Allergic disturbances are gradually increasing in children and elderly. A lot of people become allergic to pollens later on at adult age. Allergic disturbances and asthma are common in childhood. The common reasons are genetic predisposition and impaired immune system response to environmental antigens, while in recent years studies have been showing that functioning of the skin and gastrointestinal system as a barrier is also important in allergy cases. When we look at the prevalence in different societies, we see that in industrialized countries the rates are higher. Particularly, with improved hygienic conditions, shrinkage of family structure, consumption of sterile foods and improvement of health services, beginning from childhood we are exposed to fewer germs, which cause us to react abnormally to pathogens. This is called “hygiene theory”.
In an article published by Kei and colleagues in 2016 in Natural Magazine, the intestinal flora of allergic children with atopic diseases were examined and they found a flora rich of Clostridium and poor of Bifidobacterium. In this case, the question was, if we change this bacterial flora, can we get rid of allergic diseases? Yamazaki and his friends published in Allergology International Magazine in 2017 a study in which allergic children were given nutrients containing Lactobacillus rhamnosus GG (LGG) and Bifidobacterium lactis (Bb-12); allergy symptoms got more easily under control. When LGG was given to pregnant women and newborns, atopic dermatitis rate was decreased by 50%. These probiotics strengthen the intestinal mucosal barrier and reduce intestinal permeability and do not let allergic substances pass through, in addition, they increase mucosal immunity by aumenting secretory IgA production.