An innovative therapeutic approach that leverages the bidirectional communication between the gastrointestinal tract and the central nervous system to treat neuropsychiatric and neurological disorders. GBAPI combines advanced microbiome analysis (metagenomic sequencing, metabolomics), neuroimaging, and AI-driven dietary modeling to create personalized interventions that modulate gut microbial composition and activity. These interventions include precision probiotics, prebiotic fibers, fecal microbiota transplantation (FMT), and tailored dietary plans designed to optimize the production of neuroactive compounds (serotonin, GABA, short-chain fatty acids) that influence brain function. Clinical trials in 2026 have shown promising results for conditions such as depression, anxiety, Parkinson’s disease, and autism spectrum disorder, with response rates of 55-70% compared to 30-40% for traditional treatments alone. The approach represents a shift from symptom management to addressing underlying biological mechanisms, with long-term benefits including reduced medication reliance and improved quality of life. Leading research institutions like the University of Cambridge and Stanford Medicine have established specialized GBAPI clinics, while startups such as Microbiome Labs and NeuroGut are developing AI platforms to streamline patient assessment and treatment personalization.