Impact of Supplemental Fiber on Gut and Vascular Health Related in Obesity Phenotypes

Not Applicable

Recruiting

• Conditions: Metabolic Syndrome; Metabolically Healthy Obesity; Metabolically Abnormal Obesity; Healthy Participants

• Registration Number: NCT07095426
• Lead Sponsor: Ball State University

Brief Summary

Based on prior research, the investigators are interested in whether an intervention targeting gut health (supplemental fiber for 9 weeks total) will improve vascular health in individuals with obesity. Additionally, the investigators are interested in if this response differs based on whether individuals with obesity have very few heart disease risk factors or several heart disease risk factors.

Detailed Description

The investigators will recruit individuals with obesity (body mass index ≥30 kg/m2) from Ball State University Campus and the surrounding community. Participants will be grouped as "metabolically healthy" (0-1 metabolic syndrome risk factors) or "metabolically unhealthy" (≥2 metabolic syndrome risk factors) Participants will be asked to consume inulin for 9 weeks total. Participants will consume 6g of inulin per day during week 1 as a run-in period. The following 8 weeks participants will consume 12g of inulin per day.

Participants will be asked to report for in-lab assessments/visits before the study begins (baseline), halfway through the intervention which starts following the 1-week run-in period (5 weeks), and at the conclusion of the intervention (9 weeks). At all of these assessments, participants will arrive in the morning (roughly 6-10 AM) having fasted for \~10 hours. We will then collect a blood sample, followed by several vascular measurements including flow-mediated dilation, pulse wave analysis, pulse wave velocity, and an electrocardiogram. Body weight and composition will also be assessed using a bioimpedance scale at each visit. Upon completion of each in-lab visit, participants will be asked to wear an ambulatory blood pressure monitoring device for 24 hours and will complete a 3-day food record. Dual-energy X-ray absorptiometry scans will be used to assess body composition at baseline and final study visits. Participants will provide a stool sample collected at home following baseline and final study visits as an optional procedure.

Study Timeline

• Study Start: 2025-05-20
• Status Verified: 2025-07
• Study First Submitted: 2025-07-24
• Study First Submitted QC: 2025-07-24
• Last Update Submitted: 2025-07-24
• Study First Posted: 2025-07-31
• Last Update Posted: 2025-07-31
• Primary Completion: 2026-11
• Study Completion: 2027-05-01

Recruitment & Eligibility

• Status: RECRUITING
• Sex: All
• Target Recruitment: 20

Inclusion Criteria

• Participants are 18-55 years old.
• Participants BMI is ≥30 kg/m2 - this BMI requirement is due to our research aims.
• Participants have either 0-1 or 2+ of the following risk factors outside of the normal reference ranges: blood pressure, blood sugar, triglycerides, and HDL-cholesterol.
• Participants are not pregnant or expecting to become pregnant (females only). •Participants are not postmenopausal (females only).
• Participants have not been diagnosed with an advanced cardiometabolic condition (e.g., cardiovascular disease, type 2 diabetes).
• Participants have not been diagnosed with a chronic inflammatory condition (e.g., rheumatoid arthritis, inflammatory bowel disease, diverticulosis/diverticulitis).
• Participants do not regularly take anti-inflammatory drugs (more than 2x week) and are willing to suspend use of these medications for 3 days leading up to in-lab visits.
• Participants do not take weight-loss medications (e.g., Ozempic, Wegovy).
• Participants do not use tobacco products or any illicit drugs.
• Participants have not used antibiotics or probiotics in the last month.
• Participants do not have dietary restrictions prohibiting them from consuming the fiber supplement (e.g., food allergies/intolerance).
• Participants do not have a pacemaker.
• Participants are able to lie on their back (supine position) in the dark for at least 10 minutes (related to vascular measurements).

