Sarcopenia and non-alcoholic fatty liver disease: analysis of the gut microbiota

• Walking speed and appendicular muscle mass are negatively correlated with non-alcoholic fatty liver disease (NAFLD) risk, while grip strength shows no significant association. • Reverse Mendelian randomization reveals that NAFLD is negatively associated with appendicular muscle mass, suggesting a bidirectional relationship. • Thirty-nine gut microbiota taxa are significantly associated with sarcopenia, and six have a causal relationship with NAFLD, implicating the gut-liver-muscle axis. • The study highlights the potential role of short-chain fatty acid metabolism in mediating the gut-liver-muscle axis, offering new insights for cross-organ mechanisms and population-specific interventions.