Microbial diversity in homes and the risk of allergic rhinitis and inhalant atopy in two European birth cohorts

Microbial exposures in early childhood direct the development of immune system and their diversity may influence risk allergy development. We aimed to determine whether indoor microbial at early-life is associated with allergic rhinitis inhalant atopy. The study population included children within two birth cohorts: Finnish rural-suburban LUKAS (N = 312), German urban LISA from Munich Leipzig centers 248). microbiota (Chao1 richness Shannon entropy) was characterized floor dust samples collected child age 2–3 months by Illumina MiSeq sequencing bacterial fungal DNA amplicons. Allergic atopy were determined 10 years analyzed using logistic regression models. High (aOR 0.19, 95%CI 0.09–0.42 for middle aOR 0.12, 0.05–0.29 highest vs. lowest tertile) entropy lower LISA, similar trend seen LUKAS. observed some significant associations between measured atopy, but inconsistent cohorts. tended be increased rural areas, more areas. Fungal only LISA. Our suggests that a higher reduce later childhood. environment-dependent heterogeneity – visible here as results differing cohorts - specific constituents relevant.