Early gut microbiome profile in high-risk preterm infants with and without retinopathy of prematurity

Abstract

Purpose : Recent data have shown that gut microbiome changes may play a role in various ophthalmic diseases such as uveitis and age-related macular degeneration, but its role in retinopathy of prematurity (ROP) has not been explored. Although prematurity is the greatest risk factor for ROP, it is incompletely understood why some high-risk infants develop severe ROP and other high-risk infants do not. We sought to determine if there is an association between early microbiome composition and ROP development by comparing the gut microbiome in high-risk preterm infants with severe ROP needing treatment and high-risk preterm infants that did not develop any ROP.

Methods : Fecal samples were collected weekly from birth through 34 weeks postmenstrual age (PMA) from high-risk preterm neonates that underwent ROP screening at a single level III neonatal intensive care unit, and subjects were stratified into two groups: 1) high-risk preterm infants ≤27 weeks gestational age (GA) and birth weight (BW) ≤ 750g with type 1 ROP (n=9) and 2) high-risk preterm infants that did not develop ROP (n=5). Bacterial DNA was extracted from fecal samples followed by amplification of the 16S rRNA V4 region using Illumina MiSeq sequencing. For 16S rRNA analysis, 16 million paired-end reads were joined, quality filtered, and de-multiplexed with QIIME 1.9.1, and exact sequence variants (ESV) were selected using the DeBlur pipeline. ESVs present in ≤10 samples were removed. Alpha and beta diversity were analyzed using QIIME 1.9.1 and Phyloseq. Significance was determined using PERMANOVA for alpha-diversity, t-tests for beta-diversity, and ANCOM for ESV differences.

Results : Neonatal fecal samples showed divergence in microbiome composition, in which infants with type 1 ROP showed significant enrichment of Enterobacteriaceae 28 weeks PMA, enrichment of Lactobacillus, Bacteroides and Acinetobacter at 29 weeks PMA, and enrichment of Enterococcus at 32 weeks PMA compared with high-risk infants with no ROP (p<0.05 for all comparisons).

Conclusions : To our knowledge, this is the first report showing a difference in early gut microbiome composition in high-risk premature infants that developed severe ROP needing treatment compared to similarly high-risk neonates that did not develop any ROP. These data suggest that the early gut microbiome profile and abundance of specific strains may play a significant role in ROP pathogenesis.

This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.