In a recent article published in the journal Neuroscience & Biobehavioral Reviews, a team of researchers from Ireland delves into the expansive realm of fermented foods, investigating their origins, diverse fermentation techniques, and their potential to influence the microbiota-gut-brain axis. The review not only sheds light on the positive impacts of fermented foods on mental health but also addresses knowledge gaps and obstacles in studying their specific benefits.
Microbes residing in the gut play a crucial role in mediating the microbiota-gut-brain axis, creating a vital link between external signals and intrinsic functions, continuously communicating with the central nervous system. Various factors, notably diet, shape the gut microbiota, impacting the microbiota-gut-brain axis’s intestinal, immunological, and neural components. Recent advancements underscore the potential of microbiota-targeted dietary interventions, including probiotics, prebiotics, and fermented foods, in enhancing mental health by modulating the gut-brain axis.
Historically, fermented foods served purposes such as prolonging storage and enhancing flavor. Categorized by substrates like cereal, dairy, meat, fish, vegetable, and legume, each undergoing unique fermentation processes, these foods host a diverse microbial community influenced by various factors. This microbial richness offers potential benefits such as probiotics, bioactive peptides, phytochemicals, and vitamins. Researchers are actively exploring fermented foods due to their ability to shape gut microbiota composition, produce beneficial metabolites, and modulate pathways connecting the gut and brain, providing a promising avenue for dietary interventions.
The review emphasizes the crucial role of fermented foods in influencing the microbiota-gut-brain axis, touching upon immune modulation, barrier integrity, and neuroendocrine regulation. Microbes and metabolites from fermented foods interact with receptors, impacting immune responses and enhancing intestinal and blood-brain barrier integrity. These foods also influence the hypothalamic-pituitary-adrenal (HPA) axis and serotonin levels, revealing diverse immunomodulatory effects in preclinical and human studies.
Fermented foods exert profound effects on the gut-brain axis through the modulation of the enteroendocrine system (EES). By influencing gut hormones like serotonin, neuropeptide-Y, glucagon-like peptide 1 (GLP-1), ghrelin, and somatostatin, these foods regulate motility, appetite, and insulin release, impacting feeding behavior. While rich in prebiotics and probiotics, fermented foods shape the gut microbiota and enhance the production of gut hormones, particularly GLP-1.
Preclinical models, including drosophila, zebrafish, mice, and pigs, demonstrate behavioral improvements and microbiota alterations with various fermented foods. Human studies show mixed cognitive effects, with fermented dairy exhibiting diverse outcomes, and observational studies linking fermented food consumption to altered gut profiles and reduced anxiety. Despite challenges, fermented foods emerge as pivotal components in the evolution of microbiota-based therapeutics for mental health, emphasizing the need for additional human studies and standardized approaches to comprehensively understand their beneficial impacts.
