Alterations of the intestinal microbiome in patients with retinal artery occlusion

Purpose: Retinal artery occlusion usually occurs on a background of atherosclerotic disease and patients are at risk for cerebral stroke and ischemic heart disease. Atherosclerosis has been associated with alterations in the intestinal microbiome. Methods: Twenty nine patients with clinically confirmed non-arteritic retinal artery occlusion and 30 age- and sex-matched controls were included. The gut metagenome was sequenced using metagenomic shotgun sequencing following standard pipelines of the Illumina HiSeq 3000 platform. The taxonomic composition of the gut microbiomes was described and the functional profiles of the identified microbes were identified. Results: On the phylum level, the relative abundance of Bacteriodetes was decreased in patients with retinal artery occlusion (39.2 ± 16.7%) compared to controls (46.7 ± 17.6%) whereas the opposite applied for the phylum of Firmicutes (39.6 ± 20.0% in RAO and 40.8 ± 16.0% (s.d.) in controls). Several genera and species such as Actinobacter, Bacteroides stercoris, Faecalibacterium prausnitzii were relatively enriched in patients with retinal artery occlusion, whereas others such as Odoribacter or Lachnospiraceae were significantly lower. Patient's gut microbiomes were enriched in genes of the cholesterol metabolism pathway. Conclusions: Alterations in the gut microbiome are associated with retinal artery occlusion, suggesting that retinal artery occlusion could be targeted by microbiome-altering interventions.