Theoretical Perspectives on Balance Training and the Gut-Muscle-Brain Axis in Aging.

With growing global life expectancy, age-related physical problems, including balance impairments, are becoming more prevalent, increasing the risk of falls, mobility limitations, and loss of independence. This review summarizes current evidence on how balance may be influenced and improved by training modalities including reactive, strength-based, and functional exercises, through neuromuscular adaptations relevant to postural control and functional stability in older adults. Emerging evidence suggests that gut microbiota may influence neuromuscular health via neuroimmune, metabolic, and mitochondrial pathways across the gut-muscle-brain axis. However, most studies focus on muscle metabolism, inflammation, and systemic physiological processes rather than direct assessments of balance or postural control. Gut dysbiosis has been associated with sarcopenia and impaired physical function, although evidence linking microbiota alterations to balance outcomes remains limited and mainly observational. Exercise has beneficial effects on neuromuscular function and gut microbial composition, including increased diversity and metabolite production. While exercise-induced neuromuscular adaptations are well supported experimentally, little direct evidence shows the contribution of gut-related mechanisms to balance regulation. Overall, neuromuscular and gut-related processes seem to be associated with balance capacity in older adults; however, further mechanistic and interventional studies are required to clarify the role of the gut-muscle-brain axis for balance.