Colorectal CancerNCT07086833
The Food Environment, Microbial Cysteine Metabolism, and Cancer Disparities
A study testing Low Cysteine Diet and High Cysteine Diet in people with Colorectal Cancer, run by Purdue University at 2 sites in United States.
Trial 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. Read more about this study
- Who is it for?
- Ages 45 to 75 years
- Conditions the study is for
- Colorectal Cancer
- What is being tested?
- Low Cysteine Diet and High Cysteine Diet
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 40 participants
- Where
- 2 sitesUnited States
- Study dates
- 18 Aug 2025to 1 Dec 2027
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 45 to 75 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- 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
Who cannot join
- 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
Show all 17Show fewer
- 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
Trial locations and contacts
2 sites in 1 country. Contact the study team or a site near you to ask about taking part.
United States2 sites, 2 recruiting
- Not yet recruiting
University Hospital Clinical Research Center
Indianapolis, Indiana, 46202
Ariana Moffitt, MPH, 765-494-1860, amoffit@purdue.edu
- Recruiting
Purdue Clinical Research Center
West Lafayette, Indiana, 47906
Ariana Moffitt, MPH, 765-494-1860, amoffit@purdue.edu
About this study
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?
Read more
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
- Conditions
- Colorectal Cancer
- Being tested
- Low Cysteine Diet, High Cysteine Diet
- Keywords
- Intestinal Neoplasms, Neoplasms, Colonic Diseases, Colorectal Cancer, Colorectal Neoplasms, Gut Microbiome, Cysteine Metabolism, Colorectal Adenomas, Intestinal Diseases, Cancer Prevention, Diet modification, Dietary Intervention, Colorectal Cancer Risk, Colorectal Cancer Prevention
- Medical subject headings
- Colorectal Neoplasms, Intestinal Neoplasms, Neoplasms, Colonic Diseases, Intestinal Diseases
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Low Cysteine DietOther
A diet low in cysteine, about 1.4 g/1000 kcal.
High Cysteine DietOther
A diet high in cysteine, about 3 g/1000 kcal.
| Study group | Role | What they receive |
|---|---|---|
| High cysteine diet | Experimental | Participants will eat a diet higher in cysteine, relying on more animal based protein. Receives: Other: High Cysteine Diet |
| Low cysteine diet | Experimental | Participants will eat a diet lower in cysteine, relying on more plant based protein. Receives: Other: Low Cysteine Diet |
What is being measured
The primary outcome is the main question the study is designed to answer.
Colonic inflammation
Fecal calprotectin, a marker of intestinal inflammation, will be measured from 100 mg of stool collected at the respective timeframe using a CALPRO Calprotectin ELISA test.
Measured: Baseline, Week 1 (Day 8), Week 2 (Day 15), Week 4 (Day 29), Week 7 (Day 49), Week 8 (Day 57), Week 9 (Day 64), Week 11 (Day 78)
Fecal microbial content
Microbial genomic DNA will be extracted from stool obtained at the respective timeframe using a Qiagen DNeasy PowerSoil Kit. Genomic DNA will be fragmented using a Covaris S2 and processed into libraries using an Integrated DNA Technologies xGen DNA Library Prep Kit. Final libraries will be pooled and sequenced on an Illumina NovaSeq X using 25B chemistry.
Measured: Baseline, Week 1 (Day 8), Week 2 (Day 15), Week 4 (Day 29), Week 7 (Day 49), Week 8 (Day 57), Week 9 (Day 64), Week 11 (Day 78)
Systemic markers of inflammation
Serum from blood collected at the respective timeframe will be analyzed in triplicate with the Bio-Plex® Precision Pro™ (Bio rad, Hercules, CA) human cytokine 10-plex immunoassay to detect IL-1β, IL-6, IFN-γ, TNF-α, IL-2, IL-4, IL-5, IL-10, IL-12 (p70) and IL-13.
