Evans et al (2014) did some important work in understanding a factor – exercise – in influencing gut microbiota (1). This brought to mind some other studies and the question as to whether exercise influences brain health in part by altering gut microbiota.

Gut microbiota appears to play a role in brain health (2, 3) Brain derived neurotropic factor (BDNF) plays a major role in brain health. BDNF promotes resilience (4). Gut microbiota appear to possibly have an influence on the production of BDNF (5). Inflammation may play a role in mood disorders (5). Gut microbiota might influence systemic inflammation (7, 8).

Exercise appears to aid with executive function, helps protect against neurodegenerative diseases, and may reduce the risk of depression (9, 10, 11). It should also be noted that modern humans tend to get far less exercise than our ancestors did (12, 13).

Could gut microbiota play a role in the brain health effects of exercise?


References

1. Evans CC, et al. Exercise prevents weight gain and alters the gut microbiota in a mouse model of high fat diet-induced obesity. PLoS One. 9(3):e92193.
2. Matthews DM, Jenks SM Ingestion of Mycobacterium vaccae decreases anxiety-related behavior and improves learning in mice. Behav Processes. 96:27-35.
3. Farmer AD, et al. It's a Gut Feeling - how the gut microbiota affects the state of mind. J Physiol. 15;592(Pt 14):2981-2988.
4. Karatsoreos IN, McEwen BS Resilience and vulnerability: a neurobiological perspective. F1000Prine Rep. 1;5:13.
5. Savignac HM, et al. Prebiotic feeding elevates central brain derived neurotrophic factor, N-methyl-D-aspartate receptor subunits and D-serine. Neurochem Int. 63(8):756-64.
6. Rosenblat JD, et al. Inflamed moods: a review of the interactions between inflammation and mood disorders. Prog Neuropsychopharmacol Biol Psychiatry. 53:23-34
7. Galley JD, Bailey MT Impact of stressor exposure on the interplay between commensal microbiota and host inflammation. Gut Microbes. 1;5(3).
8. Walter J, et al. Holobiont nutrition: considering the role of the gastrointestinal microbiota in the health benefits of whole grains. Gut Microbes. 4(4):340-6.
9. Guiney H, Machado L Benefits of regular aerobic exercise for executive functioning in healthy populations. Psychon Bull Rev. 20(1):73-86.
10. Bherer L, et al. A Review of the Effects of Physical Activity and Exercise on Cognitive and Brain Functions in Older Adults. J Aging Res. 2013:657508.
11. Greenwood BN, Fleshner M. Exercise, learned helplessness, and the stress-resistant brain. Neuromolecular Med. 10(2):81-98.
12. Chakravarthy MV, Booth FW. Eating, exercise, and "thrifty" genotypes: connecting the dots toward an evolutionary understanding of modern chronic diseases. J Appl Physiol. 96(1):3-10.
13. Egger GJ, et al. Estimating historical changes in physical activity levels. The Medical Journal of Australia. 175(11-12):635-6.