RecruitingNot ApplicableNCT04753359

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

Sponsor

University of Illinois at Chicago

Enrollment

232 participants

Start Date

Feb 1, 2022

Study Type

INTERVENTIONAL

Conditions

Colorectal, Cancer Diet Habit

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.

Eligibility

Min Age: 45 YearsMax Age: 75 Years

Inclusion Criteria9

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 Criteria27

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.