Lactoferrin is a multifunctional glycoprotein abundantly present in milk, especially in colostrum, and plays a crucial role in the innate immune defense of breastfed infants. It exerts potent bacteriostatic and bactericidal effects in the intestinal tract by binding free iron, depriving pathogenic bacteria of this essential nutrient and thereby inhibiting their growth. Working synergistically with secretory IgA, lactoferrin helps protect the newborn’s gut from infections and supports the development of a healthy microbiome. In addition to its antimicrobial activity, lactoferrin acts as an iron-binding protein that facilitates the efficient absorption of dietary iron, contributing to the high bioavailability of iron in breast milk and reducing the risk of iron deficiency in infants.