Association between microbiome and psoriasis vulgaris and arthropathic psoriasis: a bidirectional two-sample Mendelian randomization study

Background: Research has found that a certain link between gut microbiota(GM) and arthropathic psoriasis(PsA) and psoriasis vulgaris(PV). However, the association between GM and PsA and PV has yield conflicting results due to the influence of confounding factors. GM may increase the risk of PsA and PV through the gut-skin axis. Methods: We used a two-sample Mendelian randomization (MR) study to explore the relationship between GM and PsA and PV, using genetic variation from published genome-wide association studies as an instrumental variable. Reverse variance weighting, maximum likelihood, MR Egger, weighted median, weighted model, MR-PRESSO, and cML MA were used to examine the causal relationship between GM and PsA and PV. Several sensitivity analyses were also performed to ensure the accuracy of the re-sults Cochran's Q statistics are used to quantify the heterogeneity of Instrumental variables estimation. Results: A higher genetically predicted abundance Odoribacter was associated with a reduced risk of psoriasis. While a higher genetically predicted abundance of Ruminiclostridium5 was associated with an increased risk of psoriasis. The genetically predicted relative abundance of Verrucomicrobiae , Verrucomicrobiaceae , Akkermansia , Verrucomicrobiales were positively associated with arthropathic psoriasis. A higher genetically predicted abundance of Rikenellaceae served as protective factors for arthropathic psoriasis. Specifically, a higher genetically predicted Atinomycetaceae , Eubacterium fissicatena group , Lactococcus , and Actinomycetales were associated with a higher risk of psoriasis vulgaris. In contrast, higher genetically predicted Odoribacter was a lower risk of psoriasis vulgaris. No significant heterogeneity or level pleiotropy of Instrumental variables estimation was found. Conclusion: This MR study offer novel perspectives regarding the prevention, advancement, and therapy of psoriasis by concentrating on specific bacterial groups. Additional research is required to specify the exact mechanism relating the association between gut microbiota and psoriasis along with its classifications.