Inclusion Criteria:  1. GVHD within 100 days after allogeneic hematopoietic stem cell transplantation (allo HSCT);  2. Age 18 - 65 years old, regardless of gender;  3. Patients with grade 3 or 4 gastrointestinal involvement (aGVHD) according to the International Alliance (Magic) classification standard;  4. Patients with glucocorticoid resistant GI aGVHD are diagnosed. According to the expert consensus of Chinese allogeneic hematopoietic stem cell transplantation for the treatment of hematological diseases (III) - acute graft-versus-host disease (2020 Edition), the definition of glucocorticoid resistant acute GVHD is Thomas' hematopoietic cell transplantation: stem cell transplantation (5th Edition) Glucocorticoid resistance was defined as PD at 3 days, NR at 7 days or Cr not reached at 14 days after first-line treatment.  5. ECoG 3 points or less;  6. Stop prophylactic antibiotics at least 12 hours before FMT treatment;  7. Be able and willing to sign informed consent;  8. Patients who are capable of swallowing capsules and can complete the study;  Exclusion Criteria:  1. There are active but uncontrolled infections, except GVHD complicated with infectious diarrhea;  2. Gastrointestinal perforation, active gastrointestinal bleeding, small intestinal obstruction, toxic megacolon or other serious gastrointestinal diseases not caused by GVHD;  3. Have a history of severe allergic reaction; Or known to be allergic to any ingredient of intestinal bacteria capsule xbi-302;  4. Any serious disease that can increase the risk of patients participating in the study;  5. Female subjects with positive pregnancy test and lactation, or female subjects of childbearing age who refuse to take contraceptive measures during the study;  6. According to the judgment of the researcher, the patients with high dynamic diarrhea can not stay in the intestine for enough time to dissolve the capsule.  7. HIV, HBV, HCV and syphilis are positive;  8. After colectomy;  9. Participate in other intervention clinical studies within 4 weeks before the screening period;  10. The expected survival time is less than 12 weeks;  11. The basic body function test is inferior to the following standards: total neutrophils (neu) < 0.5 (x109 / L), platelet count (PLT) < 30 (x109 / L), serum creatinine (CR) > 1.5 times the maximum normal value (ULN), albumin (ALB) < 25g / L;  12. There is any situation that the researcher thinks is not suitable for inclusion (any history of medical history, treatment history or abnormal test data that may confuse the results of this study, interfere with the subject's whole participation in the study, or harm the interests of the subject).