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Diet and Gut Microbiome in Colorectal Cancer Study

This observational study aims to understand how your diet affects the microbiome (the collection of bacteria and other tiny organisms) in your digestive system. Researchers want to see if these dietary patterns and microbiome differences are linked to colorectal cancer. They will compare dietary habits, gut microbiome makeup, and genetic changes in colon cells between people who are strict vegetarians and those who eat all types of food. You may be able to join if you are 45 or older, a non-smoker, and are having a screening colonoscopy. The study plans to enroll 30 participants, but its current status is unclear.

Study design
This is an observational study involving 30 participants to compare dietary patterns, microbiome, and genetic changes between vegetarians and omnivores.
What's involved
You will complete a dietary questionnaire (30-60 minutes) and provide stool, blood, and tissue samples for analysis.
Compensation
Not stated in the trial record.
Follow-up
Not specified.

AI-generated from the public study record. Only the study team can confirm whether you're eligible — confirm details with them before making decisions.

NCT04666727

Role of Diet on the Microbiome of the Digestive System

Recruiting
Not specifiedAges 45+Observational
M.D. Anderson Cancer Center
~30 participants
Updated 2026-05-26 on ClinicalTrials.gov

At a glance

Recruiting sites
1 of 1 listed site is recruiting right now
RecruitingSuspended, closed, or not yet open
What they're measuring
Dietary patterns
Measured over Baseline
+2 more outcomes measured

Conditions

Colorectal Carcinoma

Explore related trials

Colorectal Carcinoma

Where it's being run

1 sites across 1 states
Texas1

Study leadership

  • Anusha Thomas, MD · PRINCIPAL_INVESTIGATOR · MD Anderson Cancer Center, Houston, Texas

Who to contact

Anusha Thomas, MD
[email protected]
713-563-9600
Email the study team

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Do you actually qualify for this trial?

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Eligibility criteria

Inclusion

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

• 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

What this trial measures

  • Dietary patternsBaseline

    Will obtain estimates of dietary patterns from colonic mucosal biopsies in each group.

  • Microbiome compositionBaseline

    Will obtain estimates of microbiome composition from colonic mucosal biopsies in each group. Microbiome composition will be quantified using 16S profiling will be visualized across samples using stacked bar plots and principal coordinate analysis of the weighted Unifrac distances, and microbiome diversity within each sample will be quantified using the inverse-Simpson index.

  • Somatic mutation burdenBaseline

    Will obtain estimates of somatic mutation burden from colonic mucosal biopsies in each group.