Exercise and the microbiota

Abstract

Sedentary lifestyle is linked with poor health, most commonly obesity and associated disorders, the corollary being that exercise offers a preventive strategy. However, the scope of exercise biology extends well beyond energy expenditure and has emerged as a great 'polypill', which is safe, reliable and cost-effective not only in disease prevention but also treatment. Biological mechanisms by which exercise influences homeostasis are becoming clearer and involve multi-organ systemic adaptations. Most of the elements of a modern lifestyle influence the indigenous microbiota but few studies have explored the effect of increased physical activity. While dietary responses to exercise obscure the influence of exercise alone on gut microbiota, professional athletes operating at the extremes of performance provide informative data. We assessed the relationship between extreme levels of exercise, associated dietary habits and gut microbiota composition, and discuss potential mechanisms by which exercise may exert a direct or indirect influence on gut microbiota.

Keywords: diet; diversity; exercise; gut microbiota; host-microbe interactions.

Figures

Figure 1.

Schematic overview of potential sites of interaction between the biological adaptations to exercise and the microbiota. This is intended to be representative not comprehensive. Exercise is linked with a diversity of biological responses including a modifying influence on the brain-gut-microbe axis, diet-microbe-host metabolic interactions, neuro-endocrine and neuro-immune interactions. For example, exercise is long known to increase vagal tone - the hard wiring of the gut - which is anti-inflammatory and immune-modulatory. The latter might represent an indirect means by which exercise conditions gut microbiota composition.