Dietary determinants of susceptibility to IL-23-mediated, psoriasis-like skin and joint inflammation

Psoriasis is a chronic autoimmune skin disease with multiple co-morbidities including psoriatic arthritis (PsA). Despite many recent advances in the understanding of psoriasis, the relationship between environmental determinants and psoriasis remains largely unknown. We previously showed that exposure to a high-sugar and moderate-fat diet (i.e., Western diet, WD) in mice induces appreciable skin inflammation and enhances the susceptibility to imiquimod-induced psoriasiform dermatitis (PsD), suggesting that dietary components may render the skin susceptible to psoriatic inflammation. However, the mechanisms behind dietary regulation of inflammation in PsD are only beginning to be elucidated in experimental models. Several studies suggest that gut microbiota may potentially play key roles in shaping inflammation.In the current study, we used an IL-23 minicircle DNA (IL-23 MC)-based murine model with features of PsD and PsA to study the effect of WD on both psoriasis-like skin and joint disease and tested the hypothesis that intestinal dysbiosis is implicated in skin and joint inflammation.