The role of the gut microbiome in Alzheimer's disease pathophysiology

Purpose of review The present review aims to provide an overview of the existing understanding of the role of the gut microbiome in the Alzheimer's disease pathophysiology. Recent findings Recent research has highlighted the significant role of the gut microbiome in the pathogenesis of Alzheimer's disease via the gut-brain axis. However, the precise mechanisms by which gut microbiome and its microbial metabolites influence brain function are not clearly understood. Various factors, such as diet, drugs, lifestyle, stress, and microbial infections can provoke an imbalance in the gut microbiome homeostasis, known as dysbiosis. This dysbiosis impacts intestinal and blood-brain barrier permeability, elevating pro-inflammatory cytokines and contributing to neurodegeneration. Moreover, the gut microbiome generates neurotransmitters, amyloids, neurotoxins, and metabolites, which may play a role in systemic inflammation and in the disruption of physiological barriers. Summary In the past decade, advancements in microbiome analysis technologies and bioinformatics have significantly enhanced our understanding of the role of the gut microbiome in Alzheimer's disease. The gut microbiome plays a pivotal regulatory role in the progression of Alzheimer's disease, and closely interacts with its pathogenesis, encompassing inflammation, amyloidosis, neurodegeneration, tauopathy, and co-pathologies.