Gut-liver axis dysregulation and restoration in decompensated hepatitis B cirrhosis: rationale and research progress of fecal microbiota transplantation

Decompensated hepatitis B virus (HBV) related cirrhosis is associated with high mortality and a wide range of complications. Current antiviral and symptomatic treatments fail to reverse core pathological alterations, including disruption of the gut microbial ecosystem. Gut-liver axis imbalance represents a central hub in disease progression. Gut dysbiosis compromises the intestinal mucosal barrier, leading to endotoxin translocation into the bloodstream, which in turn exacerbates hepatic inflammation and fibrosis, thereby establishing a vicious cycle. This review synthesizes the key mechanisms, clinical efficacy, administration routes, and safety profile of fecal microbiota transplantation (FMT) in this disease. It also identifies current technical bottlenecks and research gaps in FMT application and discusses future directions toward precision based and standardized clinical translation of this therapeutic approach.