Is the intestinal microbiota linked to muscle strength? That is the question.
The intestinal microbiota acts on many aspects of our health: digestion, immunity, oral health, intimate comfort, gut-brain axis etc. It would also have an impact on the skeletal muscles. Emerging evidence supports a role for the gut microbiome on the maintenance of lean body mass and physical functioning.
Sarcopenia also called muscle wasting is an inevitable phenomenon in aging. With age, body composition, muscle strength and lean body decrease. We lose strength and muscle. Could the intestinal microbiota, which loses richness and diversity in older, play a role? An international team of researchers provide some new answers by publishing the results of their study.
The first part of the study is conducted in humans
The first phase consisted in comparing the bacteria of the intestinal microbiota of 29 elderly people:
- 18 elderly people with good physical and bodily condition (percentage of lean mass greater than that of fat mass)
- 11 elderly people with a physical impairment and a less favorable body composition.
The results of the study reveal differences in the microbiota composition between the 2 groups. Indeed, higher levels of beneficial bacteria belonging to the family of Prevotellaceae, to the genera Prevotella and Barnesiella and to the species Barnesiella intestinihominis are observed in the most active participants.
The second part of the study is conducted in mice
The second phase of the study was to assess the causal role of the microbiota on muscle function.
The researchers colonized axenic mice with the faecal samples of the first phase participants. Mice transplanted with the feces of the best performers had better grip strength. Grip strength is a simple, fast and reliable measure of maximum voluntary hand force which is used, among other things, to assess muscle strength
The same differences in intestinal microbiota composition were observed between the 2 groups of mice as those observed in humans.
A discovery that suggests the impact of bacteria from the intestinal microbiota on maintaining muscle strength in the elderly.