Measured: Baseline, Week 1 (Day 9), Week 2 (Day 16), Week 3 (Day 23), Week 4 (Day 30), Week 7 (Day 50), Week 8 (Day 58), Week 9 (Day 65), Week 11 (Day 79)
Secondary outcomes (3)
Quantification of serum hydroxycortisol and cysteine metabolism markers
Serum hydroxycortisol and measures of cysteine metabolism (cysteine, homocysteine, lanthionine, cystathionine, serine) will be determined using hydrophilic interaction liquid chromatography with triple quadrupole tandem mass spectrometry by the Purdue Metabolite Profiling Facility.
Measured: Baseline, Week 1 (Day 9), Week 2 (Day 16), Week 3 (Day 23), Week 4 (Day 30), Week 7 (Day 50), Week 8 (Day 58), Week 9 (Day 65), Week 11 (Day 79)
Absolute and relative quantification of microbial cysteine metabolic genes
Microbial genomic DNA will be extracted from stool obtained at the respective timeframe using a Qiagen DNeasy PowerSoil Kit. To estimate gene content, metagenomic libraries will be constructed from stool DNA. Metagenomic data will be processed to filter potential host DNA sequences and remove low-quality reads. Raw shotgun data will be assembled using MEGAHIT and assembled contigs will be binned using MetaBAT2. Taxonomic classification of binned contigs will be performed using CAT/BAT and differences genera that have functional genes for sulfur metabolism will be assessed. Assembled and binned metagenomes will be surveyed for genes for cysteine metabolism using custom hidden Markov model (HMM) libraries.
Measured: Baseline, Week 1 (Day 8), Week 2 (Day 15), Week 4 (Day 29), Week 7 (Day 49), Week 8 (Day 57), Week 9 (Day 64), Week 11 (Day 78)
Exfoliated intestinal epithelial cell transcriptomics
Exfoliated intestinal epithelial cells separated from stool collected at the respective timeframe with gene expression analysis
Measured: Baseline, Week 1 (Day 8), Week 4 (Day 29), Week 8 (Day 57), Week 11 (Day 78)
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted25 Jul 2025
- Study start18 Aug 2025
- Primary completion1 Dec 2027 (estimated)
- Study completion1 Dec 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Colorectal CancerStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Crossover
- Model description
- Randomized controlled cross-over feeding trial
- Masking
- Triple blind
- Who is masked
- Participant, Investigator, Outcomes assessor
- Enrolment
- 40 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Purdue University
- Sponsor type
- University, hospital or other
- Collaborators
- American Cancer Society, Inc., Indiana University
- Responsible party
- Principal investigator, Patricia Wolf, Purdue University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07086833
- Sponsor's protocol ID
- IRB-2023-1426
- Other IDs
- RSG-23-1154989-01-CSCT
- Status last verified
- May 2026
- First submitted
- 17 Jul 2025
- Last updated
- 14 May 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 14 May 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- The Food Environment, Microbial Cysteine Metabolism, and Cancer Disparities
- ClinicalTrials.gov ID
- NCT07086833
- Acronym / sponsor ID
- IRB-2023-1426
- Conditions
- Colorectal Cancer
- Keywords
- Intestinal Neoplasms, Neoplasms, Colonic Diseases, Colorectal Cancer, Colorectal Neoplasms, Gut Microbiome, Cysteine Metabolism, Colorectal Adenomas
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 40 participants (estimated)
- Lead sponsor
- Purdue UniversityUniversity, hospital or other
- Collaborators
- American Cancer Society, Inc., Indiana University
- Study start
- 18 Aug 2025 (actual)
- Primary completion
- 1 Dec 2027 (estimated)
- Study completion
- 1 Dec 2027 (estimated)
- First posted
- 25 Jul 2025 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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
Study design
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Triple blind (participant, investigator, outcomes assessor)
- Number of arms
- 2
- Model description
- Randomized controlled cross-over feeding trial
| Arm | Type | Receives |
|---|---|---|
| High cysteine diet | Experimental | Other: High Cysteine DietParticipants will eat a diet higher in cysteine, relying on more animal based protein. |
| Low cysteine diet | Experimental | Other: Low Cysteine DietParticipants will eat a diet lower in cysteine, relying on more plant based protein. |
Who may qualify
- Ages
- 45 to 75 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (6 listed)
- 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
Key exclusion criteria (17 listed)
- 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
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Low Cysteine DietA diet low in cysteine, about 1.4 g/1000 kcal. | Other | Low cysteine diet |
| High Cysteine DietA diet high in cysteine, about 3 g/1000 kcal. | Other | High cysteine diet |
Primary outcome
Colonic inflammation
Time frame: Baseline, Week 1 (Day 8), Week 2 (Day 15), Week 4 (Day 29), Week 7 (Day 49), Week 8 (Day 57), Week 9 (Day 64), Week 11 (Day 78)
Fecal calprotectin, a marker of intestinal inflammation, will be measured from 100 mg of stool collected at the respective timeframe using a CALPRO Calprotectin ELISA test.
