Microbial Biomarkers of Intestinal Barrier Maturation in Preterm Infants

Intestinal barrier immaturity, or “leaky gut,” is the proximate cause of susceptibility to necrotizing enterocolitis in preterm neonates. However, the impact of intestinal microbiota development on intestinal mucosal barrier maturation has not been evaluated in this population. In this study, we investigated a longitudinally sampled cohort of 38 preterm infants < 33 weeks gestation monitored for intestinal permeability (IP) and fecal microbiota during the first 2 weeks of life. Rapid decrease in IP indicating intestinal barrier function maturation correlated with significant increase in community diversity. In particular, members of the Clostridiales and Bifidobacterium were highly transcriptionally active, and progressively increasing abundance in Clostridiales was significantly associated with decreased intestinal permeability. Further, neonatal factors previously identified to promote intestinal barrier maturation, including early exclusive breastmilk feeding and shorter duration antibiotic exposure, associate with the early colonization of the intestinal microbiota by members of the Clostridiales, which altogether are associated with improved intestinal barrier function in preterm infants

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Transient dynamic subaortic stenosis in premature neonates after patent ductus arteriosus ligation.

We describe 2 premature infants with PDA that did not respond to medical therapy and required surgical ligation. Both infants developed transient dynamic subaortic obstruction that resolved without specific therapy. This may have occurred due to sudden changes in the left ventricular volume

Impact of red blood cell transfusions on intestinal barrier function in preterm infants

OBJECTIVE: To determine the relationships of red blood cell (RBC) transfusion and enteral feeding to changes in intestinal permeability (IP) measured by the relative intestinal uptake of lactulose (La) and rhamnose (Rh) in preterm infants \u3c33 wk gestation. DESIGN/METHODS: Infants 24 0 -32 6 wk gestation received La/Rh solution enterally on study days 1, 8 and 15.Urinary La/Rh ratio was measured by HPLC. Hematocrit preceding transfusion, total RBC transfusion volume, volume/kg, and feeding status during each study interval (birth-d1; d1-d8, and d8-d15) were determined. RESULTS: Of the seventeen (40.5%) subjects who received≥1 transfusion during the study period, 12 (70.6%) infants were \u3c28 wk gestation and 5 (29.4%) infants were≥28 wk gestation, p \u3c 0.0001. Lower pre-transfusion hematocrit was observed in intervals preceding high IP (La/Rh \u3e 0.05) than in intervals preceding low IP (La/Rh≤0.05) measurements (33 vs 35.8, p = 0.1051). RBC transfusions occurred more frequently in intervals preceding high IP than in intervals preceding low IP (26.8%; vs 8.3%, p = 0.0275) with 5-fold higher total RBC volume and volume/kg in intervals preceding any time point with high IP. RBC transfusion during an interval was associated with a three-fold increased risk of high IP (aOR 2.7; 95% C.I 0.564-12.814; p = 0.2143). Exclusive breast milk exposure and post-menstrual age reduced the risk for high IP following RBC transfusion. CONCLUSIONS: Both RBC transfusion number and volume was associated with subsequent high IP measurements in preterm infants \u3c33 weeks gestation and potentially may contribute to impairment of the preterm intestinal barrier