The goal of this clinical trial is to learn about the effect of urolithin A, a dietary supplement, on blood flow in middle-aged adults with obesity. The main question it aims to answer is:

- Does urolithin A supplementation improve blood flow in large and small blood vessels in middle-aged adults with obesity?

Participants will be asked to:

• Take the dietary supplement daily for 4 weeks
• Attend two study visits to have their blood vessels checked, answer questionnaires, and give a sample of blood

Researchers will compare people who took the dietary supplement with others who took a placebo to see if the blood flow in the blood vessels improved.

This study aims to measure the effect of urolithin A supplementation on endothelial function, cerebral blood flow regulation, and serum biomarkers of NO bioavailability and mitochondrial function in middle-aged adults with obesity. Briefly, 54 adults aged 40-64 years of age with a body mass index equal to or greater than 30 kg/m2 will be recruited to participate in a double-blind placebo-controlled parallel study for 4 weeks. Participants will be randomly assigned to intervention or control group. Those in the intervention group will consume 1,000 mg of urolithin A daily in the form of softgel capsules, whereas those in the control group will consume a placebo. Data collection will occur at baseline (day 0) and endpoint (day 28). The investigators will compare outcomes between control and intervention group. Researchers expect that urolithin A supplementation in middle-aged adults with obesity improves endothelial function and cerebral blood flow regulation, and that this improvement is accompanied by changes in biomarkers of NO bioavailability and mitochondrial function.

Inclusion Criteria:

• Age: 40-64 years old, inclusive
• Obesity [BMI ≥30 kg/m2]
• Ability to read, write, and speak English
• Competence to provide written informed consent

Exclusion Criteria:

• Pregnant or breastfeeding women, or women who intend to become pregnant within the study period
• History of uncontrolled hypertension
• History of uncontrolled type 1 or type 2 diabetes mellitus
• Significant cardiac disease or chest pain in the last 6 months
• History of untreated depression or anxiety
• History of cognitive impairment
• History of uncontrolled significant GI disease (e.g., IBS, Crohn's disease)
• Allergy or intolerance to one or more of the intervention components
• Undergoing treatment for active cancer
• History of neurodegenerative disorders (e.g., multiple sclerosis)
• Presence of any condition affecting swallowing ability
• Any other medical condition that the investigators deem would adversely affect the participant's safety or ability to complete the study

Starting 6 months after publication

By request upon PI approval