Could your diet change gut bacteria and raise colon cancer risk?
NCT ID NCT03550885
First seen Jun 27, 2026 · Last updated Jun 27, 2026
Summary
This study looked at how two different diets affect gut bacteria and markers linked to colon cancer risk in 15 African American adults at higher risk. Participants ate a high-fat, animal-based diet and a low-fat, plant-based diet for three weeks each. Researchers measured changes in gut bacteria and bile acids to understand the connection between diet and colon cancer risk.
What this could mean
Our plain-language read of the trial. This is informational only, not medical advice or a prediction.
- Active substance
- diet (high taurine and saturated fat vs. low taurine and saturated fat)
- What this could lead to
- If successful, this could help explain how certain diets increase colon cancer risk and point to dietary changes that lower that risk.
- What could go wrong
- This is a very small, early study with only 15 participants, so results may not apply to everyone. It looks at biological markers, not actual cancer outcomes.
This is an AI summary of the original study and may miss details. Read our disclaimer.
Study facts
What this study's own registry entry says, in plain language.
- Phase
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Not a phased trial
Phase numbers describe drug development. The registry uses this when they do not apply, as it does for trials of devices, procedures or behaviour changes, and for observational studies.
- Participants
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15 people
The number who actually took part.
- Started
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Aug 2018
- Finished
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Dec 2021
- Lead sponsor
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Other sponsor
The registry's catch-all category, for sponsors it does not file as a company, a government agency, or a research network.
Who can take part
This study's own entry requirements. Only the study team can say for certain whether you qualify.
- Ages
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45 to 75 years
- Sex
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Anyone
- Healthy volunteers
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Accepted
You do not need to have the condition being studied to take part.
Show the full entry requirements Hide the full entry requirements
Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.
Inclusion Criteria: 1. Adult African American; 2. Obese (defined as BMI 30 - \< 50 kg/m2); 3. Age between 45 - 75 years old; 4. Patients with an increased risk for CRC, defined as 3 or more adenomatous polyps or adenomatous polyp \> 1cm within 5-yrs of enrollment; 5. An elevated C-reactive protein (CRP) (defined as \> 3 mg/l) 6. Participants must be in good general health, not expecting major lifestyle changes in the next 6 months and willing to maintain their current activity level throughout the duration of the study. 7. Women only: Post-menopausal (natural or surgical) defined as no menstruation in the past 6 months Exclusion Criteria: 1. BMI \< 30 or \> 50 kg/m2 (for those interested and eligible, verify BMI by measuring weight and height, complete the screening consent form before assessing these measures) 2. Weight \> 450 lbs. (max weight for the body composition scanner) 3. Race other than African American 4. Women only: at least one menstrual period in the past 6 months 5. Current malignancy except non-melanoma skin cancer that has been removed 6. Current gastrointestinal (GI) illness other than gastroesophageal reflux disease or hemorrhoids (such as celiac disease, inflammatory bowel disease, malabsorptive bariatric procedures, etc.) 7. Chronic liver or kidney disease (elevated liver tests \>3 times normal or creatinine above 2.0 mg/dl) 8. History of cardiac disease (such as admission for congestive heart failure within the past 5 years, or being on anticoagulants for heart disease, or having an ejection fraction \<25%, etc.) 9. Positive genetic test for inherited polyposis syndromes (such as familial adenomatous polyps, hereditary non-polyposis colon cancer syndromes, etc) 10. Alcoholism or illicit drug use 11. Antibiotic use within the past 2 months 12. Regularly taking medications that may interfere with normal digestion (such as acarbose, cholestyramine, Orlistat, aspirin doses that exceed 81mg/day or 325 mg every other day) 13. Anticoagulant use or other factors that increase endoscopic risks 14. Non-English speaking 15. Pregnant or breast feeding 16. Dietary supplement use including pre- or probiotics within the past month 17. History of intestinal cancer, inflammatory bowel disease, celiac disease, or malabsorptive bariatric surgery 18. Inflammatory or connective tissue diseases (such as lupus, scleroderma, rheumatoid arthritis, etc.) 21\. Prior perforation at colonoscopy or gastrointestinal bleeding due to biopsies of the colon 22. Therapeutic or vegetarian diet 23. Food allergy/aversions to any foods in included in the trial 24. Any medical condition, which, in the opinion of the investigator, could adversely affect the subject's participation in the trial, or affect the trial integrity
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Conditions
The condition(s) this trial relates to.
As listed by the trial registrant
The condition terms exactly as the trial's registrant entered them.
Contacts and locations
Locations
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Rush University Medical Center and University of Illinois at Chicago
Chicago, Illinois, 60612, United States
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Other studies related to the condition(s) this trial covers.
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