The connection between diet, gut microbes, and cognitive decline

Abstract

The trillions of harmless microbes that are present in human gut are known as the gut microbiota. The consumption of food affects the composition of the gut microbiota, which leads to an imbalanced microbial population in the gut, a condition that is known as gut dysbiosis. The consumption of a diet that is high in fat and sugar can lead to development of obesity, type 2 diabetes mellitus, cardiovascular disease, and cognitive decline. The association between gut microbes and the occurrence of obesity is well established, and long-term consumption of a high-fat diet leads to cognitive decline. Obesity is strongly related to behavioral, environmental, and genetic factors. The gut microbiota contains ten times the total cells present in the human body. Gut dysbiosis is related to several diseases, such as type 2 diabetes mellitus, metabolic syndrome, obesity, nonalcoholic fatty acid syndrome, and cognitive decline. Diet has a direct role in the composition of the gut microbiota, and cognitive health in childhood and adulthood is significantly determined by the food intake. This chapter emphasizes the microbiota gut-brain axis and the role of diet in determination of cognitive functions. © 2022 Elsevier Inc. All rights reserved.