The Effect of the Low FODMAP Diet and Dietary Oligofructose on Gastrointestinal Form, Function and Microbiota

Last updated: March 17, 2015
Sponsor: University of Nottingham
Overall Status: Completed

Phase

N/A

Condition

Lactose Intolerance

Colic

Gastrointestinal Diseases And Disorders

Treatment

N/A

Clinical Study ID

NCT02259465
SoM A14082014 FOG
  • Ages > 18
  • All Genders
  • Accepts Healthy Volunteers

Study Summary

Some carbohydrates, complex sugars, which are found in grains, fruit and vegetables, cannot be digested by humans. When eaten they pass through the small bowel to the large bowel, or colon. Some bacteria that live in the colon are able to digest these carbohydrates, and use them as an energy source. This releases energy that humans can absorb, and may have other effects on health as well. The process also releases gases such as hydrogen and methane into the colon, which will eventually be released as flatulence.

There is some evidence in animals, and humans, that changing the carbohydrate content of the diet may increase the numbers of bacteria in the colon that can use this energy source. Recent work has looked at how changes in colon bacteria and carbohydrate in the diet affect transit, the speed at which food and stool moves through the stomach and bowels.

This undergraduate project will use techniques in Magnetic Resonance Imaging developed in Nottingham to investigate how a prolonged change in dietary carbohydrate might affect speed of transit through the bowel and gas production in the colon, and whether there is any immune reaction to the carbohydrate from the bowel wall.

Eligibility Criteria

Inclusion

Inclusion Criteria:

  • Aged 18 or older

  • Able to give informed consent

Exclusion

Exclusion Criteria:

  • Self-declared vegetarian, vegan or kosher/ halal diet who cannot eat carmine red dye

  • Pregnancy declared by candidate

  • History declared by the candidate of pre-existing gastrointestinal disorder that mayaffect bowel function

  • A positive diagnosis of irritable bowel syndrome based on the Rome III criteriaquestionnaire

  • Reported history of previous resection of the oesophagus, stomach or intestine (excluding appendix)

  • Intestinal stoma

  • Any medical condition making participation potentially compromising participation inthe study e.g. diabetes mellitus, respiratory disease limiting ability to lie in thescanner

  • Contraindications for MRI scanning i.e. metallic implants, pacemakers, history ofmetallic foreign body in eye(s) and penetrating eye injury

  • Will not limit alcohol intake to ≤ 35 units/ week and ≤ 8 units per day during trial

  • Unable to stop drugs known to alter GI motility including mebeverine, opiates,monoamine oxidase inhibitors, phenothiazines, benzodiazepines, calcium channelantagonists for the duration of the study (Selective serotonin reuptake inhibitors andlow dose tricyclic antidepressants will be recorded but will not be an exclusioncriteria)

  • Antibiotic or prescribed probiotic treatment in the past 8 weeks

  • 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 isdefined as working between midnight and 6.00 AM

  • 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 withthe protocol e.g. cognitive dysfunction, chaotic lifestyle related to substance abuse

Study Design

Total Participants: 45
Study Start date:
September 01, 2014
Estimated Completion Date:
December 31, 2014

Study Description

Oligofructose (OF) is a fructose- based oligosaccharide and defined in the European Union as a dietary fibre. Enzymatically derived from the longer chain inulin in chicory, it is commonly used in processed food to improve mouth feel in fat-free products. OF is poorly digested and absorbed in the small bowel so passes to the colon where it is fermented by the bacteria usually resident in the colon, termed the microbiota. This process produces gases such as hydrogen and sometimes methane, and short-chain fatty acids (SCFAs) which have a variety of roles including nutrition to colonocytes, immunological effects and modulation of intestinal motility. Its presence in the colon alters the composition of the microbiota, with reported potential benefits to health, leading to its description as a 'prebiotic'.

Recently, however, such poorly digested carbohydrates grouped together by the term FODMAP (fermentable oligo-, di-, mono-saccharides and polyols) have been proposed to exacerbate symptoms of irritable bowel syndrome (IBS) such as abdominal discomfort and bloating. Dietary exclusion of foods containing FODMAPs, such as wheat, dairy and certain fruit and vegetables, has been proposed as a treatment for IBS, with some evidence to support this. FODMAPs are thought to induce symptoms either by drawing water into the small bowel by osmosis, or through gaseous distension of the large bowel or a combination of these along with metabolite effects on motility.

The Nottingham GI MRI group has been at the forefront of elucidating the actual effects of FODMAPs on gastrointestinal (GI) physiology. We have published techniques to measure small bowel water content, colonic volume and gas volume and whole gut transit time. We have recently demonstrated that a single, large (40g) dose of inulin leads to an increase in colonic volume, mainly through an increase in colonic gas. Such a dose is beyond the usual range of dietary variation, however. Last year we piloted a model more similar to dietary practice. Participants supplemented their usual diet with 5g OF twice daily for a week. The most striking result was an 18% increase in fasting colonic volume. This could not be explained by changes in colonic gas and may represent proliferation, and increased mass, of the microbiota. That study was an open label, uncontrolled case series so we now wish to test the hypothesis in a double-blind, randomised controlled trial. For explanatory purposes we will also measure whole gut transit, colonic gas volume and hydrogen and methane expired in the breath. For exploratory purposes we will also collect stool and urine samples to allow assessment of the effect on microbiota and their metabolic output.

Connect with a study center

  • Nottingham Digestive Diseases Centre

    Nottingham, NG7 2UH
    United Kingdom

    Site Not Available

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