Small Intestinal Bacterial OvergrowthNCT06317441
The Safety And Efficacy Of A Probiotic Intervention On Lactulose Hydrogen Breath Test-Positive Patients And Related Gastrointestinal Symptoms
A study testing Probiotic in people with Small Intestinal Bacterial Overgrowth and SIBO, run by Nimble Science Ltd. at 1 site in Canada.
Trial summary
The goal of this study is to test the effect of a probiotic formulation on gastrointestinal symptoms, gut and small intestine microbiota in participants suffering from small intestinal bacterial overgrowth (SIBO). Two doses of probiotic will be evaluated against placebo. Read more about this study
- Who is it for?
- Ages 18 to 65 years
- Conditions the study is for
- Small Intestinal Bacterial Overgrowth, SIBO
- What is being tested?
- Probiotic
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 105 participants
- Where
- 1 siteCanada
- Study dates
- 10 Jul 2024to Sep 2027
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
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
- Aged 18-65 years old at the inclusion of the study, both female and male subjects.
- Signed Informed Consent; willing and able to comply with study procedures.
- Willing to maintain their diet and physical activity levels during the study.
- Able to swallow a size-00 capsule (23mm length and 9mm width).
- Participants with at least one of the following Rome IV diagnoses: FABD, functional diarrhea, IBS-M, or IBS-D.
- Baseline weekly average of worst daily (in past 24 hours) abdominal bloating/distension score of >= 3.0 on a 0-to-10-point scale.
- Participants with abnormal LHBT following the North American Consensus recommendations (A rise in hydrogen of ≥20 ppm by 90 min).
Who cannot join
- History of less than three (3) bowel movements per week.
- With the diagnosis of IBS-C.
- Prior gastrointestinal disease, surgery, or abdominal or pelvic radiation treatment which, in the Investigator's opinion, would lead to intestinal structuring or obstruction with a risk of capsule non-excretion, including, e.g., achalasia, eosinophilic esophagitis, any IBD, or previous esophageal, gastric, small intestinal, or colonic surgery. Appendectomy or cholecystectomy more than 3 months before the screening visit is acceptable.
- Persons with central venous catheters.
- History of known structural gastrointestinal abnormalities such as structures or fistulas leading to mechanical obstruction.
- Known history abdominal radiation treatment.
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- Use of any medications in the week prior to the screening study visit, unless part of regular treatment, that could substantially alter gastrointestinal motor function (e.g., opioids, anticholinergics, or GLP-1 analogues); laxative use is allowed if used less than 3 times a week and it is willing to keep unchanged in the week prior to the SIMBA capsule ingestions. Proton pump inhibitors (PPIs) are allowed provided a wash-out period of 48 hours is respected before swallowing the SIMBA capsules and PPI treatment is resumed only 4 hours thereafter.
- o Prokinetic use. Potential participants who are not using prokinetics to treat SIBO may be eligible after a 2-week washout period, and willing to not use prokinetics for the study duration.
- Unable to stop using laxatives or prokinetic medications for 4 days before the study procedure (BT). Laxatives can be resumed after the test is conducted.
- Organic motility disorder, including gastroparesis, intestinal pseudo-obstruction, systemic sclerosis, Ogilvie's syndrome.
- Celiac disease (treated or untreated).
- Any significant heart, liver, lung, kidney, blood, endocrine or nervous system disease, which in the opinion of the investigator, would adversely affect study safety or outcome.
- Cancer diagnosis or treatment within the past year (non-melanoma skin cancers are acceptable).
- Gastrointestinal inflammatory diseases, including ulcerative colitis, Crohn's disease, microscopic colitis.
- Participants with IBS presenting with alarm symptoms such as: rectal bleeding, unexplained weight loss, iron deficiency anemia, and nocturnal symptoms,
- Participants over the age of 50 or older who have not had:
- a colon cancer screening by either a negative FIT or FOBT test within the last 2 years; OR
- a colonoscopy in the prior 10 years which was negative for colorectal cancer
- Epilepsy diagnosis.
