The Microbiome of Infants Recruited to a Randomised Placebo-controlled Probiotic Trial (PiPS Trial)

Themicrobial dysbiosis associatedwith necrotizing enterocolitis (NEC) in preterminfants suggests that early exposure to probiotics may decrease and antibiotics may increase NEC risk. However, administration of Bifidobacteriumbreve strain BBG-001 to preterminfants did not affectNEC incidence in a multicenter randomised controlled phase 3 trial (PiPS trial). Using a subset of these subjects we compared the fecal microbiome of probiotic and placebo groups and assessed the impact of early antibiotic treatment. ExtractedDNA from103 fecal samples collected at 36 weeks post-menstrual age underwent PCR amplification of a fragment of the 16S rRNA gene. Heatmaps were constructed showing the proportions of sequences from bacterial families present at >1% of the community. Stepwise logistic regression assessed the association between early antibiotic exposure and microbiome group. Therewas no difference in themicrobial richness and diversity of themicrobiome of preterm infants following treatmentwith probiotic or a placebo. Conversely, early antimicrobial exposure was associated with different patterns of colonisation, specifically a relative abundance of Proteobacteria. These findings highlight that the potential influence of probiotics on the microbiome of preterm infants remains unclearwhereas themodulatory effect of antibiotic exposure onmicrobial colonisation requires further research. (C) 2017 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license.