Human Milk Oligosaccharides in Preterm and Term Milk

Abstract

BackgroundThe recommended food of preterm infants is milk from their own mothers, or, if not available, pasteurized donor milk, which typically consists of term milk from late lactation. Human milk oligosaccharides (HMOS) are important for microbial metabolism and infant health. Comparative studies of preterm and term HMOS are needed to guide neonatal nutrition practice.ObjectiveTo compare the HMOS from Cincinnati, OH mothers of infants who delivered preterm (<29 weeks gestational age [GA]) to those who delivered at term (39–42 weeks GA) in early and late lactation.MethodsMultiple milk samples were collected from Cincinnati mothers as part of the Global Exploration of Human Milk (GEHM) study, and their HMOS content was analyzed by LC‐MS. Milk collected from 10 to 23 days postpartum (Mo1M) was compared to mature milk (MatM) collected at 3 to 12 months postpartum. All 113 mothers of preterm infants and 118 mothers of term infants provided Mo1M (mean day at collection: 15.2 days – preterm, 16.5 days – term). Of the term mothers, 93 also provided MatM samples that we used to measure donor milk values. Donor milk varies in composition but typically consists of term MM.ResultsComparing preterm Mo1M to term MatM, composition was similar in total HMOS (3.6 and 3.2 g/L), though the acidic fraction of HMOS was higher in preterm Mo1M than term MatM (1.1 vs 0.6 g/L, p<0.05). But, term Mo1M differed from both preterm Mo1M and term MatM. HMOS concentration of term Mo1M was nearly 2‐fold higher than preterm Mo1M for total HMOS (6.1 vs 3.6 g/L, p<0.001), which held true for both neutral and acidic fractions of HMOS. Significantly (p<0.05) higher values for specific major HMOS were found for term Mo1M compared to preterm Mo1M and term MatM: 2′‐fucosyllactose (2′‐FL, 1.4 vs 0.6 vs 1.0 g/L); 6′‐sialyllactose (6′‐SL, 0.4 vs 0.2 vs 0.1 g/L); and disialyllacto‐N‐tetraose (DSLNT, 0.8 vs 0.2 vs 0.2 g/L). However, some HMOS, e.g., 3′‐sialyllactose (3′‐SL, ~0.2 g/L) maintained similar concentrations regardless of gestational age or timing of lactation.ConclusionsPreterm milk differs significantly from term milk in HMOS composition in the first month or later lactation, which represents most donor milk. The lower quantity of total HMOS in preterm than term milk should be examined in relation to preterm infant growth and health outcomes.Support or Funding InformationSupported in part by HD013021 and Mead‐Johnson