Gut, immune, and blood-vessel responses to a high-fat meal and prebiotic fiber in metabolically healthy obesity

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

The project has two linked parts: a single high-fat meal challenge with intensive vascular and blood-sampling measurements, and a supplementation phase testing prebiotic inulin versus a maltodextrin placebo. Adults meeting metabolically healthy criteria (0–1 cardiometabolic risk factors) and either normal or obese BMI ranges are recruited and undergo baseline vascular testing (FMD, PWA, PWV), an intravenous catheter, then a ~700 kcal high-fat meal followed by serial blood draws up to 6 hours to measure intestinal permeability and inflammatory biomarkers. Serum from timepoints will also be used in mechanistic experiments to explore how gut-derived factors affect vascular and immune responses. The supplementation portion compares inulin to placebo to see if prebiotic fiber alters those gut-immune-vascular responses in people with metabolically healthy obesity.

Why it matters

Who can join: the full rules

Inclusion Criteria:

* 18-55 years old.
* BMI is 18.5-24.9 kg/m2 or \>30kg/m2 (part 1). BMI \> 30 kg/m2 (part 2)
* Not pregnant or expecting to become pregnant (females only).
* Not postmenopausal (females only).
* Have 0-1 risk factors based on blood pressure, blood sugar, triglycerides, and HDL-cholesterol ("good cholesterol").
* Have not been diagnosed with an advanced cardiometabolic condition (e.g., cardiovascular disease, type 2 diabetes).
* Have not been diagnosed with a chronic inflammatory or gastrointestinal condition (e.g., rheumatoid arthritis, inflammatory bowel disease).
* Do not regularly take anti-inflammatory drugs (more than 2x week) or are able to temporarily suspend use of anti-inflammatory drugs three days prior to the study visit.
* Have not taken antibiotics or probiotics in the last month.
* Do not use lipid-lowering drugs (e.g., statins), glucose-lowering drugs (e.g., metformin), or anti-hypertensive drugs.
* Do not use weight-loss drugs (e.g., Ozempic, Wegovy).
* Have not had any surgery that alters the stomach/gastrointestinal tract (e.g., gastric sleeve, gastric bypass).
* Do not use tobacco products or any illicit drugs.
* Do not have a pacemaker.
* Do not have dietary restrictions prohibiting consumption of the provided meal (e.g., vegan/vegetarian diets, gluten-free diet, relevant food allergies).
* Able to stay in the supine position in the dark for at least 10 minutes (related to vascular measurements)

Exclusion Criteria:

* Not 18-55 years old.
* BMI is not 18.5-24.9 kg/m2 or \>30kg/m2 (part 1). BMI is not \> 30 kg/m2 (part 2)
* Pregnant or expecting to become pregnant (females only).
* Postmenopausal (females only).
* Do not have 0-1 risk factors based on blood pressure, blood sugar, triglycerides, and HDL-cholesterol ("good cholesterol").
* Have been diagnosed with an advanced cardiometabolic condition (e.g., cardiovascular disease, type 2 diabetes).
* Have been diagnosed with a chronic inflammatory or gastrointestinal condition (e.g., rheumatoid arthritis, inflammatory bowel disease).
* Regularly take anti-inflammatory drugs (more than 2x week) or are unable to temporarily suspend use of anti-inflammatory drugs three days prior to the study visit.
* Have taken antibiotics or probiotics in the last month.
* Use lipid-lowering drugs (e.g., statins), glucose-lowering drugs (e.g., metformin), or anti-hypertensive drugs.
* Use weight-loss drugs (e.g., Ozempic, Wegovy).
* Have had any surgery that alters the stomach/gastrointestinal tract (e.g., gastric sleeve, gastric bypass).
* Use tobacco products or any illicit drugs.
* Have a pacemaker.
* Have dietary restrictions prohibiting consumption of the provided meal (e.g., vegan/vegetarian diets, gluten-free diet, relevant food allergies).
* Not able to stay in the supine position in the dark for at least 10 minutes (related to vascular measurements)

Where it's running

• Health Professions Building
  Muncie, Indiana, United States Recruiting

Study contacts

• Principal investigator: Bryant Keirns, PhD — Ball State University
• Study coordinator: Bryant Keirns, PhD
• Email: bryant.keirns@bsu.edu
• Phone: 765-285-8356

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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.