The High Fiber Program to Increase Fiber Intake Among Patients Undergoing Allogeneic Hematopoietic Cell Transplant

Pilot Study to Evaluate the Feasibility of High Fiber Program in Patients Undergoing Allogeneic Hematopoietic Cell Transplant (HCT)

This clinical trial studies whether the High Fiber Program can be used to increase fiber intake in patients undergoing allogeneic hematopoietic cell transplant (HCT). Allogeneic HCT is a procedure in which a person receives blood-forming stem cells (cells from which all blood cells develop) from a genetically similar, but not identical, donor. This is often a sister or brother, but could be an unrelated donor. It is a potentially curative therapy for many conditions that affect the blood and blood-forming organs, but many patients must manage post-transplant complications, especially graft versus host disease (GVHD). GVHD occurs when the transplanted cells from a donor attack the body's normal cells causing skin rash or blisters, dry mouth, or dry eyes. The environment and health of the gut is important in allogeneic HCT patients, with an unhealthy gut environment and/or health leading to inflammation and possibly GVHD. Research has shown that diets high in fiber may improve the environment and health of the gut as well as outcomes following transplant; however, fiber intake remains low among patients. The High Fiber Program is a dietitian-led counseling program which teaches patients how to introduce high fiber foods into their diet and identify food choices and personalized strategies that will help them change their diet. The High Fiber Program may be an effective way to increase fiber intake in patients undergoing allogeneic HCT.

Study Overview

• Status: Not yet recruiting
• Conditions: Hematopoietic and Lymphatic System Neoplasm
• Intervention / Treatment: Other: Questionnaire Administration; Procedure: Biospecimen Collection; Other: Dietary Intervention; Other: Dietary Intervention; Other: Dietary Intervention; Other: Dietary Intervention

Detailed Description

PRIMARY OBJECTIVES:

I. To determine the feasibility of executing the High Fiber Program in HCT patients.

II. To estimate the proportion of patients who restore fiber intake to baseline levels by day 60 post-HCT.

SECONDARY OBJECTIVES:

I. To estimate the median number of days post-HCT when allogeneic HCT (alloHCT) patients achieve baseline fiber intake levels.

II. To obtain estimates of fiber intake in the pre-HCT period and over time in alloHCT patients on the High Fiber Program.

III. To evaluate the variety of fiber sources that patients have included in their diet by day 100.

IV. To evaluate the tolerability of introducing fiber into patients' diets based on when patients resume fiber intake post-transplant and the frequency of medications for controlling gastrointestinal symptoms.

V. To characterize toxicities associated with introducing fiber into patients' diets.

VI. To evaluate the median day of onset of acute GVHD and cumulative incidence of grade 2 or higher acute graft-versus (vs)-host disease (GVHD), per Mount Sinai Acute Graft Versus Host Disease International Consortium Grading System (MAGIC) criteria, at day +100 post-HCT, including incidence and severity of lower gastrointestinal acute GVHD.

VII. To evaluate incidence and severity of infections per Blood and Marrow Transplant Clinical Trials Network (BMT CTN) criteria, including bloodstream infections, up to day 100.

VIII. To obtain estimates of correlation between fiber intake and quality of life scores at day 100 post-HCT.

IX. To estimate the proportion of patients who achieve a fiber intake of at least 25g on at least one day by day 100 post-HCT.

X. To evaluate the cumulative incidence of chronic GVHD at 180 days, 1 year and 2 years post-HCT in patients on the High Fiber Program.

XI. To estimate overall survival (OS) and cumulative incidence of relapse/progression and non-relapse mortality at 100 days, 1 year and 2 years post-HCT in patients on the High Fiber Program.

EXPLORATORY OBJECTIVES:

I. To assess the feasibility of obtaining patient reported side effects and medications for symptom relief during the pre-screening period.

II. To assess how fiber intake influences immune reconstitution pattern over the course of therapy.

III. To evaluate how fiber intake relates to fecal/intestinal microbiome composition over the course of therapy.

IV. To assess relationships between fiber intake and serum inflammatory cytokines over the course of therapy.

V. To assess relationships between fiber intake and acute GVHD biomarkers, especially Reg3a produced by intestinal enterocytes.

VI. To evaluate how fiber intake relates to fecal metabolite levels over the course of therapy.

VII. To evaluate whether fiber intake relates to calorie intake over the course of therapy.

OUTLINE:

Patients attend five or six High Fiber Program dietitian-lead counseling sessions up to 30 days and/or 18 days prior to scheduled HCT, upon admission to inpatient care, at discharge, at day 42 post-transplant (approximately 20-30 days post-discharge), and at day 60 post-transplant. Patients also meet with High Fiber Program dietitian once a week (QW) and select food options from Fiber Aware Menu during admission. Additionally, patients receive a study booklet and undergo blood sample collection on study.

After completion of study intervention, patients are followed up on days 72, 100, and 180 and years 1 and 2.

