Gut, Immune, and Vascular Health in Metabolically Healthy Obesity

NCT07559227 | Recruiting

• 1 other identifier: IRB-FY2026-239
• Study Type: interventional
• Target: 70
• Locations: 1 country
• Sites: 1

Brief Summary

The investigators seek to better understand how a single high-fat meal impacts gut, immune, and vascular outcomes in individuals with "metabolically healthy obesity" (obesity and largely normal cardiometabolic profile) and "metabolically healthy normal-weight individuals." Second, the investigators seek to understand how a prebiotic fiber (inulin) impacts gut, immune, and vascular outcomes in individuals with "metabolically healthy obesity."

Conditions

Metabolically Healthy Obesity

Keywords

Gut-vascular axis; Intestinal permeability; vascular function; obesity

Outcome Measures

Primary Outcomes (7)

• Serum lipopolysaccharide binding protein

  Part 1: The investigators will measure lipopolysaccharide binding protein at baseline and , 1-, 2-, 3-, 4-, 5-, and 6-hours after the meal. Part 2: The investigators will measure lipopolysaccharide binding protein at baseline and 2-, 4-, and 6-weeks post intervention.

  Through study completion, up to 2 years

• Serum interleukin-6

  Part 1: The investigators will measure interleukin-6 at baseline and , 1-, 2-, 3-, 4-, 5-, and 6-hours after the meal. Part 2: The investigators will measure interleukin-6 at baseline and 2-, 4-, and 6-weeks post intervention.

  Through study completion, up to 2 years.

• Flow-mediated dilation

  Part 1: The investigators will measure flow-mediated dilation at baseline and 2-, 4-, 6-hours after the meal. Part 2: The investigators will measure flow-mediated dilation at baseline and 2-, 4-, and 6-weeks post intervention.

  Through study completion, up to 2 years

• Serum C reactive protein

  Part 2: The investigators will measure C reactive protein at baseline and 2-, 4-, and 6-weeks post intervention.

  Through study completion, up to 2 years

• Serum lipopolysaccharide

  Part 1: The investigators will measure lipopolysaccharide at baseline and , 1-, 2-, 3-, 4-, 5-, and 6-hours after the meal. Part 2: The investigators will measure lipopolysaccharide at baseline and 2-, 4-, and 6-weeks post intervention.

  Through study completion, up to 2 years

• Serum TNF-alpha

  The investigators will measure serum TNF-alpha at baseline and , 1-, 2-, 3-, 4-, 5-, and 6-hours after the meal. Part 2: The investigators will measure TNF-alpha at baseline and 2-, 4-, and 6-weeks post intervention.

  Through study completion, up to 2 years

• Serum zonulin

  Part 2: The investigators will measure serum zonulin at baseline and 2-, 4-, and 6-weeks post intervention.

  Through study completion, up to 2 years.

Secondary Outcomes (10)

• Augmentation Index

  Through study completion, up to 2 years

• Pulse-wave velocity

  Through study completion, up to 2 years

• Serum soluble CD14

  Through study completion, up to 2 years

• Serum IL-1 beta

  Through study completion, up to 2 years

• Serum soluble VCAM-1

  Through study completion, up to 2 years

Other Outcomes (1)

• Body fat percent

  Through study completion, up to 2 years.

Study Arms (2)

Metabolically Healthy Obesity Group

EXPERIMENTAL

Individuals with a body mass index greater than 30 kg/m2 and 0-1 of the following risk factors: blood pressure \>130/85 mmHg, triglycerides \> 150 mg/dL, glucose \> 100 mg/dL, and HDL-C \< 50 (females) or \< 40 (males).

Dietary Supplement: Inulin Supplementation; Dietary Supplement: Maltodextrin (Placebo); Other: High-fat meal

Metabolically Healthy Normal Weight Group

ACTIVE COMPARATOR

Individuals with a body mass index between 18.5-24.9 kg/m2 and 0-1 of the following risk factors: blood pressure \>130/85 mmHg, triglycerides \> 150 mg/dL, glucose \> 100 mg/dL, and HDL-C \< 50 (females) or \< 40 (males).

Other: High-fat meal

Interventions

Inulin Supplementation DIETARY_SUPPLEMENT

Half of participants in part 2 will recieve supplemental inulin or placebo (maltodextrin).

Metabolically Healthy Obesity Group

Maltodextrin (Placebo) DIETARY_SUPPLEMENT

Half of participants in part 2 will recieve supplemental inulin or placebo (maltodextrin).

Metabolically Healthy Obesity Group

High-fat meal OTHER

All participants in part 1 (both metabolically healthy normal weight and metabolically healthy obesity) will consume a high-fat meal designed to invoke changes in gut, immune, and vascular parameters.

Metabolically Healthy Normal Weight Group; Metabolically Healthy Obesity Group

Eligibility Criteria

• Age: 18 Years - 55 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• 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).

You may not qualify if:

• 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).

Sponsors & Collaborators

• Ball State University: lead

Study Sites (1)

Health Professions Building

Muncie, Indiana, 47306, United States

RECRUITING

MeSH Terms

Conditions

Obesity, Metabolically Benign; Obesity

Interventions

maltodextrin

Condition Hierarchy (Ancestors)

Overweight; Overnutrition; Nutrition Disorders; Nutritional and Metabolic Diseases; Body Weight; Signs and Symptoms; Pathological Conditions, Signs and Symptoms

Study Officials

• Bryant Keirns, PhD

  Ball State University

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Bryant Keirns, PhD

CONTACT

765-285-8356; bryant.keirns@bsu.edu

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: SINGLE
• Who Masked: PARTICIPANT
• Purpose: OTHER
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Assistant Professor

Model Details: In part 1 of the study, all participants (n=20 with metabolically healthy obesity and n=20 with metabolically healthy normal weight) will consume a single high-fat meal. There is no randomization. In part 2 of the study, metabolically healthy obese individuals (n=30) will be randomized to consume supplemental inulin or maltodextrin (placebo) for 6 weeks. The present project is approved under one IRB application, so the investigators are unable to separate part 1 and part 2 into two CT.gov entries. The investigators have selected "randomized" below, but in reality there is no randomization procedures in part 1.

Study Record Dates

• First Submitted: April 16, 2026
• First Posted: April 30, 2026
• Study Start: March 1, 2026
• Primary Completion (Estimated): December 1, 2027
• Study Completion (Estimated): December 1, 2027
• Last Updated: April 30, 2026

Record last verified: 2026-04

Data Sharing

• IPD Sharing: Will share
• Time Frame: 12/31/2027

Locations

US (1)