It has long been believed that the gut is merely the place where digestion ends. It is known to be the epicenter of our health, a sophisticated control center that communicates with the brain, the immune system and, according to the latest research, even with the muscles.
This is the finding of a group of researchers from Leiden University Medical Center (LUMC), in collaboration with the University of Granada and the University of Almería, published recently in the Gut journal. The protagonist is Roseburia inulinivorans, a genus of bacteria whose presence seems to be determinant for maintaining physical strength and preventing muscle deterioration associated with aging.
An intestinal bacterium for strong muscles?
To understand the magnitude of this finding and comprehend what role this microorganism plays in our body, we spoke with the study’s principal scientist, Borja Martínez-Téllez, a researcher at the University of Almería.
“Roseburia is a group of beneficial bacteria that naturally live in our intestine. One could say they form part of the ‘good neighbors’ of our microbiota.” This good neighborhood relationship translates into a silent biological function that is vital for metabolic balance.
According to Martínez-Tellez, “their main job is to process what we cannot digest on our own. In other words, to feed on the fiber we consume and transform it into compounds beneficial to our body, especially some called short-chain fatty acids”. Remember that these compounds do not stay in the colon, but act as chemical messengers that travel through the bloodstream.
Although for years it has been considered an important bacterium for metabolic health, the scientist tells us that it is now when they are beginning to discover that their effects could go much further.
Muscle Building
Recently, Boticaria García highlighted the relationship between training and the health of the gut microbiota. Science now detects that the relationship also goes the other way: there is a direct correlation between the abundance of Roseburia in the body and a good physical capacity.
As Borja Martínez-Téllez explains, “although it may seem surprising, the intestine and the muscles are constantly communicating. The gut bacteria produce molecules that pass into the blood and can reach distant tissues, including the muscle”.
In his study, comparing young adults (18 to 25 years) with older individuals over 65, the presence of Roseburia inulinivorans marked a large difference between the elderly group. Older people who carried this bacterium showed a 29% higher grip strength than those who lacked it.
This pattern is not exclusive to aging. In younger people, high levels of this microorganism were associated with better general physical condition, positioning this bacterium as a marker of muscle health for life.
More Muscle Fiber
To demonstrate that this was not a mere coincidence, the research team moved the study to experimental models. The results in mice, after eight weeks of receiving Roseburia strains, were conclusive: the strength of the rodents also increased. In this case, up to 30%.
What was most fascinating was not the increase in power, but the structural change. “The muscles of these animals transformed from within. They developed larger fibers and, more importantly, they produced more fast-twitch fibers“. These are, precisely, the fibers needed for explosive and powerful movements, and the ones we tend to lose the most with age.
Dumbbells and Athletic Bacteria
Although with the caution required by results in rodents and not humans, the research opens a hope to recover muscle by restoring the bacterial population. Especially as we age.
In younger people, muscle strength is something that is taken for granted, but as we age, having more or less power in the muscles makes a difference. One of the major fears we face as we age is sarcopenia or muscle atrophy. Over time, the body loses mass and strength naturally, leading to frailty, falls, and a painful loss of independence.
The researcher, though cautious, is optimistic about this possibility: “We are still investigating the exact mechanisms, but we believe that this bacterium could produce compounds capable of improving the muscle’s energy metabolism, boosting its function and helping preserve its ability to generate force”.
And what does a Roseburia eat?
Awaiting science to define specific treatments, the researcher reminds us that there are already ways to strengthen the microbiota.
- Being bacteria that feed on fiber, a diet low in vegetables, legumes, whole grains and fruit condemns them to disappearance. “Ultraprocessed foods are their greatest enemy”.
- Regular physical exercise not only tones the muscle, but also promotes a more diverse and healthier microbiota.
A Probiotic for Eternal Physical Youth?
The horizon of this research is quite ambitious: to achieve a probiotic based on Roseburia that helps prevent muscle atrophy. “Although that is precisely one of the long-term goals, it’s still early to recommend a Roseburia-based probiotic for the general population,” explains the researcher.
“We need to confirm these results in clinical trials in people and show that administering the bacterium is safe and effective. But if the upcoming studies are positive, in the future we could have new microbiota-based strategies to help prevent the loss of strength and muscle mass associated with aging“, notes.
“What is interesting is that we would be talking about a completely new approach: act on the gut to benefit the muscle!”, exclaims Martínez-Tellez.
Undoubtedly, the scientist’s optimism is contagious. From now on, the next time you think about your muscle health, also take a look inward.
