CompletedNot Applicable

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

United States180 participantsStarted 2022-02-01

Plain-language summary

A Mediterranean Diet (MedDiet), a largely plant-based dietary pattern, is relevant to CRC prevention and microbial production of anti-cancer metabolites in observational studies. A MedDiet can shift BA metabolism as shown in primates and when combined with calorie restriction, shows superior adherence and weight control in humans, given its palatability. To date, no studies have tested in an RCT the effects of a MedDiet alone (MedA), WL through lifestyle intervention (WL-A) or a calorie-restricted MedDiet for WL (WL-Med) on the BA-gut microbiome axis and its relevance to CRC prevention among AAs. A multidisciplinary team combining expertise in psychology, nutrition, microbiology, molecular cell biology, computational biology, medicine and biostatistics, proposes to conduct a four-arm RCT in which 232 obese AAs, 45-75 years old complete one of the following 6-month interventions: Med-A, weight stable; WL-A, calorie restriction with no diet pattern change; WLMed; or Control. The investigators will use samples and data collected at baseline, mid-study (month-3) and post-intervention to compare the effects of the interventions on 1) Concentration and composition of circulating and fecal BAs; 2) Gut microbiota and metabolic function; and 3) Gene expression profiles of exfoliated intestinal epithelial cells.

Who can participate

Age range

45 Years – 75 Years

Sex

ALL

See this in plain English?

AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.

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 preg…

Questions worth asking your doctor

Bring these to your next appointment. They're a starting point for a shared conversation — not a sign you qualify or a recommendation to enrol.

1Based on my diagnosis and history, is this trial worth exploring for me — or is there a standard treatment we should try first?
2What does this trial's phase tell us about how much is already known about its safety and benefit?
3What would taking part actually involve for me — visits, tests, time, and travel?
4What are the known and possible risks or side effects I should weigh, and how would they be monitored?
5If this trial isn't the right fit, what other options or trials would you suggest I look into?

Generated to help you prepare — always confirm anything about your own eligibility and care with the study team and your doctor.

Questions for the trial coordinator

The trial coordinator is the person who runs the study day to day. These cover the practical side — logistics, costs, and what taking part would actually mean for your life. The study team confirms whether you meet the criteria; these are questions to ask, not a sign you qualify.

1What does taking part actually involve week to week — how many visits, where, and how long does each one take?
2What costs are covered by the study, and what might I have to pay for myself, including travel, parking, or time off work?
3What happens during screening, and what happens if the study team confirms I don't meet the criteria after those tests?
4Who pays for the scans, blood work, and other tests the trial requires — the study, my insurance, or me?
5How will being in the trial affect my regular care, and will my own doctor stay informed and involved?
6Can I leave the trial at any point if I change my mind, and what would happen to my care if I do?

A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.

What they're measuring

Circulating and fecal bile acids

Timeframe: baseline

Circulating and fecal bile acids

Timeframe: 3 month

Circulating and fecal bile acids

Timeframe: 6 month

Gut microbiota for metabolic function

Timeframe: baseline

Gut microbiota for metabolic function

Timeframe: 3 month

Gut microbiota for metabolic function

Timeframe: 6 month

Gene expression

Timeframe: baseline

Gene expression

Timeframe: 3 month

Trial details

NCT IDNCT04753359

SponsorUniversity of Illinois at Chicago

Sponsor typeOTHER

Study typeINTERVENTIONAL

Primary completion2025-07-31

View on ClinicalTrials.gov More Colorectal Cancer trials

Plain-language summary

Who can participate

Age range

45 Years – 75 Years

Sex

ALL

See this in plain English?

AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.

What they're measuring

Circulating and fecal bile acids

Timeframe: baseline

Circulating and fecal bile acids

Timeframe: 3 month

Circulating and fecal bile acids

Timeframe: 6 month

Gut microbiota for metabolic function

Timeframe: baseline

Gut microbiota for metabolic function

Timeframe: 3 month

Gut microbiota for metabolic function

Timeframe: 6 month

Gene expression

Timeframe: baseline

Gene expression

Timeframe: 3 month