Gut bacterium linked to 29% stronger muscles in older adults, mouse study shows

Somewhere in the quiet ecology of the human gut, a single bacterial species may be holding back the tide of age. Researchers in the Netherlands and Spain have found that older adults carrying Roseburia inulinivorans in their microbiomes grip the world some 29% more firmly than those without it — a strength advantage that appears independent of cardiovascular fitness, and that mouse experiments have begun to trace toward causation. The bacterium fades with age just as muscles do, and science is now asking whether restoring one might help preserve the other.