In recent years, a surge of scientific interest has centered around the potential impact of fermented foods on mental health, with a focus on the intricate relationship between gut microbes and the brain, commonly referred to as the microbiota-gut-brain axis. A comprehensive review published in Neuroscience & Behavioral Reviews delves into the varied types of fermented foods, their fermentation techniques, and their influence on the microbiota-gut-brain axis. The study also addresses existing knowledge gaps and challenges associated with conducting human trials in this field.
The array of fermented foods under scrutiny includes kimchi, sauerkraut, kefir, miso, tempeh, and yogurt. Researchers highlight that fermented foods exert a direct influence on the enteroendocrine system, impacting hormones such as ghrelin, neuropeptide-Y, glucagon-like peptide 1 (GLP-1), and serotonin. Notably rich in prebiotics and probiotics, these foods elevate GLP-1 levels, yet researchers emphasize the need for additional studies to comprehend their effects on appetite and hunger.
Studies on fermented dairy’s impact on cognitive health have yielded mixed results, while observational research associates fermented food consumption with alterations in gut health and a reduction in anxiety.
Dr. Nicole Avena, a nutrition consultant and assistant professor of neuroscience, emphasizes the established connection between the gut and the brain. The diversity of factors influencing an individual’s unique microbiome, from maternal health to the current environment, underscores the pivotal role of food in fortifying or weakening gut flora. Avena suggests that a less diverse diet may negatively impact mental and brain health.
Dr. William Li, a medical doctor and bestselling author, elaborates on the intricate pathways linking the brain and gut. Signals produced by gut bacteria can influence brain activities through nerves like the vagus nerve, while substances from the brain can affect the gut microbiome. Li underscores the association between the gut-brain connection and various brain functions, including memory, cognition, anxiety, depression, and overall mental health.
Fermented foods, encompassing bioactives from the original food, healthy bacteria (probiotics), and metabolites created by these bacteria (post-biotics), play a crucial role in shaping the gut microbiome. According to Li, these components contribute to a healthier gut bacteria ecosystem that activates brain pathways. While numerous questions remain unanswered, current research supports the notion that fermented foods can positively influence the gut-brain connection.
In conclusion, this review underscores the potential of fermented foods in enhancing mental health through their impact on the microbiota-gut-brain axis. Further research is encouraged to unravel the complexities of this relationship and its broader implications for overall well-being.
