Relationship between intestinal microbiota and muscle mass loss (sarcopenia) in older adults: a narrative review

Background: Several studies have highlighted the role of metabolites produced by the microbiota in regulating muscle mass and functionality, particularly through the gut-muscle axis. Objective: To examine the mechanisms by which the gut microbiota interacts with skeletal muscle and to compile the most recent therapeutic strategies based on probiotic supplementation to correct alterations in the microbiota (dysbiosis) and thus prevent or treat sarcopenia in geriatric patients. Material and methods: A systematic search for studies was conducted in the PubMed and NIH databases, including systematic reviews, meta-analyses, and clinical trials, focused on geriatric patients with sarcopenia and/or frailty syndrome in which probiotic supplementation has been implemented. Results: Probiotic interventions have shown promising results in animal models to limit sarcopenia and cachexia, but the data available in humans are limited and variable. Conclusions: Research involving a broad and diverse sample is needed to evaluate the impact of probiotic supplementation on different demographic groups and health statuses, with the aim of designing personalized nutrition.