Jessica L. Metcalf

Jessica Metcalf


  • CIFAR Azrieli Global Scholar 2018
  • Humans & the Microbiome


  • Colorado State University
Department of Animal Sciences, CSU Microbiome Initiative


  • United States


PhD (Ecology and Evolutionary Biology), University of Colorado
BS (Chemistry, Biology Minor), University of Georgia


Jessica Metcalf brings together the fields of evolutionary biology, ancient DNA, and microbiome science to study the interactions between microbes and animals during life and after death.

As humans transitioned from hunter-gatherer to agrarian to industrialized societies, their long-standing microbial partnerships also changed. For example, people living in industrialized societies today lack microbes that were once ubiquitous in the guts of humans across different cultures, geographies, and millennia. Metcalf’s research has contributed to reconstructing the pre-industrial human gut microbiome by using coprolites (ancient poop) to identify microbes that lived in the guts of some of our ancestors. Additionally, Metcalf is interested in the connection between humans and livestock, which dates back thousands of years. She is interested in how human-livestock interactions affect the development of the human microbiome in infants, and how the lack of contact with livestock may contribute to missing microbes in industrialized cultures. In her current research, Metcalf focuses on an understudied group, foreign-born farm worker populations living in the United States today. She aims to understand how this population’s gut microbiomes relate to the likelihood of illnesses, and how they compare to other human populations around the world.

Metcalf is also developing microbiome tools for forensic science. While working on ancient material during her postdoc, Metcalf became interested in the microbes driving decomposition. She has developed a “microbial clock” that uses the succession of microbes that invade the human body after death as a novel forensic tool for predicting how long a person has been dead.     


AAAS/Science Program for Excellence in Science
National Science Foundation Graduate Fellowship
Barry Goldwater Scholarship for Math, Science, and Engineering

Relevant Publications

Metcalf, J.L. et al. "Evaluating the impact of domestication and captivity on the horse gut microbiome." Scientific Reports. 7 (2017): 1-9.

Metcalf, J.L. et al. "Microbial community assembly and metabolic function during mammalian corpse decomposition." Science (2016).

Metcalf, J.L. et al. 2016. "Synergistic roles of climate warming and human occupation in Patagonian megafaunal extinctions." Science Advances 2, 6 (2016).

Obregon-Tito, A.J. et al. "Subsistence strategies in traditional societies distinguish gut microbiomes." Nature Communications 6, 6505 (2015).

Clemente, J.C. et al. "The microbiome of uncontacted Amerindians." Science Advances 1, 3 (2015).