Gut Microbe Plays Major Role in Macular Degeneration

As with so many other health concerns, the leading cause of blindness in the developed world may originate in the gut.

A team from the University of Montreal led by Elisabeth MMA Andriessen recently sought to examine how the bacterial composition of the intestines may influence the risk of age-related macular degeneration in its neovascular form (nvAMD). Fat deposits in the eye, called drusen, are associated with early AMD. “Wet” AMD, the disease in its late stage, is marked by choroidal neovascularization (CNV), the formation and, occasionally, rupturing of new and fragile blood vessels in the eye. The leakage is referred to as exudate, and wet AMD is interchangeably referred to as “exudative AMD.”
According to the American Academy of Ophthalmology, obesity is among the five most common factors in the development of AMD. A press release that accompanies the new University of Montreal study says that “in men, overall abdominal obesity is the second most important environmental risk factor, after smoking, for progression to late-stage blinding AMD.” To date, the mechanism behind that remained unknown.
For the research, two sets of mice were raised on two different diets from 6 weeks old: a regular‐chow diet (RD; 16% kcal fat) or a high‐fat diet (HFD; 60% kcal fat). Expectedly, the HFD mice gained 50% more weight. They examined the composition of their gut microbiomes. “Bacteroidetes/ Firmicutes ratios shifted from 66%/33% of total bacteria in RD to 19%/67% in HFD,” the authors write. Bacteroidetes are typically the dominant of those two most common phyla in the guts of lean individuals. The study notes that HFD mice had more diverse gut flora, with “modest but important presence of Actinobacteria and Spirochaetes” which were not apparent in the guts of the RD mice….
Read more:
Source: MD All Specialties