Diet changes to see if bile acids and gut bugs shift in people with colorectal adenoma

Is this trial a fit for you?

A plain-English reading of the study's rules. Only the study team can confirm whether you qualify.

What this trial studies

This is a prospective, single-arm study evaluating whether increasing plant-based foods and reducing animal-based foods alters secondary bile acids, the gut microbiome, and related biomarkers in people with prior colorectal adenoma. Researchers will measure stool and blood metabolites, gut bacteria profiles, and gene expression related to bile acid receptors to understand potential links to colorectal cancer risk. The study builds on evidence that diet, bile acids, and the microbiome interact in ways that may influence colorectal cancer development. Participants will follow a specified dietary pattern for the study period and undergo serial sampling and biomarker analysis. The study is conducted at Massachusetts General Hospital with collaboration from the NCI.

Why it matters

Who can join: the full rules

Inclusion Criteria:

* Underwent screening or surveillance colonoscopy with removal of at least one adenoma.
* Age 18-80 years.
* Habitually consume a Western pattern diet.
* BMI of at least 18.5 kg/m2 but less than 35 kg/m2
* Weight stable in last 3 months (loss or gain \<4%).
* Subjects must be able and willing to follow study procedures and instructions.
* Ability to understand and the willingness to sign a written informed consent document.

Exclusion Criteria:

* Strict dietary patterns (e.g., vegan, carnivore, kosher, low-carb etc.).
* Diagnosis of inflammatory bowel disease, liver or kidney disease, bleeding diathesis.
* Any prior diagnosis of gastrointestinal cancer (including esophageal, small intestine, colon, pancreatic), or any diagnosis of other cancers (with the exception of nonmelanoma skin) in which there has been any active treatment within the last three years.
* Known diagnosis of Familial Adenomatous Polyposis (FAP) or Hereditary Non-Polyposis Colorectal Cancer (HNPCC, Lynch Syndrome).
* Any adenoma that was not completely removed during previous colonoscopy.
* Known bleeding tendency/condition (e.g. von Willebrand disease) or history of peptic ulcer or gastrointestinal bleed requiring hospitalization, endoscopic complications, or contraindication to colonoscopy.
* Current use of anticoagulant therapies, including Heparin, Warfarin, Dalteparin sodium, Bivalirudin, Argatroban, Lepirudin, Heparin Sodium, Heparin/Dextrose, and an unwillingness or inability to discontinue anticoagulants.
* Uncontrolled intercurrent illness including, but not limited to, ongoing or active infection, symptomatic congestive heart failure, unstable angina pectoris, cardiac arrhythmia, or psychiatric illness/social situations that would limit compliance with study requirements.
* Regular use of aspirin.
* Use of antibiotics or probiotics.
* Inability or unwillingness to abstain from limited consumption of animal-based food or to provide blood or stool samples during the study.
* Participants who are receiving any other investigational agents.
* Pregnant or breastfeeding.
* Known positive test for human immunodeficiency virus (HIV), hepatitis C virus, or acute or chronic hepatitis B infection.

Where it's running

• Massachusetts General Hospital Cancer Center
  Boston, Massachusetts, United States Recruiting

Study contacts

• Principal investigator: Andrew T. Chan, MD, MPH — Massachusetts General Hospital
• Study coordinator: Andrew T. Chan, MD, MPH
• Email: achan@mgh.harvard.edu
• Phone: 617-726-3212

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How to take part

1. Review the eligibility criteria above with your treating physician.
2. Check the official listing on ClinicalTrials.gov for the latest contact details and recruitment status.
3. Contact the study coordinator or principal investigator to ask for pre-screening. Pre-screening is free and never obligates you to enroll.