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NCT Number: NCT04666727

Role of Diet on the Microbiome of the Digestive System

This study is to learn more about how diet affects the microbiome (bacteria and microorganisms) of the digestive system. Researchers want to learn if this, in turn, has an effect on if and how people then develop colorectal cancer.

Recruiting

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Key information

Age range

45 year and older

Sex eligibility

All sexes

Study type

Observational

Primary location

M D Anderson Cancer Center

Houston, Texas, 77090, United States

Location status: Recruiting

Location contact

Anusha Thomas, MD

CONTACT

[email protected]

713-563-9600

About this study

PRIMARY OBJECTIVES:

I. To evaluate the differences in dietary patterns among individuals reporting to be vegetarian and omnivorous.

II. To compare the difference in stool microbiome pattern in the above mentioned two groups of individuals.

III. To compare somatic mutations in colorectal epithelial cells in the above mentioned two groups of individuals.

SECONDARY OBJECTIVE:

I. To identify and characterize an association between diet, the microbiome and its genotoxic effect on the colorectal epithelial cells and predisposition to colorectal carcinogenesis.

OUTLINE:

Participants complete dietary questionnaire over 30-60 minutes and undergo collection of stool, blood, and tissue samples for analysis via sequencing and laser dissection.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

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

Treatment and study plan

Primary outcomes

  1. Dietary patterns

    Time frame: Baseline

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

  2. Microbiome composition

    Time frame: Baseline

    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.

  3. Somatic mutation burden

    Time frame: Baseline

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

Study contacts

Contact information is provided by the study sponsor or research team.

Anusha Thomas, MD

CONTACT

[email protected]

713-563-9600

Sponsors and collaborators

Lead sponsor

M.D. Anderson Cancer Center

Other

Registry information

Official study title

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

Important dates

Study start
2020
Primary completion
2027
Study completion
2027
First posted
Dec 14, 2020
Registry last updated
May 26, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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