The impact of human milk oligosaccharides on infant gastrointestinal microbiota and immune function

Breastmilk provides valuable nutrients and immune protection for preventing several childhood mortality and chronic disorders throughout the life course. Human Milk Oligosaccharides (HMOs), as a bioactive constituent in breastmilk, foster a healthy microbiota for infants due to their prebiotic effects. The complex interplay between HMOs and beneficial bacteria, both directly and indirectly, promotes the growth of infants' gastrointestinal immune systems. Additionally, HMOs provide stereospecific protection against various pathogens by avoiding pathogenic adherence to epithelial cells. This protection is effective against bacteria, viruses, and parasites. This review fills in the gap in knowledge by investigating the relationship between HMOs, infant gastrointestinal microbiota, and infant immune function. This contributes to the development of infant formula feeding and HMOs-related drugs. Future studies could further investigate the diverse infant gut microbial system and the specific mechanisms of HMOs functional groups in immunomodulation. More human-based randomized controlled trials are needed.