Scientists believe that the composition of milk and changes during the lactation, are associated with the immune system of the newborn and the developing intestinal microbiome — a population of microorganisms inside the gastrointestinal tract.

Sugar in milk is not meant for the newborn. Because the body newly born children sterile from bacteria, carbohydrates are designed for the cultivation in them of intestinal microorganisms.

In addition, milk is rich in antibodies, and molecules that inhibit the growth of pathogens, and activate white blood cells in the blood of the newborn. A month later, when the child begins to form acquired immunity, the composition of breast milk changes, and maternal antibody level falls by more than 90 percent. Also reduced variety of sugars, however, increases the amount of fat and other nutrients that support the growth of the child.

Despite the many useful features of milk, the children can grow up healthy and without breastfeeding. However, breast milk can reduce infant mortality and greatly reduces the risk of intestinal and respiratory infections.

According to scientists, although breast milk that is the product of millions of years of evolution, has the optimal composition for the newborn, it remains unknown what should be the necessary power. While it must be up to the mother.