Investigation of the effects of probiotic supplements added to prebiotic foods on some neurotransmitters formed in the microbiota within the in vitro gastrointestinal system

Probiotics are live microorganisms that provide beneficial effects to the host when consumed in adequate amounts. Prebiotics are non-digestible substrates that selectively stimulate the growth or activity of beneficial intestinal bacteria. Neurotransmitters are chemicals that enable neurons to communicate with each other in the body. The microbiota establishes communication with the gut-brain axis through neural, endocrine, and metabolic pathways, modulating brain function through metabolites such as neurotransmitters and short-chain fatty acids. This study examines combinations of probiotics and prebiotics (synbiotics) that have the potential to modulate the effects of neurotransmitters, which are the communication system between the gut microbiota and the central nervous system, on the gut-brain axis in vitro. In this study, in the in vitro gastrointestinal system, as the first sample group, representing food groups; banana, kiwi, avocado, pineapple, strawberry, tomato, and onion from the fruit and vegetable group; milk, eggs, red meat, chicken, turkey, and salmon from the protein group; The effects of probiotic supplements containing different species and strains, taken as a second sample group, on the post-digestive production of neurotransmitters such as gamma-aminobutyric acid (GABA), serotonin, and dopamine were investigated. The findings showed that adding probiotic supplements containing different bacterial strains to the foods in the first sample resulted in statistically significant increases in post-digestive neurotransmitter production in vitro, and that multi-strain combinations were more effective in increasing neurotransmitter production. These results may offer an important strategy for the development of functional foods enriched in neuroactive compounds by optimizing the interaction of probiotics with foods.