The gut-muscle axis and the role of Roseburia inulinivorans in age-related muscle loss: a narrative review

Age-related muscle loss (sarcopenia) represents one of the most significant health burdens in a globally ageing population. The relationship between the gut microbiome and skeletal muscle, referred to as the gut-muscle axis, is the subject of increasing research, yet the identification of specific responsible microbial species and mechanisms has remained limited. This review aims to summarize the current evidence on the gut-muscle axis, with particular focus on the association between the intestinal bacterium Roseburia inulinivorans and muscle performance reported in a 2026 Gut publication, and to evaluate its clinical and therapeutic relevance. Narrative review based primarily on the study by Martinez-Tellez et al. (2026), supplemented by relevant literature on the gut-muscle axis, sarcopenia, and the ageing microbiome. The relative abundance of R. inulinivorans positively correlated with handgrip strength, leg press and bench press performance. Older adults with detectable R. inulinivorans showed 29% higher handgrip strength without a concomitant increase in cardiorespiratory capacity. In a murine model, oral supplementation produced approximately 30% increase in forelimb grip strength. The mechanism may operate not via butyrate but through activation of the purine and pentose phosphate pathways in muscle tissue. R. inulinivorans shows a species-specific association with muscle strength and represents a candidate target for nutraceutical interventions against sarcopenia and cachexia. Human randomized clinical trials and longitudinal studies accounting for sex differences are required to confirm these findings. Orv Hetil. 2026; 167(41): 1646-1654.