Association Between Probiotic-Based Nutritional Modulation and Psychiatric Disorders: Mechanistic Insights and Therapeutic Potential

Objective Psychiatric disorders including stress-related disorders, depression, dementia, and autism spectrum disorder represent major global health challenges affecting emotional regulation, cognition, behaviour, and overall quality of life. In recent years, nutritional approaches have gained increasing attention as supportive strategies for mental health management. Among these, probiotics and probiotic-rich fermented foods have emerged as potential nutritional modulators capable of influencing brain function, stress responses, and behavioral outcomes. This review aimed to summarize current evidence regarding the role of nutritionally derived probiotics in psychiatric health and to discuss their potential mechanisms of action and clinical relevance within the emerging field of nutritional psychiatry. Methods A narrative literature review was conducted using databases including PubMed, Scopus, Web of Science, and Google Scholar. Relevant experimental and clinical studies investigating probiotics, fermented foods, dietary interventions, and psychiatric disorders were evaluated descriptively. Results Current literature suggests that probiotics derived from nutritional and fermented food sources may contribute to mental health support through modulation of neurotransmitter activity, inflammatory responses, stress-associated pathways, and gut microbial balance. Several probiotic strains, particularly species belonging to Lactobacillus , Bifidobacterium , Bacillus , and Clostridium , have demonstrated potential associations with improvements in mood regulation, stress tolerance, emotional behavior, and cognitive function in experimental and preliminary clinical studies. Fermented foods may additionally provide nutritional matrices that support probiotic survival and microbial diversity. However, findings across studies remain heterogeneous due to differences in probiotic strains, dosage, dietary formulations, intervention duration, and study populations. Furthermore, many reported benefits are based on preclinical evidence, while human clinical findings remain limited and sometimes inconsistent. Conclusion Probiotic-based nutritional approaches represent a promising and rapidly evolving area within psychiatric and nutritional research. Although current findings suggest potential benefits of probiotics and fermented foods in supporting mental health, available evidence remains preliminary and should be interpreted cautiously.