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Recruiting

NCT Number: NCT06777498

The Precision Nutrition New York Study

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.

Recruiting

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Key information

Age range

21 year–50 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Cornell University

Ithaca, New York, 14850, United States

Location status: Recruiting

Location contact

Angela Poole, PhD

CONTACT

[email protected]

607-255-8796

Angela Poole, PhD

PRINCIPAL_INVESTIGATOR

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

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
  • Inflammatory bowel disease (IBD)
  • Ulcerative colitis (mild-moderate-severe)
  • Crohn's or celiac disease
  • Indeterminate colitis
  • Irritable bowel syndrome (IBS) (moderate-severe)
  • Persistent, infectious gastroenteritis, colitis or gastritis
  • Persistent or chronic diarrhea of unknown etiology
  • Clostridium difficile infection (recurrent)
  • 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.

Treatment and study plan

Whole Grain Intervention then fruits and vegetables

Other

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.

Fruit and Vegetable Intervention and then whole grains

Other

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.

Primary outcomes

  1. Body weight changes

    Time frame: 3-4 weeks

    For each intervention (whole grains & fruits and vegetables), investigators will measure change in body weight in kg = Post-intervention minus Pre-intervention

  2. Body fat percentage changes

    Time frame: 3-4 weeks

    For each intervention (whole grains & fruits and vegetables), investigators will measure change in fat percentage = Post-intervention minus Pre-intervention

Secondary outcomes

  1. Gut microbiome measured by 16S rRNA gene sequencing

    Time frame: 3-4 weeks

    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.

  2. Fecal short-chain fatty acid concentrations (SCFAs)

    Time frame: 3-4 weeks

    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.

Study contacts

Contact information is provided by the study sponsor or research team.

Angela Poole

CONTACT

[email protected]

607-255-8796

Colette Strathman

CONTACT

Sponsors and collaborators

Lead sponsor

Cornell University

Other

Registry information

Official study title

Optimizing Dietary Fiber Eating Patterns to Prevent Obesity and Resulting Metabolic Disorders

Acronym: PNNY

Important dates

Study start
2025
Primary completion
2025
Study completion
2025
First posted
Jan 16, 2025
Registry last updated
Jul 11, 2025

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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