Ecologies, synergies, and biological systems shaping human milk composition—a report from Breastmilk Ecology and the Genesis of Infant Nutrition (BEGIN) Working Group 2

Authors: SMILOWITZ, JENNIFER - University Of California, Davis; Allen, Lindsay - A; DALLAS, DAVIS - Oregon State University; MCMANAMAN, JAMES - University Of Colorado; RAITEN, DANIEL - National Institutes Of Health (NIH); ROZGA, MARY - Academy Of Nutrition And Dietetics; SELA, DAVID - University Of Massachusetts; SEPPO, ANTTI - University Of Rochester; WILLIAMS, JANET - University Of Idaho; YOUNG, BRIDGET - University Of Rochester; MCGUIRE, MICHELLE - University Of Idaho

Submitted to: The American Journal of Clinical Nutrition
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/15/2022
Publication Date: N/A
Citation: N/A

Interpretive Summary: Human milk should be the preferred food for infants during the first 6 months of life because it is thought to provide all the necessary nutrients and biologically active compounds needed for optimal development and growth in the infant. Despite decades of research, however, our knowledge continue to be limited in regards of the effects of human milk consumption on infant health on a biological/physiological basis. Various reasons exists for lack of information, including milk components tend to be studied in isolation, though there is reason to believe they interact, and milk composition can vary greatly within an individual as well as within and among populations. The goal of this working group within the BEGIN project was to provide an overview of human milk composition, factors impacting its variation, and how its components may function to nourish, protect, and communicate complex information to the infant. Further, ways are suggested and examples provided of how milk components might interact such that the benefits of an intact milk matrix is greater than the sum of its parts. Several examples describe how milk is better thought of as a biological system of components that synergistically support optimal infant health, rather than a more simplistic “mixture” of independent constituents.

Technical Abstract: Human milk is universally recognized as the preferred food for infants during the first 6 months of life because it not only provides essential and conditionally essential nutrients in necessary amounts but also other biologically active components that are instrumental in protecting, communicating important information to support, and promoting optimal development and growth in the infant. Despite decades of research, however, the multifaceted impacts of human milk consumption on infant health are far from understood on a biological/physiological basis. Reasons for this lack of comprehensive knowledge of human milk functions are many, including that milk components tend to be studied in isolation, though there is reason to believe they interact. In addition, milk composition can vary greatly within an individual as well as within and among populations. The objective of this working group within the BEGIN project was to provide an overview of human milk composition, factors impacting its variation, and how its components may function to coordinately nourish, protect, and communicate complex information to the recipient infant. Moreover, we discuss ways whereby milk components might interact such that the benefits of an intact milk matrix is greater than the sum of its parts. We then apply several examples to illustrate how milk is better thought of as a biological system rather than a more simplistic “mixture” of independent components to synergistically support optimal infant health.