Julia W. Neilson1, Katy Califf2, Cesar Cardona3, Audrey Copeland4, Will Van Treuren5, Karen L Josephson4, Rob Knight6, Jack A Gilbert7, Jay Quade8, J. Gregory Caporaso9 and Raina M. Maier10, (1)Department of Environmental Science, University of Arizona, Tucson, AZ, (2)Center for Microbial Genetics and Genomics, Northern Arizona University, Flagstaff, AZ, (3)Graduate Program in Biophysical Sciences, University of Chicago, Chicago, IL, (4)Soil Water and Environmental Science, University of Arizona, Tucson, AZ, (5)Department of Microbiology and Immunology, Standford University, Stanford, CA, (6)Departments of Pediatrics and Computer Science & Engineering and Center for Microbiome Innovation, University of California, San Diego, La Jolla, CA, (7)Department of Surgery, University of Chicago, Chicago, IL, (8)Geosciences, University of Arizona, Tucson, AZ, (9)Pathogen and Microbiome Institute, Northern Arizona University, Flagstaff, AZ, (10)Environmental Science, University of Arizona, Tucson, AZ