The gut microbiome: a clinically significant player in transplantation?

The intestinal microbiome is critical to digestion, metabolism and protection from pathogenic organisms. Dysbiosis, or alteration of this microbiome, can result in Clostridium difficile infection and may play a role in other conditions. Patients undergoing solid organ transplantation (e.g., kidney, lung, liver, small bowel) and hematopoietic stem cell transplantation have a shift in the gut microbiome with a decrease in predominant organisms, a loss of bacterial diversity and emergence of a new dominant population. This translates into increased morbidity and mortality with risk of infection and rejection. We discuss the changes seen in the microbiome and its possible consequences. It may be important to develop strategies to restore the normal microbiome in such patients.