Probiotic administration effect on microbiome composition, emotional memory and decision-making

The present study used a double-blind, randomized, pre- and post- intervention (4 week) assessment design to investigate the effects of a 4-week probiotic intervention on behavior, brain function, brain metabolism and gut microbial composition. Forty-five healthy participants divided equally into three groups (probiotic, placebo and control) underwent functional MRI (emotional decision-making (ED) and emotional recognition memory (ER) task) and magnetic resonance spectroscopy scans. The gut microbiome composition was analyzed along in the intervention groups, before and after administration of probiotics and placebo (four weeks). Brain activation pattern changes in response to emotional memory and emotional decision making tasks were linked to probiotic intervention, accompanied by shifts in the gut microbiome profiles. These shifts were capable of mirroring behavioral measures (questionnaires assessing emotions) and memory performance. This is the first study reporting a distinct influence of probiotic intervention on a behavioral, neuronal, and microbial level at the same time in healthy human volunteers.