- History or diagnosis of immunological diseases, infectious diseases or immune-compromised conditions, which in the opinion of the investigator, would adversely affect study safety or outcome. Such as, but not limited to, hepatitis, tuberculosis, HIV positive, Parkinson's, multiple sclerosis, AIDS, lymphoma, and long-term corticosteroid treatment.
- History of oropharyngeal dysphagia, or other swallowing disorder with a risk of capsule aspiration.
- Antibiotic use (except for topical use) ≤ 12 weeks prior to screening. Potential participants may be eligible once a 12-week washout is completed.
- Regular use of probiotics, prebiotics or synbiotics (including food and drinks containing added probiotics and/or probiotic yogurts with live, active cultures) within 1 month prior to screening. Potential participants may be eligible once a 1-month washout is completed.
- Any prior Fecal Microbiota Transplantation.
- Pregnant or breastfeeding.
- Planning to become pregnant.
- Alcohol or drug abuse.
- Allergy to the components present in the probiotic and placebo capsules.
- Are non-English speaking.
- Are scheduled for an MRI at any time during the study. Potential participants may be eligible to participate once their MRI procedure is completed.
Trial locations and contacts
1 site in 1 country.
About this study
The goal of this study is to test the effect of a probiotic formulation on gastrointestinal symptoms, gut and small intestine microbiota in participants suffering from small intestinal bacterial overgrowth (SIBO). Two doses of probiotic will be evaluated against placebo.
Read the detailed description
The goal of this double-blinded, randomized, placebo-controlled clinical study is to evaluate whether two different doses of a probiotic formulation may have effect on gastrointestinal symptoms, as well as gut and small intestine microbiota, in participats suffering from SIBO. The two probiotic doses will be compared to a placebo.
The main research questions to be answered by this study are related to:
- Probiotic effect on bloating and abdominal distension.
- Probiotic effect on other gastrointestinal symptoms.
- Probiotic effect on incidence of SIBO.
- Probiotic effect on small intestine and gut microbiota.
The study will include a 2 month intervention with the investigational products and assessments will be conducted at baseline, mid-intervention, end-of-intervention, and follow-up period, with the exception of SIBO diagnosis, which will be conducted at baseline and at follow-up.
- Conditions
- Small Intestinal Bacterial Overgrowth, SIBO
- Being tested
- Probiotic
- Keywords
- Functional abdominal bloating and distension, Functional Diarrhea, Irritable Bowel Syndrome with Diarrhea, Irritable Bowel Syndrome, Abdominal Bloating, IBS, IBS-D, FABD, Functional Gastrointestinal Disorders, FGID
- Medical subject headings
- Dilatation, Pathologic, Irritable Bowel Syndrome, Gastrointestinal Diseases
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
ProbioticDietary supplement
The intervention consists of a probiotic either with a low or high dosage
| Study group | Role | What they receive |
|---|---|---|
| Probiotic (High dose) | Experimental | A high dosage probiotic per capsule Receives: Dietary Supplement: Probiotic |
| Probiotic (Low dose) | Experimental | A low dosage probiotic per capsule Receives: Dietary Supplement: Probiotic |
| Control group (Placebo) | No intervention | No probiotic dosage |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change in bloating/distension severity
The primary outcome will assess the changes in weekly median severity of bloating/distension, defined as pressure, fullness or sensation of increased girth with a daily assessment with an ordinal scale between probiotic groups and placebo.
Measured: From baseline to end of intervention (week 8).
Secondary outcomes (12)
Median bloating-free days
Median bloating-free days per week at each intervention week and follow up
Measured: Each intervention week and follow up (week 12) compared to baseline.
Change in median bloating/distension severity
Change in median bloating/distension severity assessed by an ordinal scale (0 no severity- 10 extreme severity) at all intervention weeks (with the exception of end-of-intervention, as described in the primary outcome)
Measured: At all intervention weeks (with the exception of end-of-intervention, as described in the primary outcome) and follow-up (week 12) compared to baseline.
Change in abdominal discomfort/pain
Change in abdominal discomfort/pain assessed by an ordinal scale (0 no pain - 10 extreme pain)
Measured: At mid-intervention (week 4), end of intervention (week 8), and follow-up (week 12) compared to baseline
Changes in gastrointestinal symptoms
Changes in gastrointestinal symptoms assessed with GSRS
Measured: At mid-intervention (week 4), end of intervention (week 8), and follow-up (week 12) compared to baseline.
