Role of Diet on the Microbiome of the Digestive System

Study Overview
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Brief Summary
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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.

Detailed Description
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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.

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

Conditions
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Colorectal Carcinoma

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: GROUP I: Patients presenting for a screening colonoscopy GROUP I: Age of 50 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 50 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 samples 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

Ages Eligible for Study
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Minimum Age: 50 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Dietary patterns | Will obtain estimates of dietary patterns from colonic mucosal biopsies in each group. | Baseline | 
| Microbiome composition | 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. | Baseline | 
| Somatic mutation burden | Will obtain estimates of somatic mutation burden from colonic mucosal biopsies in each group. | Baseline |