Intestinal Permeability in Preterm Infants by Feeding Type: Mother's Milk Versus Formula

Background and Objective: Intestinal permeability in preterm infants represents a critical balance between absorption of nutritional agents and protection from dangerous pathogens. This study identified the relationship between feeding type (human milk and formula) and intestinal permeability as measured by lactulose to mannitol ratio in preterm infants in the first postnatal month. Study Design: Sixty-two preterm (<= 32 weeks of gestation) infants had assessment of feeding type and evaluation with enteral lactulose and mannitol administration and urinary measurement at three time points in the first postnatal month. Results: Infants who received the majority of feeding as human milk (>75%) demonstrated significantly lower intestinal permeability when compared to infants receiving minimal or no human milk (<25% or none) at postnatal days 7, 14, and 30 (p = 0.02, 0.02, and 0.047, respectively). When infants receiving any human milk were compared to infants receiving formula only, a significant difference existed at day 7 and day 14 but not for day 30 (p = 0.04, 0.02, and 0.15, respectively). With evaluation over the complete study period, exclusively formula-fed infants demonstrated a 2.8-fold higher composite median lactulose/mannitol ratio when compared with those who received any human milk. Infants who received >75% of enteral feeding as mother's milk demonstrated a 3.8-fold lower composite median ratio when compared to infants receiving <25% or no mother's milk. Conclusion: Preterm infant intestinal permeability was significantly decreased for those receiving human milk versus formula in a dose-related manner in the first postnatal month.