The diet-microbiome tango: how nutrients lead the gut brain axis.

Nutrients and the microbiome have a profound impact on the brain by influencing its development and function in health and disease. The mechanisms by which they shape brain function have only started to be uncovered. Here we propose that the interaction of diet with the microbiome is at the core of most mechanisms by which gut microbes affect host brain function. The microbiome acts on the host by altering the nutrients in the diet and by using them as precursors for synthetizing psychoactive metabolites. Diet is also a major modulator of gut microbiome composition making this another key mechanism by which they affect the host brain. Nutrient-microbiome-host interactions therefore provide an overarching framework to understand the function of the gut-brain axis.