Impact of Dietary Fiber Supplementation on Colonic Microbiome

NCT05643859 | Recruiting

• 2 other identifiers: STUDY00024054NCI-2022-07495
• Study Type: interventional
• Target: 120
• Locations: 1 country
• Sites: 1

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.

Conditions

Benign Colorectal Neoplasm; Non-Neoplastic Anal Disorder

Outcome Measures

Primary Outcomes (2)

• Change in microbiome colonic mucosa: taxa abundance

  Will 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.

  Baseline and post-supplementation, up to 40 days

• Change in microbiome colonic mucosa: microbiome diversity

  Will 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.

  Baseline and post-supplementation, up to 40 days

Study Arms (1)

Supportive care (oral fiber)

EXPERIMENTAL

Patients receive dietary fiber orally (PO) on study. QD for 28 days. Patients may undergo standard of care proctoscopy or anoscopy with biopsy on study and duringat 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.

Dietary Supplement: Dietary Fiber; Procedure: Proctoscopy or anoscopy with Biopsy; Procedure: Colonoscopy; Other: Questionnaire Administration

Interventions

Dietary Fiber DIETARY_SUPPLEMENT

Given PO

Also known as: Fiber

Supportive care (oral fiber)

Proctoscopy or anoscopy with Biopsy PROCEDURE

Undergo proctoscopy or anoscopy

Supportive care (oral fiber)

Colonoscopy PROCEDURE

Undergo Colonoscopy

Supportive care (oral fiber)

Questionnaire Administration OTHER

Ancillary studies

Supportive care (oral fiber)

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• 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

You may not qualify if:

• 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

Sponsors & Collaborators

• OHSU Knight Cancer Institute: lead

Study Sites (1)

OHSU Knight Cancer Institute

Portland, Oregon, 97239, United States

RECRUITING

MeSH Terms

Interventions

Dietary Fiber; Proctoscopy; Biopsy; Colonoscopy

Intervention Hierarchy (Ancestors)

Dietary Carbohydrates; Carbohydrates; Food; Diet, Food, and Nutrition; Physiological Phenomena; Food and Beverages; Endoscopy, Gastrointestinal; Endoscopy, Digestive System; Diagnostic Techniques, Digestive System; Diagnostic Techniques and Procedures; Diagnosis; Endoscopy; Diagnostic Techniques, Surgical; Digestive System Surgical Procedures; Surgical Procedures, Operative; Minimally Invasive Surgical Procedures; Cytodiagnosis; Cytological Techniques; Clinical Laboratory Techniques; Specimen Handling; Investigative Techniques

Study Officials

• Vassiliki L Tsikitis, M.D.

  OHSU Knight Cancer Institute

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Shahrose Rahman, M.D.

CONTACT

503-494-8652; rahmasha@ohsu.edu

Amber O'Connor

CONTACT

oconnoam@ohsu.edu

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NA
• Masking: NONE
• Purpose: SUPPORTIVE CARE
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Principal Investigator

Study Record Dates

• First Submitted: September 26, 2022
• First Posted: December 9, 2022
• Study Start: April 1, 2023
• Primary Completion (Estimated): December 31, 2026
• Study Completion (Estimated): December 31, 2026
• Last Updated: January 15, 2026

Record last verified: 2026-01

Data Sharing

• IPD Sharing: Will share

Locations

US (1)