This review explores the bidirectional communication between the gut microbiota and the brain, known as the microbiota-gut-brain axis (MGBA), and its role in various neurological disorders. The MGBA influences nervous system development, emotional regulation, and cognitive function through neurotransmitters, immune modulation, and metabolic pathways. Factors such as diet, lifestyle, genetics, and environment shape the gut microbiota composition. The review highlights the potential of gut microbiota in driving neurodevelopmental disorders (e.g., autism spectrum disorder, attention deficit/hyperactivity disorder), neurodegenerative diseases (e.g., Alzheimer's and Parkinson's disease), and mood disorders (e.g., anxiety and depression). It discusses current clinical and preclinical interventions, including dietary changes, probiotics, prebiotics, and fecal microbiota transplantation (FMT). The review also addresses the limitations and complexities of these interventions and calls for further research to understand the individual heterogeneity of gut microbiota and its interactions with the central/peripheral nervous systems. The gut microbiota is a personalized and multifunctional target with significant potential in the diagnosis and treatment of neurological disorders.This review explores the bidirectional communication between the gut microbiota and the brain, known as the microbiota-gut-brain axis (MGBA), and its role in various neurological disorders. The MGBA influences nervous system development, emotional regulation, and cognitive function through neurotransmitters, immune modulation, and metabolic pathways. Factors such as diet, lifestyle, genetics, and environment shape the gut microbiota composition. The review highlights the potential of gut microbiota in driving neurodevelopmental disorders (e.g., autism spectrum disorder, attention deficit/hyperactivity disorder), neurodegenerative diseases (e.g., Alzheimer's and Parkinson's disease), and mood disorders (e.g., anxiety and depression). It discusses current clinical and preclinical interventions, including dietary changes, probiotics, prebiotics, and fecal microbiota transplantation (FMT). The review also addresses the limitations and complexities of these interventions and calls for further research to understand the individual heterogeneity of gut microbiota and its interactions with the central/peripheral nervous systems. The gut microbiota is a personalized and multifunctional target with significant potential in the diagnosis and treatment of neurological disorders.