**12. Future perspectives**

ITx and its secrets have not been deciphered yet. The main issue remains the challenging balance between appropriate immunosuppression and over-immunosuppression. Therefore, ITx teams have been trying to develop markers that will provide adequate warning in case of rejection [45].

Multivisceral organ transplantation may solidify its role in the treatment of slow-growing abdominal cancers that are deemed "non-resectable" [81–83].

Another challenge will be to understand the physiology of the transplanted small bowel, such as its altered microflora and altered motility. New research has suggested that the flora composition within the graft may be a risk factor for acute rejection when more immunogenic species predominate [84].

Tolerance remains the 'Holy Grail' of transplantation and is characterized by increased allograft survival in the absence of immunosuppression and absent or reduced donor-specific response. Groups have used donor-specific blood transfusion in order to induce tolerance by upregulating graft protective memory Tregs [85]. Also, centers have introduced experimental models to induce microchimerism and tolerance by transplanting bone marrow along with the intestinal allograft [86]. These protocols could allow for sufficient immunosuppression with lower doses of immunosuppressants. This ongoing research may change the future of ITx.
