How gut microbiota contribute to neuropsychiatric disorders: evidence from neuroimaging studies

The interaction between the gut microbiota and central nervous system (CNS) diseases has emerged as a major focus in neuroscience and microbiome research. Accumulating evidence shows that gut microbiota influence the pathogenesis of neurodevelopmental, neurodegenerative, autoimmune, and psychiatric conditions via the microbiota-gut-brain axis. However, the underlying mechanisms are complex and not yet fully elucidated. Advances in multimodal magnetic resonance imaging, positron emission tomography, and diffusion tensor imaging, now enable in vivo visualization of associations between gut microbial alterations and abnormalities in brain structure and function, providing new perspectives for understanding the role of gut microbiota in CNS pathology. This review systematically reviews neuroimaging-based research linking gut microbiota to neurological diseases (e.g., Alzheimer's disease, multiple sclerosis, traumatic brain injury), and psychiatric disorders (e.g., schizophrenia, and autism spectrum disorder). It highlights the mediating roles of microbial metabolites, immune-inflammatory responses, and neuroimmune pathways, and discusses future directions integrating multi-omics data with neuroimaging technologies, as well as their potential clinical applications. What distinguishes this review from its predecessors in the same field is its explicit neuroimaging-driven framework rather than general mechanistic discussion.