Mini-pill to sample gut bacteria after meat versus plant-based meals

Is this trial a fit for you?

A plain-English reading of the study's rules. Only the study team can confirm whether you qualify.

What this trial studies

Participants will follow two different diets in a randomized, double‑blind crossover design, each diet period lasting up to three weeks. After two weeks on a diet, participants will swallow six single‑use, passive mini‑pills with a blue dye and recover the devices from stool over several days. Researchers will profile microbes from the mini‑pill contents and stool and measure blood biomarkers related to cardiometabolic risk to link diet, microbiota changes, and health signals. The mini‑pill device has been developed and tested in lab and animal models and this human study is a proof‑of‑concept for noninvasive GI sampling.

Why it matters

Who can join: the full rules

Inclusion Criteria:

* Men and postmenopausal women
* Age \>50 to \<75 years
* BMI \>20 to \<35 kg/m2
* Normotensive with or without medication
* Normal gastrointestinal function with regular bowel movements at least once every other day
* Normal kidney and liver function
* Willingness to swallow the mini-pills
* Willingness to collect and return multiple stool samples
* Adequate refrigerator and freezer space to store study entrées
* Intent to remain in the greater Boston area during the intervention periods

Exclusion Criteria:

* Individuals self-reporting adhering to any type of vegetarian diet
* Lack of willingness to restrict fish intake to less than once per week during the dietary intervention phases
* Allergy/intolerance/religious reasons to avoid study foods or food ingredients, including known hypersensitivity to Blue 1 food coloring and wheat gluten.
* Regular use of prebiotics or probiotics within the past 3 months
* Regular use of laxatives or fiber supplements
* Chronic constipation
* Chronic use of antibiotics (except topical)
* Regular use of stomach acid lowering and weight loss medications such as GLP-1 agonists
* Use of dental prophylaxis
* Planned colonoscopy 2 months prior to or during the study period
* Gastroparesis
* Swallowing disorder, or inability or difficulty taking pills
* Malabsorptive and inflammatory bowel disease, diverticulosis, and history of diverticulitis, gastric/ esophageal/intestinal surgery, including lap banding or bariatric surgery.
* History of bowel obstruction, pancreas and liver disorders.
* Any form of active substance abuse or dependence (including drug or alcohol abuse). This information will be stored in REDCAP in a subsection that has no identifiers.
* Established major chronic diseases such as cardiovascular disease, diabetes, active cancer within the last 5 years, or any significant medical condition at the study MD's discretion
* A clinical condition that, in the judgment of the study MD or principal investigator, could potentially pose a health risk to the subject while involved in the study.
* Unwillingness to adhere to study protocol
* Intent to increase or decrease body weight during the study period
* No Social Security number (for payment and IRS forms).
* Individuals who directly report to any member of the research team.

Where it's running

• Jean Mayer Human Nutrition Research Center on Aging
  Boston, Massachusetts, United States Recruiting

Study contacts

• Principal investigator: Alice H Lichtenstein, D.Sc. — Tufts University
• Study coordinator: Alice H Lichtenstein, D.Sc.
• Email: alice.lichtenstein@tufts.edu
• Phone: 617 556-3127

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How to take part

1. Review the eligibility criteria above with your treating physician.
2. Check the official listing on ClinicalTrials.gov for the latest contact details and recruitment status.
3. Contact the study coordinator or principal investigator to ask for pre-screening. Pre-screening is free and never obligates you to enroll.