Specificity of the Intestinal Lactoferrin Receptor

Abstract

In spite of a low iron content in human milk, breast-fed infants maintain adequate iron status significantly longer than formula-fed infants consuming similar amounts of iron [21, 22]. This indicates a high bioavailability of human milk iron. As the major iron-binding protein in human milk, lactoferrin has been postulated to be involved in the process of iron absorption in the suckling infant. An intestinal lactoferrin receptor was first described by Cox et al. following studies demonstrating delivery of iron from human lactoferrin (but not from transferrin), to human mucosal tissue [8]. Fransson et al. [14] found significantly faster uptake of radioiron into red blood cells of suckling piglets from a formula supplemented with bovine lactoferrin as compared with ferrous sulfate. Subsequent work has identified lactoferrin receptors in rabbit and mouse intestine [15, 20].