A multi-omics study of 1,543 milk samples identifies molecular markers associated with maternal nutrition, infant growth and the biology of the mammary gland.
Researchers have identified seven molecules in human milk that may help explain how a mother’s nutritional state is linked to infant growth, while also offering a rare look at how the mammary gland functions during lactation. The work, published in Science, drew on 1,543 milk samples from cohorts in Canada, Pakistan and Burkina Faso, giving scientists a broader view than studies that examine milk components in isolation.
The team, led by Liat Shenhav of NYU Grossman School of Medicine, used a multi-omics approach, meaning it measured several classes of molecules at once, including metabolites, proteins, vitamins, carbohydrates and human milk oligosaccharides, the complex sugars known as HMOs. By pairing those data with infant growth measurements and using machine learning, the researchers found a shared molecular pattern linked both to maternal nutritional supplementation and to better growth outcomes in infants at higher risk of faltering growth. A companion Science paper from the International Milk Composition Consortium reached a similar broad conclusion: human milk is not static, and some components shift with maternal nutrition while others remain relatively stable.
The seven strongest candidate markers were valerylcarnitine, pantothenic acid, lysine, 6′-sialyllactose, selenium, C2 acylcarnitine and C3 acylcarnitine, according to the PubMed summary of the study. The full analysis suggests these molecules reflect different aspects of mammary gland biology, including nutrient processing, tissue remodelling and immune activity, rather than simply tracking how permeable the blood-milk barrier is. Among them, the short-chain acylcarnitines stood out most strongly, especially valerylcarnitine, which the researchers linked to molecular signs of lower milk synthesis and to pathways involved in repair and remodelling.
One hypothesis emerging from the data is that vitamin B5, also known as pantothenic acid, could be part of a metabolic bottleneck. The body uses pantothenic acid to make coenzyme A, a molecule central to energy and fat metabolism, and the researchers propose that a shortage of available vitamin B5 could alter acylcarnitine metabolism and allow valerylcarnitine to build up. April Jauhal, the study’s first author, said the findings point to “the intimate link between maternal nutrition, metabolic health and mammary function”, and added that the team is now testing the proposed pantothenic acid-coenzyme A-valerylcarnitine pathway in mammary biology and lactation.
The results build on a wider body of research showing that milk composition can shape, and be shaped by, early development. Reviews and observational studies have previously reported links between human milk oligosaccharides and infant growth, as well as associations between maternal weight, milk bioactive compounds and child body composition. The new work adds a different angle by tying several milk molecules not just to infant outcomes, but to the biology of the gland that produces the milk. Shenhav said the goal is to understand milk “in the context of the biology that produces it”, with researchers now examining colostrum and transitional milk to see how these functional states emerge as lactation develops.
Disclaimer: This content is for informational purposes only and is not intended to be a substitute for professional medical judgment, advice, diagnosis, or treatment.
