Meier, P.P. (USA)
Summary on Clinical Aspects of Human Milk on Infant Health Outcomes
Donovan, S.M. (USA)
Research Gap and Opportunities
Metabolomics in Human Milk Research
Slupsky, C.M. (USA)
Human Milk Oligosaccharides: Next-Generation Functions and Questions
Bode, L. (USA)
Guiding Development of the Neonate: Lessons from Mammalia
Nicholas, K.R.; Modepalli V.; Watt, A.P.; Hinds, L.A.; Kumar, A.; Lefevre, C.; Sharp, J.A. (Australia)
Milk Lipids: A Complex Nutrient Delivery System
German, J.B. (USA); Argov-Argaman, N. (Israel); Boyd, B.J. (Australia)
Summary on Research Gap and Opportunities
German, J.B. (USA)
For more information on related publications, please consult the NNI website: www.nestlenutrition-institute.org
Human milk is a complex biological fluid that contains all of the essential nutrients as well as other functional components that are thought to contribute to the short- and long-term health outcomes of breast- versus formula-fed infants. The goal of this workshop was to review the current evidence for the composition of human milk and its effects on the developing infant, to identify existing knowledge gaps, and to suggest future opportunities for research in human milk and lactation.
The first session set the stage with speakers providing a historical perspective of the place of breastfeeding in medicine, a biological perspective for the role of breastfeeding in infant health and an overview of the physiological basis and mechanics of breastfeeding. It is a goal of many organizations, governments, and health professionals that babies should be breastfed for at least the first year of life and exclusively for the first 6 months. Thus, breastfeeding may be regarded as major global public health intervention. In general, public health interventions should be rooted in sound scientific evidence. Unfortunately, in the past some of the key scientific pillars that have supported this important field have been based on flawed science and mistaken biological thinking. It was one goal of this session to identify such flaws in order to help pave the way to a new evidence-based “breastfeeding medicine” for the future. A key premise of this session was that a firm scientific evidence base in this rapidly developing field would have practical implications for the care of breastfed babies which in turn would be in the interests of population health. Breastfeeding itself is a mechanical process; therefore, the success of breastfeeding as a public health intervention depends on successful suckling, and for those that assist professionally with breastfeeding management, best practices are underpinned by a scientific understanding of the mechanics of suckling. However, despite the intensity and complexity of a new wave of current research into the mechanics of suckling, this work did not displace the long-standing best practices in breastfeeding management, derived from historical studies. Session 1 as a whole emphasized the importance of getting the science of breastfeeding right, the need for relevant health professionals to understand this science and the great potential that breastfeeding has, as a branch of medical practice, for influencing short- and long-term population health outcomes.
Next session has presented an update on our current understanding of the composition of human milk components and their potential physiological benefits. In the past decade, our understanding of human milk composition has rapidly advanced through the application of sophisticated, high-throughput analytical tools. Infant nutrient requirements are largely based on nutrient intakes of breastfed infants, which are generally assumed to be adequate. Information on nutrient concentrations in human milk and how they may be affected by various factors, such as maternal stores and diet, ethnicity, and length of lactation, is therefore imperative. This is particularly important for micronutrients as they have been difficult to analyze, and micronutrient deficiencies may have short- and long-term physiological implications for infant growth and development. Recent studies performed at multiple geographical locations and with adequate sampling methodology and analytical methods provide essential information for understanding requirements and establishing better recommendations. The composition of human milk proteins, fatty acids, oligosaccharides, and fat- and water-soluble vitamins was presented, along with emerging evidence on human milk microRNAs and exosomes, which may constitute biological messengers affecting infant development. Improvements in dairy technology have enabled the isolation of bioactive proteins from bovine milk for supplementation to infant formula. Findings of a randomized clinical trial with a milk fat globule membrane fraction demonstrate beneficial effects on multiple outcomes ranging from immune and cognitive development to microbiome modulation.
Session 3 extended upon Session 2 by focusing on the clinical aspects of human milk on infant health outcomes, including growth and metabolic outcomes and cognitive, immune, and microbiome development. Overall, breastfeeding “programs” a healthier growth trajectory and reduces the risk of overweight and obesity. However, the effects of human milk are specific to the infant’s physiological state (term vs. preterm very-low birthweight) and environment (developing vs. developed country). In preterm infants, the effect of mother’s own milk (MOM) on reducing diseases associated with prematurity is affected by the dose of MOM and the timing of the exposure, suggesting disease-specific mechanisms that are impacted by MOM. Human milk contains factors that influence the development of the infant microbiota, including human milk oligosaccharides. The microbiota, in turn, shapes immune development. Components in human milk may also directly influence gut mucosal immunity and promote immune tolerance. Recent evidence has underscored the interrelationship between the gut, microbiome, and the brain (microbiome-gut-brain axis) in cognitive development, and human milk components are key players in all aspects of this relationship. The application of noninvasive imaging techniques is providing new insight into the effect of early-life nutrition on brain structural and functional development, with links to learning and memory.
The final session reviewed the current state of human milk research, which is challenged by the complexity of lactation even with respect to defining the simple composition of milk. In addition, the full implications of emerging data on lactation as a remarkable biological process and the diversity of functions of human milk to the protection, development, and education of the infant has not been integrated into our current views about breastfeeding and lactation, particularly in the medical community. Future research is needed to build a more complete and predictive understanding of milk’s diversity, which will be accelerated by recruiting diverse scientific fields and disciplines complete with their tools, perspectives, and insights into biological structures and functions. Biological research has been revolutionized by the science of genomics and its associated global platforms of proteomics and metabolomics. It is impossible to think about complexity of human milk and lactation without evolution and anthropological aspects. The session presented a remarkably insightful anthropologic perspective to lactation in its broadest sense from molecular mechanisms to infant behavior. Additionally, lactation within the context of comparative biology was discussed. This area of research has been a powerful engine for scientific discovery by providing scientists with the tools of biology itself to understand the basic mechanisms by which living