The Connection Between the Digestive System and the Brain

Researchers are learning how the biochemical processes of food intake and digestion interact with changes in the brain. They are finding that the gut microbiome — the community of viruses, bacteria and other microbes in the digestive system — may influence the onset and progression of Alzheimer’s disease.

Studies in mice and humans show that the composition of the gut microbiome in Alzheimer’s and mild cognitive impairment is different from that in cognitively normal beings.

Changes in the gut microbiome as people age have been linked to disruptions in the immune system, persistent inflammation and chronic diseases, including neurological disorders such as Alzheimer’s. Researchers are exploring how these changes are related to each other and to brain changes related to Alzheimer’s, including neurodegeneration and the accumulation of toxic proteins beta-amyloid and tau.

Identifying the good and bad gut microbes associated with Alzheimer’s could help scientists learn more about the biology of the disease and develop a new way to predict and potentially treat it.