The purpose of the Cohort Administration and Biospecimen Core (Core C) is to provide coordination of efforts and staff to facilitate the recruitment, enrollment, retention and sampling of participants in the new cohort; to process, track and store participant biospecimens; and, to deliver stool and swab samples to Dr. Lynch's laboratory at UCSF (Core D) for microbiome analyses, plasma samples to Dr. Ownby's laboratory at Georgia University (Core E) for IgE analysis and stool and breastmilk samples to the Mass Spectrometry Core at Michigan State University (MSU) for lipid analysis for this renewal project `Microbiota and Allergic Asthma Precision Prevention' (MAAP2). This Core facility currently acts as the central processing laboratory and clearinghouse for all biological and environmental samples obtained from study participants in the initial P01, the `Microbes, Allergy, Asthma & Pets' (MAAP) study. This Core facility also serves as a repository for long-term storage of specimens (plasma, breast milk, stool, urine, DNA, RNA, dust) for use in ongoing and future studies. This laboratory has substantial experience performing all the tasks that are proposed for this Core in the present proposal. The Cohort Administration and Biospecimen core is essential to the overall goals of this PPG application as it represents the management and monitoring arm for the new birth cohort, whose samples will inform all four projects. Core C will be responsible for programming and coordinating technical aspects of recruitment and retention that provide Project Coordination staff with direction in these efforts. Core C will direct the programmatic aspects of participant recruitment and retention that Project 1 and Project 2 will implement. In addition, all projects will rely on Core C to process, track, store and ship the stool, swab, breastmilk and plasma samples. By centralizing cohort management activities, the Cohort Administration and Biospecimen Core will provide efficiency, consistency, and reliability. The centralization of biospecimen handling will provide skilled laboratory staff experienced in the sample processing protocols, eliminating duplication of effort. Core C will retain the programming staff needed for monitoring recruitment and retention, and for biospecimen identification, storage, and distribution. The Core is under the leadership of Kim Woodcroft, PhD, who has 15 years of experience in directing the Molecular Epidemiology Research Laboratory at HFHS. Christine Joseph, PhD, will also provide leadership in the recruitment and retention monitoring aspects of the Core. Dr. Joseph has over a decade of experience in observational studies and clinical trials, and in recruitment and retention of research participants.