The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been endorsed by the ANZCTR. Before participating in a study, talk to your health care provider and refer to this information for consumers
Trial registered on ANZCTR


Registration number
ACTRN12617000465358
Ethics application status
Approved
Date submitted
28/03/2017
Date registered
30/03/2017
Date last updated
2/03/2018
Type of registration
Prospectively registered

Titles & IDs
Public title
The effect of a low fementable oligosaccharide, disaccharide, monosaccharide and polyol (FODMAP) diet on intestinal transit, the intestinal microbiome and metabolome in adults with irritable bowel syndrome..
Scientific title
An intervention study investigating the effect of a low fermentable oligosaccharide, disaccharide, monosaccharide and polyol (FODMAP) diet on gastrointestinal transit time and diversity of the microbiome and metabolome in adults with irritable bowel syndrome.
Secondary ID [1] 291554 0
None
Universal Trial Number (UTN)
U1111-1186-5261
Trial acronym
Linked study record
ACTRN12616001162404

Health condition
Health condition(s) or problem(s) studied:
Irritable bowel syndrome 302649 0
Condition category
Condition code
Oral and Gastrointestinal 302164 302164 0 0
Other diseases of the mouth, teeth, oesophagus, digestive system including liver and colon

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
10 participants with diarrhea predominant irritable bowel syndrome [IBS(D)] or [IBS(M)] from study ACTRN12616001162404 who do not have small intestinal bacteria overgrowth will be asked to participate.
They will be educated on a low FODMAP diet which is low in fermentable short chain carbohydrates. Foods which participants need to reduce include but are not limited to wheat products, apples, onion and garlic. They will be shown the Monash University low FODMAP app, which includes a traffic light system on which foods are suitable and a video clip on how the diet works as well as recipes. They will be given additional recipes to use that are low FODMAP. They will be asked to follow this diet strictly. Dietary education will be given by a New Zealand registered dietitian with 10 years experience who is familiar with a low FODMAP diet. These education session with be conducted individually and last for 45 minutes.

Timeline for the diet and investigations:
Week 1: participants follow usual diet
Week 2: participants provide a second urine and stool sample (the first fecal and urine samples were given in the earlier trial ACTRN12616001162404) after which they consume a smart pill while on their usual diet
Week 3-6: participants follow a strict low FODMAP diet (receiving 45 minutes dietary education at the beginning of week 3)
Week 7: participants provide a third urine and stool sample after which they consume a smart pill. During this week they remain on a strict low FODMAP diet
Week 8-12: Participants will be given 30 minutes education on how to reintroduce FODMAP containing foods to tolerance

Adherence to the diet will be measured by 7 telephone diet recalls conducted by two nutrition students (done in weeks 1-7). They will be checking for evidence of high FODMAP food intake and reporting on this.

Each participant will act as their own control therefore 10 participants should be sufficient for this part of the study.
Intervention code [1] 297618 0
Lifestyle
Comparator / control treatment
Each participant will serve as their own control
Control group
Uncontrolled

Outcomes
Primary outcome [1] 301591 0
Diversity of the microbiome

DNA will be extracted from the fecal samples and sequenced. The Shannon’s index of diversity will be used to compare diversity of the samples. The composition of the samples prior to commencing a low FODMAP diet and after following the diet will be compared using techniques designed for the analysis of compositional data under the guidance of Professor Greg Gloor who has extensive experience in analyzing microbiome data sets.
Timepoint [1] 301591 0
Before commencing a low FODMAP diet and after 4 weeks on the diet
Primary outcome [2] 301592 0
Intestinal transit time using the smart pill
Timepoint [2] 301592 0
Before commencing a low FODMAP diet and after 4 weeks on the diet
Secondary outcome [1] 333230 0
pH (using the smart pill)
Timepoint [1] 333230 0
Before commencing a low FODMAP diet and after 4 weeks on the diet
Secondary outcome [2] 333231 0
Change in metabolome

LC/MS and GC/MS will be used to detect the small molecules present in the urine. Data will then be analyzed using techniques designed for the analysis of compositional data
Timepoint [2] 333231 0
Before commencing a low FODMAP diet and after 4 weeks on the diet
Secondary outcome [3] 333232 0
Change in IBS symptom severity scoring system (IBS SSS)

This is the clinical outcome measure, the subscales within this will also be analyzed individually
Timepoint [3] 333232 0
Before commencing a low FODMAP diet and after 4 weeks on the diet
Secondary outcome [4] 333233 0
Change in IBS quality of life (IBS QoL)
Timepoint [4] 333233 0
Before commencing a low FODMAP diet and after 4 weeks on the diet

Eligibility
Key inclusion criteria
*Previously enrolled in study ACTRN12616001162404
*IBS (D) or IBS (M) according to Rome III criteria
*Fluent in English
Minimum age
18 Years
Maximum age
65 Years
Gender
Both males and females
Can healthy volunteers participate?
No
Key exclusion criteria
* Organic gastrointestinal disease
* Diabetes
* Serious neurological or respiratory conditions
* Pancreatitis
* Small intestinal bacteria overgrowth
* Antibiotics within the last six week

Study design
Purpose of the study
Treatment
Allocation to intervention
Non-randomised trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Masking / blinding
Who is / are masked / blinded?



