IL17A and psoriasis: The key differential gut microbiota in the B. breve CCFM1078 group was not identified, but the B. breve CCFM1078 strain largely ameliorated psoriasis, and was most successful in suppressing inflammatory responses of all the probiotic groups; therefore, it was speculated that B. breve CCFM1078 ameliorated psoriasis directly through the IL-23/IL-17 axis rather than exerting effects on gut microbiota.