An interventional study of Whole Grain Intervention then fruits and vegetables and Fruit and Vegetable Intervention and then whole grains in Body Composition Changes and Body Weight Changes, sponsored by Cornell University. Recruiting at 1 site in United States. Open to participants aged 21 Years to 50 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2025-07-11.
Sponsored by Cornell University · Not applicable, Interventional, and Supportive care
Dietary fiber has been shown to have beneficial effects on human health through its impact on microbes present in the gut. However, these effects can vary between individuals, and everyone may not reap the same health benefits by eating the same sources of fiber. Factors predicting how an individual's gut microbes as well as the beneficial metabolites produced by these microbes change in response to different sources of fiber would be helpful in developing precision nutrition approaches that maximize the benefits of dietary fiber. The objective of this study is to evaluate candidate predictors of gut microbiota response to fiber sources from either whole grains or fruits and vegetables.
231 studies on the registry are indexed under Body Weight Changes; 30 are open to participants now.
This study's planned enrollment of 15 is below the median of 80 across 179 interventional studies indexed under Body Weight Changes.
Browse Body Weight Changes studies →Cornell University is the lead sponsor of 103 studies on the registry; 16 are open to participants now.
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
A history of active UNTREATED gastrointestinal disorders or diseases including
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
BMI (body mass index)
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Clinically significant
Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Immunosuppression
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
HIV
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Whole grain intervention then fruits and vegetables
Other: Whole Grain Intervention then fruits and vegetables
Fruits and vegetables intervention then whole grains
Other: Fruit and Vegetable Intervention and then whole grains
TREATMENT 1: Participants will eat whole grains that add up to the required daily fiber needs. Investigators will provide participants with these products. Participants will follow this intervention for a set period of time. The beginning of the intervention will include a ramp up phase when they eat half of the daily fiber needs to prevent any gastrointestinal distress from suddenly consuming a higher fiber diet than usual. TREATMENT 2: Participants will eat fruits and vegetables that add up to the required daily fiber needs. Investigators will provide participants with these products. Participants will follow this intervention for a set period of time. The beginning of the intervention will include a ramp up phase when participants eat half of the daily fiber needs to prevent any gastrointestinal distress from suddenly consuming a higher fiber diet than usual.
TREATMENT 1: Participants will eat fruits and vegetables that add up to the required daily fiber needs. Investigators will provide participants with these products. Participants will follow this intervention for a set period of time. The beginning of the intervention will include a ramp up phase when participants eat half of the daily fiber needs to prevent any gastrointestinal distress from suddenly consuming a higher fiber diet than usual. TREATMENT 2: Participants will eat whole grains that add up to the required daily fiber needs. Investigators will provide participants with these products. Participants will follow this intervention for a set period of time. The beginning of the intervention will include a ramp up phase when they eat half of the daily fiber needs to prevent any gastrointestinal distress from suddenly consuming a higher fiber diet than usual.
Body weight changes
For each intervention (whole grains \& fruits and vegetables), investigators will measure change in body weight in kg = Post-intervention minus Pre-intervention
Time frame: 3-4 weeks
Body fat percentage changes
For each intervention (whole grains \& fruits and vegetables), investigators will measure change in fat percentage = Post-intervention minus Pre-intervention
Time frame: 3-4 weeks
Gut microbiome measured by 16S rRNA gene sequencing
For each intervention (whole grains \& fruits and vegetables), investigators will calculate changes in relative abundance (proportion) of each gut bacterium from Pre-intervention to Post-intervention.
Time frame: 3-4 weeks
Fecal short-chain fatty acid concentrations (SCFAs)
For each intervention (whole grains \& fruits and vegetables), investigators will measure change in SCFA concentrations = Post-intervention minus Pre-intervention. We will report the SCFAs acetate, butyrate, and propionate.
Time frame: 3-4 weeks
Plan to share: Undecided — We will NEVER share de-identified data about the participants. Our previous publications show aggregated data results. This study is identical to our previous in design, sample types, and data being collected. We shared the de-identified 16S rRNA sequence data of the participants in a public database as requested by the journals. When requested by a journal, we have shared eligibility criteria. Some journals may require us to share our statistical code.
No publications or documents are linked to this record.
Started Jan 2025 (actual). Primary completion is estimated for Oct 2025, 8 months after the start.
Of 90 non-industry interventional studies with no phase under Body Weight Changes, half reached primary completion within 12 months of starting (the median), counting those still running; a quarter within 5 and three quarters within 28. This study's planned 8 months is below that.
Counting every sponsor, half of 99 studies reached it within 12 months; a quarter within 5 and three quarters within 27.
How these figures are worked out, and which studies are left out of them.
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