The individual-specific and diverse nature of the preterm infant microbiota

Arch Dis Child Fetal Neonatal Ed. 2013 Jul;98(4):F334-40. doi: 10.1136/archdischild-2012-303035. Epub 2013 Jan 8.

Abstract

Objective: To examine the composition of the evolving microbiota of preterm infants at weeks 2 and 4 of life.

Settings: The paediatric intensive care unit of the Cork University Maternity Hospital.

Methods: The microbial diversity of faecal samples from 10 preterm infants was determined using 16S rRNA amplicon pyrosequencing technology.

Results: In total, 452 863 sequences were obtained from 20 faecal samples collected from 10 preterm infants, allowing a level of analysis not previously reported. The preterm infant microbiota samples were dominated by Proteobacteria (46%), followed by Firmicutes (45%), while the phyla Actinobacteria (2%) and Bacteroidetes (7%) were detected at much lower levels at week 2 of life. This colonisation pattern was similar at week 4 of life. At the family level, Enterobacteriaceae were detected at 50% and 58% at weeks 2 and 4, respectively. The preterm infants were characterised by a lack of detectable Bifidobacterium and Lactobacillus genera commonly associated with the infant gut. In addition to the dominance of the Proteobacteria, a high level of interindividual variation was observed, indeed the relative proportions of different phyla, families and genera in different infants ranged from <1% to >90%.

Conclusions: The results indicate that in addition to an uncharacteristic microbiota relative to that reported for healthy term infants, there was a large interindividual variation in the faecal microbiota diversity of preterm infants suggesting that the preterm microbiota is individual-specific and does not display a uniformity among infants.

Keywords: Microbiology; Molecular Biology.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Feces / microbiology*
  • Fungi / isolation & purification
  • Gastrointestinal Tract / microbiology*
  • Gram-Negative Bacteria / isolation & purification
  • Gram-Positive Bacteria / isolation & purification
  • Humans
  • Infant, Newborn
  • Infant, Premature
  • Ireland
  • Metagenome*