However, the immune system of children under the age of five is tuned to the widest possible range of "encounters" with the environment and to actively recognize aggressive microorganisms. Deprived of "work", the defense system can crash while trying to find an "enemy" among "friends", which leads to the development of allergic reactions. The absence of aggressive microflora encounters and the excessive presence of antiseptics prevent the child from developing immunity to potentially dangerous microorganisms. Therefore, the risk arises of the child not being exposed to microflora common in kindergartens, schools, homes of relatives and friends. Of course, this does not mean that a newborn baby needs to be bathed in a roadside puddle—it is important to observe the "golden mean". The guidelines for caring for babies have been created over the centuries in accordance with certain climatic and cultural conditions and have been passed down from generation to generation. Follow the rules of hygiene, wash your hands after using the toilet, do not let strangers kiss your baby, monitor the quality of their food, do not abuse medications, and your child will most likely live happy and healthy!