Enhanced nutrient supply and intestinal microbiota development in very low birth weight infants

Background: Promoting a healthy intestinal microbiota may have positive effects on short- and long-term outcomes in very low birth weight (VLBW; BW < 1500 g) infants. Nutrient supply influences the intestinal microbiota. Methods: Fifty VLBW infants were randomized to an intervention group receiving enhanced nutrient supply or a control group. Fecal samples from 45 infants collected between birth and discharge were analyzed using 16S ribosomal RNA (rRNA) amplicon sequencing. Results: There was considerable individual variation in microbiota development. Microbial richness decreased towards discharge in the controls compared to the intervention group. In the intervention group, there was a greater increase in diversity among moderately/very preterm (MVP, gestational age ≥ 28 weeks) infants and a steeper decrease in relative Staphylococcus abundance in extremely preterm (EP, gestational age < 28 weeks) infants as compared to controls. Relative Bifidobacterium abundance tended to increase more in MVP controls compared to the intervention group. Abundance of pathogens was not increased in the intervention group. Higher relative Bifidobacterium abundance was associated with improved weight gain. Conclusion: Nutrition may affect richness, diversity, and microbiota composition. There was no increase in relative abundance of pathogens among infants receiving enhanced nutrient supply. Favorable microbiota development was associated with improved weight gain