Abstract: Osteopontin (OPN) is a highly phosphorylated acidic protein with O-glycosylation modification and has attracted much attention in recent years. According to the distribution of OPN in the body, it can be divided into secreted OPN and intracellular OPN. It can be synthesized or secreted by a variety of tissues and cells in the body, and widely exists in bone, kidney, brain, muscle and other tissues and cells. Recent studies have found that secretory OPN is high in breast milk, especially in colostrum, and that secretory OPN plays an important role in intestinal growth, immune regulation and nervous system development in early life. This article reviews the research progress in the effects of OPN in milk on early life growth and health.

Key words: osteopontin; intestinal development; immunity; infants and young children