Gut-muscle axis in sarcopenia: from mechanisms to microbiome-based therapies.

Sarcopenia is a disease characterized by reduced muscle mass and strength. In recent years, increasing evidence suggests that gut microbiota (GM) may play an important role in the pathogenesis of sarcopenia. GM is associated with muscle health by affecting muscle metabolism, regulating inflammatory responses, and promoting nutrient absorption. Despite recent rapid research progress, there are still many uncertainties regarding the causal relationship between GM and sarcopenia, key effector molecules, and individualized intervention strategies. We review the mechanisms of GM in the pathogenesis of sarcopenia with a focus on four interconnected pathways: chronic inflammation, nutrient absorption, amino acid metabolism, and GM-derived metabolites. This review aims to propose an integrated framework linking GM to muscle homeostasis to guide future research directions. Interventions targeting GM may offer a new approach for the treatment of sarcopenia, but more research is needed to clarify the causal relationship and optimize intervention measures.