Altzheimer’s and the Gut Connection

Altzheimer’s dementia is a disease which can rob one of their memory and affect thinking and behavior. In this disease, memory loss and confusion happen when the brain develops plaques and tangles and neurons cannot connect information. This is a devastating disease which affects about 6 million people and with the increase in the aging population, it will become more prevalent.

The exact causes of Altzheimer’s is unknown, but lifestyle, genetics as well as environmental factors may play a role in determining who gets Altzheimer’s. New findings from a National Institutes of Health indicate that the human gut microbiome changes before Altzheimer’s cognitive decline. The gut microbiome is made up of trillions of bacteria, archaea and yeast and resides within our intestine.  No two people have the same gut microbiome which makes it that much more complicated to study.

The research team at Washington University School of Medicine decided to look at the connection between the gut microbiome before Altzheimer’s diagnoses on 164 healthy volunteers aged 68-90 years. Findings showed that 49 of the volunteers had signs of early Altzheimer’s disease or pre-clinical Altzheimer’s disease. These subjects also had a different microbiome. It is too early to say if these changes in the gut microbiome are causes or results of the brain changing. More research needs to be conducted over longer term to see if the gut and brain are connected in Altzheimer’s disease.


Ferreiro AL, Choi J, Ryou J, Newcomer EP, Thompson R, Bollinger RM, Hall-Moore C, Ndao IM, Sax L, Benzinger TLS, Stark SL, Holtzman DM, Fagan AM, Schindler SE, Cruchaga C, Butt OH, Morris JC, Tarr PI, Ances BM, Dantas G. (2023). Gut microbiome composition may be an indicator of preclinical Alzheimer’s disease. Science Translational Medicine. 15(700): eabo2984. 10.1126/scitranslmed.abo2984.

Vogt NM, Kerby RL, Dill-McFarland KA, Harding SJ, Merluzzi AP, Johnson SC, Carlsson, CM, Asthana S, Zetterberg H, Blennow K, Bendlin BB, Rey FE. (2017). Gut microbiome alterations in Alzheimer’s disease. Science Rep. 7(1):13537.  10.1038/s41598-017-13601-y.