Gut Bacteria Linked to Stronger Muscles in Older Adults, New Research Finds

New research has found a link between specific gut bacteria and muscle strength in older adults, adding to growing evidence that the gut microbiome plays a role in physical health beyond digestion.

Scientists identified that higher levels of a bacterium called Roseburia inulinivorans in the gut are associated with greater muscle strength. The finding points to what researchers are calling the gut-muscle axis, a biological pathway that may influence how well muscles function as people age.

Muscle loss is a major concern for older adults. After age 60, muscle mass can decline rapidly, increasing the risk of falls, disability, and loss of independence. Current interventions focus mainly on exercise and protein intake, but researchers say the gut microbiome may offer an additional lever.

The study, published in a peer-reviewed journal, analyzed gut microbiome data alongside muscle strength measurements from a large group of older adults. Participants with higher levels of Roseburia inulinivorans consistently showed better grip strength and physical performance scores.

Researchers caution that the study shows an association, not a direct cause-and-effect relationship. More work is needed to determine whether boosting this bacterium through diet or supplements could actually improve muscle strength.

Roseburia inulinivorans feeds on dietary fiber, which suggests that eating more fiber-rich foods could support its growth. Experts say this is another reason to prioritize vegetables, legumes, and whole grains, particularly for older adults concerned about maintaining strength and mobility.

The research team plans to conduct follow-up studies to test whether targeted dietary changes can shift gut bacteria levels and produce measurable improvements in muscle function.