Changes in stool frequency and consistency
Changes in stool frequency and consistency assessed with the Bristol Stool Scale (scoring 1 watery - 7 hard)
Measured: At mid-intervention (week 4), end of intervention (week 8), and follow-up (week 12) compared to baseline.
Changes in the quality of life
Changes in the quality of life assessed with the Short Form (SF)-36 questionnaire
Measured: At mid-intervention (week 4), end of intervention (week 8), and follow-up (week 12) compared to baseline.
Changes in reflux incidence and severity
Changes in reflux incidence and severity assessed with the modified reflux symptoms (mRESQ)
Measured: At mid-intervention (week 4), end of intervention (week 8), and follow-up (week 12) compared to baseline.
Changes in the severity of IBS symptoms
Changes in the severity of IBS symptoms assessed with IBS Severity Scoring System (IBS-SSS) questionnaire
Measured: At mid-intervention (week 4), end of intervention (week 8), and follow-up (week 12) compared to baseline.
Recovery rate of the probiotic strain
Recovery rate of the probiotic strain in small intestine and stool specimens
Measured: At mid-intervention (week 4) end of intervention (week 8), and follow-up (week 12) compared to baseline.
Microbiome changes within small intestine, fecal and saliva samples
Changes in the the bacterial populations with the small intestine, fecal and saliva microbiomes represented as a diversity ratio
Measured: At mid-intervention (week 4), end of intervention (week 8), and follow-up (week 12) compared to baseline.
Investigation how the microbiome and SIBO associate with each other though bacterial population analyses.
Exploring the correlation of select bacterial populations with SIBO through analysis of the small intestine and fecal microbiomes using metagenomics methodologies.
Measured: Through study completion, an average of 1 year
Change in SIBO positivity rate
Change in SIBO positivity rate assessed by glucose breath test
Measured: Through study completion, an average of 1 year
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted19 Mar 2024
- Study start10 Jul 2024
- Primary completionApr 2027 (estimated)
- Study completionSep 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Small Intestinal Bacterial OvergrowthStudies 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 N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind
- Who is masked
- Participant, Care provider, Investigator, Outcomes assessor
- Enrolment
- 105 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Nimble Science Ltd.
- Sponsor type
- Industry (pharma, biotech, devices)
- Collaborators
- Lallemand Health Solutions
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06317441
- Sponsor's protocol ID
- NIMCSF137
- Status last verified
- Sep 2026
- First submitted
- 27 Feb 2024
- Last updated
- 30 Sep 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: Select data with be shared with the participants
Study at a glance
From the registry record, last updated by the sponsor on 30 Sep 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- The Safety And Efficacy Of A Probiotic Intervention On Lactulose Hydrogen Breath Test-Positive Patients And Related Gastrointestinal Symptoms
- ClinicalTrials.gov ID
- NCT06317441
- Acronym / sponsor ID
- NIMCSF137
- Conditions
- Small Intestinal Bacterial Overgrowth, SIBO
- Keywords
- Functional abdominal bloating and distension, Functional Diarrhea, Irritable Bowel Syndrome with Diarrhea, Irritable Bowel Syndrome, Abdominal Bloating, IBS, IBS-D, FABD
- Study type
- Interventional
- Recruitment status
- Active, not recruiting
- Enrolment
- 105 participants (estimated)
- Lead sponsor
- Nimble Science Ltd.Industry (pharma, biotech, devices)
- Collaborators
- Lallemand Health Solutions
- Study start
- 10 Jul 2024 (actual)
- Primary completion
- Apr 2027 (estimated)
- Study completion
- Sep 2027 (estimated)
- First posted
- 19 Mar 2024 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The goal of this study is to test the effect of a probiotic formulation on gastrointestinal symptoms, gut and small intestine microbiota in participants suffering from small intestinal bacterial overgrowth (SIBO). Two doses of probiotic will be evaluated against placebo.
