human gut metagenome Raw sequence reads

The purpose of this study was to establish the influence of nutritional exposures on the intestinal microbiome in a cohort of preterm infants early in life. Principal component analysis of 199 samples from 30 preterm infants (<32 weeks) over the first 60 days following birth showed that the intestinal microbiome was influenced by postnatal time, birth weight, and nutrition. Infants who were fed breast milk had a greater initial bacterial diversity and a more gradual acquisition of diversity when compared to infants who were fed infant formula. The microbiome of infants fed breast milk were more similar regardless of birth weight, in contrast to the microbiome of infants fed infant formula, which clustered differently based on birth weight. By adjusting for differences in gut maturity, an ordered succession of microbial genera was observed in breast milk fed infants. This appeared to be disrupted in those fed infant formula. Supplementation with pasteurized human donor milk had some success in promoting a more breast-milk like microbiome and moderating increases in bacterial diversity. These findings not only suggest a microbial mechanism underpinning the body of evidence showing that breastmilk promotes intestinal health in the preterm infant, but also a dynamic interplay of host and dietary factors that facilitate colonization of and enrichment for specific microbes during establishment of the preterm infant microbiota.