Age-related Macular Degeneration (AMD) 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). It is the leading cause of
irreversible blindness in the industrialized world, affecting over 10
million individuals in North America.
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. It is therefore important
to find new ways to prevent the onset of this debilitating disease.
‘Diets rich in fat alter the gut microbiome in a way that aggravates wet age-related Macular Degeneration (AMD), a vascular disease of the aging eye.’
A study lead by 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
, uncovered that bacteria in your intestines may play an important role in determining if you will develop blinding wet AMD.
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 suggests that in men, overall
abdominal obesity is the second most important environmental risk
factor, after smoking, for progression to late-stage blinding AMD. Until
now, the mechanisms that underscore this observation remained ill
Elisabeth Andriessen, a PhD student in the lab of Professor
Sapieha 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.
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", says Dr. Sapieha. Professor
Sapieha holds the Wolfe Professorship in Translational Vision Research
and a Canada Research Chair in retinal cell biology.
The study was
funded by the Foundation Fighting Blindness, the Canadian Institutes of
Health Research, and thr Fond de Recherche en Ophthalmologie de
l'Université de Montreal.