The article reviews the interactions between the gut microbiota, immune system, and nervous system in health and disease. It highlights the critical role of the gut microbiota in influencing brain development, behavior, and immune system maturation. The gut microbiota modulates the maturation and function of microglia and astrocytes, which are key components of the central nervous system (CNS). Microglia, the most abundant resident immune cells in the brain, are involved in immune surveillance, synaptic pruning, and neuronal circuit wiring. Astrocytes, another important glial cell type, regulate blood-brain barrier integrity, neurotransmitter turnover, and cerebral blood flow. The gut microbiota also influences peripheral immune responses, affecting brain inflammation, injury, and behavior. Studies show that microbial metabolites, such as short-chain fatty acids (SCFAs), can modulate the activity of astrocytes and microglia. Additionally, the gut microbiota plays a role in neurodegenerative diseases like Alzheimer's and Parkinson's, as well as psychiatric disorders such as autism spectrum disorder, depression, and anxiety. The article discusses the bidirectional communication between the gut microbiota and the CNS through various pathways, including the vagus nerve and neuroendocrine pathways. Finally, it emphasizes the need for further research to understand the molecular mechanisms underlying these interactions and to develop therapeutic strategies based on microbial and immune-based approaches.The article reviews the interactions between the gut microbiota, immune system, and nervous system in health and disease. It highlights the critical role of the gut microbiota in influencing brain development, behavior, and immune system maturation. The gut microbiota modulates the maturation and function of microglia and astrocytes, which are key components of the central nervous system (CNS). Microglia, the most abundant resident immune cells in the brain, are involved in immune surveillance, synaptic pruning, and neuronal circuit wiring. Astrocytes, another important glial cell type, regulate blood-brain barrier integrity, neurotransmitter turnover, and cerebral blood flow. The gut microbiota also influences peripheral immune responses, affecting brain inflammation, injury, and behavior. Studies show that microbial metabolites, such as short-chain fatty acids (SCFAs), can modulate the activity of astrocytes and microglia. Additionally, the gut microbiota plays a role in neurodegenerative diseases like Alzheimer's and Parkinson's, as well as psychiatric disorders such as autism spectrum disorder, depression, and anxiety. The article discusses the bidirectional communication between the gut microbiota and the CNS through various pathways, including the vagus nerve and neuroendocrine pathways. Finally, it emphasizes the need for further research to understand the molecular mechanisms underlying these interactions and to develop therapeutic strategies based on microbial and immune-based approaches.