Assessing the Short-Term Effects of Multi-Fiber Supplementation on Gut Health

August 24, 2026 updated by: Brown University
This is a randomized, parallel-group interventional study evaluating the short-term gastrointestinal effects of a standardized multi-fiber supplement in healthy adults. Approximately 100 participants (50 per arm) aged 18 and older will be randomized to receive either the multi-fiber supplement or a control (flavoring agent only) daily for 10 days. Objectives include assessing effects on stool characteristics, specifically frequency and consistency, as well as changes in metagenomically inferred short-chain fatty acid production potential from the microbiota. Eligible participants must be free of chronic disease, acute illness, and recent antibiotic, probiotic, or prebiotic use. Total participation duration is 10 days.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Estimated)

100

Phase

  • 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 Locations

  • United States
    • Rhode Island
      • Providence, Rhode Island, United States, 02912
        • Recruiting
        • Biomedical Center
        • Contact:
        • Principal Investigator:
          • Peter Belenky, PhD

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

  • Adult
  • Older Adult

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • in self-reported good health (i.e. no chronic disease, no acute illness)

Exclusion Criteria:

  • chronic disease
  • acute illness
  • antibiotic, or probiotic, or prebiotic use in the prior 3 months
  • allergies to any of the following: psyllium husk powder, mustard, sesame, soy, tree nuts, pectin, citric acid, wheat, milk, egg, beta-glucan, barley, inulin, agave, resistant maltodextrin, arabinoxylan
  • adherence to any food-group strict diet (e.g. vegan, vegetarian, keto, etc.)
  • any of the following groups: adults unable to consent, individuals that are not yet adult, pregnant women, prisoners

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: Basic Science
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Triple

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Mixed Fiber Supplementation Intervention Arm
Dietary supplement: Prebiotic
Formulated prebiotic supplement designed to be accessible to gut microbiota members and assist with bowel movement regularity
Placebo Comparator: Placebo Supplementation Arm
Dietary supplement: Placebo
Placebo supplementation intervention, with only flavoring agents and no prebiotic fiber

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Change in metagenomically inferred SCFA production potential
Time Frame: Change observed from baseline sample (Day 0) to second sample (Day 10)
Through metagenomic sequencing analysis, change in relative abundance of short-chain fatty acid producing genes from sequenced timepoint stool samples will be assessed.
Change observed from baseline sample (Day 0) to second sample (Day 10)

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Bowel Movement Regularity
Time Frame: Change observed over time from baseline (Day 0) through completion of the study (Day 10)
From a questionnaire that participants will fill out each day of the study, the number of bowel movements, the Bristol stool scale value, and amount of strain experienced during defecation will be assessed.
Change observed over time from baseline (Day 0) through completion of the study (Day 10)

Other Outcome Measures

Outcome Measure
Measure Description
Time Frame
Observed changes in stool microbiome composition as profiled by metagenomic sequencing analysis
Time Frame: Change observed from baseline sample (Day 0) to second sample (Day 10)
Statistically significant shifts in composition, diversity, and functionality
Change observed from baseline sample (Day 0) to second sample (Day 10)

Collaborators and Investigators

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

Sponsor

Brown University

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 (Estimated)

August 1, 2026

Primary Completion (Estimated)

August 1, 2028

Study Completion (Estimated)

August 1, 2029

Study Registration Dates

First Submitted

August 20, 2026

First Submitted That Met QC Criteria

August 24, 2026

First Posted (Actual)

August 26, 2026

Study Record Updates

Last Update Posted (Actual)

August 26, 2026

Last Update Submitted That Met QC Criteria

August 24, 2026

Last Verified

July 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • STUDY00000994

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

No

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.

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