Supplemental Leuconostoc mesenteroides strain NTM048 attenuates imiquimod-induced psoriasis in mice

Aims Psoriasis, a chronic inflammatory skin disease, is associated with altered intestinal microbiota. Here, we investigated the ameliorative effect of Leuconostoc mesenteroides NTM048 strain in imiquimod (IMQ)-induced psoriasis in mice. Methods and results Mice were administered NTM048 for 21 days alongside the topical application of IMQ on the dorsal skin for 6 consecutive days. IMQ induced psoriatic symptoms such as erythema and scaling and also upregulated interleukin (IL)-17, a key effector cytokine of psoriasis, in the skin. Supplemental NTM048 suppressed these abnormalities, increased the levels of plasma deoxycholic acid (DCA), a secondary bile acid, and altered the fecal microbiota composition, as indicated by the increased abundance of Akkermansia and decreased abundance of Staphylococcus and Streptococcus. Notably, DCA treatment of murine splenocytes reduced IL-17 production. Conclusions The NTM048-mediated reduction of psoriasis was shown to involve the downregulation of IL-17 in mouse skin, which was possibly associated with the plasma DCA derived from intestinal microbiota. Significance and impact of study Our findings propose not only a novel approach for psoriasis reduction but also a crosstalk between the skin and intestine in psoriasis.