What Makes Human Milk Unique?

Julie Chen
November 1, 2020

You might wonder, what makes human milk unique? A magical component in human milk includes human milk oligosaccharides (HMOs). They are structurally diverse long chains of simple sugars that are highly unique to human milk. Far fewer oligosaccharides are found in the milk of farm animals, while they are structurally much less complex as well. For this reason, HMOs have been studied extensively for their health effects, though the mechanism in which they provide for us is yet to be discovered.

What makes this component in breast milk magical? HMOs are known to increase intestinal health of the infant by influencing the types of bacteria which colonize the infant’s GI tract. Establishing a healthy gut microbiome in an infant from birth is essential to their development of a long-lasting healthy digestive system as they mature. Furthermore, HMOs present promising effects on preventing infection through their anti-adhesive properties. As HMOs may resemble the structures of viral receptors, they can block viral adherence to target cells,  in turn preventing infectious diseases in the gut, respiratory, and urinary tracts of the infant. In addition, consumption of HMOs can beneficially alter the infant’s epithelial and immune cell responses, assisting in immune system development. Furthermore, a component of HMOs includes sialic acid, which is a potentially essential nutrient for infant brain development and cognition.

It is not until recently that a method was developed to synthesize HMO on an industrial scale, permitting infant formulas to achieve higher similarity to a Mother’s milk. Currently, there are minimal studies to examine the health benefits of these synthesized HMOs. Two widely studied synthesized HMOs are Lacto-N-Neotetraose (LNnT) and 2′-Fucosyllactose (2’-FL). So far, only 2′-FL has shown to provide similar health benefits to natural HMOs with no negative effects, while the use of LNnT is still limited in infant formula production. As research and development continue to improve infant nutrition, we hope to see more infant formula options supplemented with HMOs being fully aware of its abundant health benefits and essentialness to infant development.