DefinePK

Abstract

Background: The gut–brain axis, a bidirectional communication system between the gastrointestinal tract and the central nervous system, has gained increasing attention for its potential role in the pathogenesis and management of psychiatric disorders such as depression and anxiety. Alterations in gut microbiota composition and function have been linked to neuroinflammation, hypothalamic–pituitary–adrenal axis dysregulation, and changes in neurotransmitter metabolism, making this a promising yet evolving area in mental health research.
Objective: This narrative review explores the emerging role of gut microbiota and the gut–brain axis in the development, progression, and management of depression and anxiety, with an emphasis on recent findings, clinical implications, and research gaps.
Main Discussion Points: Key themes include evidence of microbial dysbiosis in psychiatric populations, mechanistic pathways linking microbiota to brain function, psychobiotic and dietary interventions, and the heterogeneity of clinical outcomes. Limitations such as small sample sizes, short follow-up durations, methodological biases, and lack of standardized outcome measures are critically evaluated.
Conclusion: Current evidence suggests that microbiota–gut–brain interactions contribute to psychiatric pathophysiology and hold potential as adjunctive therapeutic targets. However, stronger, multicenter randomized controlled trials with standardized methodologies are required before clinical integration. Recognizing and addressing current research limitations will be essential for translating microbiome science into effective mental health interventions.