Human milk oligosaccharides (HMOs) are abundantly present in HM and exert multiple beneficial functions, such as support of colonization of the gut microbiota, reduction of pathogenic infections and support of immune development.
Link to Publication: https://www.ncbi.nlm.nih.gov/pubmed/29333864
Akkerman R, et al. Non-digestible carbohydrates in infant formula as substitution for human milk oligosaccharide functions: Effects on microbiota and gut maturation. Crit Rrev Food Sci Nutr. 2018:1-12. doi: 10.1080/10408398.2017.1414030.