Aspects of Gut Microbiome Composition Correlate with Physical Activity in Older People
Exercise influences the composition of the gut microbiome, which in turn influences capacity for exercise. Thus we see correlations in older people between the composition of the gut microbiome and observed level of physical activity and fitness, but breaking that down into specific contributing mechanisms and their relative importance is a challenge. The fastest path to answers is to alter the gut microbiome composition in defined ways and see how it affects capacity for physical activity. Approaches to alteration are in their infancy; the only approaches robustly demonstrated to produce lasting change are flagellin immunization and fecal microbiota transplantation, but while beneficial in the sense of reversing age-related changes in the composition of the gut microbiome, these approaches do not produce a well defined outcome. The future of this field will likely involve cultivation of defined mixes of hundreds or thousands of species in a synthetic microbiome, a major step up in complexity from the present manufacturing processes for probiotics.
Gut microbiota (GM) plays a crucial role in maintaining health through metabolic, endocrine, and immune functions. With ageing, shifts in GM composition, characterised by increased pathogenic and decreased health-promoting bacteria, contribute to dysbiosis, which is linked to several age-related diseases. Given the global trend of increasing sedentary behaviour (SB) and declining physical activity (PA) among older adults, this study aims to explore the relationships between GM and two critical indicators of healthy ageing, movement behaviours, and physical function.
This cross-sectional study assesses the GM composition, PA levels and physical function of 101 healthy, community-dwelling older adults aged 65-85 years. Participants undertook anthropometric measures and functional tests, wore an accelerometer for 7 days and provided a faecal sample which was analysed using 16s rRNA sequencing. All the results were adjusted for key covariates such as diet, age and activity levels.
Key findings include positive associations of Prevotella copri with moderate-to-vigorous PA, physical function, and negative associations with SB, while Roseburia species were linked to better mobility and strength measures. Conversely, potentially pathogenic taxa like Bilophila wadsworthia and Eggerthella were negatively associated with PA and handgrip strength, underscoring their possible detrimental roles in muscle function and healthy ageing. This cross-sectional study highlights the associations between GM, PA, physical function and healthy ageing in older adults. These findings emphasise the potential for leveraging GM and PA interactions to develop nonpharmacological strategies for promoting healthy ageing, warranting further research through interventional and longitudinal studies.