Effects of FODMAPs on Small Bowel Water Content: an MRI Study

Study Overview
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Brief Summary
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Some carbohydrates, particularly fructose, the sugar found in fruit and bread may cause bloating, pain and erratic bowel habits (diarrhoea and constipation) particularly in patients suffering from the irritable bowel syndrome (IBS). This may be because they are not well absorbed in the small intestine and cause water to be trapped in the bowel causing distension. Studies have shown that reducing the amount of these sugars in the diet can relieve these symptoms. There is some evidence that combining fructose and glucose can reduce the symptoms caused by fructose but just why is unclear. In this study, the investigators will use a non invasive medical imaging technique called magnetic resonance imaging (or MRI) to look at the behaviour of drinks containing these sugars in the bowels of healthy human volunteers. The investigators will give four different drinks: one beverage consisting of a very well absorbed sugar, glucose, another consisting of the less well absorbed sugar fructose, a third which is a mixture of glucose and fructose, and a fourth consisting of several fructose subunits joined together (called fructan). The investigators will take MRI images of the stomach and intestines at intervals for 5 hours and compare these with the feelings of distension and bloating in our volunteers. The results will act as control for subsequent studies in IBS patients and these may help design diets to reduce symptoms in IBS.

Detailed Description
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Title: Effects of FODMAPs (Fermentable Oligo-, Di-, and Mono-saccharides, And Polyols) on small bowel water content: an MRI study Background. FODMAPs consist of fructose, lactose, fructo- and galacto-oligosaccharides such as fructans and galactans, and polyols such as sorbitol and mannitol. These carbohydrates are poorly absorbed in the small intestine and have been shown to trigger symptoms of irritable bowel syndrome (IBS). Previous studies have shown that fructose malabsorption results in an increased osmotic load in the small bowel, which can have a laxative effect. Physical proof of this has only been obtained using an ileostomy model on patients. This study indicated increased small bowel water content (SBWC) but this has never been established in intact humans .). We have been using noninvasive magnetic resonance imaging (MRI) to provide novel insights on the fate of food materials within the gastro-intestinal tract (GIT) of humans for the last decade. Aims (to include hypothesis to be tested) This study aims to investigate whether fructose alone will increase SBWC compared to an equivalent mass of glucose, and if adding glucose to fructose will reduce its effect on the SBWC. The study also aims to determine if fructans alter colonic transit.The main hypothesis is that fructose will increase small bowel water while fructans will mainly affect colonic transit.. Experimental protocol and methods. A single-centre, randomized, cross-over design study consisting of a screening visit and four test days, which will be approximately 1 week apart The subjects (18 healthy volunteers for main study plus 4 for pilot studies) will receive (according to a randomization schedule) each test day one out of four test products: 1) glucose (control) 2) fructose, 3) glucose with fructose and 4) fructans. On each test day, volunteers will have a baseline scan in a 1.5T scanner, consume one of the products instead of breakfast at 09:00 and will be imaged in the scanner at intervals for 5 hours using a range of MRI sequences. All the tested ingredients are food grade, have a history of safe use at intended usage levels, and are regarded as safe. Four test products will be evaluated: 500 mL of glucose (40g of glucose dissolved in water with pure lime juice as flavorant) 500 mL fructose (40g fructose dissolved in water with pure lime juice as flavorant) 500 mL of glucose with fructose (40g glucose and 40g fructose dissolved in water with pure lime juice as flavorant, 40 or 80 gm) 500 mL fructan (40g of 100% fructan (inulin) dissolved in water with pure lime juice as flavorant) 4. Measurable end points/statistical power of the study. Primary endpoint: small bowel water content area under the curve (AUC) -45 - 315 minutes. Secondary endpoint: gastric emptying T50, colonic volume as characterised by AUC -45 - 315 minutes of ascending colon, colonic motility, symptoms questionnaires, small bowel transit time, breath hydrogen concentrations and tryptase faecal content. Previous work using mannitol and glucose indicates that mean (SD) SBWC at 40 minutes postprandial after ingesting 300ml glucose was 47 (SD 15) and using n=12 the investigators calculate the investigators can detect an increase of 20 ml in excess of this with 90% power which is very much less than the investigators are predicting. The investigators plan to use 18 to ensure the investigators can assess our secondary endpoints for which there is no data with which to perform a power calculation.

Official Title
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Effects of FODMAPs (Fermentable Oligo-, Di-, and Mono-saccharides, And Polyols) on Small Bowel Water Content: an MRI Study

Conditions
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Healthy

Intervention / Treatment
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* Dietary Supplement: Glucose
* Dietary Supplement: Fructose
* Dietary Supplement: Fructan
* Dietary Supplement: Fructose and glucose


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Apparently healthy: no medical conditions which might effect study measurements. No reported participation in another nutritional or biomedical trial 3 months before the pre-study examination or during the study. Age ≥ 18 and ≤ 60 year at pre-study investigation. Body mass index (BMI) ≥ 18.0 and ≤ 30.0 kg/m2 No reported participation in night shift work two days prior to pre-study investigation or during the study. Night work is defined as working between midnight and 6.00 AM. Strenuous exercise ≤ 10 hours per week. Gender: male or female Consumption of ≤ 21 alcoholic drinks in a typical week Currently not smoking Suitable for MRI scanning (e.g., absence of metal implants, infusion pumps and pacemakers) as assessed by the attached MRI safety questionnaire. Exclusion Criteria: - use of medication which interferes with study measurements or bowel motility (as judged by the study physician). Antibiotics in the 3 weeks before pre-study examination Probiotics or during the study

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 60 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Basic Science
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Glucose drink<br>Serial MRI of the gastrointestinal tract upon 500 ml water drink containing 40g glucose | Dietary Supplement: Glucose<br>* 500 ml water drink containing 40g glucose<br>|
| Experimental: Fructose drink<br>Serial MRI of the gastrointestinal tract upon 500 ml water drink containing 40g fructose | Dietary Supplement: Fructose<br>* 500 ml water drink containing 40g fructose<br>|
| Experimental: Fructan drink<br>Serial MRI of the gastrointestinal tract upon 500 ml water drink containing 40g fructan | Dietary Supplement: Fructan<br>* 500 ml water drink containing 40g fructan<br>|
| Experimental: Fructose and glucose drink<br>Serial MRI of the gastrointestinal tract upon 500 ml water drink containing 40g fructose and 40 g glucose | Dietary Supplement: Fructose and glucose<br>* 500 ml water drink containing 40g fructose and 40g glucose<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| small bowel water content area under the curve | Area Under the curve for small bowel water content, methods as Marciani, L., et al., Gastroenterology, 2010. 138(2): p. 469-U90. Hoad, C.L., et al.,. Physics in Medicine and Biology, 2007. 52(23): p. 6909-6922. | -45 min to 315 min | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| gastric emptying T50 | time to half empty the stomach | -45 min to 315 min | 
| ascending colon volume | AUC of the geometric volume of the ascending colon | -45 min to 315 min | 
| ascending colon motility | motility index of the ascending colon as determined from dynamic MRI scan | -45 min to 315 min | 
| symptoms questionnaires | bloating, nausea, gas belching and abdominal pain | -45 min to 315 min | 
| bowel transit time | first time to detect sweetcorn markers in the stool | 24 hours | 
| fecal tryptase activity | activity of stool triptase in trypsin units of activity | 24 h | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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MRI, Gastrointestinal physiology, Gastrointestinal response to sugars, gastrointestinal, stomach, small bowel, colon, glucose, fructose, fructan, FODMAP