The gut microbiota (GM) is the total microbial mass that colonizes the digestive tract of a host. It is composed of trillions of bacteria, viruses, archaea, and fungi that are distributed throughout the digestive tract with different abundances. 1,2 Our knowledge of the GM has dramatically increased over the last few decades principally because of the development of new genetic tools. 3 Solid organ transplantation (SOT) can only be considered medically when accompanied by the long-term use of immunosuppressive treatments (IST) to avoid graft rejection. However, ISTs are