Lin Phoebe, McClintic Scott M, Nadeem Urooba, Skondra Dimitra
Casey Eye Institute, Oregon Health & Science University, Portland, OR 97239, USA.
Retina Consultants, LLC, Salem, OR 97302, USA.
J Clin Med. 2021 May 12;10(10):2072. doi: 10.3390/jcm10102072.
Blindness from age-related macular degeneration (AMD) is an escalating problem, yet AMD pathogenesis is incompletely understood and treatments are limited. The intestinal microbiota is highly influential in ocular and extraocular diseases with inflammatory components, such as AMD. This article reviews data supporting the role of the intestinal microbiota in AMD pathogenesis. Multiple groups have found an intestinal dysbiosis in advanced AMD. There is growing evidence that environmental factors associated with AMD progression potentially work through the intestinal microbiota. A high-fat diet in apo-E-/- mice exacerbated wet and dry AMD features, presumably through changes in the intestinal microbiome, though other independent mechanisms related to lipid metabolism are also likely at play. AREDS supplementation reversed some adverse intestinal microbial changes in AMD patients. Part of the mechanism of intestinal microbial effects on retinal disease progression is via microbiota-induced microglial activation. The microbiota are at the intersection of genetics and AMD. Higher genetic risk was associated with lower intestinal bacterial diversity in AMD. Microbiota-induced metabolite production and gene expression occur in pathways important in AMD pathogenesis. These studies suggest a crucial link between the intestinal microbiota and AMD pathogenesis, thus providing a novel potential therapeutic target. Thus, the need for large longitudinal studies in patients and germ-free or gnotobiotic animal models has never been more pressing.
年龄相关性黄斑变性(AMD)导致的失明是一个日益严重的问题,然而AMD的发病机制尚未完全明确,治疗方法也有限。肠道微生物群对包括AMD在内的具有炎症成分的眼内和眼外疾病具有重大影响。本文综述了支持肠道微生物群在AMD发病机制中作用的数据。多个研究小组发现晚期AMD患者存在肠道菌群失调。越来越多的证据表明,与AMD进展相关的环境因素可能通过肠道微生物群发挥作用。载脂蛋白E基因敲除(apo-E-/-)小鼠的高脂饮食加剧了湿性和干性AMD的特征,推测是通过肠道微生物群的变化,尽管与脂质代谢相关的其他独立机制可能也在起作用。年龄相关性眼病研究组(AREDS)补充剂逆转了AMD患者肠道微生物的一些不良变化。肠道微生物影响视网膜疾病进展的部分机制是通过微生物群诱导的小胶质细胞激活。微生物群处于遗传学与AMD的交叉点。在AMD中,较高的遗传风险与较低的肠道细菌多样性相关。微生物群诱导的代谢产物生成和基因表达发生在AMD发病机制中的重要途径中。这些研究表明肠道微生物群与AMD发病机制之间存在关键联系,从而提供了一个新的潜在治疗靶点。因此,对患者以及无菌或悉生动物模型进行大规模纵向研究的需求从未如此迫切。