Interactions Between Gut Microbiome and Muscle Tissue in the Development of Sarcopenia
Researchers here discuss what is known of the bidirectional relationship between the aging of skeletal muscle and the aging of the gut microbiome. Muscle tissue is metabolically active, generating myokine signals influential on other tissues. This signaling is far from fully mapped, but is known to be important to health, such as via mediating some of the benefits of exercise. Myokine signaling can also affect the composition of the gut microbiome. In turn, changes in the gut microbiome can contribute to the characteristic loss of muscle mass and strength that takes place with advancing age via increased inflammatory signaling or reduced generation of beneficial metabolites known influence muscle metabolism, such as butyrate.
The interplay between gut microbiota and sarcopenia has emerged as a cutting-edge research topic in the medical field, garnering significant attention. Sarcopenia is an age-related syndrome characterized by a progressive decline in skeletal muscle mass, strength, and function, which profoundly impacts the quality of life in older adults and imposes substantial socioeconomic burdens on many counties. Accumulating evidence indicates that alterations in the gut microbiota are not only linked to various intestinal disorders but also to aging-associated conditions, such as sarcopenia.
The gut microbiota plays a pivotal role in regulating skeletal muscle homeostasis via its metabolic products and is increasingly recognized as a potential pathophysiological factor contributing to sarcopenia development. Skeletal muscle, functioning as both a motor and endocrine organ, secretes myokines that exert critical regulatory effects on the gut microbiota. In sarcopenic individuals, reduced secretion of myokines correlates with decreased microbial diversity and compositional shifts, marked by diminished beneficial microbes and increased potentially harmful species. This establishes a vicious cycle of gut dysbiosis-sarcopenia-gut dysbiosis.
Modulation of the gut microbiota has been demonstrated to enhance muscle mass and function in elderly patients with sarcopenia. Metabolites derived from the gut microbiota, such as amino acids, lipopolysaccharides, and short-chain fatty acids, are known to modulate skeletal muscle protein metabolism by influencing anabolic and catabolic pathways. Nevertheless, the bidirectional mechanisms underlying the relationship between gut microbiota and age-related sarcopenia remain incompletely understood.