Gut Dysbiosis and Neurodegeneration: The Expanding Role of the Microbiome in Alzheimer's Disease Pathogenesis and Therapy

Alzheimer’s disease (AD) is a progressive neurodegenerative disorder characterized by amyloid-beta (Aβ) plaques, neurofibrillary tangles (tau), and chronic neuroinflammation. Emerging research highlights the gut-brain axi98s (GBA) as a critical mediator in AD pathogenesis, where gut dysbiosis disrupts neural, endocrine, immune, and metabolic signalling. This review synthesizes current evidence on how microbial metabolites (e.g., short-chain fatty acids, tryptophan derivatives), gut barrier dysfunction, and systemic inflammation contribute to Aβ aggregation, tau hyperphosphorylation, and microglial activation. We explore therapeutic interventions including probiotics, prebiotics, fecal microbiota transplantation (FMT), and dietary modifications that target the GBA to mitigate AD progression. Clinical and preclinical studies underscore the potential of microbiome-based therapies, though challenges in standardization and causality remain. Future research should integrate multi-omics approaches and personalized medicine to harness the GBA for AD prevention and treatment.