The reasons for the steep rise in the prevalence of atopic diseases such as asthma, atopic eczema and allergic rhinitis are unexplained. Studies have shown that immune regulation in the intestinal mucosa-associated lymphoid tissue (MALT) plays an important role in atopic sensitization and is influenced by the intestinal microflora. The hypothesis presented here is based on the following assumptions: 1. Mothers transfer some of their intestinal microflora to their children at birth and by close contact. 2. The intestinal microflora has the properties of an ecosystem that may react unexpectedly to changing conditions. 3. Modern lifestyle and diets negatively influence the intestinal ecosystem during the lifespan. Thus, from one generation to the next, there may be cumulative degradation of the intestinal microflora. Children inherit a non-physiological gut flora that is further degraded in later life and contributes to atopic sensitization in the following generation. Linear changes in environmental conditions and lifestyle may lead to non-linear changes in the gut flora and, possibly, to an increasing susceptibility to atopic diseases. Clinical studies using probiotics and dietary intervention should be the focus of future research.

Keywords: Child, Environmental Exposure, Epidemiologic Methods, Hypersensitivity - epidemiology, Hypersensitivity - immunology, Hypersensitivity - microbiology, Intestines - immunology, Intestines - microbiology, Risk Factors, Child, Environmental Exposure, Epidemiologic Methods, Hypersensitivity - microbiology, Intestines - microbiology, Risk Factors