My current research has several different foci. One is the use of probiotics in immunocompromised hosts to prevent microbial resistance or to reduce graft versus host disease as well as explorations on the microbiota of such patients. Two, I am involved in studies on the role of iron and hepcidin in infectious complications in liver transplantation as well as hospital infections. Three, the role of mannose binding lectin and outcome in immunocompromised hosts. Four, the role of Bacteroides fragilis toxin production on diarrheal illness.