Intestinal microbiota of preterm infants differ between sites and over time: a comparison of two large neonatal intensive care units (637.8)

Abstract

Neonatal intensive care units (NICUs) differ in their rates of necrotizing enterocolitis (NEC) and sepsis. Intestinal microbiota are implicated in these diseases, but the microbiota of different NICUs have not been compared. To address this, we included 90 infants <29 weeks gestational age with stool samples collected during week 2 of life who survived free of NEC and sepsis. Infants were enrolled at either Good Samaritan Hospital (GSH) in Cincinnati or University of Alabama Birmingham Medical Center (UAB) in 2010‐2011. The 16s rRNA gene in DNA from stool samples was sequenced with universal primers by Illumina MiSeq. Resulting operational taxonomic unit tables were analyzed for differences between hospitals by year and delivery mode using linear discriminant analysis effect size algorithm (p<0.05). A major shift occurred in the microbiota of UAB infants between 2010 and 2011 with a significant increase in Firmicutes in 2011 ‐ coinciding with a hospital move. At GSH, only minor shifts in microbiota occurred by year. Microbiota differed between the NICUs, with significantly more phylum Bacteroidetes present at UAB in 2011; other differences depended upon delivery mode and year. We conclude that colonizing microbiota differ by NICU and over time. Multi‐site, longitudinal studies of preterm microbiota are needed to assess the impact of intestinal microbiota on conditions affecting preterm infants.Grant Funding Source: Supported by NIAID contract no. HHSN272200900018C; NICHD R01 HD059140; and NIEHS T32 ES010957