Ruth Ley
Associate Professor
Ruth Ley




Department of Molecular Biology & Genetics and
Department of Microbiology
Cornell University
465 Biotechnology Building
Ithaca, NY  14853


Web Sites

Department Profile (Molecular Biology & Genetics)
Department Profile (Microbiology)

Lab Website


Ruth Ley received a BA in Integrative Biology from the University of California at Berkeley in 1992. After a 3-year stint as an assistant researcher in the forest ecosystems of Hawai’i, Ley pursued a Ph.D. investigating the microbial ecology of extreme high altitude soils at the University of Colorado, Boulder. After completing her Ph.D. in 2001, Ley received a NRC-NASA Fellowship to study the microbial diversity of hypersaline microbial mats of Baja, Mexico with Dr. Norman Pace at CU Boulder. She then moved to Washington University School of Medicine to work with Dr. Jeffrey Gordon on the microbiome within the contexts of human obesity and mammalian evolution. She was named an Instructor in 2005 and a Research Assistant Professor at Washington University School of Medicine in 2007. In July 2008, Ley joined the Department of Microbiology at Cornell University as an Assistant Professor, and in 2013 became an Associate Professor with tenure in the Department of Molecular Biology and Genetics at Cornell. Ley’s awards include a Fellowship in Science and Engineering from the David and Lucile Packard Foundation, a fellowship from The Hartwell Foundation, and a Beckman Young Investigator Award from the Arnold and Mabel Beckman Foundation. She was a recipient of the NIH Director’s New Innovator Award in 2010, and the 2014 ISME Young Investigator Award.

Research Description

Our research has two broad goals. The first is to better understand the relationships between host genetic variation and variation in the microbiome. We aim to identify relationships between host genetics and aspects of the host microbiome that can point to novel mechanisms underlying host control of the microbiome. To answer this question we work in human and maize genetics. The second goal is to better understand how interactions between host immunity and microbiota in the mammalian gut result in inflammation, and how adaptive immunity can be utilized to reshape pathogenic microbiomes. We study microbiota-immune interactions using mouse models and gnotobiotics.


J. K. Goodrich, J. L. Waters, A. C. Poole, J. L. Sutter, O. Koren, R. Blekhman, M. Beaumont, W. Van Treuren, R. Knight, J. T. Bell, T. D. Spector, A. G. Clark and R. E. Ley. Human genetics shape the gut microbiome. Cell 159: 789-799. (2014)

Cullender, T. C., B. Chassaing, A. Janzon, K. Kumar, C. Muller, J. J. Werner, L. T. Angenent, M. E. Bell, A. G. Hay, D. A. Peterson, J. Walter, M. Vijay-Kumar, A. T. Gewirtz and R. E. Ley. Innate and adaptive immunity interact to quench microbiome flagellar motility in the gut. Cell Host Microbe 14: 571-581. (2013)

DiRienzi, S. C., I. Sharon, K. C. Wrighton, O. Koren, L. A. Hug, B. C. Thomas, J. K. Goodrich, J. T. Bell, T. D. Spector, J. F. Banfielda and R. E. Ley.  The human gut and groundwater harbor non-photosynthetic bacteria belonging to a new candidate phylum sibling to Cyanobacteria. eLife 2:e01102 (2013)

Koren, O., J. K. Goodrich, T. C. Cullender, A. Spor, K. Laitinen, H. Backhed, A. Gonzalez, J. J. Werner, L. T. Angenent, R. Knight, F. Backhed, E. Isolauri, S. Salminen and R. E. Ley. Remodeling of the gut microbiome and metabolic changes during pregnancy. Cell 150: 1-11 (2012).

Koenig, J. E., A. Spor, N. Scalfone , A. D. Fricker, J. Stombaugh, R. Knight, L. T. Angenent and R. E. Ley. 2011. Succession of microbial consortia in the developing infant gut microbiome. Proceedings of the National Academy of Sciences USA 108 Suppl1: 4578-4585. (2011)

Walter. J. and R. E. Ley. The human gut microbiome: ecology and recent evolutionary changes.  Annual Reviews of Microbiology 65: 411- 429 (2011)

Spor, A, O. Koren, and R. Ley.  Unraveling the effects of environment and host genotype on the gut microbiome. Nature Reviews Microbiology 9:279-90. (2011)