We have all seen it, the age-related loss of muscle mass and increasing frailty that generally accompanies advancing age. Recently the World Health Organization classified this age-related muscle wastage as a disease and thus sarcopenia entered official usage to describe it. There are a number of potential causes of sarcopenia and new research suggests that there is a nutritional link between the microbiota and development of the condition.
What is Sarcopenia?
Sarcopenia is the condition that causes the familiar, age-related loss of muscle strength and mass in older people, and it leads to ever-increasing frailty. Frailty makes everyday tasks difficult, affects balance, and can lead to falls, which can be very dangerous for older people.
How sarcopenia develops is a more complex matter; there are a number of possible causes for sarcopenia, including reduced protein intake, sedentary lifestyle, chronic inflammation that inhibits cell function and tissue repair, reduced stem cell activity from the same inflammatory signals, mitochondrial dysfunction, and reduced oxygenation resulting from deteriorating blood vessels.
These are only some of the possible factors involved in the onset of sarcopenia, and more research is needed to determine the exact cause, although it currently appears that reduced stem cell activity is a strong contender.
Could the gut influence sarcopenia?
A new study has researchers considering that age-related changes of the gut microbiota may possibly contribute to sarcopenia. In recent years, the role of the gut microbiota in aging has increasingly become the focus of research. In this paper, the researchers focus on age-related changes in these populations of gut microbes in an attempt to explain the link between nutrition and sarcopenia.
There is certainly ample evidence to suggest that changes in the gut microbiota can promote inflammation and contribute to the smoldering chronic inflammation known as “inflammaging”. It may be the case that changes to the microbiota promote inflammation, which inhibits stem cell activity and thus provokes sarcopenia; we know that inflammatory signals do inhibit stem cells, so this is certainly plausible.
The interaction of the gut microbiota with the aging processes and other metabolic systems is intriguing. However, the interplay of the gut microbiome with our biology is highly complex, so it remains to be seen if anything useful will come from this particular line of research in the near future.
As ever, our interest lies in research that focuses on the root causes of aging and has the potential to prevent sarcopenia at its root. A repair-based approach to aging, as proposed in the Hallmarks of Aging and the SENS model, is what we believe could lead to the most significant increases of healthy longevity, making these approaches the ones we consider most worthy of development and funding. That said, research such as this is still intriguing and adds to our scientific understanding, and that is a never a bad thing.
 Ticinesi, A., Lauretani, F., Milani, C., Nouvenne, A., Tana, C., Del Rio, D., … & Meschi, T. (2017). Aging Gut Microbiota at the Cross-Road between Nutrition, Physical Frailty, and Sarcopenia: Is There a Gut–Muscle Axis?. Nutrients, 9(12), 1303.