Intervention assignment
Single group
Other design features
Phase
Not Applicable
Type of endpoint(s)
Statistical methods / analysis
Statistical analysis will be performed using Stat (Version 13.1 CITY, TX, USA). Data will be presented as mean and standard deviation unless otherwise stated. Students’ t tests will be used to compare baseline continuous data and Fisher’s exact test for categorical data. Paired students’ t test will be used to compare differences in continuous variables before commencing the low FODMAP diet and after 4 weeks on the diet. A p value of =0.05 will be deemed statistically significant.

The microbiome data will be analysed using the approaches of compositional data (CoDa) analysis that we have pioneered in the fields of microbiome and RNA-seq research, and all approaches used below follow a CoDa paradigm. CoDa analysis methods ensure that the analysis is robust to which OTU sequences are included, the order of the sequences, sequencing depth and random sampling. In essence, the CoDa approach examines the ratios between the OTU abundances, similar to what would be done with a quantitative PCR approach with an internal standard. The essential steps here are to convert the data into logarithms of ratios, and this step opens up the entire multivariate statistical toolkit.

Recruitment
Recruitment status
Stopped early
Data analysis
Data collected is being analysed
Reason for early stopping/withdrawal
Participant recruitment difficulties
Date of first participant enrolment
Anticipated
Actual
Date of last participant enrolment
Anticipated
Actual
Date of last data collection
Anticipated
Actual
Sample size
Target
Accrual to date
Final
Recruitment outside Australia
Country [1] 8768 0
Canada
State/province [1] 8768 0
Ontario

Funding & Sponsors
Funding source category [1] 296045 0
University
Name [1] 296045 0
University of Otago
Address [1] 296045 0
Dunedin School of Medicine

First Floor, Dunedin Hospital
Great King Street
Dunedin 9016
New Zealand
Country [1] 296045 0
New Zealand
Primary sponsor type
Individual
Name
Michael Schultz
Address
Dunedin School of Medicine

First Floor, Dunedin Hospital
Great King Street
Dunedin 9016
New Zealand
Country
New Zealand
Secondary sponsor category [1] 294936 0
Charities/Societies/Foundations
Name [1] 294936 0
Lawson Health Research Institute, London, Ontario
Address [1] 294936 0
268 Grosvenor St,
London,
ON N6A 4V2
Country [1] 294936 0
Canada

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 297301 0
Western University Health Science Research Ethics Board
Ethics committee address [1] 297301 0
Western University
Research Support Services Building Rm 5150
London
Ontario
N6G 1G9
Ethics committee country [1] 297301 0
Canada
Date submitted for ethics approval [1] 297301 0
07/12/2016
Approval date [1] 297301 0
08/02/2017
Ethics approval number [1] 297301 0
107228

Summary
Brief summary
The low FODMAP diet has been shown to be effective for ~70% of IBS patients. However, concerns have been raised that as it is lower in oligosaccharides it may reduce the variety of bacteria in the bowel (microbial diversity). Microbial diversity is associated with health. Two recently published studies have suggested that for people with IBS(D) following a low FODMAP diet may not have a reduction in microbial diversity. One other factor associated with increased diversity is longer transit time through the gastrointestinal tract. We are using a wireless motility capsule or a “smartpill” to measure intestinal transit time, pH, temperature and pressure when participants are following a normal diet and when they are following a low FODMAP diet.

The purpose of this study is to see if a low FODMAP diet slows down transit through the intestines and if it has an effect on pH inside the gastrointestinal tract.

10 people with IBS who enrolled for ACTRN12616001162404 but did not have SIBO will be asked to participate in this study.
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 73634 0
A/Prof Michael Schultz
Address 73634 0
Department of Medicine
9th Floor, Dunedin Hospital
Great King Street
Dunedin Central
Dunedin 9016
New Zealand
Country 73634 0
New Zealand
Phone 73634 0
+64 3 474 0999
Fax 73634 0
Email 73634 0
michael.schultz@otago.ac.nz
Contact person for public queries
Name 73635 0
Ms Ruth Harvie
Address 73635 0
c/- The Canadian centre for the human microbiome and probiotics
Lawson Research Institute
268 Grosvenor St
London
Ontario
N6A 4V2
Country 73635 0
Canada
Phone 73635 0
+1 519 317 2384
Fax 73635 0
Email 73635 0
ruth.harvie@postgrad.otago.ac.nz
Contact person for scientific queries
Name 73636 0
A/Prof Michael Schultz
Address 73636 0
Department of Medicine
9th Floor, Dunedin Hospital
Great King Street
Dunedin Central
Dunedin 9016
New Zealand
Country 73636 0
New Zealand
Phone 73636 0
+64 3 474 0999
Fax 73636 0
Email 73636 0
michael.schultz@otago.ac.nz

No data has been provided for results reporting
Summary results
Have study results been published in a peer-reviewed journal?
Other publications
Have study results been made publicly available in another format?
Results – basic reporting
Results – plain English summary