title: The individual-specific and diverse nature of the preterm infant microbiota.
abstract: OBJECTIVE
  To examine the composition of the evolving microbiota of preterm infants at weeks 2 and 4 of life.
  
  
  METHODS
  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.
authors.affiliation: Food Biosciences Department, Teagasc Food Research Centre, Moorepark, Fermoy, County Cork, Ireland.
authors.forename: Eoin
authors.initials: E
authors.lastname: Barrett
authors.forename: Colm
authors.initials: C
authors.lastname: Kerr
authors.forename: Kiera
authors.initials: K
authors.lastname: Murphy
authors.forename: Orla
authors.initials: O
authors.lastname: O'Sullivan
authors.forename: C Anthony
authors.initials: CA
authors.lastname: Ryan
authors.forename: Eugene M
authors.initials: EM
authors.lastname: Dempsey
authors.forename: Brendan P
authors.initials: BP
authors.lastname: Murphy
authors.forename: Paul W
authors.initials: PW
authors.lastname: O'Toole
authors.forename: Paul D
authors.initials: PD
authors.lastname: Cotter
authors.forename: Gerald F
authors.initials: GF
authors.lastname: Fitzgerald
authors.forename: R Paul
authors.initials: RP
authors.lastname: Ross
authors.forename: Catherine
authors.initials: C
authors.lastname: Stanton
mesh_terms: D005243:Feces / Q000382:microbiology*; D005658:Fungi / Q000302:isolation & purification; D041981:Gastrointestinal Tract / Q000382:microbiology*; D006090:Gram-Negative Bacteria / Q000302:isolation & purification; D006094:Gram-Positive Bacteria / Q000302:isolation & purification; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature; D007494:Ireland; D054892:Metagenome
keywords: Microbiology; Molecular Biology