CompletedNot Applicable

Walnuts and Colon Health

United States140 participantsStarted 2022-01-24

Plain-language summary

The purpose of this research study is to examine whether adding walnuts to your diet can have a beneficial effect on the gut bacteria population, inflammatory markers in the blood, and the tissue that lines the inside of the colon.

Who can participate

Age range39 Years – 75 Years

SexALL

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 between the ages of 39-75 years old who meet the criteria of one of the following groups and are eligible to undergo a routine screening or surveillance colonoscopy for colorectal cancer (CRC):
✓. Individuals who have a family history of colon polyps or CRC in a first-degree relative diagnosed with CRC under the age of 65 years, or
✓. Individuals who are referred for colonoscopy following a positive fecal immunochemical test (FIT) or a positive Cologuard screening test and have not had a high-quality colonoscopy in the past 3 years, or
✓. Individuals who have a personal history of colon polyps
✓. Willing and able to provide written informed consent for study participation
✓. Willing to consume 2 ounces (56 grams) of walnuts daily for 3 weeks
✓. Willing to avoid intake of EA/ET-rich foods and beverages (e.g., pomegranates, hazelnuts, pistachios, strawberries, raspberries, blackberries, oak-aged wines, and other items on a list given by researchers) and fermented dairy products containing viable Bifidobacteria or Lactobacilli)
✓. Willing to stop taking dietary supplements, including probiotics

Exclusion criteria

✕. Individual has a personal history of CRC, or a history of any malignancy (other than skin cancer) within the past 5 years
✕. Individual meets the Amsterdam criteria for Lynch Syndrome or has a history of familial adenomatous polyposis (FAP)
✕. Individual has been treated with immunosuppressive agents or systemic steroids, excluding inhalers, at least two weeks prior to the Screening Visit and for the duration of the study
✕. Use of antibiotics at least one month prior to the Screening Visit and for the duration of the study
✕. Patients with severe medical illness or those at high risk for anesthesia, as determined by good clinical practice
✕. Current evidence or previous history of ulcerative colitis or Crohn's disease
✕. Colonoscopy performed for reasons other than screening or surveillance for CRC
✕. HIV infection, chronic viral hepatitis

What they're measuring

Bacterial composition and taxonomy changes in the fecal microbiome

Timeframe: Day 7 and Day 28

Bacterial diversity changes and strain-level variations in the fecal microbiome

Timeframe: Day 7 and Day 28

Bacterial gene expression profile changes in the fecal microbiome

Timeframe: Day 7 and Day 28

Urolithin levels in urine

Timeframe: Day 0, Day 7 and Day 30

Association of urolithin levels with presence (and type) of colonic lesions

Timeframe: Day 30

Correlation of urolithin levels with fecal microbiome composition

Timeframe: Day 7 and Day 28

Correlation of colonic lesion gene expression with urolithin production

Timeframe: Day 30

Association of urolithin levels with the immune composition of the tumor microenvironment

Timeframe: Day 30

Trial details

NCT IDNCT05195970

SponsorUConn Health

Sponsor typeOTHER

Study typeINTERVENTIONAL

Primary completion2026-01-30

View on ClinicalTrials.gov More Colorectal Cancer trials

Who can participate

Age range39 Years – 75 Years

SexALL

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 between the ages of 39-75 years old who meet the criteria of one of the following groups and are eligible to undergo a routine screening or surveillance colonoscopy for colorectal cancer (CRC):
✓. Individuals who have a family history of colon polyps or CRC in a first-degree relative diagnosed with CRC under the age of 65 years, or
✓. Individuals who are referred for colonoscopy following a positive fecal immunochemical test (FIT) or a positive Cologuard screening test and have not had a high-quality colonoscopy in the past 3 years, or
✓. Individuals who have a personal history of colon polyps
✓. Willing and able to provide written informed consent for study participation
✓. Willing to consume 2 ounces (56 grams) of walnuts daily for 3 weeks
✓. Willing to avoid intake of EA/ET-rich foods and beverages (e.g., pomegranates, hazelnuts, pistachios, strawberries, raspberries, blackberries, oak-aged wines, and other items on a list given by researchers) and fermented dairy products containing viable Bifidobacteria or Lactobacilli)
✓. Willing to stop taking dietary supplements, including probiotics

Exclusion criteria

✕. Individual has a personal history of CRC, or a history of any malignancy (other than skin cancer) within the past 5 years
✕. Individual meets the Amsterdam criteria for Lynch Syndrome or has a history of familial adenomatous polyposis (FAP)
✕. Individual has been treated with immunosuppressive agents or systemic steroids, excluding inhalers, at least two weeks prior to the Screening Visit and for the duration of the study
✕. Use of antibiotics at least one month prior to the Screening Visit and for the duration of the study
✕. Patients with severe medical illness or those at high risk for anesthesia, as determined by good clinical practice
✕. Current evidence or previous history of ulcerative colitis or Crohn's disease
✕. Colonoscopy performed for reasons other than screening or surveillance for CRC
✕. HIV infection, chronic viral hepatitis

What they're measuring

Bacterial composition and taxonomy changes in the fecal microbiome

Timeframe: Day 7 and Day 28

Bacterial diversity changes and strain-level variations in the fecal microbiome

Timeframe: Day 7 and Day 28

Bacterial gene expression profile changes in the fecal microbiome

Timeframe: Day 7 and Day 28

Urolithin levels in urine

Timeframe: Day 0, Day 7 and Day 30

Association of urolithin levels with presence (and type) of colonic lesions

Timeframe: Day 30

Correlation of urolithin levels with fecal microbiome composition

Timeframe: Day 7 and Day 28

Correlation of colonic lesion gene expression with urolithin production

Timeframe: Day 30

Association of urolithin levels with the immune composition of the tumor microenvironment

Timeframe: Day 30