Human milk oligosaccharides (HMOs) are complex sugars with unique structural diversity which are found in breast milk at significant concentrations.

HMOs are important prebiotics and display many unique health effects for infants. These sugars act by promoting growth of beneficial bacteria in the large intestine, thereby generating short-chain fatty acids which are critical for gut health.

As antiadhesive antimicrobials, HMOs selectively reduce binding of pathogenic bacteria and viruses to the gut epithelium, preventing the emergence of a disease.

Certain HMOs can help establish immunocompetence, both locally and systemically. HMOs may also participate in a gut–brain connection, thereby modulating brain and cognitive development.