IBS (Irritable Bowel Syndrome)Phase 3BoWell Sb252NCT07168434
Saccharomyces Boulardii CNCM I-745 in Irritable Bowel Syndrome
A Phase 3 study testing Saccharomyces Boulardii 250 MG in people with IBS (Irritable Bowel Syndrome) and IBS-D (Diarrhea-predominant), run by Biocodex at 10 sites in 2 countries.
Trial summary
This is a double-blind, randomized (group assignment by chance), placebo-controlled, multicenter trial which will be conducted over a 13.5-months period The main objective of the research is to demonstrate the efficacy of Saccharomyces boulardii CNCM I-745 on global IBS symptoms, measured by the Irritable Bowel… Read more about this study
- Who is it for?
- Ages 18 to 65 years
- Conditions the study is for
- IBS (Irritable Bowel Syndrome), IBS-D (Diarrhea-predominant), IBS, Mixed Symptoms
- What is being tested?
- Saccharomyces Boulardii 250 MG
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 406 participants
- Where
- 10 sitesin 2 countries
- Study dates
- 22 Oct 2025to 11 Oct 2026
- Phase
- Phase 3
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 65 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Male or female aged ≥ 18 and ≤ 65 years.
- Diagnosis of IBS of any subtype, except constipation predominant (IBS-C), according to Rome IV criteria.
- IBS-SSS total score ≥ 175 at inclusion.
- Able and willing to maintain their nutrition habits throughout the study participation.
- Able to understand and willing to comply with study requirements and to provide written informed consent.
- For women of childbearing potential: willing to use one or more acceptable birth control method throughout the study participation.
Who cannot join
- Diagnosis of IBS-C according to Rome IV criteria.
- Patient with more than 5 bowel movements per day on average during the screening period, according to the patient's diary (BSFS).
- Severe illness(es) or medical condition(s), including gastrointestinal pathologies (other than IBS): gastrointestinal ulcers, coeliac disease, inflammatory bowel disease, bowel cancer, acute or chronic diarrhea secondary to confirmed infectious gastroenteritis, or enteral or parenteral nutrition.
- History of abdominal surgery (except for appendectomy, cholecystectomy, surgery for hemorrhoids or cesarian section, more than 6 months prior to inclusion).
- Familial colorectal cancer syndrome (Lynch, Familial Adenomatous Polyposis).
- Fecal transplant within 6 months prior to screening.
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- Use of products marketed as prebiotics, probiotics or synbiotics within 2 weeks prior to screening. These products, with the exception of the investigational product, will not be allowed during the trial. Regular cheese or yogurt containing lactic acid bacteria are not an exclusion criterion.
- Systemic antibiotic or antimycotic treatment within 2 weeks prior to randomization. These treatments are not allowed during the study.
- Laxatives, antibloating agents, antidiarrheal medication, antispasmodics, within 2 weeks prior to screening. These treatments are not allowed during the study, except loperamide which can be used as rescue medication.
- Daily or regular non-steroidal anti-inflammatory drugs (NSAIDS) at doses above cardiovascular prophylaxis (low dose aspirin) are not allowed within 2 weeks prior to screening and throughout the study participation.
- Use of opioids or narcotic analgesics, including tramadol and codeine, within 6 weeks prior to screening. These treatments are not allowed during the study.
- Treatment with two or more antidepressant/anxiolytic/antipsychotic within 3 months prior to study entry or during the trial. Treatment with a single antidepressant or anxiolytic or antipsychotic agent before and during the trial is allowed provided that the dose is stable within 3 months prior to study entry and during the trial participation.
- Treatment with anticholinergics for overactive bladder such as solifenacin, darifenacin, oxybutynin, tolterodine, fesoterodin, propiverin, trospium chloride, or mirabegron, within 1 week prior to screening. These treatments are not allowed during the study.
- Allergy to yeast, especially Saccharomyces boulardii, or known hypersensitivity to one of the components.
- Patients having a central venous catheter, critically ill patients, and immunocompromised patients.
- Patients with rare hereditary problems of galactose or fructose intolerance, total lactase deficiency, glucose-galactose malabsorption or sucrase-isomaltase insufficiency.
- Excessive alcohol consumption (>7 units/week) and/or drug abuse.
