PROJECT SUMMARY/ABSTRACT – COHORT ADMINISTRATION & BIOREPOSITORY CORE A large body of data suggests that living on farms is associated with a decreased risk of asthma and atopic diseases, including studies from Europe and the North America. The individual factors that appear to be associated with this “farm-life effect” include consumption of unpasteurized farm milk and exposure to farm animals and stables. Farm children have higher numbers of regulatory T cells, compared to urban children, and their innate immune system also appears to be the target for these exposures. House dust in farm homes has greater microbial diversity that is strongly negatively associated with the incidence of asthma. The studies thus far have focused on outcomes of asthma at school-age. However, atopic dermatitis and food allergy commonly precede development of respiratory allergies in a so-called “atopic march”. Our studies in the Old Order Mennonite Community have indicated that they are at low risk for atopic diseases and the infant gut microbiome composition is different from Rochester infants. The Cohort Admin and Biorepository Core will form the sample and data infrastructure for the distinct but complementary Projects 1-3 of this U19 Program, “Biomarkers of Atopy Beginning Early” (BABE). The Core will follow up and expand an ongoing longitudinal birth cohort study of OOM neonates at a very low risk for atopic dermatitis, food allergies, hayfever and asthma and Rochester neonates from atopic families with a high risk for developing these atopic manifestations. We will test the overall hypothesis that infant gut microbiome associated metabolic pathways and innate stimulation promote tolerance and barrier function in the OOM. The specific aims of the Core are to Aim 1) sample and clinically follow up already recruited Cohort 1 infants until 6 years of age for additional allergic diseases, Aim 2) recruit, sample and clinically follow up a similar cohort 2 of 120 infants for the development of atopic dermatitis and food allergy until 24mo of age, and Aim 3) prepare, store and share samples utilized in the Projects 1-3 (cord and infant peripheral blood, stool, skin swabs and tape strips) to assess farming lifestyle effect on children's gut microbiome, innate and adaptive immune composition, and skin barrier function and microbiome composition. These studies aim for novel strategies for primary and secondary prevention of early childhood allergic diseases.