Probiotics and their metabolite spermidine enhance IFN-γ+CD4+ T cell immunity to inhibit hepatitis B virus

The therapeutic potential of commensal microbes and their metabolites is promising in the functional cure of chronic hepatitis B virus (HBV) infection, which is defined as hepatitis B surface antigen (HBsAg) loss. Here, using both specific-pathogen-free and germ-free mice, we report that probiotics significantly promote the decline of HBsAg and inhibit HBV replication by enhancing intestinal homeostasis and provoking intrahepatic interferon (IFN)-γ