Metagenomics Analysis of Altered Gut Microbiome in Psoriasis and the Mediation Analysis: A Case-Control Study.

Purpose: Psoriasis is an inflammatory disease linked to gut microbiome dysbiosis. However, the mechanisms underlying gut microbiome changes caused by dietary habits in psoriasis remain unclear. Patients and Methods: We performed a case-control study including 64 psoriasis patients and 64 age-, sex-, and body mass index (BMI)-matched controls. Stool samples were collected for metagenomics sequencing. The differential abundance analysis was performed to identify differentially abundant taxa between psoriasis and control groups. The dietary intake frequency information of each included subject was obtained through face-to-face interviews. Mediation analysis was used to identify potential mediators of the gut microbiome alterations in psoriasis. Results: The gut microbiome of psoriasis patients was significantly alterated when compared to controls. Anaerostipes Hadrus, Blautia Wexlerae, and the other six species may be beneficial to psoriasis. However, Prevotella Copri and Eggerthellaceae could be pathogenic bacteria. The study also identified correlations between specific dietary habits and psoriasis, with the largest correlation observed between poultry consumption and psoriasis (OR=0.735, P=0.001), followed by red meat (OR=0.784, P=0.007) and fresh vegetables (OR=0.794, P=0.028). Mediation analysis revealed that Anaerostipes hadrus, Dorea longicatena, and Eggerthella lenta mediated the association between poultry and psoriasis. Conclusion: The characteristics of intestinal flora in psoriasis patients were significantly different from controls. Intestinal flora mediated the association between diet and psoriasis to some extent. This study provides new insights for adjuvant treatments of psoriasis through dietary and intestinal microbiota interventions.