Skin microbes and development of allergic disease

Project Summary/Abstract Bacteria that colonize the skin of adults with allergic diseases such as Atopic Dermatitis (AD) are different than those on healthy skin and influence severity of disease, but the function of the microbiome in early life is less well known. New data from a test cohort of children with AD has discovered that several strains of Streptococcus produce high protease activity, are more abundant on children with AD, and can induce skin barrier breakdown and Th2 inflammation on mice. Skin barrier defects associate with both AD and food allergy (FA). We therefore hypothesize that colonization by strains of Streptococci that can damage the skin barrier will increase the risk of development of allergic diseases such as AD and FA. To test this hypothesis, we propose to test skin swabs obtained from the SUNBEAM early life study. This study is collecting multiple swabs and other data from approximately 2000 children at birth until age 3. Analysis of bacterial protease activity, cytotoxic activity and antimicrobial activity will be conducted on approximately 6000 swabs to identify the genes in specific bacterial strains that are responsible for damaging and protective functions. Metagenomic and Metabolomic analysis will further clarify the composition and actions of the microbiome on the skin of participants in this study, thus providing essential information to enable better understanding of how the microbiome influences the onset of AD or FA. This information will further clarify how the functions of bacteria on the skin can impact the immune system.