Scientists have found that lack of exposure to bacteria and germs in childhood is one of the main reasons for the sharp increase in diabetes cases among people under the age of five in recent years. Children living in rural areas are less likely to suffer from diseases such as allergies, asthma and eczema because they are exposed to bacteria earlier and have more opportunities to spend time with pets. 
Most of the bacteria on human skin play a protective role and create a unique body odor for everyone
 an environment that destroys bacteria too thoroughly may do harm to children's health.