Precision Nutrition New York: Whole grains versus fruits & vegetables for your gut and body
Optimizing Dietary Fiber Eating Patterns to Prevent Obesity and Resulting Metabolic Disorders
NA · Cornell University · NCT06777498
This trial will test whether increasing fiber from whole grains versus fruits and vegetables changes gut microbes, short-chain fatty acids, and body composition in adults aged 21–50 with BMI 25–30.
Quick facts
| Phase | NA |
|---|---|
| Study type | Interventional |
| Enrollment | 15 (estimated) |
| Ages | 21 Years to 50 Years |
| Sex | All |
| Sponsor | Cornell University (other) |
| Locations | 1 site (Ithaca, New York) |
| Trial ID | NCT06777498 on ClinicalTrials.gov |
What this trial studies
Adults with BMI 25–30 will follow two different fiber-focused diets—one emphasizing whole grains and one emphasizing fruits and vegetables—in alternating order. Participants provide repeated stool and saliva samples, body composition and anthropometric measurements, and weekly food records over an 11-week period with a total of 10 stool collections. The study looks for predictors that explain why some people’s gut microbiota and microbial metabolites (like SCFAs) respond differently to different fiber sources. Findings will be used to inform more personalized dietary fiber recommendations.
Who should consider this trial
Good fit: Ideal candidates are adults aged 21–50 with BMI 25–30 who can follow diet instructions to increase fiber, provide weekly food records, and provide multiple stool and saliva samples while maintaining stable weight.
Not a fit: People outside the age or BMI range, those unable to comply with frequent sample collection or dietary changes, or those with major medical conditions not mentioned in eligibility may not benefit from participating.
Why it matters
Potential benefit: If successful, the results could help personalize fiber recommendations so people get more consistent gut and body-composition benefits from their diet.
How similar studies have performed: Prior research shows dietary fiber can change the gut microbiome and SCFA production, but individual responses are variable and methods to predict those differences are still emerging.
Eligibility criteria
Show full inclusion / exclusion criteria
Inclusion Criteria: * Age is between 21-50 years * BMI is between 25-30. You can check your BMI here: https://www.cdc.gov/bmi/adult-calculator/index.html * Must be able to have height, weight, waist, and hip circumference, and body composition measured during the study * Must be able to provide saliva samples. * Must be able to provide a phone number and email address at which the study investigators can contact for study-related matters. * Must be able to increase dietary fiber intake to the recommended level following the instructions on the USDA MyPlate website: https://www.myplate.gov/myplate-plan * Must be able to provide food records of everything consumed (food, beverage, and supplements) on one weekday and one weekend day (example Tuesday, Saturday) every week during the study. This will be done using an online survey. * Must be able to provide 10 stool samples over 11 weeks of the study duration. 18) Must have stable weight (within ±3% of usual body weight) for the last two months. * Must be able to to take an online survey to assess recent dietary fiber intake to determine eligibility. Exclusion Criteria: * Electronic medical implant, for example, a pacemaker. * An existing, UNTREATED, thyroid condition. * Use of systemic antibiotics (intravenous injection, intramuscular, or oral) within the last 4 months. * An acute disease at the time of enrollment (Acute disease is defined as the presence of a moderate or severe illness with or without fever). * A chronic, clinically significant (unresolved, requiring ongoing medical management or medication) pulmonary, cardiovascular, gastrointestinal, hepatic, or renal functional abnormality. * Any suspected state of immunosuppression or immunodeficiency including HIV. * A history of active UNTREATED gastrointestinal disorders or diseases including 1. Inflammatory bowel disease (IBD) 2. Ulcerative colitis (mild-moderate-severe) 3. Crohn's or celiac disease 4. Indeterminate colitis 5. Irritable bowel syndrome (IBS) (moderate-severe) 6. Persistent, infectious gastroenteritis, colitis or gastritis 7. Persistent or chronic diarrhea of unknown etiology 8. Clostridium difficile infection (recurrent) 9. Chronic constipation * Previously had bariatric surgery. * An unstable dietary history as defined by major changes in diet during the previous month. For example, elimination or significantly increased intake of a major food group in the diet. * Recent history of chronic alcohol consumption defined as more than 5 drinks (or servings) of alcohol per day. * Female participants: pregnant/lactating.
Where this trial is running
Ithaca, New York
- Cornell University — Ithaca, New York, United States (RECRUITING)
Study contacts
- Study coordinator: Angela Poole
- Email: pnnystudy@cornell.edu
- Phone: 607-255-8796
How to participate
- Review the eligibility criteria above with your treating physician.
- Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
- Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions: Body Composition Changes, Body Weight Changes, dietary fiber, gut microbiome, gut microbiota, short-chain fatty acids, SCFAs, whole grains