Impact of High Dietary Fiber on Microbiome and Vaccine Responses

August 13, 2026 updated by: M.D. Anderson Cancer Center
To learn if diet can enhance the microbes (such as bacteria and viruses) found in your gut and improve the body's immune response to the influenza (flu) vaccine.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Active, not recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

Primary Objectives:

--To determine the feasibility of two dietary intervention strategies focused on fiber-rich and prebiotic foods prior to seasonal influenza vaccination. Feasibility is defined as ≥ 80% of subjects being compliant with the intervention.

Secondary Objectives:

  • To evaluate the effects of each dietary intervention on the composition, diversity and function of the gut microbiome.
  • To assess the effects of each dietary intervention on response to influenza vaccination as measured by vaccine-specific immune response.
  • To assess the effects of each dietary intervention on systemic immunity.

Exploratory Objectives:

  • To interrogate the overlap between the identified gut microbial and dietary patterns associated with vaccine response and those associated with excellent or poor responses to cancer immunotherapy (from our own published work and internal cohorts).
  • To identify components and determinants of the gut microbiome that could be modulated to enhance vaccine response.
  • To determine how modulation of the gut microbiome can be achieved through fiber and prebiotic-focused dietary changes.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
31

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

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 Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Locations

  • United States
    • Texas
      • Houston, Texas, United States, 77030
        • M D Anderson Cancer Center

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

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

14 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  1. MD Anderson employees with existing MRNs
  2. Body Mass Index (BMI) 18.5-40 kg/m2
  3. Age 18 or older
  4. Intends to receive the seasonal influenza vaccine at MD Anderson through Employee Health (starting Fall of 2022)
  5. Willing to adhere to the provided dietary interventions
  6. Willing to provide blood and stool specimens, complete diet questionnaires and logs, and pick up food on-site within the study schedule
  7. English-speaking
  8. Has easy access to a scale at home, work, or in their community

Exclusion Criteria:

  1. Contraindication to the recommended annual influenza vaccine
  2. Medical contraindications to the intervention diet
  3. Major dietary restrictions (including vegetarian or vegan diets) or food allergies
  4. Unable or unwilling to undergo study procedures
  5. Has diabetes mellitus requiring medical treatment
  6. Has inflammatory bowel disease
  7. Has a history of bariatric surgery
  8. Has a history of major gastrointestinal surgery (not including appendectomy or cholecystectomy)
  9. Antibiotic use within 30 days of study initiation or planned antibiotic treatment during study course
  10. Habitual consumption of a high fiber diet
  11. Use of a supplement containing fiber/prebiotics/probiotics within 30 days of study initiation
  12. Women who are pregnant, planning to become pregnant, or who are lactating may not be included in this study

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: Supportive Care
  • Allocation: Randomized
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: High-Fiber Diet (HFD) Intervention
Participants are expected to eat only the study meals and snacks provided
Dietary supplement: High-Fiber Diet (HFD)
Participants are assigned to the high fiber diet, all meals and snacks will be provided to participants during the study. This diet includes fruits, vegetables and whole grains, a maximum of 18 oz. cooked red meat (including beef, pork, and lamb) per week, and little or no processed meats or added sugars.
Experimental: Prebiotic Food-Enriched Diet (PreFED) Intervention
Participants are expected to incorporate study snacks and meal components provided into your usual diet.
Dietary supplement: Prebiotic Food-Enriched Diet (PreFED)
Participants are assigned to the prebiotic food enriched diet, participants will receive 2 prepared snacks and 1 meal component (a key prebiotic ingredient to incorporate into meals and simple recipes) each day. Participants will also receive a handout that includes key prebiotic foods to incorporate into your own diet.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Time Frame
Feasibility of dietary intervention prior to seasonal influenza vaccination defined as ≥ 80% of subjects being compliant with the intervention in the cohort
Time Frame: through study completion an average of 1 year.
through study completion an average of 1 year.

Collaborators and Investigators

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

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
M.D. Anderson Cancer Center

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Jennifer Wargo, MD, M.D. Anderson Cancer Center

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

Helpful Links

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)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
August 23, 2022

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
January 2, 2029

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
January 2, 2029

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
September 19, 2022

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
October 3, 2022

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
October 4, 2022

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
August 14, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
August 13, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
August 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • 2022-0450
  • NCI-2022-07926 (Other Identifier: NCI-CTRP Clinical Trials Registry)

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

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.

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