Longevity Briefs: Can Probiotics Prevent Muscle Ageing?

Longevity briefs provides a short summary of novel research in biology, medicine, or biotechnology that caught the attention of our researchers in Oxford, due to its potential to improve our health, wellbeing, and longevity.

The problem:

As we age, we undergo a gradual loss of muscle mass, strength, and function—a condition known as sarcopenia. Sarcopenia increases the risk of falls and fractures, and lowers overall quality of life. Sarcopenia can largely be prevented through physical exercise, but research is also beginning to point to the gut microbiota—the trillions of microorganisms living in our digestive system—as a potential target for sarcopenia prevention and treatment. The gut microbes break down dietary fibre and produces various bioactive compounds such as short-chain fatty acids (SCFAs) that can influence muscle health. Understanding how these microorganisms and their metabolites affect muscle function could pave the way for new treatments and interventions. In this review, researchers summarise what we know so far.

Key takeaways:

• Gut Dysbiosis and Muscle Health: There is a strong correlation between sarcopenia and gut dysbiosis – the imbalance and disruption of the microbial population of the gut. Animal studies and some recent human studies support the idea that this is a causal relationship, not just a correlation. This imbalance can disrupt the production of essential metabolites like SCFAs and bile acids, which are crucial for muscle health.
• Mechanisms: Animal and human studies suggest that the microbiota affects muscle function through a variety of different mechanisms. For example, SCFAs regulate muscle protein synthesis and degradation, while bile acids activate signaling pathways that affect muscle growth.
• Diagnostic potential: While in its infancy, research suggests that the gut microbiota could be a valuable tool for predicting who is at risk of sarcopenia and intervening with preventative measures.
• Therapuetic potential: It’s clear from animal models that interventions that restore microbiota health also improve muscle health. In humans, clinical trials generally show that interventions like probiotic supplementation can enhance muscle function in both healthy and sarcopenic individuals, but these trials are few in number and are sometimes contradictory.

The implications:

The prospects of harnessing the gut microbiota to prevent or treat sarcopenia appear to be promising, but we need more research. The devil is in the detail – everyone’s microbiota is different and there are some complications when it comes to pinning down which specific gut microbes are ‘good’ and which are ‘bad’. An alternative strategy to probiotic supplementation is a faecal microbiota transplant – transferring stool from someone with a healthy microbiota into the recipient’s gut. This might be preferable because, unlike probitotics, the donor stool contains human microbes that can survive in the gut indefinitely, so you do not need to keep receiving them. Unfortunately, there is currently even less research behind faecal microbiota transplantation than there is behind probiotics.

While we wait for more research to emerge, the priority should be maintaining the health of the microbiota you already have. This can be achieved through a diet rich in fibre combined with physical exercise, the latter having the added benefit of directly supporting muscle health.