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

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.

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.