Pohang University of Science & Technology (POSTECH) Feb 4 2026 A research team from POSTECH and ImmunoBiome in Korea, led by Professor Sin-Hyeog Im, has uncovered a new mechanism showing how butyrate-a short-chain fatty acid produced by gut commensal bacteria-enhances T follicular helper (Tfh) cell activity to promote antibody production and strengthen mucosal vaccine efficacy. This study identifies a new microbiota–immune–antibody production axis linking microbial metabolism to mucosal immune