High-Fat Diets Alter Gut Microbiota, Leading to Increased Choroidal Neovascularization

Researchers have early evidence that modifying gut microbiomes could slow down or even prevent age-related macular degeneration (AMD). An article detailing the study findings, authored by Elisabeth MMA Andriessen, of the Department of Biomedical Sciences at Maisonneuve-Rosemont Hospital Research Center at the University of Montreal in Canada, and colleagues, was published in the journal EMBO Molecular Medicine.

The authors stated that environmental risk factors have been strongly implicated in AMD in previous studies, including obesity They noted, “it was recently demonstrated that each increase of 0,1 in waist/hip ratio was associated with a 13% increase in the odds of early AMD and a 75% increase in the odds of late AMD in men, making obesity the second most important environmental risk factor for late AMD after cigarette smoking.”

Additionally, recent studies have shown a relationship between the intestinal microbiota and low-grade inflammation. In describing the aim of the study, the researchers said, “We sought to evaluate the contribution of intestinal flora to progression of NV [neovascularization] AMD, particularly in the context of obesity-driven CNV [choroidal neovascularization]”.

“In light of epidemiologic data linking obesity to CNV we first investigated the propensity of diets with elevated fat content to exacerbate CNV,” wrote the authors. They used two groups of mice: one received a regular diet (RD), and the other a high-fat diet (HFD). At 13 weeks, the mice in the HFD group had gained 50% more weight than the regular diet group.

The HFD mice were given an antibiotic so that researchers could better ascertain the contribution of the gut microbes to increased CNV. They reported, “Remarkably, HFD-fed mice treated with neomycin displayed levels of CNV akin to RD-fed control mice.” They added that the antibiotic did not impact weight, “hence uncoupling mouse weight from extent of CNV and strengthening the link between gut flora and pathological angiogenesis.”

Next, the researchers profiled the gut microbiomes, and found evidence they claimed shows that “diets rich in fat alter the gut microbiome and in turn elevate choroidal and systemic inflammation and heighten pathological choroidal neovascularization.”

“Modifying gut microbiomes may thus provide minimally intrusive and cost-effective paradigms to prevent or delay exudative AMD,” concluded the researchers.

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