- Other medical conditions or comorbidities, treatment, which in the opinion of the investigator, would interfere with study compliance or data interpretation.
- Presenting any significant biological or clinical anomalies that are not compatible with participation in the study according to the investigator.
- Participant at risk of pregnancy, pregnant or breastfeeding female.
- Participant under guardianship or curatorship.
- Participant under the protection of the Court or deprived of liberty.
- Participant participating in another interventional clinical trial which could interfere with the trial's results or impact the other trial's results; or within 5 half-lives of the study investigational treatment, whichever is longer.
- Participant whose current state of health does not allow him/her to give consent.
Trial locations and contacts
10 sites in 2 countries. Contact the study team or a site near you to ask about taking part.
10 sites in 2 countries
Spain8 sites, 8 recruiting
- Not yet recruiting
Hospital Universitario Vall d'Hebron
Barcelona, 08035
Jordi SERRA
- Recruiting
Hospital Universitario de León
León, 24008
Ana Belen DOMINGUEZ
- Recruiting
Hospital Universitario Gregorio Marañon & Centro de Salud Pavones
Madrid, 28007
Virginia FLORES
- Not yet recruiting
Hospital Clínico San Carlos
Madrid, 28040
Enrique REY
- Not yet recruiting
Hospital Universitario La Paz & Hospital Carlos III
Madrid, 28046
Lucía TORTAJADA
- Not yet recruiting
Hospital Universitario Regional de Málaga
Málaga, 29010
Miguel JIMENEZ
- Not yet recruiting
Hospital Universitario Costa del Sol
Marbella, 29603
Angeles PEREZ AISA
- Not yet recruiting
Hospital Universitario Central de Asturias & Centro de Salud la Lila
Oviedo, 33011
Enrique BARBEITO
Portugal2 sites, 2 recruiting
- Recruiting
Hospital de Braga
Braga
Sofia DA SILVA MENDES
- Not yet recruiting
Hospital da Luz
Lisbon
Mónica VELOSA
About this study
Official title: A Double-blind, Randomized, Placebo-controlled, Multicenter Trial Evaluating the Efficacy and Safety of Saccharomyces Boulardii CNCM I-745 in Adult Patients With Non-constipated Irritable Bowel Syndrome
This is a double-blind, randomized (group assignment by chance), placebo-controlled, multicenter trial which will be conducted over a 13.5-months period The main objective of the research is to demonstrate the efficacy of Saccharomyces boulardii CNCM I-745 on global IBS symptoms, measured by the Irritable Bowel Syndrome Symptom Severity Scale (IBS-SSS), in comparison to placebo after 8 weeks.
Secondary efficacy objectives are to evaluate the impact of Saccharomyces boulardii CNCM I-745 on quality of life of IBS patients and on global and individual IBS symptoms, using the IBS-SSS, in comparison to placebo at regular intervals over a 3-month treatment period. This research also aims to evaluate the proportion of patients who improved ≥ 50 points on IBS-SSS and the proportion of responders according to the European Medicines Agency (EMA) definition (based on the patient's global assessment of efficacy and on abdominal pain score), after 8 weeks of treatment. Secondary safety objective is to evaluate the safety profile and tolerability of Saccharomyces boulardii CNCM I-745 capsules 500 mg/day in IBS patients in comparison to placebo
- Being tested
- Saccharomyces Boulardii 250 MG, Placebo 250 mg
- Keywords
- IBS, Irritable Bowel Syndrome, Saccharomyces boulardii, Non-constipated IBS
- Medical subject headings
- Irritable Bowel Syndrome, Ichthyosis Bullosa of Siemens
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Saccharomyces Boulardii 250 MGDrug
Saccharomyces boulardii CNCM I-745, 250 mg, 2 capsules/day
Placebo 250 mgDrug
Placebo, 250mg, 2 capsules/day
| Study group | Role | What they receive |
|---|---|---|
| Treatment | Experimental | Saccharomyces boulardii CNCM I-745, 250 mg, 2 capsules/day Receives: Drug: Saccharomyces Boulardii 250 MG |
| Placebo | Placebo comparator | Placebo, 250mg, 2 capsules/day Receives: Drug: Placebo 250 mg |
What is being measured
The primary outcome is the main question the study is designed to answer.
