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Effect of Watermelon on Gut and Cardiometabolic Health

Effect of Daily Fresh Watermelon Consumption on Gut and Cardiometabolic Health in Young Adults With Overweight and Obesity

Status
Recruiting
Phases
NA
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT06588218
Enrollment
36
Registered
2024-09-19
Start date
2024-10-13
Completion date
2026-08-31
Last updated
2025-10-15

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Obesity and Overweight, Dysbiosis

Keywords

Gut Microbiome, Dysbiosis, Diet, Overweight, Obesity, Watermelon, Lycopene, Citrulline, Metagenomic, vascular

Brief summary

The goal of this clinical trial is to evaluate the effect of daily fresh watermelon consumption for 6-weeks on gut health, including microbiome diversity, gut barrier and immune function in young adults with overweight and obesity. The main questions it aims to answer are: 1. Will consuming fresh watermelon daily for 6-weeks will improve intestinal barrier health and increase microbiome diversity such as an increased population of beneficial 'probiotic' bacteria when compared to control participants consuming a low-fat snack? 2. Will consuming fresh watermelon daily for six-weeks will improve other health measures, including body-composition, blood pressure, blood vessel function, blood lipid profiles, and measures of inflammation, as compared to control participants consuming a low-fat snack for the same time period?

Interventions

2.5 cups of whole fresh watermelon (\ 375 grams, 115 kcals, 0.5g fat, 1.5g fiber, 17,225mcg lycopene, 30.75mg vitamin C) of fresh watermelon daily for six weeks

OTHERBelvita Breakfast Sandwich + 12 oz Water

Belvita breakfast sandwich; 115 kcals, 1.5g fiber, 4.5g fat, 0mg lycopene, 0mg vitamin C) as well as 12 ounces of water

Sponsors

Florida State University
Lead SponsorOTHER

Study design

Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
BASIC_SCIENCE
Masking
NONE

Eligibility

Sex/Gender
ALL
Age
18 Years to 30 Years
Healthy volunteers
No

Inclusion criteria

* Between 18 and 30 years old * Ability to speak and read in English * Overweight or Obese Class 1 and 2 (BMI ≥ 25 - 39.9 kg/m2)

Exclusion criteria

* Intake of antibiotics in the last 3 months * Intake of pre/pro/postbiotics in the last 3 months * Current or past (within the last 6 months) user of tobacco, marijuana, or E-cigarette products * Cardiovascular disease (will not exclude for hypertension), gastrointestinal disease (ulcerative colitis, celiac, Crohn's disease, diverticulosis, peptic ulcers, small intestinal bacterial overgrowth, short bowel syndrome), neurological (multiple sclerosis, meningitis, recent stroke) or endocrine disorders (uncontrolled thyroid disorders, growth hormone disorders, adrenal gland disorders, uncontrolled diabetes - A1C greater than 9%). * Food allergy to study foods * Any allergy to melon * Any allergy to the isocaloric snack (gluten) * Regular consumption of watermelon greater than 2 servings / week * Current heavy alcohol use (≥ 15 drinks / week for men, ≥ 8 drinks / week for women * Class 3 Obesity (BMI > 40 kg/m2) * Current user of Citrulline, Arginine, Nitric Oxide or other supplements known to affect nitric oxide synthesis (beet root juice or any beet supplement, Pycnogenol / Pine bark extract) * Known to be currently pregnant (self-disclosed)

Design outcomes

Primary

MeasureTime frameDescription
Change in Gut Microbiome DiversityBaseline (day 0), Visit 2 (week 6), Visit 3 (week 10), Visit 4 (week 16).Collected fecal samples will be used to determine microbiome profiles, including diversity and composition of bacteria.
Change in Oral Microbiome DiversityBaseline (day 0), Visit 2 (week 6), Visit 3 (week 10), Visit 4 (week 16).Oral swab samples are collected to determine oral diversity and composition of bacteria in the mouth before and after intervention.

