The Food Environment, Microbial Cysteine Metabolism, and Cancer Disparities (NCT07086833) | Clinical Trial Compass
RecruitingNot Applicable
The Food Environment, Microbial Cysteine Metabolism, and Cancer Disparities
United States40 participantsStarted 2025-08-18
Plain-language summary
The goal of this clinical trial is to learn if changing cysteine levels in the diet can influence how the body processes cysteine in Black and White individuals aged 45-75 with a history of non-cancerous polyps. The main questions it aims to answer are:
* At the beginning of the study, do Black participants have higher levels of cortisol (a stress hormone) and compounds made from cysteine in their blood when compared to White participants?
* Does eating less cysteine lower the body's natural cysteine activity and lead to less gut bacteria that break down cysteine?
* Does eating less cysteine lead to less inflammation in the gut and lower levels of markers of inflammation in the blood?
Research will compare a high cysteine diet and a low cysteine diet, and each participant will eat both diets.
Participants will be in the study for 11 weeks and 2 days. Over the course of the study, participants will:
* Eat a high cysteine diet for 3 weeks, and a low cysteine diet for 3 weeks
* Eat a moderate cysteine diet for 1 week before each study diet
* Complete surveys
* Provide blood, stool, and saliva samples
* Maintain food logs
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:
* Aged 45-75
* Up to date with CRC screening colonoscopy with a high risk of CRC, defined as a history of 3 or more adenomatous polyps (APs) or an AP \>1 cm in the past 5 years
* Identify as Black or Non-Hispanic White
* If female, no menstrual period for at least six months
* Willingness to donate oral wash and stool samples
* Willingness to complete 24-hour dietary recalls
Exclusion Criteria:
* Antibiotic use within the last 6 months
* Abnormal gastrointestinal transit
* A history of organ transplantation
* Use of illicit drugs, combustible tobacco, or dietary supplements
* Pre- or probiotics within the last two months
* A history of cancer treatment within the past 12 months
* CRC or a genetic predisposition to CRC
* A baseline body weight \> 450 lbs
* Weight gain or loss \> 4 kg 3 months prior to study
* Significant food allergies, food preferences or therapeutic or vegetarian diets
* Menstrual cycle within the last 6 months
* Antibiotics in the last 2 months
* Cannot keep a food record for 7 consecutive days during screening after detailed instruction
* Significant medical conditions
* History of eating disorders
* Alcoholism
* Individuals under the age of 18
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.