To demonstrate the efficacy of Saccharomyces boulardii CNCM I-745 on global Irritable Bowel Syndrome (IBS) symptoms, measured by the Irritable Bowel Syndrome Symptom Severity Scale (IBS-SSS), in comparison to placebo after 8 weeks.
Irritable Bowel Syndrome Symptom Severity Scale (IBS-SSS) is a scale evaluating the severity of the disease from 0 (minimum score : not severe) to 500 (maximum score : severe).
Measured: From baseline to day 56
Secondary outcomes (8)
To evaluate the impact of Saccharomyces boulardii CNCM I-745 on quality of life of Irritable Bowel Syndrome (IBS) patients in comparison to placebo.
Absolute change measured in the Irritable Bowel Syndrome-Quality of Life (IBS-QOL). Minimum score is 0 : poor quality of life. Maximum score : 100 : better quality of life.
Measured: From baseline to day 56 and from baseline to day 84
To demonstrate the efficacy of Saccharomyces boulardii CNCM I-745 on global and individual Irritable Bowel Syndrome (IBS) symptoms, measured by the Irritable Bowel Syndrome Symptom Severity Scale (IBS-SSS), at each time point, in comparison to placebo.
Irritable Bowel Syndrome Symptom Severity Scale (IBS-SSS) is a scale evaluating the severity of the disease from 0 (minimum score : not severe) to 500 (maximum score : severe).
Measured: From baseline to day 28, day 56 and day 84
To evaluate the proportion of patients who improved ≥ 50 points on Irritable Bowel Syndrome Symptom Severity Scale (IBS-SSS).
Irritable Bowel Syndrome Symptom Severity Scale (IBS-SSS) is a scale evaluating the severity of the disease from 0 (minimum score : not severe) to 500 (maximum score : severe).
Measured: At day 28, day 56 and day 84 compared with baseline
To evaluate the proportion of responders according to the European Medicines Agency (EMA) definition, after 8 weeks of treatment
Proportion of responders at D56 and D84 according to the EMA definition (patients with a subject's global assessment of efficacy scale (Irritable Bowel Syndrome - Global Improvement Scale, IBS-GIS) of the highest two improvement grades of a 7-point scale (1 : significantly relieved to 7 : significantly worse), and with an abdominal pain score which has improved at least 30% compared to baseline). The abdominal pain score will be taken from the abdominal pain 11-point NRS.(0 : no pain to 10 : worse possible pain)
Measured: Day 56 and day 84
Assessment of the safety and tolerability of Saccharomyces boulardii CNCM I-745. Irritable Bowel Syndrome (IBS) patients in comparison to placebo. Recording adverse events
Safety endpoint : Recording of adverse events and serious adverse events (number of events and number of participants with at least one event)
Measured: From baseline to day 84
Assessment of the safety and tolerability of Saccharomyces boulardii CNCM I-745. Irritable Bowel Syndrome (IBS) patients in comparison to placebo. Recording changes in pulse rate
Safety endpoint : changes in pulse rate (beats per minute)
Measured: From baseline to day 84
Assessment of the safety and tolerability of Saccharomyces boulardii CNCM I-745. Irritable Bowel Syndrome (IBS) patients in comparison to placebo. Recording changes in blood pressure
Safety endpoint : changes in blood pressure (millimeter of mercury (mmHg))
Measured: From baseline to day 84
Assessment of the safety and tolerability of Saccharomyces boulardii CNCM I-745. Irritable Bowel Syndrome (IBS) patients in comparison to placebo. Recording changes in body weight
Safety endpoint : changes in body weight (kilograms (kg))
Measured: From baseline to day 84
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted11 Sep 2025
- Study start22 Oct 2025
- Primary completion11 Oct 2026 (estimated)
- Study completion11 Oct 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for IBS (Irritable Bowel Syndrome)Studies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 3
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind
- Who is masked
- Participant, Care provider, Investigator, Outcomes assessor
- Enrolment
- 406 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Biocodex
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
- Investigators
- Oana Bernard, DR, Study director, Biocodex
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07168434
- Sponsor's protocol ID
- BoWell Sb252
- Other IDs
- 2024-520276-10-00
- Acronym
- BoWell Sb252
- Status last verified
- Nov 2025
- First submitted
- 22 Aug 2025
- Last updated
- 18 Nov 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No