• Study Type: Interventional
• Enrollment (Estimated): 44
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • California
    • Duarte, California, United States, 91010
      • City of Hope Medical Center
      • Contact: Ryotaro Nakamura; Email: RNakamura@coh.org
      • Principal Investigator: Ryotaro Nakamura
      • Contact: Phone Number: 6262184673

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• PRE-SCREENING INCLUSION: Documented informed consent of the participant and/or legally authorized representative
• PRE-SCREENING INCLUSION: Age: ≥ 18 years
• PRE-SCREENING INCLUSION: Within healthy body mass index (BMI) range 18-29 at the time of pre-screening consent
• PRE-SCREENING INCLUSION: Ability to read and understand English for questionnaires
• PRE-SCREENING INCLUSION: Patients must be scheduled to receive HCT within the next 30 days after pre-screening consent
• MAIN INCLUSION: Documented informed consent of the participant and/or legally authorized representative

• MAIN INCLUSION: Age: ≥ 18 years

  • Patients ≥ 75 years of age that are otherwise eligible to undergo allogeneic HCT are included
• MAIN INCLUSION: Karnofsky performance status ≥ 70%
• MAIN INCLUSION: Within healthy BMI range 18-29 at the time of consent
• MAIN INCLUSION: Ability to read and understand English for questionnaires
• MAIN INCLUSION: Patients receiving myeloablative or reduced intensity conditioning regimens
• MAIN INCLUSION: Adequate organ function consistent with institutional standards for HCT
• MAIN INCLUSION: Patients must be scheduled to receive HCT within 3 weeks of consent

• MAIN INCLUSION: Women of childbearing potential (WOCBP): negative urine or serum pregnancy test (within 45 days prior to the start of conditioning)

  • If the urine test is positive or cannot be confirmed as negative, a serum pregnancy test will be required

• MAIN INCLUSION: Agreement by females and males of childbearing potential to use an effective method of birth control or abstain from heterosexual activity for the course of the study through at least 6 months post-HCT

  • Childbearing potential defined as not being surgically sterilized (men and women) or have not been free from menses for > 1 year (women only)

Exclusion Criteria:

• PRE-SCREENING EXCLUSION: Clinically significant uncontrolled illness
• PRE-SCREENING EXCLUSION: Active infection requiring antibiotics
• PRE-SCREENING EXCLUSION: History of chronic gastrointestinal conditions such as inflammatory bowel disease or Crohn's disease
• PRE-SCREENING EXCLUSION: Medical contraindications to incorporating fiber in their diet as determined by the treating physician
• PRE-SCREENING EXCLUSION: Self-reported major dietary restrictions limiting fiber intake
• PRE-SCREENING EXCLUSION: Any other condition that would, in the investigator's judgment, contraindicate the patient's participation in the clinical study due to safety concerns with clinical study procedures
• PRE-SCREENING EXCLUSION: Prospective participants who, in the opinion of the investigator, may not be able to comply with all study procedures (including compliance issues related to feasibility/logistics)
• MAIN EXCLUSION: Clinically significant uncontrolled illness
• MAIN EXCLUSION: Active infection requiring antibiotics
• MAIN EXCLUSION: History of chronic gastrointestinal conditions such as inflammatory bowel disease or Crohn's disease
• MAIN EXCLUSION: Medical contraindications to incorporating fiber in their diet as determined by the treating physician
• MAIN EXCLUSION: Self-reported major dietary restrictions limiting fiber intake
• MAIN EXCLUSION: Any other condition that would, in the investigator's judgment, contraindicate the patient's participation in the clinical study due to safety concerns with clinical study procedures
• MAIN EXCLUSION: Prospective participants who, in the opinion of the investigator, may not be able to comply with all study procedures (including compliance issues related to feasibility/logistics)

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Supportive Care
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm

Intervention / Treatment

Experimental: Supportive care (High Fiber Program); Patients attend five or six High Fiber Program dietitian-lead counseling sessions up to 30 days and/or 18 days prior to scheduled HCT, upon admission to inpatient care, at discharge, at day 42 post-transplant (approximately 20-30 days post-discharge), and at day 60 post-transplant. Patients also meet with High Fiber Program dietitian QW and select food options from Fiber Aware Menu during admission. Additionally, patients receive a study booklet and undergo blood sample collection on study.

Other: Questionnaire Administration; Ancillary studies; Procedure: Biospecimen Collection; Undergo blood sample collection; Other Names: Biological Sample Collection; Biospecimen Collected; Specimen Collection; Sample Collection; Other: Dietary Intervention; Attend High Fiber Program counseling sessions; Other Names: Dietary Modification; intervention, dietary; Nutrition Intervention; Nutrition Interventions; Nutritional Interventions; Other: Dietary Intervention; Attend High Fiber Program weekly sessions; Other Names: Dietary Modification; intervention, dietary; Nutrition Intervention; Nutrition Interventions; Nutritional Interventions; Other: Dietary Intervention; Make Fiber Aware Menu food selections; Other Names: Dietary Modification; intervention, dietary; Nutrition Intervention; Nutrition Interventions; Nutritional Interventions; Other: Dietary Intervention; Receive study booklet; Other Names: Dietary Modification; intervention, dietary; Nutrition Intervention; Nutrition Interventions; Nutritional Interventions

