The Gut Microbiome and Alzheimer’s Disease: Can the Gut be Used to Prevent or Treat Dementia?

Alzheimer’s disease (AD) is a neurodegenerative disease and the most common cause of dementia1. There are currently no effective therapies for AD and its etiology remains poorly understood. Recent research has suggested that the gut microbiome may modulate risk for AD, as well as the disease process itself. This paper reviews the current knowledge surrounding AD and the gut microbiome, and aims to explore how this relationship may be used to advance our clinical understanding of the disease; including whether the gut microbiome could be a novel drug target or even serve as a potential biomarker for AD. Although this relationship between AD and the microbiome has not yet been fully elucidated, the gut microbiome is known to dynamically respond to lifestyle factors including sleep, exercise, and nutrition, all of which impact AD-risk. This body of evidence suggests that there may be a relationship between microbiome health and AD. Early studies are investigating whether the microbiome is changed in individuals with AD, and whether any metabolites or bacterial signatures unique in AD populations could be used as a biomarker for early detection of the disease. This review will discuss these points and reflect on how the clinical landscape for AD may be improved by assaying the microbiome and implementing lifestyle factors that both improve microbiome health and reduce AD risk.