Development of gut microbiota and metabolic changes in preterm babies

Abstract

Gut microbiota are an important component of the human organism, contributing to metabolism and believed to play a role in the maintenance of health. Preterm babies are exposed to different early life interventions than full-term ones. They are exposed to prolonged courses of antibiotics and often fed parenterally, with delayed or limited enteral nutrition intake. The aim of this research was to assess how early life interventions (type of parenteral nutrition, type of milk, mode of delivery) and other factors (gestational age at birth, postnatal age, sex of the baby) affect the development of gut microbiota and the consequent metabolic impact in preterm babies. Two thousand stool and urine samples were collected from 160 babies. Gut microbiota were identified by 16S rRNA gene sequencing, while the activity of bacteria was assessed by metabolic profiling using 1H NMR. A new DNA and faecal water extraction method was developed and validated. Metabolic differences in stool and urine in relation to early life interventions were observed. Higher postnatal age was associated with vit. B5 and vit. B1, while lower was associated with increased bile acids and sugars. Increasing GA was correlated with higher concentration of GABA and glutamate. Breast-fed babies had higher concentration of lactose than formula-fed ones. There was no metabolic difference in relation to mode of delivery or sex of the baby. Microbial profiles were mostly affected by route of nutrition (oral – more Staphylococcaceae, intravenous – more Enterobacteriaceae), type of milk (breast milk – more Enterobacteraceae) and mode of delivery (Caesarean section – more Staphylococcus and Clostridium). The most abundant phylum was Proteobacteria. Average abundance of Bifidobacteria was 10%. Those results contribute to current understanding of the establishment of gut microbiota in preterm babies. Future work should focus on repeating the analysis on a larger sample set from a trial designed for this purpose.