The intestinal microbiome and the liver transplant recipient: What we know and what we need to know

The intestinal microbiome and immune system are in close symbiotic relationship in health. Gutmicrobiota plays a role in many chronic liver diseases and cirrhosis. However, alterations in the gut microbiome after liver transplantation and the implications for liver transplant recipients are not well understood and relymainly on experimental animal studies. Recent advances inmolecular techniques have identified that increased intestinal permeability, decreased beneficial bacteria, and increased pathogenic species may play important roles in the early posttransplant period. The associations between microbiota perturbation and postliver transplant infections and acute rejection are evolving. The link with metabolic syndrome, obesity, and cardiac disease in the general population require translation into the transplant recipient. This review focuses on our current knowledge of the known and potential interaction of the microbiome in the liver transplant recipient. Future human studies focused on microbiota changes in liver transplant patients are warranted and expected.