Fecal microbial content
Time frame: Baseline, Week 1 (Day 8), Week 2 (Day 15), Week 4 (Day 29), Week 7 (Day 49), Week 8 (Day 57), Week 9 (Day 64), Week 11 (Day 78)
Microbial genomic DNA will be extracted from stool obtained at the respective timeframe using a Qiagen DNeasy PowerSoil Kit. Genomic DNA will be fragmented using a Covaris S2 and processed into libraries using an Integrated DNA Technologies xGen DNA Library Prep Kit. Final libraries will be pooled and sequenced on an Illumina NovaSeq X using 25B chemistry.
Systemic markers of inflammation
Time frame: Baseline, Week 1 (Day 9), Week 2 (Day 16), Week 3 (Day 23), Week 4 (Day 30), Week 7 (Day 50), Week 8 (Day 58), Week 9 (Day 65), Week 11 (Day 79)
Serum from blood collected at the respective timeframe will be analyzed in triplicate with the Bio-Plex® Precision Pro™ (Bio rad, Hercules, CA) human cytokine 10-plex immunoassay to detect IL-1β, IL-6, IFN-γ, TNF-α, IL-2, IL-4, IL-5, IL-10, IL-12 (p70) and IL-13.
3 secondary outcomes
Quantification of serum hydroxycortisol and cysteine metabolism markers
Time frame: Baseline, Week 1 (Day 9), Week 2 (Day 16), Week 3 (Day 23), Week 4 (Day 30), Week 7 (Day 50), Week 8 (Day 58), Week 9 (Day 65), Week 11 (Day 79)
Absolute and relative quantification of microbial cysteine metabolic genes
Time frame: Baseline, Week 1 (Day 8), Week 2 (Day 15), Week 4 (Day 29), Week 7 (Day 49), Week 8 (Day 57), Week 9 (Day 64), Week 11 (Day 78)
Exfoliated intestinal epithelial cell transcriptomics
Time frame: Baseline, Week 1 (Day 8), Week 4 (Day 29), Week 8 (Day 57), Week 11 (Day 78)
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 14 May 2026.
- Individual participant dataSharing planned: No
Related trials for Colorectal Cancer
Not yet recruitingPhase 1
Hepatic Artery Infusion of Carfilzomib in Participants With Liver Metastatic Disease Previously Treated With Hepatic Artery Infusion Pump Therapy
Colorectal Neoplasms, Neoplasms
Active, not recruiting
Streamlined Geriatric and Oncological Evaluation Based On IC Technology
Breast Cancer, Comorbidities and Coexisting Conditions
RecruitingObservational study
Pre- and On-treatment Multi-omics Profiling of Locally Advanced Rectal Cancer
Rectal Neoplasms
Enrolling by invitationObservational study
Natural History Study of Early Life Exposures in Agriculture (ELEA)
Prostate Cancer, Leukemia
RecruitingPhase 2
Tislelizumab in People With Colorectal Cancer
Colorectal Cancer
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
2 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Low Cysteine Diet and High Cysteine Diet in people with Colorectal Cancer, run by Purdue University at 2 sites in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 6 inclusion and 17 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 14 May 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 2 sites in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Patricia G Wolf, PhD, RD (765-494-1860, wolfpm@purdue.edu), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Colonic inflammation (time frame: Baseline, Week 1 (Day 8), Week 2 (Day 15), Week 4 (Day 29), Week 7 (Day 49), Week 8 (Day 57), Week 9 (Day 64), Week 11 (Day 78)). The study lists 3 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 14 May 2026.