Fecal Microbiota Transplant and Dietary Fiber Supplementation for the Treatment of Gut Graft Versus Host Disease

March 9, 2026 updated by: Fred Hutchinson Cancer Center

A Randomized, Controlled, Phase I Study of Fecal Microbiota Transplant and Dietary Fiber Supplementation in Graft Versus Host Disease

This phase I trial studies how well fecal microbiota transplant and dietary fiber supplementation work in treating patients with gut graft versus host disease. Fecal microbiota transplant entails inoculating donor stool into a recipient's gastrointestinal tract. Changing the gut microbiome by fecal microbiota transplant and fiber supplementation may help treat gut graft versus host disease.

Study Overview

Detailed Description

OUTLINE: Patients are randomized to 1 of 4 arms.

ARM I: Patients receive upper FMT capsules orally (PO) over 5 days or via post-pyloric or nasogastric (NG) feeding tube over 2 days.

ARM II: Patients undergo lower FMT via colonoscopy on day 0.

ARM III: Patients receive upper FMT capsules PO over 5 days or via post-pyloric or NG feeding tube over 2 days. Patients also receive fiber supplementation PO or via post-pyloric or NG feeding tube from the first day of FMT administration and up to 6 weeks post FMT.

ARM IV: Patients undergo lower FMT via colonoscopy on day 0. Patients also receive fiber supplementation PO or via post-pyloric or NG feeding tube from day 0 up to 6 weeks post FMT.

Patients also undergo tissue, stool, stool swabs, and blood sample collection throughout the study.

After completion of study treatment, patients are followed up for 365 days.

Study Type

Interventional

Enrollment (Estimated)

72

Phase

  • Phase 1

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Locations

    • Washington
      • Seattle, Washington, United States, 98109
        • Recruiting
        • Fred Hutch/University of Washington Cancer Consortium
        • Contact:
        • Principal Investigator:
          • David Fredricks

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • 18 years of age or older
  • History of allogeneic hematopoietic stem cell transplant in the past 365 days
  • Post-engraftment, defined by time period following three consecutive days of sustained neutrophil engraftment with an absolute neutrophil count of at least 500 cells/mm^3
  • Mild to severe acute GI GvHD, at least stage 1, as measured by one of the following:

    • Modified Glucksberg criteria for GI GvHD averaged over 3 consecutive days and without another explanation for diarrhea such as laxative use or infection. In patients who have already had GI biopsy, biopsy histology must be compatible with GVHD, although biopsy is not required
    • Biopsy evidence of GI GVHD in the upper or lower GI tract

Exclusion Criteria:

  • History of previous serious adverse events associated with FMT
  • History of bowel perforation in the last 90 days
  • History of gastrointestinal resection in the last 90 days
  • History of intestinal obstruction in the last 90 days
  • History of diverticulitis in the last 90 days
  • History of celiac disease confirmed by serologic testing or small bowel biopsy
  • History of severe dietary allergy as designated by World Allergy Organization Subcutaneous Immunotherapy Systemic Reaction Grading System grade 2 or more
  • Subjects who are cytomegalovirus (CMV) seronegative at the time of enrollment as indicated by clinical testing unless the fecal microbiota transplant (FMT) donor is CMV seronegative with negative plasma polymerase chain reaction (PCR) assays for CMV.
  • Known allergies to loperamide, sodium chloride, glycerol, theobroma oil, hide bovine gelatin, sodium lauryl sulfate, colorants FD&C, titanium dioxide, polyethylene glycol, sodium sulfate, sodium bicarbonate, sodium phosphate, benzalkonium chloride, disodium EDTA or potassium chloride.
  • Currently pregnant, planning to become pregnant or breastfeeding during the study period. Women of childbearing potential (those who are not post-menopausal or post-hysterectomy) must be negative for pregnancy per urine pregnancy test at enrollment
  • Individuals with the ability to conceive children who are not willing to abstain from sexual activity or use an effective form of birth control during the duration of the study
  • Unwilling or unable to participate in study procedures including oral intake of FMT, colonoscopy, fiber supplementation, collection of stool samples and completion study surveys
  • Cannot reasonably and safely participate in the study in the opinion of the investigators

