Commensal microbe-derived butyrate enhances T follicular helper cell function to boost mucosal vaccine efficacy

Our study underscores the crucial role of the gut microbiota, particularly neomycin-depleted butyrate producing taxa, in regulating PP-Tfh cell function and IgA production. Butyrate emerges as a metabolite linking microbial metabolism to Tfh differentiation and IgA class switching. Together, these findings establish a microbiota-metabolite-Tfh cell axis essential for mucosal immune homeostasis and suggest novel strategies for enhancing vaccine efficacy and protection against enteric infections. Video Abstract.