Human Milk Bioactives: Future Perspective.

Human milk is a dynamic, complex fluid that offers much more than nutrition to infants. The macronutrient content of human milk has been well characterized and described. However, human milk is not a simple matrix of protein, carbohydrate, fat, and micronutrients. The National Institutes of Health have defined bioactives in food as elements that "affect biological processes or substrates and hence have an impact on body function or condition and ultimately health." Bioactives are cells, anti-infectious and anti-inflammatory agents, growth factors, and prebiotics that are naturally present in human milk. They may explain the differences in health outcomes observed between breastfed and non-breastfed infants. They influence the development of the immune and gastrointestinal systems, gut microbiota, neurodevelopment, metabolic health, and protection against infection. Human milk oligosaccharides are one bioactive that have been an increasingly popular area of research. This review provides a broad overview of some bioactive components that positively affect the immune system and touches on certain well-known growth factors present in human milk. Future research will look at the interplay of the multitude of bioactive components in human milk as a biological system and beyond singular compounds.