Gut, immune, and blood-vessel responses to a high-fat meal and prebiotic fiber in metabolically healthy obesity
Impaired Gut-Vascular Axis as a Unique Driver of Cardiovascular Disease in Metabolically Healthy Obesity
This project will test how a single high-fat meal affects gut, immune, and blood-vessel responses in adults with metabolically healthy obesity and normal weight, and whether taking the prebiotic inulin changes those responses.
Quick facts
| Phase | Not applicable |
|---|---|
| Study type | Interventional |
| Enrollment | 70 (estimated) |
| Ages | 18 Years to 55 Years |
| Sex | All |
| Sponsor | Ball State University Academic / other |
| Locations | 1 site (Muncie, Indiana) |
| Trial ID | NCT07559227 on ClinicalTrials.gov |
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.
Who should consider this trial
Good fit: Adults 18–55 years old with BMI 18.5–24.9 or >30 kg/m2 who are metabolically healthy (0–1 risk factors), not pregnant or postmenopausal, and not taking antibiotics, probiotics, lipid-/glucose-/blood-pressure-lowering or weight-loss drugs are the intended participants.
Not a fit: People with established cardiometabolic disease (type 2 diabetes, cardiovascular disease), chronic inflammatory or gastrointestinal disorders, recent antibiotic/probiotic use, or those on statins, antihypertensives, metformin, or weight-loss drugs are unlikely to benefit or be eligible.
Why it matters
Potential benefit: If successful, the work could point to dietary or prebiotic approaches to reduce acute gut-derived inflammation and vascular stress after high-fat meals in people with obesity.
How similar studies have performed: Previous research has shown that single high-fat meals can transiently impair endothelial function and that prebiotics like inulin can alter gut microbial markers, but the combined effect on vascular outcomes in metabolically healthy obesity remains incompletely established.
Eligibility criteria
Show full inclusion / exclusion criteria
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 this trial is running
Muncie, Indiana
- 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
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.