Assessing the Effect of Lettuce on Intestinal Water Content Through Magnetic Resonance Imaging of the Small Bowel

Not Applicable

Completed

Conditions: Asymptomatic Conditions

Interventions: Other: Bread
Other: Lettuce
Other: Rhubarb

Registration Number: NCT02939716

Lead Sponsor: University of Nottingham

Brief Summary: When patients have bowel surgery they are sometimes left with a stoma, where the small bowel exits onto the wall of the abdomen, not into the colon. Certain foods have been shown to increase the amount of water lost through a stoma. This can lead to dehydration. Such patients are encouraged to avoid such foods but knowing which ones to avoid relies partly on trial and error.

In a survey 1 in 3 patients said that rhubarb increased stoma output. Rhubarb is known to contain chemicals that can stimulate the bowel. 1 in 6 patients also reported the same effect with lettuce which has not previously been shown to have such an effect. Latex found in lettuce leaves may stimulate the bowel to produce more fluid, explaining this effect.

In Nottingham the investigators have developed techniques that use Magnetic Resonance Imaging (MRI) to measure water in the small bowel. They want to use these techniques to explore whether eating lettuce increase small bowel water content. They will compare lettuce to rhubarb and to bread, which they know reduces small bowel water. They will see if they can detect any relationship between water in the bowel and feelings of bloating.

Detailed Description: Background:

In recent years fermentable oligo-, di-, mono-saccharides and polyols, have been proposed to exacerbate symptoms of irritable bowel syndrome (IBS) such as abdominal discomfort and bloating. This phenomenon has also been observed in patients with an ileostomy, where certain foods have been associated with increased fluid output from the stoma. This is in accordance with past work surveying ileostomy patients on foods that altered stoma function. However, there may be other factors that drive fluid output from a stoma. Rhubarb, a food listed by 1 in 3 patients as exacerbating watery diarrhoea, also contains anthraquinones that have laxative effects, such as in senna.

A food less commonly associated with laxative effects is lettuce but 1 in 6 patients reported that eating lettuce led to an increase in watery stoma output. Certain lettuce varieties exude a milk-like latex material when cut, giving rise to the latin name Lactuca sativa. While the methylcellulose is insoluble and would not be expected to hold water in the lumen of the small bowel, latex could be expected to stimulate intestinal secretion. This may contribute to post-prandial sensations of bloating by a different mechanism to the osmotic effects and colonic fermentation seen with poorly absorbed but fermentable carbohydrates..

The Nottingham GI MRI group has been at the forefront of elucidating the effects of poorly digested carbohydrates on gastrointestinal physiology. the investigators have published techniques to measure free water in the small bowel and assessment of viscosity in the colon using MR relaxometry. This includes the demonstration that fructose ingestion on its own leads to increased free water in the small bowel compared to co-ingestion with glucose - see panel. The investigators wish to apply these techniques to compare the effect of different foods: white bread, lettuce and rhubarb. The investigators have previously shown that bread led to a reduction in small bowel water and so can active as a negative control. Rhubarb should serve as a positive control.

Aims: The purpose of the study is gather pilot data on the effect of different foods on intestinal physiology.

Recruitment & Eligibility

Status: COMPLETED

Sex: All

Target Recruitment: 18

Inclusion Criteria

Aged 18 or older
Able to give informed consent

Exclusion Criteria

Pregnancy declared by candidate
History declared by the candidate of pre-existing gastrointestinal disorder that may affect bowel function
A positive diagnosis of irritable bowel syndrome based on the Rome III criteria questionnaire
Reported history of previous resection of the oesophagus, stomach or intestine (excluding appendix)
Intestinal stoma
Any medical condition making participation potentially compromising participation in the study e.g. diabetes mellitus, respiratory disease limiting ability to lie in the scanner, known allergy to one of the food products
Contraindications for MRI scanning i.e. metallic implants, pacemakers, history of metallic foreign body in eye(s) and penetrating eye injury
Will not agree to dietary restrictions required in 24 hours before each study day
Unable to stop drugs known to alter GI motility including mebeverine, opiates, monoamine oxidase inhibitors, phenothiazines, benzodiazepines, calcium channel antagonists for the duration of the study (Selective serotonin reuptake inhibitors and low dose tricyclic antidepressants will be recorded but will not be an exclusion criteria)
Inability to lie flat or exceed scanner limits of weight <120kg
Poor understanding of English language
Participation in night shift work the week prior to the study day. Night work is defined as working between midnight and 6.00 in the morning
Participation in any medical trials for the past 3 months
Anyone who in the opinion of the investigator is unlikely to be able to comply with the protocol e.g. cognitive dysfunction, chaotic lifestyle related to substance abuse

Study & Design

Study Type: INTERVENTIONAL

Study Design: CROSSOVER

Arm && Interventions

Group	Intervention	Description
Bread	Bread	2 slices of white bread, 40g each; served with 10g butter
Lettuce	Lettuce	300g lettuce; served with 30g mayonnaise
Rhubarb	Rhubarb	300g frozen rhubarb, microwaved; served with 65g lactose free cream and saccharine sweetener

Primary Outcome Measures

Name	Time	Method
Small Bowel Water Content Measured by MRI	0-3 hours	Area under the curve of postprandial change from fasting small bowel water, 0-3 hours, measured by MRI, in mL\*min

Secondary Outcome Measures

Name	Time	Method
Bloating VAS Score	0-180 min	Area under the curve of postprandial change from fasting bloating score, 0-180 min, measured by a 100 point visual analogue scale (VAS), where 0 is no symptom and 100 is worst symptom. Measured every 30 mins.
Satiety VAS Score	0-180 mins	Area under the curve of postprandial change from fasting satiety score, 0-180 min, measured by a 100 point visual analogue scale (VAS), where 0 is no symptom and 100 is worst symptom. Measured every 30 mins.
Relaxation Time in Ascending Colon	0-3 hours	Area under the curve of postprandial change from fasting small bowel water, 0-3 hours, measured by MRI in milliseconds.min
Ascending Colon Water Content	0-3 hours	Area under the curve of postprandial change from fasting ascending colon water, 0-3 hours, measured by MRI, in mL\*min

Trial Locations

Locations (2): Sir Peter Mansfield Imaging Centre
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Nottingham, United Kingdom
Nottingham Digestive Diseases Centre
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Nottingham, United Kingdom