A child's diet is very important for the development of milk teeth, as well as permanent teeth, which starts as early as in intrauterine life, and also for their mineralisation which continues after birth. A diet is assumed as satisfying the child's needs for nutrients (proteins, carbohydrates and fats), but also for vitamines and minerals which are needed for a tnormal growth and development. In order to ensure that, breastfeeding is the only recommended diet in the first six months, which continues until the second year accompanied by intoducing food into a diet. Mother's milk is, apart from necessary nutrients and minerals, a good source of immunoglobulins and antibodies which are crucial in the protection from infections. It is also proved that it contains bacteria which belong to the group of probiotics, as well as indigestible carbohydrates which serve them as food, that is prebiotics. Probiotics are live microorganisms which in sufficient amounts have a positive effect on the health of the host. Their activity/function is based on modifying the bacterial composition of the oral cavity because they prevent the settlement of bacteria which cause the emergence of cavities and parodontal disease. They also cause better absorption of calcium and better mineralization of bones and hard dental tissues.