The Food Environment, Microbial Cysteine Metabolism, and Cancer Disparities

NCT07086833 | Recruiting

• 2 other identifiers: IRB-2023-1426RSG-23-1154989-01-CSCT
• Study Type: interventional
• Target: 40
• Locations: 1 country
• Sites: 2

Brief 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

Conditions

Colorectal Cancer Risk; Colorectal Cancer Prevention; Colorectal Cancer; Diet Modification; Dietary Intervention; Cancer Prevention

Keywords

Intestinal Neoplasms; Neoplasms; Colonic Diseases; Colorectal Cancer; Colorectal Neoplasms; Gut Microbiome; Cysteine Metabolism; Colorectal Adenomas; Intestinal Diseases

Outcome Measures

Primary Outcomes (3)

• 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.

  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.

  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.

  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 (4)

• Quantification of serum hydroxycortisol and cysteine metabolism markers

  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

  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)

• Whole body composition

  Baseline, Week 4 (Day 30), Week 11 (Day 79)

• Exfoliated intestinal epithelial cell transcriptomics

  Baseline, Week 1 (Day 8), Week 4 (Day 29), Week 8 (Day 57), Week 11 (Day 78)

Other Outcomes (3)

• Psychosocial health

  Baseline, Week 4 (Day 30), Week 8 (Day 58),Week 11 (Day 79)

• Medication use

  Baseline, Week 4 (Day 30), Week 8 (Day 58),Week 11 (Day 79)

• Bowel habits

  Baseline, Week 4 (Day 30), Week 8 (Day 58),Week 11 (Day 79)

Study Arms (2)

High cysteine diet

EXPERIMENTAL

Participants will eat a diet higher in cysteine, relying on more animal based protein.

Other: High Cysteine Diet

Low cysteine diet

EXPERIMENTAL

Participants will eat a diet lower in cysteine, relying on more plant based protein.

Other: Low Cysteine Diet

Interventions

Low Cysteine Diet OTHER

A diet low in cysteine, about 1.4 g/1000 kcal.

Low cysteine diet

High Cysteine Diet OTHER

A diet high in cysteine, about 3 g/1000 kcal.

High cysteine diet

Eligibility Criteria

• Age: 45 Years - 75 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• 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

You may not qualify if:

• 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

Sponsors & Collaborators

• Purdue University: lead
• American Cancer Society, Inc.: collaborator
• Indiana University: collaborator

Study Sites (2)

University Hospital Clinical Research Center

Indianapolis, Indiana, 46202, United States

NOT YET RECRUITING

Purdue Clinical Research Center

West Lafayette, Indiana, 47906, United States

RECRUITING

MeSH Terms

Conditions

Colorectal Neoplasms; Intestinal Neoplasms; Neoplasms; Colonic Diseases; Intestinal Diseases

Condition Hierarchy (Ancestors)

Gastrointestinal Neoplasms; Digestive System Neoplasms; Neoplasms by Site; Digestive System Diseases; Gastrointestinal Diseases; Rectal Diseases

Central Study Contacts

Patricia G Wolf, PhD, RD

CONTACT

765-494-1860; wolfpm@purdue.edu

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: TRIPLE
• Who Masked: PARTICIPANT, INVESTIGATOR, OUTCOMES ASSESSOR
• Purpose: PREVENTION
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Dr. Patricia Wolf, Assistant Professor, Department of Nutrition Science

Model Details: Randomized controlled cross-over feeding trial

Study Record Dates

• First Submitted: July 17, 2025
• First Posted: July 25, 2025
• Study Start: July 30, 2025
• Primary Completion (Estimated): June 1, 2027
• Study Completion (Estimated): August 1, 2027
• Last Updated: July 25, 2025

Record last verified: 2025-05

Data Sharing

• IPD Sharing: Will not share

Locations

US (2)