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Arm II (Lower FMT)
Patients undergo lower FMT via colonoscopy on day 0. Patients also undergo tissue, stool, stool swabs, and blood sample collection throughout the study.
Ancillary studies
Undergo lower FMT via colonoscopy
Other Names:
  • Fecal Material Transplantation
  • Fecal Transplantation
  • FMT
  • Poo Transplant
  • Poop Transplant
  • Stool Transplant
Undergo lower FMT via colonoscopy
Undergo tissue, stool, stool swabs, and blood sample collection
Other Names:
  • Biological Sample Collection
Given upper FMT PO or via post-pyloric or NG feeding tube
Other Names:
  • Fecal Material Transplantation
  • Fecal Transplantation
  • FMT
  • Poo Transplant
  • Poop Transplant
  • Stool Transplant
Experimental: Arm I (upper FMT)
Patients receive upper FMT capsules PO over 5 days or via post-pyloric or NG feeding tube over 2 days. Patients also undergo tissue, stool, stool swabs, and blood sample collection throughout the study.
Ancillary studies
Undergo lower FMT via colonoscopy
Other Names:
  • Fecal Material Transplantation
  • Fecal Transplantation
  • FMT
  • Poo Transplant
  • Poop Transplant
  • Stool Transplant
Undergo tissue, stool, stool swabs, and blood sample collection
Other Names:
  • Biological Sample Collection
Given upper FMT PO or via post-pyloric or NG feeding tube
Other Names:
  • Fecal Material Transplantation
  • Fecal Transplantation
  • FMT
  • Poo Transplant
  • Poop Transplant
  • Stool Transplant
Experimental: Arm III (upper FMT, fiber supplementation)
Patients receive upper FMT capsules PO over 5 days or via post-pyloric or NG feeding tube over 2 days. Patients also receive fiber supplementation PO or via post-pyloric or NG feeding tube from the first day of FMT administration and up to 6 weeks post FMT. Patients also undergo tissue, stool, stool swabs, and blood sample collection throughout the study.
Ancillary studies
Undergo lower FMT via colonoscopy
Other Names:
  • Fecal Material Transplantation
  • Fecal Transplantation
  • FMT
  • Poo Transplant
  • Poop Transplant
  • Stool Transplant
Undergo tissue, stool, stool swabs, and blood sample collection
Other Names:
  • Biological Sample Collection
Given upper FMT PO or via post-pyloric or NG feeding tube
Other Names:
  • Fecal Material Transplantation
  • Fecal Transplantation
  • FMT
  • Poo Transplant
  • Poop Transplant
  • Stool Transplant
Given dietary fiber supplementation PO or via post-pyloric or NG feeding tube
Other Names:
  • Supplementation
Experimental: Arm IV (Lower FMT, fiber supplementation)
Patients undergo lower FMT via colonoscopy on day 0. Patients also receive fiber supplementation PO or via post-pyloric or NG feeding tube from day 0 up to 6 weeks post FMT. Patients also undergo tissue, stool, stool swabs, and blood sample collection throughout the study.
Ancillary studies
Undergo lower FMT via colonoscopy
Other Names:
  • Fecal Material Transplantation
  • Fecal Transplantation
  • FMT
  • Poo Transplant
  • Poop Transplant
  • Stool Transplant
Undergo lower FMT via colonoscopy
Undergo tissue, stool, stool swabs, and blood sample collection
Other Names:
  • Biological Sample Collection
Given upper FMT PO or via post-pyloric or NG feeding tube
Other Names:
  • Fecal Material Transplantation
  • Fecal Transplantation
  • FMT
  • Poo Transplant
  • Poop Transplant
  • Stool Transplant
Given dietary fiber supplementation PO or via post-pyloric or NG feeding tube
Other Names:
  • Supplementation

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Bacterial composition of stool
Time Frame: At baseline
Analyses will consist of summary statistics of the bacterial diversity in the microbiome (e.g., the alpha diversity, the abundance of bacterial species associated with protection from graft versus host disease [GvHD]).
At baseline
Incidence of adverse events
Time Frame: Up to 3 years
Will by assessed by computing the total number of adverse events (AE)s and serious adverse events (SAE)s, the number per patient, and the number of patients with at least one event. The type of AE/SAE and whether the AE/SAE is related to the fecal microbiota transplant (FMT) or not will be tabulated. These summaries will be computed overall as well as by randomization arm and stratification factor (steroid-responsive, versus steroid-dependent or -refractory disease status). The odds will be compared of at least one SAE per patient by randomization arm and stratification factor using logistic regression with independent variables for route of FMT administration, fiber supplementation, and steroid-responsive, versus steroid-dependent or -refractory disease status. Interaction terms will be considered between these factors and may use exact or firth logistic regression in the event that some categories have zero patients with a SAE.
Up to 3 years
Bacterial genes in stool
Time Frame: At baseline
Specifically abundance of genes related to fiber fermentation and short chain fatty acids production metabolites in stool, specifically short chain fatty acids will be assessed.
At baseline