Exclusion Criteria

• Participants are not 18-55 years old.
• Participants BMI is not ≥30 kg/m2 - this BMI requirement is due to our research aims.
• Participants do not have either 0-1 or 2+ of the following risk factors outside of the normal reference ranges: blood pressure, blood sugar, triglycerides, and HDL-cholesterol.
• Participants are pregnant or expecting to become pregnant (females only).
• Participants are postmenopausal (females only).
• Participants have been diagnosed with an advanced cardiometabolic condition (e.g., cardiovascular disease, type 2 diabetes).
• Participants have been diagnosed with a chronic inflammatory condition (e.g., rheumatoid arthritis, inflammatory bowel disease, diverticulosis/diverticulitis). •Participants regularly take anti-inflammatory drugs (more than 2x week) and are not willing to suspend use of these medications for 3 days leading up to in-lab visits.
• Participants take weight-loss medications (e.g., Ozempic, Wegovy).
• Participants use tobacco products or any illicit drugs.
• Participants have used antibiotics or probiotics in the last month.
• Participants have dietary restrictions prohibiting them from consuming the fiber supplement (e.g., food allergies/intolerance).
• Participants have a pacemaker.

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: SINGLE_GROUP

Primary Outcome Measures

Name	Time	Method
Serum Soluble Cluster of Differentiation 14 (sCD14)	Through study completion, up to 1.5 years.	The investigators will measure fasting sCD14 at each visit. These measurements will take place immediately and a complete dataset will be compiled upon study completion.
Serum Lipopolysaccharide Binding Protein (LBP)	Through study completion, up to 1.5 years.	The investigators will measure fasting LBP at each visit. These measurements will take place immediately and a complete dataset will be compiled upon study completion.
Serum C-Reactive Protein (CRP)	Through study completion, up to 1.5 years.	The investigators will measure fasting CRP at each visit. These measurements will take place immediately and a complete dataset will be compiled upon study completion.
Heart Rate Variability (HRV)	Through study completion, up to 1.5 years.	The investigators will measure HRV at each visit. These measurements will take place immediately and a complete dataset will be compiled upon study completion.
Flow-Mediated Dilation (FMD)	Through study completion, up to 1.5 years.	The investigators will measure FMD at each visit. These measurements will take place immediately and a complete dataset will be compiled upon study completion.
Pulse Wave Velocity (PWV)	Through study completion, up to 1.5 years.	The investigators will measure PWV at each visit. These measurements will take place immediately and a complete dataset will be compiled upon study completion.
Aortic Aumentation	Through study completion, up to 1.5 years.	The investigators will measure aortic augmentation at each visit. These measurements will take place immediately and a complete dataset will be compiled upon study completion.
Augmentation Index (AIx)	Through study completion, up to 1.5 years.	The investigators will measure AIx at each visit. These measurements will take place immediately and a complete dataset will be compiled upon study completion.

Secondary Outcome Measures

Name	Time	Method
Blood Pressure	Through study completion, up to 1.5 years.	The investigators will measure peripheral, central, and ambulatory blood pressure at each visit. These measurements will take place immediately and a complete dataset will be compiled upon study completion.
Glucose	Through study completion, up to 1.5 years.	The investigators will measure fasting glucose at each visit. These measurements will take place immediately and a complete dataset will be compiled upon study completion.
High-Density Lipoprotein Cholesterol (HDL-C)	Through study completion, up to 1.5 years.	The investigators will measure fasting HDL-C at each visit. These measurements will take place immediately and a complete dataset will be compiled upon study completion.
Triglycerides	Through study completion, up to 1.5 years.	The investigators will measure fasting triglycerides at each visit. These measurements will take place immediately and a complete dataset will be compiled upon study completion.
Digestive Symptoms	Through study completion, up to 1.5 years.	The investigators will measure digestive symptoms at each visit. These measurements will take place immediately and a complete dataset will be compiled upon study completion.

Trial Locations

Locations (1)

Health Professions Building; 🇺🇸 Muncie, Indiana, United States