Psychobiotics and fermented food interventions targeting the gut-brain axis in Alzheimer’s diseases

In recent years, the intricate relationship between the gut and the brain has garnered significant attention, leading to exciting developments in understanding mental health. One of the most promising areas in this field is the study of psychobiotics, defined as specific strains of probiotics and prebiotics that impact the gut microbiome and, consequently, mental well-being. As researchers explore how gut health influences mood, cognition, and behavior, psychobiotics as a nutritional approach, have emerged as a potential intervention for mental health issues such as neurodegenerative diseases (Alzheimer’s disease), anxiety, depression, and stress by modulating neurotransmitter production, inflammatory responses, and the hypothalamic-pituitary-adrenal (HPA) axis. Common psychobiotic species ( Lactobacillus spp and Bifidobacterium spp ) and fermented foods have been associated with reductions in Alzheimer’s disease-related pathology and improvement in cognitive function. These findings are based on animal models, and therefore the clinical applicability and preventive efficacy in humans remain uncertain and require validation in well-designed randomized controlled trials. While psychobiotics present an innovative, natural method to support mental well-being, further research is needed to refine their clinical application and establish standardized treatment guidelines in strain selection and dosages, and limited long term data. Overall, psychobiotics and fermented foods may confer neuroprotective effects via gut–brain axis modulation, including regulation of neurotransmitters, inflammation, and BDNF-mediated PI3K/Akt/GSK-3β signaling, thereby reducing amyloid-β and tau pathology; however, clinical validation remains limited and requires well-designed trials.