Human milk oligosaccharides: Functionality in infants Oligosacaridos de la leche materna: Evidencia de su funcionalidad en lactantes

Abstract

Human milk is a very complex fluid that contains numerous bioactive compounds. Among them, it includes very high con-centrations of oligosaccharides (human milk oligosaccharides [HMOs]) that group more than a hundred complex sugars. We present an extensive review of the composition and functions of the HMOs, highlighting the influence of the maternal genotype FUT2 on the type and concentration, being the latter much higher in FUT secretory women. The HMOs are non digestible in the intestine of the infant, therefore, they provide a substrate for the development of an intestinal microbiota, mainly rich in bifidobacteria. In addition, since some of these HMOs share some structural sequences with receptors for intestinal pathogens, they act as decoy blocking these receptors prevent-ing their adhesion and proliferation. The benefits of the con-sumption of these HMOs are considered unique, therefore the synthesis of HMOs structurally identical to those found in breast milk and with similar functionality demonstrated through clinical studies, opens a very interesting line of re-search in the field of infant nutrition. The first clinical studies conducted with HMOs are analyzed, considering necessary new clinical intervention trials in infants to confirm these ef-fects on the immune system and reducing the frequency of re-spiratory and gastrointestinal infections.