Mediterranean Diet and Weight Loss to Reduce Colorectal Cancer Risk

Mediterranean Diet and Weight Loss: Targeting the Bile Acid/Gut Microbiome Axis to Reduce Colorectal Cancer

This study is testing if following a Mediterranean diet or losing weight can help reduce the risk of colorectal cancer in obese African Americans aged 45-75.

Quick facts

• Phase: NA
• Study type: Interventional
• Enrollment: 232 (estimated)
• Ages: 45 Years to 75 Years
• Sex: All
• Sponsor: University of Illinois at Chicago (other)
• Locations: 1 site (Chicago, Illinois)
• Trial ID: NCT04753359 on ClinicalTrials.gov

What this trial studies

This clinical trial investigates the effects of a Mediterranean Diet (MedDiet) and weight loss interventions on the bile acid-gut microbiome axis to reduce colorectal cancer (CRC) risk among obese African Americans aged 45-75. Participants will be randomized into four groups: MedDiet without weight loss, weight loss without dietary changes, calorie-restricted MedDiet, or a control group. The study aims to understand how these dietary approaches can alter gut microbiota and bile acid metabolism, potentially lowering CRC incidence. A multidisciplinary team will oversee the trial, ensuring a comprehensive approach to the interventions.

Who should consider this trial

Good fit: Ideal candidates are African American men and women aged 45-75 with a BMI between 30-50 kg/m2.

Not a fit: Patients with significant gastrointestinal diseases, a history of colorectal cancer, or other severe health conditions may not benefit from this study.

Why it matters

Potential benefit: If successful, this study could provide a dietary intervention that significantly reduces the risk of colorectal cancer in high-risk populations.

How similar studies have performed: While similar dietary interventions have shown promise in observational studies, this randomized controlled trial approach is novel in targeting the bile acid-gut microbiome axis specifically for CRC prevention.

Eligibility criteria

Inclusion Criteria:

* Men and women 45-75 years of age
* Self-identify as AA
* BMI 30-50 kg/m2
* Willingness to participate in all procedures including maintaining weight/current physical activity if randomized to Med-A/Control
* Willingness and ability to provide informed consent
* Willingness to be randomized
* Understands English
* Has access to a phone
* Plans to reside in Chicago for the next 8-10 months.

Exclusion Criteria:

* renal disease
* autoimmune disorders
* immunodeficiency
* malabsorptive disorders
* significant gastrointestinal and/or hepatic diseases
* severe ischemic heart disease
* severe pulmonary disease
* history of bariatric surgery
* alcohol abuse (\> 50 grams/day)
* illicit drug abuse (other than marijuana based on self-report)
* combustible tobacco use
* uncontrolled diabetes based on HbA1c\>9.0%
* eating disorder
* cancer treatment within the past 12 months
* history of CRC
* genetic predisposition to CRC (e.g., Lynch syndrome)
* weight \> 450 lbs. (weight limitation of the DXA scanner)
* currently adhering to a MedDiet based on a diet screener
* self-reported WL \> 3% in the past 12 months
* currently on a WL diet or actively involved in a formal WL program (e.g., Weight Watchers)
* food allergies that would interfere with adopting a MedDiet
* antibiotic use in the past 3 months
* night-shift work
* regular use (i.e., ≥ 3 times per week) of prebiotics/probiotics/synbiotics, dietary fiber supplements, or laxatives,
* Gait disorder
* currently pregnant
* active Covid-19 infection within 6 weeks of recruitment/data collection.

Where this trial is running

Chicago, Illinois

• University of Illinois at Chicago — Chicago, Illinois, United States (RECRUITING)

Study contacts

• Principal investigator: Lisa Tussing-Humphreys, PhD, RD — University of Illinois at Chicago
• Study coordinator: Lara Blumstein

Conditions: Colorectal Cancer, Diet Habit