Understanding how diet influences the gut microbiome and colorectal cancer risk

The Role of Diet and the Microbiome in Inducing Somatic Mutations in Colorectal Epithelial Cells and Its Predisposition to Carcinogenesis - A Pilot Study

Observational M.D. Anderson Cancer Center · NCT04666727

This study looks at how different diets, like vegetarian or omnivore, affect the gut bacteria and the risk of developing colorectal cancer.

Quick facts

Study typeObservational
Enrollment30 (estimated)
Ages45 Years and up
SexAll
SponsorM.D. Anderson Cancer Center Academic / other
Drugs / interventionsradiation
Locations1 site (Houston, Texas)
Trial IDNCT04666727 on ClinicalTrials.gov

What this trial studies

This observational study aims to explore the relationship between dietary patterns and the microbiome in the digestive system, specifically focusing on individuals who are either strict vegetarians or omnivores. Researchers will evaluate differences in dietary habits, stool microbiome patterns, and somatic mutations in colorectal epithelial cells between these two groups. Participants will complete a dietary questionnaire and provide stool, blood, and tissue samples for detailed analysis. The goal is to identify potential associations between diet, microbiome composition, and colorectal cancer predisposition.

Who should consider this trial

Good fit: Ideal candidates are individuals aged 45 and above who are either strict vegetarians or omnivores and are undergoing screening colonoscopy.

Not a fit: Patients who are current smokers, have a positive family history of colon cancer, or have a history of inflammatory bowel disease may not benefit from this study.

Why it matters

Potential benefit: If successful, this study could provide insights into dietary modifications that may reduce the risk of colorectal cancer.

How similar studies have performed: While studies have explored diet and microbiome interactions, this specific focus on colorectal cancer and dietary patterns is relatively novel.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* GROUP I: Patients presenting for a screening colonoscopy

  * GROUP I: Age of 45 and above
  * GROUP I: Strict vegetarian diet, determined by using diet history questionnaire 3.0 National Institutes of Health (NIH)
  * GROUP I: Non smoker
  * GROUP I: Ability to understand and willingness to sign an informed consent form, complete web based dietary assessment and provide stool, colonic mucosa and blood samples
  * GROUP II: Patients presenting for a screening colonoscopy
  * GROUP II: Age of 45 and above
  * GROUP II: Omnivorous diet
  * GROUP II: Non smoker
  * GROUP II: Ability to understand and willingness to sign an informed consent form, complete web based dietary assessment and provide stool, colonic mucosa and blood sample

Exclusion Criteria:

* • Current smokers (nicotine abuse only)

  * Positive family history of colon cancer or colon cancer related syndromes
  * Recent use of antibiotics in 1 month
  * History of inflammatory bowel disease, and/or radiation enteritis or colitis
  * Pregnant and breastfeeding women
  * Women of child-bearing potential who have positive urine or serum pregnancy test
  * Heavy drinker (defined as more than 14 drinks per week)
  * Currently using anti-flatulence medications, probiotics and/or fiber supplements
  * Major dietary restrictions and/or following a special diet
  * Patient with positive fecal test/symptoms

Where this trial is running

Houston, Texas

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Colorectal Carcinoma
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.