Effects of Changing Intestinal Transit Time on Gut Microbial Composition and Metabolism During a Dietary Intervention with Low and High Fiber.
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 入组人数
- 22
- 试验地点
- 1
- 主要终点
- Fecal butyrate over urine p-cresol sulfate ratio
研究概览
简要总结
The aim of this study is to investigate how a short versus a long transit time impacts the gut microbiome's response to a high-fiber and a low-fiber diet, respectively. Such insights could help us understand personal responses to diets and be a first step towards personalized dietary recommendations targeting the gut microbiome.
详细描述
The study consists of two parallel arms of whole-meal diets, a low-fiber diet, and a high-fiber diet, respectively. Each arm is designed as a cross-over where participants, in random order, are administered a laxative (Movicol) along with the provided diet to shorten their intestinal transit time or simply consume the provided whole-meal diet (control).
The two intervention periods both involve the following:
- One week of run-in where participants consume the provided whole-meal diet.
- One week where participants either consume Movicol with the provided whole-meal diet or simply continue consuming the provided whole-meal diet (control).
Both arms begin with a screening visit and one week where participants consume and record their habitual diets. Subsequently, the first intervention period follows with one visit before and after each of the two weeks (visit 1-3) followed by the second intervention period with one visit before and after each of the two weeks (visit 4-6). The two cross-over periods are split by a washout of at least two weeks.
The study thus runs for approximately 7-8 weeks depending on the length of the washout and consists of seven visits (one screening visit and six regular visits) in total.
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
- None
入排标准
- 年龄范围
- 18 Years 至 75 Years（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- •18.5-30.0 kg/m2 BMI
- •Self-reported ≤3.5 spontaneous bowel movements per week
- •Willing to collect urine and stool samples at home and able to temporarily store them in their own freezer in a provided container.
- •Willing to eat the foods provided.
- •Owns a smartphone (iOS 11.0 and later or Android 5.0 and up) with access to the internet.
排除标准
- •Pregnant or lactating women.
- •Diagnosis of irritable bowel syndrome (IBS), small intestinal bacterial overgrowth (SIBO), inflammatory bowel diseases (IBD), Gastrointestinal obstruction, or Ischemic colitis
- •Diagnosed constipation according to the ROME IV criteria
- •Intake of antibiotics ˂ 1month, or any medication that can affect the outcomes of the study
- •Regular use of diarrhea inhibitors or laxatives
- •Dysphagia
- •Any chronic disease that can affect the outcomes of the study or pose a risk when consuming Movicol
- •Intake of medications potentially altering gastric pH (proton pump inhibitors, histamine receptor antagonists, antacids)
- •Intake of medications potentially altering the gastrointestinal motility (prokinetics, antiemetic agents, anti-cholinergic agents, narcotic analgetics, nonsteroidal anti-inflammatory drugs, and peroral glucocorticoids)
- •Concurrent participation in another trial
- •Any condition that makes the project responsible researcher to doubt the feasibility of the volunteer´s participation
研究组 & 干预措施
High-fiber diet
The high-fiber diet will consist of foods rich in dietary fiber such as coarse vegetables, wholegrain bread, and fruits representing a broad range of dietary fibers aiming for ≈40 g of fiber/10 MJ.
干预措施: Diet + laxative (Drug)
High-fiber diet
The high-fiber diet will consist of foods rich in dietary fiber such as coarse vegetables, wholegrain bread, and fruits representing a broad range of dietary fibers aiming for ≈40 g of fiber/10 MJ.
干预措施: Diet only (Other)
Low-fiber diet
The low-fiber diet will consist of foods poor in fiber such as white bread and refined foods aiming for ≈10 g of fiber/10 MJ.
干预措施: Diet + laxative (Drug)
Low-fiber diet
The low-fiber diet will consist of foods poor in fiber such as white bread and refined foods aiming for ≈10 g of fiber/10 MJ.
干预措施: Diet only (Other)
结局指标
主要结局
Fecal butyrate over urine p-cresol sulfate ratio
时间窗: From visit 1 through to study completion, an average of 7 weeks
Changes in ratio between fecal butyrate (reflecting saccharolytic fermentation) and urine p-cresol sulfate (reflecting proteolytic fermentation) between interventions.
次要结局
- Concentration of fasting plasma short-chain fatty acids(From visit 1 through to study completion, an average of 7 weeks)
- Fasting plasma concentrations of bile acids(From visit 1 through to study completion, an average of 7 weeks)
- Fecal metabolome as assessed by untargeted metabolomics(From visit 1 through to study completion, an average of 7 weeks)
- Gut microbiome assessed by 16S amplicon sequencing(From visit 1 through to study completion, an average of 7 weeks)
- Fasting breath methane and hydrogen levels in parts per million(From visit 1 through to study completion, an average of 7 weeks)
- Change in bowel movement frequency(From visit 1 through to study completion, an average of 7 weeks)
- Whole gut transit time measured by sweet corn(From visit 1 through to study completion, an average of 7 weeks)
- Whole gut transit time measured by blue muffins(From visit 1 through to study completion, an average of 7 weeks)
- Stool consistency(From visit 1 through to study completion, an average of 7 weeks)
- Fecal water content in percentage of stool weight(From visit 1 through to study completion, an average of 7 weeks)
- Fecal concentration of short-chain fatty acids(From visit 1 through to study completion, an average of 7 weeks)
- Fecal pH(From visit 1 through to study completion, an average of 7 weeks)
- Fecal ammonia concentration(From visit 1 through to study completion, an average of 7 weeks)
- Gut microbiome assessed by shotgun sequencing(From visit 1 through to study completion, an average of 7 weeks)
- Microbial metabolites in urine from proteolytic fermentation as assessed by mass spectrometry(From visit 1 through to study completion, an average of 7 weeks)
- Microbial metabolites in blood from proteolytic fermentation as assessed by mass spectrometry(From visit 1 through to study completion, an average of 7 weeks)
研究者
Henrik Munch Roager
Associate Professor
University of Copenhagen