This project takes advantage of challenge studies with an important human pathogen, Vibrio cholera, the etiological agent of cholera, which causes severe diarrhea in developed countries. The goal of this study is to understand the dynamic interactions between the host, pathogen and microbiota and how these interactions play a role in determining the pathogen population in the host, the development of an immune response, and the diversity and ecology of the microbiota. The project uses a combination of genomic, transcriptomic and metagenomic technologies together with human challenge studies to generate new insights into the interaction of host, pathogen, and microbiota.