The Role of the Gut Microbiota and Microbial Metabolites in the Pathogenesis of Alzheimer’s Disease

Abstract

Alzheimer’s disease is a neurodegenerative disease that causes memory loss, cognitive dysfunction and dementia. It is a multifactorial disease involving a wide range of pathological factors that have yet to be fully understood. As proposed by scientists and supported by a growing amount of evidence in recent years, the gut microbiota plays an important role in the pathogenesis of Alzheimer’s disease via a constant bidirectional communication through the brain-gut-microbiota axis which is a multifunctional network involving the nervous system and the peripheral circulatory system. This communication pathway facilitates the exchange of information and signals between the brain and the gut, such as microbe-derived metabolites and neurotransmitters, which allows gut microbes to influence the central nervous system. This review summarizes recent research findings on the pathological risk factors of Alzheimer’s disease, the brain-gut-microbiota axis, the role of gut microbe-derived products in neurological disorders, and clinical/preclinical studies investigating the role of the gut microbiota in Alzheimer’s disease. In addition, some suggestions for future research are proposed.

Precious but convenient means of prevention and treatment: physiological molecular mechanisms of interaction between exercise and motor factors and Alzheimer’s disease

“…In AD brain, an increase in the abundance of harmful intestinal microorganisms was found ( Goyal et al, 2021 ), and consequently, the type of short-chain fatty acids (SCFAs) produced by the intestinal microbiota changed, which is an important nutrient for maintaining the stability of the intestinal barrier and the BBB, and significant changes in SCFAs adversely affected the maintenance of BBB stability ( Wang D. et al, 2021 ). For example, in mice treated with antibiotics, changes in intestinal flora species were found, with the consequent effect of suppressing SCFA homeostasis and expression levels of the claudin family of proteins and occludin proteins, two transmembrane proteins that are important for the maintenance of TJs, as discussed earlier ( Wang, 2023 ). This highlights the relationship between maintaining a stable gut microbiota and BBB stability.…”