Survival of bioactive milk protein across digestion in preterm infants fed with fresh human milk plus bovine milk fortifier.
The composition of human milk evolved to match the needs of the human infant. Yet a large portion of infants consume formula for various reasons. Companies that produce infant formula should strive to match human milk composition and functionality. Human milk contains hundreds to thousands of distinct bioactive molecules that affect biological processes and have an impact on infant body function and, ultimately, health.
Part of human milk’s functionality derives from its complex array of hundreds of proteins, including many with known functions within the infant. These potential functions include enhancing mineral absorption (e.g., lactoferrin and α-lactalbumin), controlling nutrient absorption (e.g., bile salt-stimulated lipase, milk proteases and antiproteases), defending against bacterial and viral pathogens (e.g., lactoferrin, lysozyme, immunoglobulins, lactoperoxidase, mucin and haptocorrin), modulating the immune system (e.g., cytokines and osteopontin) and guiding the development of the gastrointestinal system (e.g., epidermal growth factor, insulin-like growth factor 1, transforming growth factor β and lactoferrin). Yet, to exert functional effects within the infant, milk proteins must survive intact within the digestive system.
The extent to which the array of human milk proteins at least partially survive infant digestion remains unclear. Determining which proteins survive intact will point to key bioactive roles for these proteins. Proteins from human milk that survive intact would represent targets for the formula industry to match to better mimic the functionality of human milk.
The extent to which bovine milk protein ingredients used in infant formulas survive across digestion, and to what degree this survival aligns with the survival of human milk proteins, is unknown. Identifying ingredient streams (whether from bovine milk or recombinant proteins) that can deliver functionality within the infant gut will be key for advancing infant formula’s capacity to improve infant health outcomes.
About the Research Team
Led by Principle Investigator Dave Dallas, PhD and his team at Oregon State University in Corvallis, Oregon. The overall aim of Dr. Dallas’s research is to improve the health of premature infants, a population that suffers greatly reduced health outcomes in comparison with term-delivered, breast milk-fed infants. The reduced digestive capacity of premature infants results in an inability break down milk proteins in the same way as term infants.
Dr. Dallas completed his doctoral and postdoctoral research at UC Davis where he focused on the characterization of the human milk glycans and human milk protein digestion in infants. Methods developed allowed for the identification of thousands of naturally occurring peptides released from milk proteins by native milk enzymes. His work showed that milk enzymes continue to break down milk proteins within the infant's stomach to release functional peptide fragments. Dr. Dallas grew up on a wheat farm in Pendleton, Oregon.
Study Communications
Initial results about quantification of human milk proteins across infant digestion were presented at the American Society for Mass Spectrometry (AMS) conference in June of 2023.