The brain and gastrointestinal tract are closely interconnected as important sensory organs processing signals from both environmental and internal cues. Recent studies have shown that dysregulation of the gut microbiota in inflammatory bowel disease activates the gut immune system. The cross-talk mechanism along the gut-brain axis is implicated in the development of neuropsychiatric disorders such as autism, depression, anxiety, Alzheimer's disease, and Parkinson's disease. Here, we discuss the molecular mechanisms involved in signaling across the gut-brain axis, including the immune and neuroendocrine system, intestinal permeability, microbial composition, and bacterial extracellular vesicles. We focus on the link between specific inflammatory bowel disease, microbial genera and psychiatric and neurological disorders, and propose that the results of preclinical and clinical studies open up the possibility of targeting the gut microbiota to treat neuropsychiatric disorders that are altered by gut interactions.
Keywords: GBA; Gut–brain axis; IBD; MGBA; inflammatory bowel disease; microbiome–gut–brain axis; neuropsychiatric disorders; probiotics; psychobiotics.
There is a strong bidirectional communication between the brain and the digestive system. Dysregulation of the gut microbiota (GM) in inflammatory bowel disease (IBD) activates the gut immune system and contributes to brain disorders. Targeting the gut-brain axis has the potential to treat both neurological disorders such as depression, autism, Alzheimer’s disease, and Parkinson’s syndrome, and to ameliorate intestinal disorders such as IBD.
© 2025 Tian et al.