The Gut Bacteria and AMD in Aging Women

The proposed research to study the gut microbiome as a modifiable risk factor for age-related macular degeneration (AMD) is relevant to public health because AMD is the leading cause of vision loss in the U.S. Using data from the Carotenoids in Age-Related Eye Disease Study 2 (CAREDS2) of postmenopausal women, we propose to conduct one of the first large epidemiologic studies to examine associations between the composition and diversity of the gut microbiome and the prevalence and stage of AMD (no AMD, intermediate AMD, and advanced/vision-threatening AMD). Evidence of a protective association between certain profiles of the gut microbiome content and AMD could lead, in the long-term, to easily implemented, low-cost interventions to modify the gut microbiome with diet, or highlight potential metabolic pathways for intervention, to prevent AMD.

We are examining the composition and diversity of the gut microbiome to see if it differs between postmenopausal women with and without age-related macular degeneration (AMD). This study will be conducted within the ongoing Carotenoids in Age-Related Eye Study (CAREDS), which is an ancillary study to the Women’s Health Initiative Observational Study. We aim to see if any differences in the composition and diversity of the gut microbiome differ by AMD status (no AMD, intermediate AMD, or advanced AMD), and by whether or not a woman has evidence of reticular pseudodrusen, a relatively new biomarker for progression to geographic atrophy. Limited studies of the gut microbiome in such large samples of free-living individuals exist which are also linked to rich environmental and phenotypic (personal characteristic) data of participants over decades. To our knowledge there are few studies, worldwide, which are actively following participants and have rich diet, environmental, phenotypic, and prospective data on AMD for over 20 years (e.g., The Rotterdam Study and the Melbourne Collaborative Cohort Study), but collection of gut microbiome samples have not been reported to be part of these studies. Thus, we believe our study will be the first to examine associations between the gut microbiome and AMD in a cohort of elderly individuals. This research project will expand our understanding of nutrition in age-related eye disease as mediated through the gut microbiome. Evidence of a protective association between certain profiles of the gut bacteria content and AMD could lead, in the long term, to easily implemented, low-cost interventions to modify the gut bacteria with diet, or highlight potential metabolic pathways for treatment, to prevent AMD.