The gut-brain axis and cognition

Abstract

The gut and the brain are in constant communication through pathways that include the immune system, the nervous system, neurotransmitters, and hormones. Modifications in the gut, especially the gut microbiome, have the potential to cause changes in the brain resulting in behavioral and cognitive changes. A healthy and diverse microbiome, which may be achieved by a high fiber diet or probiotic or prebiotic treatments, is associated with improvements in cognition. Gut dysbiosis and a decrease in diversity of the microbiota, which may be caused by a western diet or antibiotic treatments, is associated with cognitive decline and decreased memory. There are many possible pathways through which these changes in the gut act to change cognition, including the immune system, the expression of brain derived neurotropic factor, metabolites such as short chain fatty acids, gut hormones, and neurotransmitters. If researchers can decipher which pathways are involved in modifying cognition, they may be able to identify treatments that can help improve memory and specifically decrease age-related cognitive decline.