Lactobacilli, best allies of mental health: a probiogenomic approach to identify potential psychobiotic strains.

Targeted dietary strategies and supplements represent a promising approach for the treatment of cognitive problems. Multi-omic approaches may facilitate and accelerate the discovery of new psychobiotic strains and their applications. In this work, we applied metagenomics and comparative genomics to guide the isolation and screening of novel psychobiotic strains from fermented foods. Metagenomes of 1185 fermented food were screened, revealing the occurrence of genes coding for the biosynthesis of neuroactive molecules, supporting the isolation of 73 novel Lactic Acid Bacteria (LAB) strains. Comparative genomic analysis highlighted species-specific patterns, identifying Levilactobacillus brevis, Lactiplantibacillus plantarum, Limosilactobacillus fermentum as potential psychobiotics. In vitro functional screening for the production of neuroactive metabolites confirmed four strains, Lactiplantibacillus plantarum TUCC00000144, Limosilactobacillus fermentum TUCC00000777, Levilactobacillus brevis TO10, Lentilactobacillus diolivorans B92, as the most promising candidates for the development of dietary supplements or innovative fermented food products aimed at supporting mental health.