We have investigated the possible role of bovine lactoferrin in protecting the intestinal epithelium from bacterial infections, using as an in vitro model enterocyte-like cell lines HT-39 and Caco-2 infected with a food-borne pathogen, Listeria monocytogenes . When infection occurred in the presence of 1 mg/ml of bovine lactoferrin, in the form of apolactoferrin or iron- or manganese-saturated forms, the adhesion of bacteria to eukaryotk cells was unaffected, but the number of internalized bacteria was reduced by 42- to 125-fold. The possibility of a toxic effect of lactoferrin was excluded, because bovine lactoferrin was used at nonbactericidal and noncytotoxic concentrations
