Gut Microbe May Boost Muscle Strength

Study links bacterium Roseburia inulinivorans to increased muscle power in humans and mice.

Mar. 20, 2026 at 4:30am

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A recent study suggests that the gut microbiome may influence an important aspect of fitness - muscle strength. Researchers found that higher levels of the bacterium Roseburia inulinivorans were linked to stronger muscle performance across various measures. Further experiments in mice indicated this microbe can directly enhance muscle strength, potentially by influencing how muscles use energy. The findings raise the possibility of using probiotics containing R. inulinivorans to help maintain muscle function as people age.

Why it matters

Muscle strength is crucial for health, supporting joints, boosting athletic performance, and helping maintain independence in older adults. Understanding what influences muscle strength is an important part of healthy aging research. This study provides new insights into how the gut microbiome may play a role in regulating this important aspect of physical fitness.

The details

Researchers analyzed the gut microbiomes and muscle strength of two groups - 90 young adults aged 18-25 and 33 older adults aged 65-75. They found that higher levels of the bacterium Roseburia inulinivorans were linked to stronger grip strength and other measures of muscle power. Further experiments in mice showed that introducing R. inulinivorans led to increased grip strength, larger muscle fibers, and more active energy-related pathways in muscle cells. The researchers also noted that older adults tended to have lower levels of this bacterium compared to younger participants.

  • The study was published on March 20, 2026.

The players

Rachel Woods

An Associate Professor at the University of Nottingham and the University of Lincoln who authored the article.

Roseburia inulinivorans

A bacterium found in the human gut microbiome that was linked to increased muscle strength in the study.

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What they’re saying

“Finding a link like this is interesting, but it does not necessarily mean the microbe is responsible. Many things can be associated without one directly causing the other.”

— Rachel Woods, Associate Professor

What’s next

Larger human studies will be needed to further investigate the relationship between Roseburia inulinivorans and muscle strength, and whether this bacterium could be developed into a probiotic to help maintain muscle function as people age.

The takeaway

This study adds to growing evidence that the gut microbiome may influence many aspects of human health, including physical fitness and muscle strength. While more research is needed, the findings suggest that supporting a healthy, diverse gut microbiome through diet and exercise may be an important strategy for maintaining muscle power as we get older.