Modulation of human psychobiology by gut bacterial metabolites: The role of short-chain fatty acids.

When we consume foods rich in dietary fiber such as fruits, vegetables, legumes, and cereals, we rely on the gut bacteria to break it down for us in a process called fermentation. This results in the production of specific bacterial metabolites, called short-chain fatty acids that we absorb and that affect our health. We established that gut-derived short-chain fatty acids reduce the physiological reactivity of the major stress response system in the body – the hypothalamic-pituitary-adrenal axis – in response to an acute laboratory stress task, resulting in lower concentrations of the “stress hormone” cortisol. The results of this research highlight that, at least partly due to the production of short-chain fatty acids, consumption of highly fermentable fibers may help “calm the body” under stressful encounters and potentially protect against the harmful effects of stress.

Keywords:Stress and fear, Microbiota-gut-brain axis, Gut bacterial fermentation, Human psychobiology, Translational research

Disciplines:Psychopharmacology, Biological psychology, Gastro-enterology, Food fermentation