About the Authors

Chana Palmer

Affiliation Department of Genetics, Stanford University School of Medicine, Stanford, California, United States of America

Elisabeth M Bik

Affiliation Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, California, United States of America

Daniel B DiGiulio

Affiliations Department of Medicine, Stanford University School of Medicine, Stanford, California, United States of America , Veterans Affairs Palo Alto Health Care System, Palo Alto, California, United States of America

David A Relman

Affiliations Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, California, United States of America , Department of Medicine, Stanford University School of Medicine, Stanford, California, United States of America , Veterans Affairs Palo Alto Health Care System, Palo Alto, California, United States of America

Patrick O Brown

To whom correspondence should be addressed. E-mail: pbrown@pmgm.stanford.edu

Affiliations Department of Biochemistry, Stanford University School of Medicine, Stanford, California, United States of America , Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, California, United States of America

Competing Interests

POB is an investigator of the Howard Hughes Medical Institute.

Author Contributions

CP, EMB, DBD, DAR, and POB conceived and designed the experiments and analyzed the data. CP, EMB, and DBD performed the experiments. CP, EMB, DBD, and POB wrote the paper.