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ARS Home » Pacific West Area » Davis, California » Western Human Nutrition Research Center » Obesity and Metabolism Research » Research » Research Project #436408

Research Project: Mothers, Infants and Lactation Quality-Extra Analyses (MILQ II) Project

Location: Obesity and Metabolism Research

Project Number: 2032-51530-025-039-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 Bill & Melinda Gates Foundation. 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 (from well-nourished contexts) is critical to understanding normal biologic variability vs. deficiency and insufficiency in human milk (HM) and how it impacts infant health and growth. The additional HM analytes to be assessed will include: specific proteins such as lactoferrin, lysozymes, lactalbumin, antitrypsin and osteopontin; appetite-regulating hormones such as leptin, and insulin; and cytokines. Also added will be HM selenium and vitamin D, metabolomics including amino acids and lipids in milk and serum, genetic/epigenetic contributors to human milk traits including milk volume and composition, and colostrum analysis for sIGA. The microbial community structure in all infant stool (up to 3,000 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. A subset of 300 samples will be chosen for shotgun sequencing. 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. The research outcomes from this study 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 (HMOs) 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. Based on laboratory capacities, costs, and to ensure a reasonable time line for sample and data analysis, we propose to use an “omics-subset” of samples on all of which we will measure metabolomics with Biocrates, milk HMOs, protein and glycoproteins. This subset = 1,000 samples; from 250 dyads per site of which 150 are from Visit 2, 50 from Visit 3 and 50 from Visit 4. We are collecting an additional 600 milk samples to determine intra-individual variability in milk composition and improve estimates of Reference Values, which will also be analyzed with the supplemental funds as an indicator of selenium content of soil, water and food across geographic locations, information of which is lacking across the MILQ study sites.