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Percent of scheduled dietary counseling sessions attended and withdrawal status (Feasibility)	Feasibility in each patient will be assessed based on patient participating in ≥ 80% of scheduled dietary counseling sessions by the study dietitian and not withdrawing by day 60. Point estimates and corresponding 95% confidence intervals will be reported. Will be estimated with exact binomial 95% confidence intervals.	Up to day 60
Highest daily fiber intake	Point estimates and corresponding 95% confidence intervals will be reported. Will be estimated with exact binomial confidence intervals. Distributions of baseline and day +60 intake will be summarized.	Baseline up to day 60

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Longitudinal dietary fiber intake	Point estimates and corresponding 95% confidence intervals will be reported. Fiber intake trajectories will be analyzed using linear mixed-effects models with random intercepts for participants.	Pre-hematopoietic cell transplant up to day +100 post-transplant
Number of types of plant-based fiber sources included in diet	Point estimates and corresponding 95% confidence intervals will be reported. The number and diversity of fiber sources will be summarized.	Up to day 100
Duration that patients were not able to consume fiber	Point estimates and corresponding 95% confidence intervals will be reported. Will be analyzed using Kaplan-Meier methods. Median time and 95% confidence intervals will be reported.	Up to day +100 post-transplant
Incidence of gastrointestinal toxicities and attribution to fiber intake	Point estimates and corresponding 95% confidence intervals will be reported. Assessed per Common Terminology Criteria for Adverse Events (CTCAE) version (v) 6.	Up to day +100 post-transplant
Frequency and doses of medications for constipation, diarrhea or any other gastrointestinal discomfort	Point estimates and corresponding 95% confidence intervals will be reported.	Up to day +100 post-transplant
Incidence of systemic toxicities and attribution to fiber intake	Point estimates and corresponding 95% confidence intervals will be reported. Assessed per CTCAE v6.	Up to day +100 post-transplant
Incidence of acute grafter versus host disease (GVHD)	Point estimates and corresponding 95% confidence intervals will be reported. Cumulative incidence of acute GVHD by day +100 will be estimated using competing-risk methods, with death without GVHD treated as a competing event, if appropriate.	Up to day +100 post-transplant
Involvement of lower gastrointestinal acute GVHD	Point estimates and corresponding 95% confidence intervals will be reported. Assessed per Mount Sinai Acute Graft Versus Host Disease International Consortium Grading System consensus criteria.	Up to day +100 post-transplant
Incidence of severity of infections	Point estimates and corresponding 95% confidence intervals will be reported. Will be assessed per Blood and Marrow Transplant Clinical Trials Network criteria.	Up to day +100 post-transplant
Quality of life score	Point estimates and corresponding 95% confidence intervals will be reported. Associations between fiber intake and quality of life measures will be evaluated using correlation and exploratory regression.	At day +100 post-transplant
Incidence of chronic GVHD	Point estimates and corresponding 95% confidence intervals will be reported. Will be estimated using competing-risk methods.	At day +180, 1 year and 2 years post-transplant
Overall survival	Point estimates and corresponding 95% confidence intervals will be reported. Will be analyzed using Kaplan-Meier methods.	At day +100 and 1 year and 2 years post-transplant
Relapse	Point estimates and corresponding 95% confidence intervals will be reported. Will be analyzed using cumulative incidence functions.	At day +100 and 1 year and 2 years post-transplant
Non-relapse mortality	Point estimates and corresponding 95% confidence intervals will be reported. Will be analyzed using cumulative incidence functions.	At day +100 and 1 year and 2 years post-transplant

Collaborators and Investigators

• Sponsor: City of Hope Medical Center
• Collaborators: National Cancer Institute (NCI)
• Investigators: Principal Investigator: Ryotaro Nakamura, City of Hope Medical Center

Study record dates

Study Major Dates

• Study Start (Estimated): February 13, 2027
• Primary Completion (Estimated): June 3, 2028
• Study Completion (Estimated): June 3, 2028

Study Registration Dates

• First Submitted: June 9, 2026
• First Submitted That Met QC Criteria: June 16, 2026
• First Posted (Actual): June 24, 2026

Study Record Updates

• Last Update Posted (Actual): June 24, 2026
• Last Update Submitted That Met QC Criteria: June 16, 2026
• Last Verified: June 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Investigative Techniques; Therapeutics; Clinical Laboratory Techniques; Diagnostic Techniques and Procedures; Diagnosis; Nutrition Therapy; Specimen Handling; Diet Therapy
• Other Study ID Numbers: 25887 (Other Identifier: City of Hope Medical Center); P30CA033572 (U.S. NIH Grant/Contract); NCI-2026-03804 (Registry Identifier: CTRP (Clinical Trial Reporting Program))

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No