Human milk oligosaccharides are unconjugated complex carbohydrates which are found abundantly in human milk. It is the third most abundant ingredient after fat and carbohydrates in breast milk. It functions as a probiotic helping to establish commensal bacteria. It also functions as anti-adhesives which help in preventing attaching of microbial pathogens to mucosal surfaces. It helps in lowering the risk of viral, bacterial and protozoan parasite infections.