Dose-Response Efficacy and Mechanisms of Orally Administered Bifidobacterium breve CCFM683 on IMQ-Induced Psoriasis in Mice.

This study aimed to investigate the dose-response effect of Bifidobacterium breve CCFM683 on relieving psoriasis and its underlying patterns. Specifically, the expression of keratin 16, keratin 17, and involucrin were substantially decreased by administration of 10 9 CFU and 10 10 CFU per day. Moreover, interleukin (IL)-17 and TNF-α levels were substantially decreased by 10 9 and 10 10 CFU/day. Furthermore, the gut microbiota in mice treated with 10 9 or 10 10 CFU/day was rebalanced by improving the diversity, regulating microbe interactions, increasing Lachnoclostridium , and decreasing Oscillibacter . Moreover, the concentrations of colonic bile acids were positively correlated with the effectiveness of the strain in relieving psoriasis. The gavage dose should be more than 10 8.42 CFU/day to improve psoriasis according to the dose-effect curve. In conclusion, CCFM683 supplementation alleviated psoriasis in a dose-dependent manner by recovering microbiota, promoting bile acid production, regulating the FXR/NF-κB pathway, diminishing proinflammatory cytokines, regulating keratinocytes, and maintaining the epidermal barrier function. These results may help guide probiotic product development and clinical trials in psoriasis.