(12):e23518. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1002/jcla.23518\u003c/span\u003e\u003cspan address=\"10.1002/jcla.23518\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eYu J, Zhao Y, Wang X, Xu Y (2022) Evaluation of Anti-Helicobacter pylori IgG Antibodies for the Detection of Helicobacter pylori Infection in Different Populations. Diagnostics 12(5). \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.3390/diagnostics12051214\u003c/span\u003e\u003cspan address=\"10.3390/diagnostics12051214\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eSanchez Caraballo A, Guzman Y, Sanchez J, Munera M, Garcia E, Gonzalez-Devia D (2023) Potential contribution of Helicobacter pylori proteins in the pathogenesis of type 1 gastric neuroendocrine tumor and urticaria. In silico approach. PLoS ONE 18(4):e0281485. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1371/journal.pone.0281485\u003c/span\u003e\u003cspan address=\"10.1371/journal.pone.0281485\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":true,"hideJournal":true,"highlight":"","institution":"the National Natural Science Foundation of China","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Pancreatic cancer, Helicobacter pylori, Antibody-mediated immune response, mendelian randomization, Genetic Summary-data-based Mendelian Randomization","lastPublishedDoi":"10.21203/rs.3.rs-7168408/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7168408/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cstrong\u003eIntroduction\u003c/strong\u003e: Helicobacter pylori(H. pylori), a common gram-negative bacterium and known carcinogen, causes chronic infection. Recent studies suggest its link to extra-gastric cancers, including pancreatic cancer, but conflicting findings due to confounding factors hinder clear association.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eMethods\u003c/strong\u003e: Using summary-level data from genome-wide association studies, we analyzed the bidirectional causal relationship between H. pylori-related antibody-mediated immune responses and pancreatic cancer. We further validated the results using generalized summary-data-based Mendelian randomization(GSMR).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eResults\u003c/strong\u003e: We found that the levels of H. pylori outer membrane protein(OMP) antibody can significantly increase the risk of pancreatic cancer (OR: 1.8122, 95% CI: 1.3192 to 2.4894, P \u0026lt; 0.001). These results were consistent with the weighted median algorithm (OR: 1.9638, 95% CI: 1.2686 to 3.0399, P = 0.002). Furthermore, the results from GSMR were also consistent with the above results (OR: 1.7099, 95% CI: 1.2632 to 2.3144, P \u0026lt; 0.001).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConclusion\u003c/strong\u003e: Our study found that H. pylori OMP antibody levels significantly increase pancreatic cancer risk. With rising antibiotic resistance, OMP’s adhesive properties and immune-triggering potential make it a promising target for H. pylori vaccine development, offering future prospects for prevention and treatment.\u003c/p\u003e","manuscriptTitle":"Use of bidirectional Mendelian randomization to unveil the association of Helicobacter pylori infection and Pancreatic cancer","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-07-23 19:12:48","doi":"10.21203/rs.3.rs-7168408/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"22110a30-60c3-45ae-9883-9ec09a82d256","owner":[],"postedDate":"July 23rd, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[{"id":51805491,"name":"Bioinformatics"},{"id":51805492,"name":"Gastroenterology \u0026 Hepatology"}],"tags":[],"updatedAt":"2025-07-23T19:12:48+00:00","versionOfRecord":[],"versionCreatedAt":"2025-07-23 19:12:48","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-7168408","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7168408","identity":"rs-7168408","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}