A specific gut bacterium appears to play a significant role in muscle strength, according to a new study by Spanish researchers.
The research, published in the journal Gut, focuses not on the entire gut microbiome, but on a particular bacteria of the Roseburia genus. Understanding the connection between gut health and physical capabilities is a growing area of scientific interest, with implications for aging and muscle-wasting diseases.
“The fact that it’s associated with a particular species is particularly intriguing,” said Professor Frédéric Raymond, a specialist in the intestinal microbiome at the Faculty of Agriculture and Food Sciences at Laval University.
The study examined stool samples from 90 young adults aged 18 to 25, and 33 older adults aged 65 and over. All participants reported being sedentary, non-smokers, and having maintained a stable weight for the previous three months. Researchers measured participants’ muscle strength in their arms and legs, as well as grip strength, and also assessed their cardiovascular health.
While the stool samples contained a wide variety of bacteria, those from the Roseburia genus were most closely linked to muscle measurements. More specifically, the study found that “the relative abundance of Roseburia inulinivorans, but not other Roseburia species, was positively associated with several measures of strength, including grip strength, leg push strength, and bench press strength in humans.”
“R. Inulinivorans appears as a specific modulator of muscle strength, establishing a link between the intestinal microbiome and muscle metabolism and function,” the researchers wrote. They suggest the findings confirm its potential as a probiotic candidate for interventions targeting age-related muscle loss.
Grip strength in older adults with R. Inulinivorans in their stool samples was approximately 30% higher than in those without the bacteria. The bacteria was also associated with greater grip strength in younger adults, as well as improved cardiovascular health.
In laboratory experiments, mice that received a transplant of R. Inulinivorans subsequently showed a “remarkable” increase in muscle strength.
“Supplementation with R. Inulinivorans in mice significantly improved grip strength of the forelimbs, while other Roseburia species had no effect,” the researchers explained.
The discovery could have practical applications in several fields, including fitness, assisting older adults experiencing loss of independence, and treating degenerative diseases.
“I’m fairly certain [the Spanish researchers] will have patented all of this and will launch clinical trials to validate that it works [in humans],” said Professor Raymond.
If the results are as promising as the study suggests, he added, “it could indeed be a remarkably interesting avenue for older people or those with muscle strength problems.”
The human intestinal microbiome is estimated to consist of around 4,500 different types of bacteria, all contributing to the proper functioning of the body. An imbalance in the microbiome can have significant health consequences, particularly regarding digestion, weight, the immune system, and mental health.
More broadly, the impact of the intestinal microbiome on multiple aspects of human health is receiving increasing attention from the scientific community. Studies published in recent years have shown a potential association between the microbiome and the health of organs such as the heart, brain, and even the eyes.
