A recent study has identified a specific gut bacterium that may play a role in muscle strength, offering potential insights into healthy ageing. Researchers found that higher levels of Roseburia inulinivorans in the gut were associated with stronger muscle performance in both young and older adults.
The study analysed the gut microbiomes of 90 young adults (aged 18–25) and 33 older adults (aged 65–75). Participants provided stool samples for DNA sequencing to identify bacterial species, and underwent muscle strength tests including a handgrip test, which is a reliable indicator of overall muscle strength. The results showed that those with higher levels of Roseburia inulinivorans had better grip strength and other muscle measures.
To investigate whether the bacterium directly influences muscle strength, researchers conducted experiments in mice. Mice given Roseburia inulinivorans developed stronger grip strength and larger type II muscle fibres, which are associated with powerful movements. Further analysis indicated that the bacterium may enhance energy-related pathways in muscle cells while reducing certain amino acids in the gut and bloodstream.
Interestingly, older participants had lower levels of Roseburia inulinivorans compared to younger ones, aligning with age-related muscle decline. While the human data shows only an association, the mouse experiments suggest a causal link. Larger human studies are needed to confirm the direction of the relationship.
If confirmed, this bacterium could be developed into a probiotic to help maintain muscle function in older age. Alternatively, diet can support beneficial gut microbes; prebiotic fibres, which feed bacteria like Roseburia inulinivorans, may promote their growth. The bacterium's name, inulinivorans, hints at its preference for inulin, a type of prebiotic fibre found in foods like chicory root and garlic.
