The microbiota-gut-brain axis: novel mechanisms and therapeutic frontiers in obesity and type 2 diabetes.

The microbiota-gut-brain axis (MGBA) is a bidirectional network linking gut microbes to the CNS. This review elucidates how microbial messengers-short-chain fatty acids, bile acids, neuroactive metabolites, and extracellular vesicles-drive obesity and type 2 diabetes via neural, endocrine, and immune pathways. MGBA dysregulation triggers hypothalamic dysfunction, adipose inflammation, incretin axis impairment, and β‑cell failure. We discuss MGBA-targeted therapies and their translational challenges.