The role of Microbiota in the Pathogenesis of Alzheimer’s Disease

The World Health Organization has reported that in 2020 approximately 55 million people live with dementia worldwide with 10 million new cases every year.Alzheimer's disease (AD) is the most common form of dementia and contributes to 60-70% of dementia cases.The role of gut microbiota with host metabolic regulation that acts as a bridge between the food lipids and the health of AD individuals has become of major concern.Microbiome composition has been linked to neurodegenerative disease and plays a critical role in the gut and brain axis.Microbial fermentation may release short-chain fatty acids such as butyric acid that have a major influence on the gut-brain axis with effects on brain amyloid beta levels and plaque deposition.Butyric acid is involved in brain histone acetylation and deacetylation plays an important role in metabolic regulation, brain amyloidosis and the pathogenesis of AD.Several mechanistic studies are required to determine the underlying mechanisms for effective and safe probiotic treatment for AD and the relevance of gut dysbiosis may be the cause of the induction of the pathogenesis of AD.The safety of probiotic therapy for AD patients requires investigation with relevance to the induction of dyslipidemia and the release of bacterial lipopolysaccharides and amyloid beta from gram-negative bacteria needs to be controlled in these probiotic formulations.In this review, we will summarize the knowledge of the characteristics of the gut microbiota and the communication pathways of the microbiota-gut-brain axis, analyse the role of dysbiosis of the gut microbiota in the pathogenesis of AD, and highlight the modification of gut microbiota composition as a preventive or therapeutic approach for AD) and the benefits, limitations and safety of gut microbiota and probiotics on the metabolic regulation by LPS and lipids are required to delay or reverse the pathogenesis of Alzheimer's disease.