Abstract: The newborn is in a susceptible immune state after birth, the adaptive immune system is immature and it relies on the innate immune system for protection. The intestinal barrier is an important component of innate immunity and consists mainly of the mucosal layer, the intestinal epithelial cell layer and the lamina propria. Human milk is the perfect source of nutrition for infants. It is rich in bioactive factors, which is crucial for the establishment and maturation of neonatal intestinal barrier function. This article reviews the roles of oligosaccharides, phospholipids, long-chain polyunsaturated fatty acids, active proteins and miRNAs in breast milk in protecting intestinal barrier function.

Key words: human milk components, immunity, gastrointestinal barrier