Intestine Bacteria Plays Role in Preventing Eye Disease

17 Nov 2016 --- Bacteria in the intestines may play an important role in determining if a person will develop blinding wet Age-related Macular Degeneration (AMD), according to a study published in EMBO Molecular Medicine.

As the leading cause of irreversible blindness in the industrialized world, Age-related Macular Degeneration (AMD) affects over 10 million individuals in North America, and is characterized by a heightened immune response, sizeable deposits of fat debris at the back of the eye called soft drusen (early AMD), destruction of nerve cells, and growth of new diseased blood vessels (wet AMD, late form).

While many studies on the genetics of AMD have identified several genes that predispose to AMD, no single gene can account for development of the disease.

Epidemiological data has suggested that in men, overall abdominal obesity is the second most important environmental risk factor, after smoking, for progression to late-stage blinding AMD.

However, until now, the mechanisms that underscore this observation remained ill defined. Reseachers found that changes in the bacterial communities of your gut, such as those brought on by a diet rich in fat, can cause long-term low-grade inflammation in your whole body and eventually promote diseases such as wet AMD.

Among the series of experiments conducted as part of this study, the group performed fecal transfers from mice receiving regular fat diets, compared to those receiving a high fat diet, and found a significant amelioration of wet AMD.

“Our study suggests that diets rich in fat alter the gut microbiome in a way that aggravates wet AMD, a vascular disease of the aging eye,” says Dr. Przemyslaw (Mike) Sapieha, researcher at Hôpital Maisonneuve-Rosemont (CIUSSS de l’Est-de-l’Île-de-Montréal) and professor at the University of Montreal, published in EMBO Molecular Medicine.

“Influencing the types of microbes that reside in your gut either through diet or by other means may thus affect the chances of developing AMD and progression of this blinding disease.”

While only accounting for roughly 10% of cases of AMD, wet AMD is the primary form leading to blindness. Current treatments becomes less effective with time, so the researchers stress it is therefore important to find new ways to prevent the onset of this debilitating disease.