Microbial exposure and onset of allergic diseases - potential prevention strategies?

Chronic inflammatory diseases are a major health problem with global dimension. Particularly, the incidence of allergic diseases has been increased tremendously within the last decades. This world-wide trend clearly indicates the demand for new approaches in the investigation of early allergy development. Recent studies underlined the basic postulate of the hygiene hypothesis that early exposure to microbial stimuli plays a crucial role in the prevention of chronic inflammatory conditions in adulthood. There is ample evidence that, both, exogenous microbes and endogenous microbial communities, the human microbiota, shape the developing immune system and might be involved in prevention of pathologic pro-inflammatory trails. According to the Barker hypothesis, epidemiological studies pointed to transmaternal transmission from the mother to the offspring already in prenatal life. Experimental data from murine models support these findings. This state of the art review provides an overview on the current literature and presents new experimental concepts that point out to future application in the prevention of allergic diseases.