AIM:To explore the efficacy and safe-ty of fecal microbiota transplantation combined with immune checkpoint inhibitors(ICIs)for malig-nant tumor patients with failed multi line anti-tu-mor treatment and concomitant cachexia,and to explore the changes in blood immunity and intesti-nal microbial environment in patients.METHODS:Five patients with malignant tumors who failed multi line anti-tumor treatment were enrolled and treated with ICIs combined with fecal microbiota transplantation.The efficacy was evaluated every 2-3 cycles,and adverse reactions were observed.Fe-cal 16srRNA gene sequencing and serum immuno-logical indicators were dynamically detected.RE-SULTS:Except for one patient who died 2.5 months after transplantation due to excessive tumor bur-den at enrollment,the overall survival of the re-maining four patients were extended(7.4,8.3,28.5,52.3 months).One patient with multiple intra-cranial metastases of lung adenocarcinoma signifi-cantly reduced the intracranial metastasis after in-testinal microbiota transplantation and almost dis-appeared.The serum IL-2,IL-10,TGF-β and other indicators of patients increased rapidly and then slowly decreased with the increase of transplanta-tion time,and finally were higher than before trans-plantation,with statistical differences.16srRNA gene sequencing analysis revealed significant differ-ences in the overall distribution of gut microbiota in patients after transplantation,gradually ap-proaching healthy transplant donors.All patients did not experience grade 2 or above adverse reac-tions,and the safety was good.CONCLUSION:For patients with malignant tumors,the combination of fecal microbiota transplantation and immuno-therapy may improve their quality of life,serum im-mune environment,and intestinal microbiota com-position,have a positive impact on survival progno-sis,and are safe and controllable,opening up new treatment methods for end-stage patients.

AIM:To explore the efficacy and safe-ty of fecal microbiota transplantation combined with immune checkpoint inhibitors(ICIs)for malig-nant tumor patients with failed multi line anti-tu-mor treatment and concomitant cachexia,and to explore the changes in blood immunity and intesti-nal microbial environment in patients.METHODS:Five patients with malignant tumors who failed multi line anti-tumor treatment were enrolled and treated with ICIs combined with fecal microbiota transplantation.The efficacy was evaluated every 2-3 cycles,and adverse reactions were observed.Fe-cal 16srRNA gene sequencing and serum immuno-logical indicators were dynamically detected.RE-SULTS:Except for one patient who died 2.5 months after transplantation due to excessive tumor bur-den at enrollment,the overall survival of the re-maining four patients were extended(7.4,8.3,28.5,52.3 months).One patient with multiple intra-cranial metastases of lung adenocarcinoma signifi-cantly reduced the intracranial metastasis after in-testinal microbiota transplantation and almost dis-appeared.The serum IL-2,IL-10,TGF-β and other indicators of patients increased rapidly and then slowly decreased with the increase of transplanta-tion time,and finally were higher than before trans-plantation,with statistical differences.16srRNA gene sequencing analysis revealed significant differ-ences in the overall distribution of gut microbiota in patients after transplantation,gradually ap-proaching healthy transplant donors.All patients did not experience grade 2 or above adverse reac-tions,and the safety was good.CONCLUSION:For patients with malignant tumors,the combination of fecal microbiota transplantation and immuno-therapy may improve their quality of life,serum im-mune environment,and intestinal microbiota com-position,have a positive impact on survival progno-sis,and are safe and controllable,opening up new treatment methods for end-stage patients.