Could a gut microbe help power up your muscles?

Researchers linked higher gut levels of the bacterium Roseburia inulinivorans with stronger muscle performance in adults; in mice, introducing the microbe improved grip strength, increased muscle fiber size and a shift toward more powerful type II fibers, and altered energy pathways and amino-acid levels. Older adults tended to have fewer of these bacteria, suggesting a possible role in age-related muscle decline. While the mouse data imply a causal effect, human findings remain correlational, and larger studies are needed. If confirmed, probiotics or a high-fibre diet to support such microbes could help maintain muscle function alongside regular exercise.