Compositional Differences of Meconium Microbiomes of Preterm and Term Infants, and Infants That Developed Necrotizing Enterocolitis or Feeding Intolerance

Abstract

The primary aim of this study was to investigate the compositional differences of the first passed meconium microbiome in preterm and term infants, and the secondary aim was to compare the meconium microbiomes of preterm and term infants that later developed necrotizing enterocolitis (NEC)/Feeding intolerance (FI) compared to those that did not develop NEC/FI. During the study period, a total of 108 preterm and term newborns' first passed meconium occurring within 72 hours of birth were collected and microbiome analyzed. Meconium microbiomes showed a disruption in the percentages of the core microbiome constituents in both the phylum and genus levels in infants born < 30 weeks of gestational age (GA) compared to those born ≥ 30 weeks of GA. In the phylum level, Bacteroidetes and Firmicutes, and in the genus level, Prevotella and Bacteroides, were predominant, with Prevotella accounting for 20–30% of the relative abundance. As GA increased, a significant increase in the relative abundance of Bacteroidetes (P for trend < 0.001) and decrease in Proteobacteria (P for trend = 0.049) was observed in the phylum level. In the genus level, as GA increased, Prevotella (P for trend < 0.001) and Bacteroides (P for trend = 0.002) increased significantly, whereas Enterococcus (P for trend = 0.020) decreased. Compared to the control group, the meconium of infants that later developed NEC/FI had significantly lower alpha diversities but similar beta-diversities. Furthermore, the NEC/FI group showed a significantly lower abundance of Bacteroidetes (P < 0.001), and higher abundance of Firmicutes (P = 0.034). To conclude, differences were observed in the composition of the first passed meconium in preterm and term infants that later develop NEC/FI compared to those that did not.

Gut Dysbiosis in the First-Passed Meconium Microbiomes of Korean Preterm Infants Compared to Full-Term Neonates

“…The R package decontam (version 1.8.0) was used to filter out environmental contaminants from each sample type [22]. The detailed sampling, preprocessing, and analysis methods used for the meconium samples have been published elsewhere [13].…”

“…However, recently, it was reported that the mode of delivery had a transitional and small effect on neonates' gut microbiota and that gestational age (GA) seems to be the main driver of neonates' gut microbiota [12]. Because GA at birth represents the time of first microbial exposure, the microbiota composition of preterm infants is significantly different from that of full-term (FT) infants [13,14]. Very preterm (VP) infants present three main gut microbiota phyla: Firmicutes, Bacteroidetes, and Proteobacteria, which account for most community dynamics.…”