Daniel E. Freedberg, MD, MS

I am a clinical and translational investigator focused on enteric infections and the gastrointestinal microbiome in the setting of critical illness. I have experience in molecular laboratory research, clinical training as a physician, a dual appointment in Medicine and Epidemiology, and am the recipient of several grants supporting ICU-based human subjects research focused around enteric colonization in the ICU. With funding from the NIH, the American Gastroenterological Association (AGA), and the Department of Defense, I have built large ICU patient cohorts containing longitudinal clinical data, serial rectal swabs, whole stools, and other bio-samples. These data have allowed us to interrogate the dynamic changes that take place within the gastrointestinal microbiome during critical illness and to ask how these changes may impact risk for ICU-acquired infections. Our preliminary studies show that colonizing enteric organisms such as vancomycin-resistant Enterococcus (VRE) are important determinants of patients’ subsequent risk for infection. We have also found that colonizing enteric organisms can change health outcomes for patients who share the same hospital environment, even if these neighboring patients are not themselves colonized. The normal native microbiota resists colonization with VRE, C. difficile, and similar multidrug-resistant or antibiotic-associated organisms, and a major focus of our current work is how to augment enteric colonization resistance in the face of ICU antibiotics.