Location: Immunity and Disease Prevention Research
Project Number: 2032-51530-026-10-T
Project Type: Trust Fund Cooperative Agreement
Start Date: Aug 29, 2019
End Date: Aug 15, 2024
This grant will continue and expand the research begun in the MILQ multi-center study, funded in 2016 by the BMGF. In addition to continuing to develop Reference Values (RVs) for nutrients and other constituents of human milk, to improve estimates of nutrient requirements and intake gaps for infants and lactating women, and to evaluate human milk (HM) composition and nutrition interventions, this grant will allow the inclusion of numerous additional analytes and analysis of infant stool specimens for assessing the gut microbiome. We plan to round out analytes of interest to better understand the biological system in human milk.
This cohort of longitudinally collected specimens in four geographic sites that is collecting a vast amount of data on maternal and infant factors (from well-nourished contexts) is critical to understanding normal biologic variability vs. deficiency and insufficiency in human milk and microbiome and how it impacts infant health and growth. The microbial community structure in all infant stool (up to 3000 samples) collected in the four cohorts will be characterized using 16S rRNA sequencing. The infant stool microbiome is involved in the development of infant immunity. It potentially affects the development of lifelong health and acquisition of non-transmissible diseases (type 2 diabetes, obesity, allergy and atopy). The abundance of the beneficial organism Bifidobacterium spp. in the infant gut is associated with beneficial health outcomes and with consumption by the infant of complex human milk oligosaccharides found in breast milk. Specific HMOs, lacto-N-tetraose (LNT), 2’-fucosyllactose (2’FL), and 6’-siallylactose (6’SL), correlate with abundance of pathogenic organisms Enterobacter/Klebsiella in both milk and stool microbiomes. Additionally, the micronutrient iron has been shown to promote Escherichia and Clostridium spp. in the infant gut. We will use the 16S rRNA sequence data collected from the four cohorts to examine relationships between infant stool microbial community and (1) maternal diet, (2) breast milk HMO profile and total HMO abundance (3) the breast milk micronutrient profile, (4) infant health outcomes and (5) infant micronutrient status. While 16S rRNA surveys enable analysis of overall gut microbial community structure, shotgun metagenomics sequencing is necessary to identify specific keystone species or strains and to quantify functional capacity via gene content. A subset of 300 samples will be chosen for shotgun sequencing based on 16S rRNA screening, DNA quantity/quality, and availability of other data sets (e.g., milk oligosaccharides, milk microbiome, and infant dietary data). The selected samples would include stool from 50 infants at all three time points in one cohort (150 samples) and from 50 infants at only one-time point in the other three cohorts (another 150 samples). The latest time point is ideal to study the weaning transition and how the introduction of solid foods affects saccharolytic capability and antimicrobial resistance, for example.