Correlation between gut microbiota and pancreatitis: a bidirectional Mendelian randomization.

ObjectiveThe causative role of gut microbiota in pancreatitis remains unknown. This study aimed to investigate potential causal associations between gut microbiota and pancreatitis, using bidirectional Mendelian randomization (MR) analysis.MethodsWe analyzed genome-wide association study (GWAS) summary statistics for gut microbiota (211 taxa from gut microbiota, n  = 18 340) and two types of pancreatitis, namely acute pancreatitis (AP, 5509 cases and 301 383 controls) and chronic pancreatitis (CP, 3002 cases and 301 383 controls). A reverse MR analysis was also performed to assess the possibility of reverse causation.ResultsNine features (one family + eight genera) showed a causal association with AP. According to inverse-variance weighted (IVW) estimates, phylum Firmicutes ( P  = 4.10 × 10 -2 ), genus Erysipelatoclostridium ( P  = 4.80 × 10 -2 ), genus Flavonifractor ( P  = 4.10 × 10 -2 ), genus Methanobrevibacter ( P  = 3.40 × 10 -2 ), and genus Prevotella9 ( P  = 4.60 × 10 -2 ) were found to have a protective effect on AP. Additionally, genus Eubacteriumeligensgroup ( P  = 4.10 × 10 -2 ), genus Eubacteriumfissicatenagroup ( P  = 4.00 × 10 -3 ), genus Coprococcus3 ( P  = 4.10 × 10 -2 ), and genus Haemophilus ( P  = 4.60 × 10 -2 ) exhibited a positive correlation with AP. Four features (two families + two genera) were causally associated with CP. IVW results also confirmed that family Clostridiaceae1 ( P  = 3.30 × 10 -2 ), genus LachnospiraceaeFCS020group ( P  = 4.60 × 10 -2 ), and genus Prevotella9 ( P  = 1.90 × 10 -2 ) were protective factors for CP, whereas the presence of family Victivallaceae ( P  = 2.60 × 10 -2 ) correlated with CP risk. No causal effects of pancreatitis (AP or CP) on these gut microbiota taxa were found in the reverse MR analysis.ConclusionThis study confirms a potential causal relationship between gut microbiota and pancreatitis, highlighting the gut microbiota-pancreas axis in the pathogenesis of pancreatitis.