Condition category
Digestive System
Date applied
Date assigned
Last edited
Retrospectively registered
Overall trial status
Recruitment status
No longer recruiting

Plain English Summary

Background aims and objectives
Irritable bowel syndrome (IBS) can be a painful and debilitating condition; it is associated with many different symptoms, the most common of which is abdominal (stomach) pain. It is one of the most frequent disorders seen by doctors at general gastroenterology clinics. Conventional treatment of IBS involves a combination of drugs, supportive psychotherapy and dietary manipulation; however, current drugs don’t work very well in many sufferers and often have unpleasant and severe side effects. The main aim of this study is to investigate the potential benefits of using a particular multi-strain (more than one bacteria) liquid probiotic (Symprove) in IBS. Benefits will be measured by asking patients to answer a special questionnaire that has been designed as a means for clinicians to monitor and assess IBS symptoms in patients under their care.

Who can participate?
The study aims to recruit adults, aged 18-65 years, who have had moderate to severe IBS for at least 6 months.

What does the study involve?
All patients would undergo an interview, physical examination and routine studies before the start of the trial. These studies would include many tests that are used routinely for IBS workup including blood tests and stool sampling. Patients will be randomly allocated into two groups; one group will receive the probiotic Symprove taken as a drink once a day, while the other will receive a similar placebo (dummy) drink once a day. Each participant will take probiotic or placebo for a period of three months followed by a two-month follow-up period, so the total length of the study for each participant will be about five months. Participants will visit the clinic every four weeks for monitoring and some of the studies undertaken at the start of the study may be repeated after one and three months treatment as part of routine care and at the end of the follow-up period of the study.

What are the possible benefits and risks of participating?
Many members of the public with IBS have taken this probiotic for their IBS symptoms. Anecdotally they have spoken of feeling better with a lessening of symptoms when taking the probiotic but this was not done in the context of a clinical trial. It is expected that participants in this study will have similar benefits. Some participants may experience some loosening of bowel motions in the first few days as the bacteria colonise the large bowel. No other adverse effects are anticipated.

Where is the study run from?
The study will be undertaken at King’s College Hospital, London (UK).

When is the study starting and how long is it expected to run for?
The study started in September 2008 and will run for about 2 years.

Who is funding the study?
The trial is funded by Kings College Hospital NHS Foundation Trust (UK).

Who is the main contact?
Prof. Ingvar Bjarnason (Chief investigator),
Dr Guy Sisson (Lead Investigator) ,

Trial website

Contact information



Primary contact

Dr Guy Sisson


Contact details

Department of Gastroenterology
Kings College Hospital
Denmark Hill
United Kingdom

Additional identifiers

EudraCT number number

Protocol/serial number


Study information

Scientific title

Assessment of the probiotic symprove as a dietary supplement in patients with irritable bowel syndrome: a double-blind randomised placebo-controlled trial


Study hypothesis

Current hypothesis as of 22/10/2013:
The probiotic Symprove when taken as a dietary supplement can significantly improve symptoms in patients with irritable bowel syndrome (IBS).
The above protocol change was made prior to the trial opening.

Previous hypothesis:
The probiotic symprove when taken as a dietary supplement can significantly improve the quality of life (QOL) of patients with irritable bowel syndrome (IBS).

As of 10/05/2011 the anticipated end date for this trial has been extended from 01/04/2010 to 31/07/2011 as there has been a delay in recruiting patients.

Ethics approval

Bromley NRES Committee gave approval in July 2008 (ref: 08/H0809/31). Subsequent SSI (site specific inquiry) was confirmed by a chairman's action by the local NRES committee in August 2008.

Study design

Double-blind randomised placebo-controlled trial

Primary study design


Secondary study design

Randomised controlled trial

Trial setting


Trial type


Patient information sheet

Not available in web format, please use the contact details below to request a patient information sheet


Irritable bowel syndrome


Symprove probiotic dietary supplement (1 ml/kg) or placebo. Following a 1-week run-in period, all patients will receive 12 weeks of treatment (either placebo or active treatment) followed by a further 4-week follow-up. Patient randomisation in a 2:1 ratio active:placebo.

Intervention type



Not Specified

Drug names


Primary outcome measures

Current primary outcome measures as of 22/10/2013:
1. Efficacy – change in IBS Symptom Severity Score (IBS-SSS) from baseline to week 12
2. Safety – tolerability of the multistrain probiotic
The above change in protocol was made prior to the trial opening

Previous primary outcome measures:
Improvement in quality of life (QOL) as measured by a validated QOL questionnaire on week 12 of the study

Secondary outcome measures

Current secondary outcome measures as of 22/10/2013:
Improvements in symptoms and QoL as described by:
1. Change in IBS-QoL score from baseline to week 12
2. Change in IBS-SSS component scores at week 12
3. Changes in IBS-SSS and QoL between week 12 and 16
The above change in protocol was made prior to the trial opening

Previous secondary outcome measures:
1. Improvement in Sleep Quality Assessment
2. Improvement in Global Symptom Severity Score and specific symptom sub-scores (abdominal pain, bloating, stool frequency and stool consistency)
These will all be assessed at 4 weekly intervals (4, 8 and 12 weeks of treatment and week 16 - 4 weeks after treatment)

Overall trial start date


Overall trial end date


Reason abandoned


Participant inclusion criteria

1. Aged between 18 - 65 years, either sex
2. A firm diagnosis of IBS (ROME III criteria)
3. Moderate to severe symptoms

Participant type


Age group




Target number of participants

186 patients

Participant exclusion criteria

1. Diagnosis of inflammatory bowel disease or other organic bowel disease
2. Significant co-morbidity
3. Major psychological disorders
4. Previous/current history of alcohol or drug dependence
5. Pregnancy

Recruitment start date


Recruitment end date



Countries of recruitment

United Kingdom

Trial participating centre

Department of Gastroenterology
United Kingdom

Sponsor information


Kings College Hospital (UK)

Sponsor details

Denmark Hill
United Kingdom
+44 (0)20 3299 9000

Sponsor type

Hospital/treatment centre



Funder type


Funder name

Investigator initiated and funded (UK)

Alternative name(s)

Funding Body Type

Funding Body Subtype


Results and Publications

Publication and dissemination plan

Not provided at time of registration

Intention to publish date

Participant level data

Not provided at time of registration

Results - basic reporting

Publication summary

2014 results in:

Publication citations

  1. Results

    Sisson G, Ayis S, Sherwood RA, Bjarnason I, Randomised clinical trial: A liquid multi-strain probiotic vs. placebo in the irritable bowel syndrome--a 12 week double-blind study., Aliment. Pharmacol. Ther., 2014, 40, 1, 51-62, doi: 10.1111/apt.12787.

Additional files

Editorial Notes