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Complete response (CR) after the initial FMT
Time Frame: At day 28
Will be defined by stage 0 on the Modified Glucksberg GvHD scale, without abdominal pain or hematochezia. To account for variability in this measure, patient stool volume (inpatients only) and survey data (both inpatients and outpatients) from days 25-27 will be used to determine whether patients meet these criteria or not. Inpatients will be a compare measured stool volumes to those reported via survey, to assess how well the survey data may serve as a surrogate for stool volume. Subjects who die before day 28 will be counted as no CR. The number and proportion of patients with CR by steroid-responsive, versus steroid-dependent or -refractory disease status, and each randomization arm (route of FMT administration and receipt of fiber supplementation) as well as within combinations of these factors will be computed. To test for differences in CR by these factors, logistic regression models similar to those described above for SAE comparisons.
At day 28
CR or partial response (PR) after the initial FMT
Time Frame: At day 28
Will be assessed by CR or PR at day 28 will use similar analysis methods as to the CR at day 28 outcome analysis.
At day 28
Gut and overall GvHD grade
Time Frame: Up to 6 months
Will be assessed using the Modified Glucksberg scale measurements at baseline and throughout follow-up to summarize decrease in stool volume. For both of these ordinal outcomes (GvHD grade and Modified Glucksberg scale stage), descriptive statistics and graphical summaries to show changes over time by stratification factor and randomization arm. Generalized linear mixed effects models to test for differences in these outcomes by stratification factor and randomization arm.
Up to 6 months
Six-month survival
Time Frame: At 6 months
Will be evaluated using Kaplan-Meier curves and Cox proportional hazards regression with independent variables for the steroid- responsive, versus steroid-dependent or - refractory disease and randomization arm as specified in previous models.
At 6 months
Decrease in stool volume
Time Frame: Up to 6 months
Up to 6 months
Levels of MAIT cells in the periphery
Time Frame: Up to 6 months
Will be assessed using plot cell counts and percentage of lymphocytes for MAIT cells over time to compare longitudinal patterns by study arm and stratification factor. Mann-Whitney tests will be used to evaluate differences in cell counts and percentage of lymphocytes for MAIT cells in recipients of upper versus lower FMT, and individuals who receive fiber supplementation versus those who do not at specific time points post-FMT. Linear mixed effects models may be used to test for differences in longitudinal patterns of these outcomes by randomization arm and stratification factor.
Up to 6 months
Levels of Treg cells in the periphery
Time Frame: Up to 6 months
Will be assessed using plot cell counts and percentage of lymphocytes for Treg cells over time to compare longitudinal patterns by study arm and stratification factor. Mann-Whitney tests will be used to evaluate differences in cell counts and percentage of lymphocytes for Tregs in recipients of upper versus lower FMT, and individuals who receive fiber supplementation versus those who do not at specific time points post-FMT. Linear mixed effects models may be used to test for differences in longitudinal patterns of these outcomes by randomization arm and stratification factor.
Up to 6 months
Quality of life
Time Frame: Up to 3 years
Will be summarized at baseline and during study using descriptive statistics.
Up to 3 years

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Investigators

  • Principal Investigator: David Fredricks, Fred Hutch/University of Washington Cancer Consortium

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

January 24, 2025

Primary Completion (Estimated)

December 31, 2027

Study Completion (Estimated)

December 31, 2027

Study Registration Dates

First Submitted

December 10, 2019

First Submitted That Met QC Criteria

September 30, 2021

First Posted (Actual)

October 5, 2021

Study Record Updates

Last Update Posted (Actual)

March 11, 2026

Last Update Submitted That Met QC Criteria

March 9, 2026

Last Verified

March 1, 2026

More Information

Terms related to this study

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

Clinical Trials on Intestinal Graft Versus Host Disease

Clinical Trials on Survey Administration

Subscribe