Establishing Global Reference Values for Human Milk

The primary purpose of the proposed research is to establish Reference Values (RVs) for micronutrients (MN) and macronutrients in human milk. The investigators' research to date has revealed highly variable milk MN concentrations among populations, and very low values in some low income countries (LICs) likely caused by poor maternal status and/or diet but RVs are needed to interpret these values. During the past year the investigators conducted a review of human milk nutrient composition, and formed a Technical Advisory Group (TAG) which developed the current proposal. Here, the investigators are conducting a longitudinal project on well-nourished women and infants. The Mothers, Infants and Lactation Quality (MILQ) study is a multi-center cohort project, investigating breast milk nutrient composition in well-nourished women across the first 8.5 months of lactation in four different populations. The countries involved are Denmark, Brazil, Bangladesh and The Gambia. Exclusive breastfeeding is an eligibility criterion up until the second post-partum study visit (between 1 - 3.4 months postpartum), with the exception of the first week after delivery. Other data collected on mothers and infants, including maternal and infant nutrient intake and status, morbidity, milk volume, and infant development, will inform interpretation and support application of the results. While the priority is to develop RVs for MN, other analyses will include human milk oligosaccharides (HMOs) and proteins, and free amino acids (FAA) in infant plasma. Thus, with the samples obtained the investigators will perform (a) laboratory analyses of milk, plasma and urine nutrients to construct RVs for global application, (b) analyses of HMOs and proteins in milk, and (c) metabolomic analysis of FAA and other metabolites in infant plasma. By request of the Bill and Melinda Gates Foundation (BMGF), colostrum and fecal microbiota samples will also be collected and stored for later analyses.