Secondary

MeasureTime frameDescription
Change in Endothelial FunctionBaseline (day 0), Visit 2 (week 6), Visit 3 (week 10), Visit 4 (week 16).Evaluate the effects of watermelon on macrovascular endothelial function, which will be evaluated using the flow-mediated dilation (FMD) technique using a Finapres device, which measures the arterial dilation response following acute occlusion of the brachial artery.
Change in Ambulatory Blood PressureBaseline (day 0), Visit 2 (week 6), Visit 3 (week 10), Visit 4 (week 16).Evaluate the effect of watermelon on ambulatory blood pressure (systolic and diastolic), determined using a 12-hour ambulatory blood pressure monitor (TM-2440). The 12-hour ambulatory blood pressure monitor will collect blood pressure readings every 20 minutes during waking hours only.
Change in Waist and Hip CircumferenceScreening, Baseline (day 0), Visit 2 (week 6), Visit 3 (week 10), Visit 4 (week 16).Evaluate changes in waist and hip circumference (centimeters), as well as waist-hip ratio at each study visit before, after and during watermelon consumption.
Change in Body CompositionScreening, Baseline (day 0), Visit 2 (week 6), Visit 3 (week 10), Visit 4 (week 16).Evaluate changes in body composition, including lean mass (kg), fat mass kg), and total body water (kg). This is assessed using a bioimpedance spectroscopy device (ImpediMed SBF7) at each study visit before, after and during watermelon consumption.
Change in Habitual Dietary IntakeBaseline (day 0), Visit 2 (week 6), Visit 3 (week 10), Visit 4 (week 16).Assess changes in habitual dietary intake via 3-day food logs, analyzed using nutrient analysis software.
Change in Biomarkers of InflammationBaseline (day 0), Visit 2 (week 6), Visit 3 (week 10), Visit 4 (week 16).Relevant biomarkers are to be collected via venous blood samples to determine changes in inflammation, including but not limited to C-reactive protein (CRP), IL-1 (Interleukin-1), IL-1 beta, IL-6, IL-10, IL-17, IL-23, Tumor Necrosis Factor Alpha (TNF-a), Interferon-gamma (IFN-Y). All will be expressed in units of pg/mL.
Change in Gut Transit TimeBaseline (day 0), Visit 2 (week 6), Visit 3 (week 10), Visit 4 (week 16).Evaluate changes in gut transit time after watermelon or control snack consumption from baseline to final analysis, using a blue-dye capsule.
Change in Biomarkers of Intestinal Barrier FunctionBaseline (day 0), Visit 2 (week 6), Visit 3 (week 10), Visit 4 (week 16).Relevant biomarkers are to be collected via venous blood samples to determine changes in intestinal barrier function including LPS (lipopolysaccharides), LBP (lipopolysaccharide binding protein), CD14, Secretory IgA. All will be expressed in units of pg/mL.
Change in Biomarkers of Cardiometabolic HealthBaseline (day 0), Visit 2 (week 6), Visit 3 (week 10), Visit 4 (week 16).Relevant biomarkers are to be collected via venous blood samples to determine changes in cardiometabolic health including HDL, LDL, total cholesterol, and triglycerides. All will be expressed in units of mg/dL.
Change in Recent Dietary IntakeScreening, Baseline (day 0), Visit 2 (week 6), Visit 3 (week 10), Visit 4 (week 16).Assess changes in dietary intake via 24 hr recalls, analyzed using nutrient analysis software.
Change in Body WeightScreening, Baseline (day 0), Visit 2 (week 6), Visit 3 (week 10), Visit 4 (week 16).Evaluate changes in body weight (kg) at each study visit before, after and during watermelon consumption.
Change in Body Mass IndexBaseline (day 0), Visit 2 (week 6), Visit 3 (week 10), Visit 4 (week 16).Evaluate changes in Body Mass Index (kg/m2) before, during and after consumption of watermelon.
Change in Biomarkers of AppetiteBaseline (day 0), Visit 2 (week 6), Visit 3 (week 10), Visit 4 (week 16).Relevant biomarkers are to be collected via venous blood samples to determine changes in appetite including Insulin, Glucagon, glucagon-like peptide 1 (GLP-1), Adiponectin, Leptin, Ghrelin, and Peptide YY. All will be expressed in units of pg/mL.
Change in Arterial StiffnessBaseline (day 0), Visit 2 (week 6), Visit 3 (week 10), Visit 4 (week 16).Evaluate the effects of watermelon on arterial stiffness, determined by measuring Pulse Wave Analysis (PWA) and Pulse Wave Velocity (PWV). These are captured by the SphygmoCor XCEL System through the descending aorta to the femoral artery. The aortic pulse wave velocity is detected from carotid and femoral arterial pulses measured non-invasively and simultaneously

Countries

United States

Contacts

Primary ContactRavinder Nagpal, PhD
rnagpal@fsu.edu850-644-1829
Backup ContactCole Patoine, M.S
cjp23a@fsu.edu

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026