The role of gut microbiota in the neurobiology and treatment of Alzheimer's disease.

Alzheimer's disease (AD) is the most common cause of dementia in the elderly population and characterized by progressive cognitive decline. The major pathological features of AD are the accumulation of extracellular amyloid-beta protein as neuritic plaques and intracellular hyperphosphorylated tau protein as neurofibrillary tangles. Studies have shown that gut microbiota are involved in several central nervous system disorders through regulation of neurotransmitter production, blood-brain barrier permeability and immune responses. The gut microbiota establishes a two-way communication between the gut and the brain through neural, endocrine, and immune pathways, which play a role in various neurological diseases, including AD. Alterations in the composition and function of the gut microbiota may influence neuroinflammation, amyloid-beta accumulation, and tau pathology. Targeting the balance of the gut microbiota through probiotics, prebiotics, and fecal microbial transplantation could be promising therapeutic approach against neurodegeneration. Understanding the complex relationship between the gut microbiota and AD pathobiology could pave the way for novel preventive and therapeutic strategies. Here, we summarized advances in the role of gut microbiota in AD pathobiology and updated rising concerns from recent reports. Moreover, the possibility of applying the capability of the gut microbiota as a promising treatment against AD has been discussed in this review.