Development of a plant-based psychobiotic yogurt-like for the Gut brain axis

Plant based fermented foods may improve gastrointestinal health and provide other health benefits, including the release of molecules with the potential to modulate pathways of the microbiota–gut–brain-axis. Several lactic acid bacteria (LAB) can synthesize a wide range of metabolites such as neurotransmitters and are considered as Psychobiotics bacteria (PB). This study was focused on the development of a plant-based, yogurt-like (containing rice, chickpea and pea flour) fermented with selected PB and tested for their ability to colonize the human gut in a invitro gastrointestinal model. A total of 71 LAB was isolated from Italian typical fermented foods. A whole genome sequencing was performed to identify isolates with potential psychobiotic genes. A total of 18 potential psychobiotic strains were tested in vitro for their ability to survive the gastrointestinal tract (GIT) and screened for antibiotic resistance/sensibility. The ability of the strains to produce GABA, catecholamine, epinephrine, norepinephrine, dopamine, acetylcholine and serotonin production was then evaluated. Lentilactobacillus diolivorans (B92), Levilactobacillus brevis (TO10) and Limosilactobacillus fermentum (TO24) were selected and used to produce a plant-based, yogurt-like (YL). The impact of a long-term administration of YL on gut microbiome was evaluated using the Simulator of the Human Intestinal Microbial Ecosystem (SHIME®). Fecal inoculum was prepared from one patient with depressive disorder. The metataxonomic analysis showed the persistence of L. brevis and L. fermentum during the washout period in lumen and mucin samples. Beta diversity PCoA didn’t show a strong separation, suggesting that the treatment didn’t drastically change the microbiota composition. Detection of genes and neurotransmitters either short-chain fatty acids will be evaluated.