Purpose of review: Numerous studies have attempted to describe specific microbiota deviations that may precede atopic sensitization and atopic disease in childhood. This has given rise to a hypothesis suggesting that a reduced intestinal microbial diversity in infancy increases the risk of allergic manifestations. This review intends to sum up the main findings and discuss relevant exposures that regulate intestinal microbial diversity.
Recent findings: Taken together the three studies in this review lend support to the diversity hypothesis, but reported differences related to atopic sensitization and clinical expression are discussed. A summary on analytic methods and functional aspect of the microbiota in allergic disease is presented to ameliorate a presentation of recent articles on environmental and host-factors regulating microbiota composition and diversity.
Summary: The current evidence indicates that intestinal microbiota diversity can be associated with allergic diseases, but the exact mechanisms and interactions contributing to this effect are far from understood and need further investigation.