Insight into the key bridge for infant’s nutrition and health: how to explore personalized utilization pathways from diverse human milk oligosaccharides

Breast milk is the preferred gold standard food for infants. Human milk oligosaccharides (HMOs) are the third most natural component in breast milk. But breast milk is often insufficient, so they rely solely on breast milk substitutes. HMOs provide nutrients to beneficial gut microbiota such as Lactobacilli and Bifidobacteria, helping to establish and maintain a balance of microbial communities in the infant gut. HMOs mimic the receptors of pathogens, preventing them from attaching to the baby’s intestinal cells, thereby preventing pathogen infection. This function is particularly crucial for newborns and infants. How to individually use HMOs is important. We focused on classification and characteristics of HMOs, their impact, intake, development/utilization mechanism on infant health, aiming to provide HMOs data support for the development. HMOs are quite different (more than 200 kinds), so it is necessary to make targeted selection, and those associated with intestinal microorganisms (Bifidobacterium), which can utilize HMOs, have the greatest application potential. Oligosaccharide-binding protein (OBPs) are an important medium for ATP-binding cassette transporter channel of intestinal HMOs transport; the influence of key OBPs of Bifidobacterium on HMOs recognition in infants from various countries has been explored, which is helpful to accelerate the establishment of precise and personalized milk powder in the future. The more important significance of the results of this review is to help consumers better choose HMOs, thereby promoting the long-term health of infants, especially the early development of their immune system.