Feed your microbes to deal with stress: a psychobiotic diet impacts microbial stability and perceived stress in a healthy adult population.

The impact of diet on the microbiota composition and the role of diet in supporting optimal mental health has received much attention in the last decade. However, whether whole dietary approaches can exert psychobiotic  effects is largely understudied. Thus, researchers investigated the influence of a psychobiotic  diet (high in prebiotic and fermented foods) on the microbial profile and function as well as on mental health outcomes in a healthy human population. Forty-five adults were randomized into either a psychobiotic  (n = 24) or control (n = 21) diet for 4 weeks. Fecal  microbiota composition and function was characterized using shotgun sequencing. Stress, overall health and diet were assessed using validated questionnaires. Metabolic profiling of plasma, urine and fecal  samples were performed. Intervention with a psychobiotic  diet resulted in reductions in perceived stress (32% in diet vs. 17% in control group), but not between groups. Similarly, biological markers of stress were not affected. Additionally, higher adherence to the diet resulted in stronger decreases in perceived stress. During the dietary intervention elicited only subtle changes in microbial composition and function, significant changes in the level of 40 specific fecal  lipids and urinary tryptophan metabolites were observed. Lastly, microbial volatility was linked to greater changes in perceived stress scores in those on the psychobiotic  diet. These results highlight that dietary approaches can be used to reduce perceived stress in a human cohort. Using microbiota-targeted diets to positively modulate gut-brain communication holds possibilities for the reduction of stress and stress-associated disorders, but additional research is warranted to investigate underlying mechanisms, including the role of the microbiota.

Link to article: https://www.nature.com/articles/s41380-022-01817-y