Fermented Vegetables as a Source of Psychobiotics: A Review of the Evidence for Mental Health Benefits.

The human gut microbiome, comprised of trillions of microorganisms, plays a pivotal role in both physical and mental health. Recent research underscores the intriguing connection between gut bacteria and mental well-being, leading to the emergence of psychobiotics-microbes with mental health benefits. This review aims to explore fermented vegetables, a traditional dietary staple experiencing renewed interest, as a potential source of psychobiotics. Fermentation alters the microbial composition of vegetables, enriching them with beneficial bacteria such as Lactobacillus and Bifidobacterium. Various fermented vegetables, including kimchi, sauerkraut, and tempeh, host distinct bacterial communities. The review investigates how these psychobiotics may impact mental health through the gut-brain axis, a communication network between the gut and the central nervous system. Possible mechanisms encompass neurotransmitter modulation (e.g., serotonin, GABA), inflammation reduction and immunity modulation, and stress response enhancement through the hypothalamic-pituitary adrenal (HPA) axis. Clinical studies exploring the influence of fermented vegetables on mental health outcomes, including anxiety, depression, and cognitive function, are critically evaluated. The review assesses the efficacy of different fermented vegetables and probiotic strains while recognizing limitations in existing research and the necessity for further investigation.