Recruiting

Dietary Intervention

Sponsor:

Massachusetts General Hospital

Code:

NCT07162337

Conditions

Colorectal Cancer Prevention

Colorectal Adenoma

Eligibility Criteria

Sex: All

Age: 18 - 70+

Healthy Volunteers: Not accepted

Interventions

Increased Plant-Based Diet and Decreased Animal-Based Diet

Study Details

Brief summary:

This research study is a prospective, single-arm clinical trial to assess the effect of a dietary intervention for more plant-based and less animal-based food intake on secondary bile acid production, gut microbiota, circulating biomarkers and gene expression associated with colonic bile acid receptor activation and colorectal cancer.

Conditions

Colorectal Cancer Prevention

Colorectal Adenoma

Study ID

NCT07162337

Start date

Jun 18, 2026

Status verified date

Jun, 2026

Completion date

Jun 1, 2028

Anticipated

Primary completion date

Jun 18, 2027

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 18 - 70+

Healthy Volunteers: Not accepted

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.

Study Design

Enrollment

40 participants

Anticipated

Intervention Model

Single group

Primary purpose

Prevention

Interventions and Outcome Measures

Arms

experimental: Increased Plant-Based Diet and Decreased Animal-Based Diet

Participants will be instructed to self-regulate their diet by increasing the amount of plant-based foods while decreasing the amount of animal-based foods for a 4-week period.

Interventions

Increased Plant-Based Diet and Decreased Animal-Based Diet

Self-regulated diet; increased plant-based foods with decreased animal-based foods

Primary outcome measure

  • Change in Stool Metabolomics [ Time Frame: From Baseline to Final Visit (5 weeks) ]

Central Contacts and Locations

Central contacts

Andrew T. Chan, MD, MPH

617-726-3212achan@mgh.harvard.edu

Kai Wang, PhD

617-817-9246kwang41@mgh.harvard.edu

Locations

Massachusetts General Hospital Cancer Center

Recruiting

Boston, Massachusetts, United States, 02114

Contacts

Andrew T. Chan, MD, MPH

617-726-3212achan@mgh.harvard.edu

Principal Investigator:

Andrew T. Chan, MD, MPH

More Information

Sponsor

Massachusetts General Hospital

Last update posted

Jun 23, 2026

Last verified

Jun, 2026

Keywords

  • colorectal cancer
  • colorectal cancer prevention
  • colorectal adenoma
  • obesity
  • western diet

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-10. This information was provided to ClinicalTrials.gov by Massachusetts General Hospital on 2026-06-23.