Pharmacological Targeting of the Gut–Brain Axis: New Horizons in Neurology and Psychiatry

The gut–brain axis (GBA) is an intricate bidirectional communication system linking the gastrointestinal tract and the central nervous system. This crosstalk is mediated through neural, immune, endocrine, and metabolic pathways, with the gut microbiota emerging as a pivotal regulator. Accumulating evidence highlights the role of gut microbiota in mood regulation, stress response, cognitive function, and neurodevelopmental processes. Dysbiosis, or imbalance of gut microbes, has been implicated in major depressive disorder, anxiety disorders, Parkinson’s disease, Alzheimer’s disease, and autism spectrum disorders. Consequently, pharmacological targeting of the GBA has become an exciting frontier encompassing probiotics, prebiotics, postbiotics, fecal microbiota transplantation (FMT), antibiotics, dietary interventions, and psychobiotic drugs. This review synthesizes mechanistic understanding, preclinical and clinical evidence, therapeutic strategies, limitations, and future directions, emphasizing precision microbiome medicine and translational challenges.