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Impact of Dietary Fiber Supplementation on Colonic Microbiome

Changes in Colonic Microbiome With Fiber Supplementation

Status
Recruiting
Phases
NA
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT05643859
Enrollment
120
Registered
2022-12-09
Start date
2023-04-01
Completion date
2026-12-31
Last updated
2026-01-15

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Benign Colorectal Neoplasm, Non-Neoplastic Anal Disorder

Brief summary

This clinical trial tests whether daily fiber supplementation will change the mucosal microbiome of the colon. The microbiome are microorganisms that live in the human gut. They serve a vital role in maintaining health. Certain microbial strains are associated with the growth of colon polyps, which eventually could go on to form colon cancer. Giving dietary fiber supplements may help prevent precancerous polyps from ever developing.

Detailed description

PRIMARY OBJECTIVE: I. To identify how diet, specifically fiber supplementation, alters the microbiome of the colonic mucosa. OUTLINE: Patients receive dietary fiber orally (PO) once daily (QD) for 28 days. Patients may undergo standard of care proctoscopy or anoscopy with biopsy on study and at follow up or may undergo standard of care colonoscopy on study. All patients also undergo collection of blood samples on study and at follow up.

Interventions

DIETARY_SUPPLEMENTDietary Fiber

Given PO

PROCEDUREProctoscopy or anoscopy with Biopsy

Undergo proctoscopy or anoscopy

PROCEDUREColonoscopy

Undergo Colonoscopy

OTHERQuestionnaire Administration

Ancillary studies

Sponsors

OHSU Knight Cancer Institute
Lead SponsorOTHER

Study design

Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
SUPPORTIVE_CARE
Masking
NONE

Eligibility

Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No

Inclusion criteria

* Age \>= 18 years * Ability to understand and the willingness to sign a written informed consent document * Patients who present with a chief complaint of a benign anorectal pathology including hemorrhoids, anal fissures, and anal fistulas without underlying conditions such as colorectal cancer or Crohn's disease or are undergoing a standard of care colonoscopy procedure

Exclusion criteria

* Patients with an active malignancy, Crohn's disease, ulcerative colitis, and immunosuppressed patients * Patients with hereditary colon cancer syndrome including Lynch syndrome or Familial Adenomatous Polyposis (FAP) * Patients with a prior history of total or partial colon resection * Colorectal pathology, such cancer or proctitis, after initial study scope

Design outcomes

Primary

MeasureTime frameDescription
Change in microbiome colonic mucosa: taxa abundanceBaseline and post-supplementation, up to 40 daysWill use data visualization techniques to understand the data and determine if microbiome count overall (richness) changes occur in patients who are started on fiber supplementation. In order to visualize overall changes after fiber supplementation, will generate plots showing relative abundance of the detected taxa for each subject at baseline and post-supplementation. For each taxa, will generate box plots to visually compare the median and interquartile range (IQR) of abundance between the two time points. Wilcoxon signed rank tests with an alpha level of 0.05 will determine if there is a difference in microbial derived short chain fatty acids after fiber supplementation in the blood and mucosa. Wilcoxon signed rank tests with an alpha level of 0.05 will determine if there is a difference in microbial derived short chain fatty acids after fiber supplementation in the blood and mucosa.
Change in microbiome colonic mucosa: microbiome diversityBaseline and post-supplementation, up to 40 daysWill use data visualization techniques to understand the data and determine if the types of metabolites (microbiome diversity) cases occur in patients who are started on fiber supplementation. In order to visualize overall changes after fiber supplementation. To assess for changes in microbiome diversity, our primary analysis will compare median Shannon diversity index values at baseline and post-supplementation. The Shannon index estimates diversity using richness and abundance. Will calculate Shannon index values for each participant at each time point and use a Wilcoxon signed rank test with an alpha level of 0.05 to determine if there is a difference in microbiome diversity after fiber supplementation.

Countries

United States

Contacts

Primary ContactShahrose Rahman, M.D.
rahmasha@ohsu.edu503-494-8652
Backup ContactAmber O'Connor
oconnoam@ohsu.edu

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026