The role of Clostridium butyricum and its metabolites in modulating gut mucosal immunity: implications for viral infections and inflammatory diseases.

With global viral emergence and increasing antiviral resistance, there is an urgent need for innovative immunomodulatory strategies. Gut microbiota modulation has gained attention as a promising therapeutic approach. Clostridium butyricum (C. butyricum) plays a pivotal role in shaping microbial composition, preserving intestinal barrier integrity, and enhancing mucosal immunity. Its major metabolites, short-chain fatty acids (SCFAs), further strengthen mucosal defenses and exert antiviral and anti-inflammatory effects. This review proposes a unified "gut-centric hypothesis" that intestinal barrier integrity, microbial homeostasis, and mucosal immune balance collectively determine the host's resilience to viral invasion and inflammation. The collective findings delineate a mechanistic axis whereby C. butyricum orchestrates antiviral and anti-inflammatory immunity through the induction of type I/III interferons, modulation of inflammasome signaling, and expansion of regulatory immune populations, reinforcing its therapeutic promise. This review provides a new conceptual framework linking probiotic action to antiviral immunity, identifying C. butyricum as a potential next-generation microbial therapeutic for viral and inflammatory diseases.