This study investigated the effects of a psychobiotic diet (high in prebiotics and fermented foods) on the gut microbiota and mental health in healthy adults. Forty-five participants were randomized to either a psychobiotic or control diet for four weeks. The psychobiotic diet led to a 32% reduction in perceived stress compared to a 17% reduction in the control group, with higher adherence correlating with greater stress reduction. While microbial composition changes were subtle, significant alterations in fecal lipids and urinary tryptophan metabolites were observed. Microbial stability was linked to stress reduction in the psychobiotic group. These findings suggest that dietary interventions can reduce perceived stress, highlighting the potential of microbiota-targeted diets to improve gut-brain communication and mental well-being.

Kirsten Berding, Thomaz F S Bastianssen, Gerard M Moloney, Serena Boscaini, Conall R Strain, Andrea Anesi, Caitriona Long-Smith, Fulvio Mattivi, Catherine Stanton, Gerard Clarke, Timothy G Dinan, John F Cryan