The influence of milk oligosaccharides on microbiota of infants: opportunities for formulas

Abstract

In addition to a nutritive role, human milk also guides the development of a protective intestinal microbiota in the infant. Human milk possesses an overabundance of complex oligosaccharides that are indigestible by the infant yet are consumed by microbial populations in the developing intestine. These oligosaccharides are believed to facilitate enrichment of a healthy infant gastrointestinal microbiota, often associated with bifidobacteria. Advances in glycomics have enabled precise determination of milk glycan structures as well as identification of the specific glycans consumed by various gut microbes. Furthermore, genomic analysis of bifidobacteria from infants has revealed specific genetic loci related to milk oligosaccharide import and processing, suggesting coevolution between the human host, milk glycans, and the microbes they enrich. This review discusses the current understanding of how human milk oligosaccharides interact with the infant microbiota and examines the opportunities for translating this knowledge to improve the functionality of infant formulas.

Figure 1

43 Kb gene cluster in B. infantis ATCC15697 containing glycosyl hydrolases and transport-related genes (TRG) required for importing and metabolizing HMOs. SBP: solute binding protein, M: major facilitator superfamily, P: ABC transporter permease component, and A: ABC transporter ATPase subunit. Adapted from Sela et al. (2008).