Original Article
Intestinal Microbial Ecology in Premature Infants Assessed with Non–Culture-Based Techniques

https://doi.org/10.1016/j.jpeds.2009.06.063Get rights and content

Objectives

To use high throughput techniques to analyze intestinal microbial ecology in premature neonates, who are highly susceptible to perturbations of the luminal environment associated with necrotizing enterocolitis (NEC) and late-onset sepsis.

Study design

With non–culture-based techniques, we evaluated intestinal microbiota shortly after birth and during hospitalization in 23 neonates born at 23 to 32 weeks gestational age. Microbiota compositions were compared in 6 preterm infants in whom NEC, signs of systemic inflammation, or both developed with matched control subjects by using 16S ribosomal RNA pyrosequencing.

Results

Microbial DNA was detected in meconium, suggesting an intrauterine origin. Differences in diversity were detected in infants whose mothers intended to breast feed (P = .03), babies born to mothers with chorioamnionitis (P = .06), and in babies born at <30 weeks gestation (P = .03). A 16S ribosomal RNA sequence analysis detected Citrobacter-like sequences only in cases with NEC (3 of 4) and an increased frequency of Enterococcus-like sequences in cases and Klebsiella in control subjects (P = .06). The overall microbiota profiles in cases with NEC were not distinguishable from that in control subjects.

Conclusions

Microbial DNA in meconium of premature infants suggests prenatal influences.

Section snippets

Methods

The study protocol was approved by the ethics committee at the University of Florida. Informed consent was obtained from the parents. The study protocol involved all babies <32 weeks gestational age at birth. Parents of 3 infants refused to participate in the study. The first stool sample (meconium) and weekly samples thereafter were collected from 27 preterm infants, born at 23 to 32 weeks gestational age, who had been admitted to the neonatal intensive care unit. Four of these babies' samples

Results

During a period of approximately 1 year, 27 preterm infants were enrolled (Table I). The time of first stool collection varied from day 2 to day 22 of life; 1 infant born at 23 weeks gestational age had a delayed passage of meconium on day 22 of life. Depending on the length of hospital stay, the number of stool samples collected per infant varied from 1 to 15.

Discussion

The goal of this study was to gain insight into the establishment of intestinal microbiota composition in premature infants born at <32 weeks of gestational age. We investigated changes in microbiota over time to evaluate potential associations with environmental factors such as gestational age, mode of delivery, premature rupture of membranes, use of maternal antibiotics, and breast versus formula feeding. In addition, we generated initial data on potential contributions of distortions in

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    Supported in part by grants from the National Institute of Research Resources, National Institutes of Health (RO1 HD 059143 and M01RR00082) and an educational grant (M.M.) from the European Society for Pediatric Research. The authors declare no conflicts of interest.

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