In a recent review published in a magazine Neuroscience and Biobehavioral ReviewsIrish researchers investigated the ability of fermented foods to influence the microbiome-gut-brain axis, exploring the diversity of fermented foods, their sources and fermentation techniques. Additionally, we identified knowledge gaps and challenges in studying the mental health benefits of specific fermented foods and proposed solutions to further understand their therapeutic potential.
Research: Fermented foods: Harnessing their potential for mental health by modulating the microbiota-gut-brain axis. Image credit: Molishka / Shutterstock
background
Microorganisms that colonize the intestine act as important mediators in the microbiota-gut-brain axis, connecting the body's external signals and intrinsic functions and continuously communicating with the central nervous system. A variety of factors, including diet, influence the gut microbiota, which in turn influences the intestinal, immune, and neural components of the microbiota-gut-brain axis. Recent advances highlight the potential for microbiome-targeted diets, such as probiotics, prebiotics, and fermented foods, to improve mental health by modulating the gut-brain axis.
Fermented foods have historically been used to extend shelf life and enhance flavor. They are diverse and categorized by substrates such as grains, dairy products, meat, fish, vegetables, and legumes, each of which undergoes its own fermentation process. These foods harbor rich microbial communities that are influenced by substrate type, geographic location, pH, and cooking method, providing potential probiotics, bioactive peptides, phytochemicals, and vitamins. . Researchers continue to study fermented foods due to their ability to shape the composition of the gut microbiome, produce beneficial metabolites, and modulate the pathways that connect the gut and brain, making them useful for dietary interventions. offers a promising avenue.
This review explores the mental health benefits of fermented foods, explores their effects on the microbiota-gut-brain axis, and discusses challenges in preclinical and human studies.
Fermented foods and the microbiome-gut-brain axis
Fermented foods influence the microbiota-gut-brain axis through immunomodulation, barrier integrity, and neuroendocrine regulation. Microorganisms and metabolites from fermented foods interact with receptors and influence immune responses. Fermented foods strengthen the integrity of the gut and blood-brain barrier, which may be mediated by microbial metabolites. They also affect the hypothalamic-pituitary-adrenal (HPA) axis and serotonin levels. Preclinical and human studies have revealed diverse immunomodulatory effects of fermented foods, highlighting the need to further investigate the complex interactions with the microbiota-gut-brain-immune axis.
Fermented foods have a significant impact on the gut-brain axis through regulation of the enteroendocrine system (EES), affecting gut hormones such as serotonin, neuropeptide Y, glucagon-like peptide 1 (GLP-1), ghrelin, and somatostatin. give. These hormones regulate motility, appetite, insulin release, and influence feeding behavior. Fermented foods rich in prebiotics and probiotics shape the intestinal flora and increase the production of intestinal hormones, especially GLP-1. However, research on the effects of fermented foods on satiety is inconclusive, and fluctuations in hormone release have been observed. Additionally, fermented foods alter ghrelin and leptin levels, which may contribute to appetite regulation. Understanding these complex interactions is important to harnessing the potential health benefits of fermented foods.
Preclinical and clinical situation
Fermented foods influence gut-brain communication pathways, influencing immune responses, gut microbiota, microbial metabolites, and the enteric nervous system. Preclinical models such as fruit flies, zebrafish, mice, and pigs have revealed behavioral improvements and microbiota changes with fermented dairy products, soy, sugar-based products, and other substrates. Human studies on fermented dairy products have shown a variety of cognitive effects, while observational studies have linked the consumption of fermented foods to altered gut profiles and reduced anxiety. Fermented soy products, particularly isoflavones, may benefit cognitive function in women, in contrast to their negative association with tofu intake. Previous meta-analyses suggest that fermented foods hold promise for cognitive outcomes.
Future trends and challenges
Standardization of fermented foods is challenged by diverse microbial communities that are influenced by factors such as geography, production scale, and substrate type. Environmental conditions, fermentation duration, salinity, pH, moisture, and aging time all contribute to complexity. Regulatory guidelines provide limited insight and require cultural sensitivity. Although 'omics' technologies are useful for understanding and data archiving, the diversity of fermented foods requires further exploration towards effective standardization, taking into account both bioactivity potential and cultural preservation. . Setting up human studies for fermented food interventions presents challenges such as accounting for controls, highlighting the need for nonfermented controls in evaluations. Accurate measurement of fermented food intake is hampered by the diversity of recommended foods and requires detailed methods such as 24-hour food recalls and food diaries. Biomarkers related to the consumption of fermented foods leverage advances such as plant metabarcoding to unique fingerprints to provide precise measurements. Employing appropriate microbiome capture methods requires choosing high-resolution techniques such as shotgun metagenomics over 16S rRNA (abbreviation for ribosomal ribonucleic acid) sequencing.
conclusion
In summary, this study reviews the substantial health impacts of fermented foods by leveraging diverse microbial strains, metabolites, and bioactive compounds to optimize neurological and mental health benefits. doing. We highlight the need for additional human studies, specifically targeting non-fermenting controls, to comprehensively identify and understand the beneficial effects of fermented foods on the microbiota-gut-brain axis. Despite the challenges, fermented foods are emerging as a pivotal element in the evolution of microbiome-based mental health treatments.
