Based upon recent studies, it appears more and more evident that exclusive breast-feeding can be said as the best functional food, the last being defined as: "a food that has components or ingredients bringing a specific medical or physiological benefit to the host, other than purely nutritional effects". In particular, human breast milk does favour optimal bacterial intestinal colonization with bifidobacteria and lactic acid bacteria in the neonates and contains a large number of components with antimicrobial activity.