Each of us harbors an enormous microbial community. In the gut, these microbes form a metabolic organ whose cells outnumber our own by 10-fold, whose genes outnumber those in the human genome by 100-fold, and whose composition can be transformed overnight. It is becoming increasingly clear that variation in these communities has important consequences for health.
The central hypothesis that guides our research is that resident human-associated microbes play critical roles in our response to nutrients, toxins, and pathogens. We use genomics and biochemistry to study the process of selection and competition that shapes these communities.