Milks Mean More: The Role of Milk in Nutrition, Digestion and Metabolism Across the Lifespan

Mammalian milk is a physical representation of the mother-child relationship: an intriguing fluid synthesized at the mother’s expense, shaped throughout evolution to nourish the infant and improve its rate of survival. Human milk is perhaps the most personalized food, providing all the necessary nutrients to meet the nutritional and physiological demands of the newborn in a concentrated form.

Indisputably, mammalian milks provide nutrition for nurturing the neonate, but more than this, groundbreaking research has provided insights into biological activities of milk beyond nutrition, indicating important roles for structural diversity in mammalian milks. Such research has shown the importance of a range of molecules and structures in milk for wellbeing; in the case of humans, these may be relevant across the lifespan. Inter-species nutrient compositional differences in milk lead to a diversity in structural assemblies e.g., micellar and non-micellar proteins and surface-functionalized milk-fat globules. Understanding this diversity and its consequences for health is a major endeavour in nutrition and food research.

After birth, digestion of macronutrients and the structural assemblies found in mammalian milk is a critical process driving development of the digestive system and sets the scene for a future healthy life. The newborn infant cannot adequately digest many milk components. Several enzymes naturally present in human milk, as well as host and microbial metabolic processes, are critical to aid digestion during this early stage. The plastic nature of the microbiota during early stages of life results in compositional and associated biochemical changes in this “organ” and its host, that have immediate consequence for digestion and metabolism. It is increasingly recognized that they can also have long-lasting impacts on the adult host. However, the mechanisms by which these interactions influence host physiology and how nutrition can modulate them across the lifespan are still ill-defined.

The aim of this Research Topic is therefore to provide the reader with an objective and comprehensive overview of the current knowledge on mammalian milks, their complex food matrix and composition, and how these aspects of diversity in milk interact and influence nutritional and physiological demands across the lifespan. We welcome the submission of Reviews, Systematic Reviews, Mini-Reviews, Hypothesis and Theory, Perspectives, Clinical Trials and Original Research articles that will help to narrow existing knowledge gaps in this field.

Dr. Sagar Thakkar is an employee of Nestlé Research (Société des Produits Nestlé SA) with a research focus on human milk sciences, maternal nutrition and early life nutrition. All other Topic Editors declare no competing interests with regards to the Research Topic subject.