Preclinical studies comparing germ-free mice (without any microbes) with conventional microbiome mice revealed a link between microbiome and retina, showing a differential expression of multiple genes in these mice populations, including CHF (complement factor H), HIF-1 (hypoxia-inducible factor), VEGF (vascular endothelial growth factor), AMPK (5′ ANO-activated protein kinase), among others, which are implicated in AMD pathogenesis [71,72]. Here, CFH is linked to age-related macular degeneration.