Anti-inflammatory Activities of Vitamin C Supplementation on the Gut Barrier Function in Adults With Obesity
试验速览
- 阶段
- 不适用
- 状态
- 招募中
- 入组人数
- 34
- 试验地点
- 2
- 主要终点
- Small Intestinal Permeability
研究概览
简要总结
This study is testing whether taking vitamin C every day can help improve gut health and reduce inflammation in adults with obesity. Poor gut health-sometimes called "leaky gut"-can allow harmful substances from bacteria to enter the bloodstream, which may lead to inflammation and increase the risk of heart disease and liver problems.
Participants will complete two study periods, each lasting two weeks, with a two-week break in between. In one period, they will take vitamin C; in the other, a placebo. During each period, researchers will collect blood, urine, and stool samples, ask participants to track their diet and activity, and perform a test to measure gut permeability.
There are minimal risks, such as discomfort from blood draws or temporary stomach upset from a sugar drink. While participants may not directly benefit, their involvement will help researchers learn whether vitamin C is a safe and effective way to improve gut health in people with obesity.
详细描述
This clinical study aims to evaluate the impact of vitamin C supplementation on gut barrier function and systemic inflammation in adults with obesity. The research builds on preclinical findings that suggest vitamin C plays a critical role in maintaining gut integrity and reducing inflammation. Approximately 40% of Americans have suboptimal vitamin C status, with even higher prevalence among individuals with obesity.
The primary hypothesis is that improving vitamin C status through dietary supplementation will reduce intestinal permeability and metabolic endotoxemia. A secondary hypothesis is that vitamin C will also reduce biomarkers of intestinal inflammation and promote favorable changes in gut microbiota composition, including increased production of short-chain fatty acids (SCFAs), which are essential for intestinal health.
This randomized, double-blind, placebo-controlled crossover trial will enroll 34 obese adults (BMI 30-40 kg/m², aged 18-50 years). Participants will complete two 2-week intervention periods separated by a 2-week washout. In one period, they will receive vitamin C (500 mg capsules taken twice daily); in the other, a placebo. During both periods, participants will follow a low-vitamin C diet to minimize variability in circulating vitamin C levels.
Assessments will occur on Days 0, 7, and 14 of each intervention period and include: Anthropometric measurements; Resting blood pressure; Fasting blood samples; and 3-day food records. On Day 14 of each period, participants will: Provide a stool sample and Complete a gut permeability test using a non-digestible sugar probe solution followed by a 24-hour urine collection. After the first intervention period, participants will undergo a 2-week washout before repeating the procedures with the alternate supplement.
Primary Outcome: Intestinal permeability
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Crossover
- 主要目的
- Basic Science
- 盲法
- Triple (Participant, Investigator, Outcomes Assessor)
入排标准
- 年龄范围
- 18 Years 至 50 Years（Adult）
- 性别
- All
- 接受健康志愿者
- 否
入选标准
- •English speaking
- •Men and women between 18-50 years of age
- •BMI 30-40 kg/m²
- •Resting blood pressure <140/90 mm Hg
- •No use of multivitamin/vitamin C supplement within past 1-month
- •Non-vegetarian/non-vegan
- •Willingness to follow a diet low in fruits and vegetables for two, 2-week periods
排除标准
- •Current smoker or vaper, including tobacco, cannabis, or nicotine products
- •Alcohol consumption >2 drinks/day
- •Use of antibiotics within past 1-month
- •Use of probiotic supplements within past 1-month
- •Use of anti-inflammatory drugs within past 1-month
- •Individuals with unmanaged or poorly controlled diabetes, dyslipidemia, hypertension
- •Known history of bleeding disorders, hemochromatosis, or kidney stones
- •For Women: Pregnancy, lactation, or change in birth control within the past 3-months
- •Use of certain medications that may interact with vitamin C, including blood thinners, some antiviral drugs (e.g., indinavir), and certain antipsychotic medications (e.g., fluphenazine).
研究组 & 干预措施
Inadequate Vitamin C Status
Placebo + Low Vitamin C Diet
干预措施: Placebo + Low Vitamin C Diet (Dietary Supplement)
Adequate Vitamin C Status
Vitamin C Supplement + Low Vitamin C Diet
干预措施: Vitamin C Supplement + Low Vitamin C Diet (Dietary Supplement)
结局指标
主要结局
Small Intestinal Permeability
时间窗: Between-treatment arm comparison on day 14 following 2-week intervention.
Urinary excretion ratio of lactulose/mannitol following oral ingestion of these sugar probes.
次要结局
- Fecal Acetate(Between-treatment arm comparison on day 14 following 2-week intervention.)
- Serum Endotoxin Concentration(Between-treatment arm comparison on day 14 following 2-week intervention.)
- Fecal Myeloperoxidase(Between-treatment arm comparison on day 14 following 2-week intervention.)
- Large Intestinal Permeability(Between-treatment arm comparison on day 14 following 2-week intervention.)
- Fecal Calprotectin(Between-treatment arm comparison on day 14 following 2-week intervention.)
- Fecal Butyrate(Between-treatment arm comparison on day 14 following 2-week intervention.)
- Fecal Proprionate(Between-treatment arm comparison on day 14 following 2-week intervention.)
- Plasma Lipopolysaccharide Binding Protein/Soluble Cluster of Differentiation-14(Between-treatment arm comparison on day 14 following 2-week intervention.)
- Plasma C-Reactive Protein(Between-treatment arm comparison on day 14 following 2-week intervention.)
- Plasma Myeloperoxidase(Between-treatment arm comparison on day 14 following 2-week intervention.)
- Plasma Tumor Necrosis Factor-α(Between-treatment arm comparison on day 14 following 2-week intervention.)
- Plasma Trimethylamine N-oxide(Between-treatment arm comparison on day 14 following 2-week intervention.)
- Large Intestinal Permeability(Between-treatment arm comparison on day 14 following 2-week intervention.)
- Plasma Vitamin C(Within-treatment arm comparison from day 0 to day 14 following 2-week intervention.)
- Fecal Calprotectin(Between-treatment arm comparison on day 14 following 2-week intervention.)
- Fecal Myeloperoxidase(Between-treatment arm comparison on day 14 following 2-week intervention.)
- Fecal Butyrate(Between-treatment arm comparison on day 14 following 2-week intervention.)
- Serum Endotoxin Concentration(Between-treatment arm comparison on day 14 following 2-week intervention.)
- Plasma Lipopolysaccharide Binding Protein/Soluble Cluster of Differentiation-14(Between-treatment arm comparison on day 14 following 2-week intervention.)
- Plasma C-Reactive Protein(Between-treatment arm comparison on day 14 following 2-week intervention.)
- Plasma Myeloperoxidase(Between-treatment arm comparison on day 14 following 2-week intervention.)
- Plasma Tumor Necrosis Factor-α(Between-treatment arm comparison on day 14 following 2-week intervention.)
- Fecal Proprionate(Between-treatment arm comparison on day 14 following 2-week intervention.)
- Plasma Trimethylamine N-oxide(Between-treatment arm comparison on day 14 following 2-week intervention.)
- Fecal Acetate(Between-treatment arm comparison on day 14 following 2-week intervention.)
研究者
Richard Bruno
Principal Investigator
Ohio State University