Gut flora connects obesity with pathological angiogenesis in the eye

Abstract

Neovascular age‐related macular degeneration (nvAMD) can cause severe vision loss among the elderly. Genetic risk factors for AMD include several variants related to the immune system and lipid metabolism. Obesity is a well‐known predisposing factor for nvAMD but how this metabolic disorder modulates angiogenesis in the posterior eye segment was largely unknown. In this issue of EMBO Molecular Medicine, Andriessen et al (2016) show that high‐fat diet‐induced obesity causes dysbiosis in the gut that drives retinal inflammation and pathological angiogenesis in a mouse model of laser‐induced choroidal neovascularization (CNV).

Figure 1. Host–microbiota interactions that regulate physiological and pathological immunity

A healthy diet and physiological microbiota regulate physiological immunity that also controls microglia homeostasis in the central nervous system including the retina. Prolonged high‐fat diet and obesity can cause dysbiosis with impairment of the gut barrier and systemic inflammation. Microbial molecular pattern molecules and pro‐inflammatory cytokines appear in the systemic circulation and trigger immune responses in the retina. Microglia reactivity and inflammatory macrophage recruitment support the pro‐angiogenic milieu and finally lead to enhanced CNV.