Researchers from University of Granada, University of Almería, and Leiden University Medical Center have identified a Roseburia inulinivorans bacterium in the human gut that correlates with improved muscle strength and physical condition. The study published in Gut supports the existence of an intestine-muscle axis, potentially opening new probiotic interventions for age-related muscle loss.

The team analyzed stool samples from 123 young and older adults, finding those with the bacterium showed 29% greater handgrip strength. In mouse experiments, animals treated with the bacteria exhibited approximately 30% increased grip strength and developed larger muscle fibers with higher proportions of strength-boosting type II fibers.

While these findings suggest promising applications for muscle maintenance during aging, researchers note limitations including the bacteria's inability to permanently colonize the gut in mice. The study, published in Gut, represents an important step toward understanding gut-muscle connections but requires further investigation into long-term effects and biological mechanisms.