Detailed description
The goal of this double-blinded, randomized, placebo-controlled clinical study is to evaluate whether two different doses of a probiotic formulation may have effect on gastrointestinal symptoms, as well as gut and small intestine microbiota, in participats suffering from SIBO. The two probiotic doses will be compared to a placebo.
The main research questions to be answered by this study are related to:
- Probiotic effect on bloating and abdominal distension.
- Probiotic effect on other gastrointestinal symptoms.
- Probiotic effect on incidence of SIBO.
- Probiotic effect on small intestine and gut microbiota.
The study will include a 2 month intervention with the investigational products and assessments will be conducted at baseline, mid-intervention, end-of-intervention, and follow-up period, with the exception of SIBO diagnosis, which will be conducted at baseline and at follow-up.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind (participant, care provider, investigator, outcomes assessor)
- Number of arms
- 3
| Arm | Type | Receives |
|---|---|---|
| Probiotic (High dose) | Experimental | Dietary Supplement: ProbioticA high dosage probiotic per capsule |
| Probiotic (Low dose) | Experimental | Dietary Supplement: ProbioticA low dosage probiotic per capsule |
| Control group (Placebo) | No intervention | –No probiotic dosage |
Who may qualify
- Ages
- 18 to 65 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (7 listed)
- Aged 18-65 years old at the inclusion of the study, both female and male subjects.
- Signed Informed Consent; willing and able to comply with study procedures.
- Willing to maintain their diet and physical activity levels during the study.
- Able to swallow a size-00 capsule (23mm length and 9mm width).
- Participants with at least one of the following Rome IV diagnoses: FABD, functional diarrhea, IBS-M, or IBS-D.
Key exclusion criteria (30 listed)
- History of less than three (3) bowel movements per week.
- With the diagnosis of IBS-C.
- Prior gastrointestinal disease, surgery, or abdominal or pelvic radiation treatment which, in the Investigator's opinion, would lead to intestinal structuring or obstruction with a risk of capsule non-excretion, including, e.g., achalasia, eosinophilic esophagitis, any IBD, or previous esophageal, gastric, small intestinal, or colonic surgery. Appendectomy or cholecystectomy more than 3 months before the screening visit is acceptable.
- Persons with central venous catheters.
- History of known structural gastrointestinal abnormalities such as structures or fistulas leading to mechanical obstruction.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| ProbioticThe intervention consists of a probiotic either with a low or high dosage | Dietary supplement | Probiotic (High dose), Probiotic (Low dose) |
Primary outcome
Change in bloating/distension severity
Time frame: From baseline to end of intervention (week 8).
The primary outcome will assess the changes in weekly median severity of bloating/distension, defined as pressure, fullness or sensation of increased girth with a daily assessment with an ordinal scale between probiotic groups and placebo.
12 secondary outcomes
Median bloating-free days
Time frame: Each intervention week and follow up (week 12) compared to baseline.
Change in median bloating/distension severity
Time frame: At all intervention weeks (with the exception of end-of-intervention, as described in the primary outcome) and follow-up (week 12) compared to baseline.
Change in abdominal discomfort/pain
Time frame: At mid-intervention (week 4), end of intervention (week 8), and follow-up (week 12) compared to baseline
Changes in gastrointestinal symptoms
Time frame: At mid-intervention (week 4), end of intervention (week 8), and follow-up (week 12) compared to baseline.
Changes in stool frequency and consistency
Time frame: At mid-intervention (week 4), end of intervention (week 8), and follow-up (week 12) compared to baseline.
Changes in the quality of life
Time frame: At mid-intervention (week 4), end of intervention (week 8), and follow-up (week 12) compared to baseline.
Changes in reflux incidence and severity
Time frame: At mid-intervention (week 4), end of intervention (week 8), and follow-up (week 12) compared to baseline.
Changes in the severity of IBS symptoms
Time frame: At mid-intervention (week 4), end of intervention (week 8), and follow-up (week 12) compared to baseline.
Recovery rate of the probiotic strain
Time frame: At mid-intervention (week 4) end of intervention (week 8), and follow-up (week 12) compared to baseline.
Microbiome changes within small intestine, fecal and saliva samples
Time frame: At mid-intervention (week 4), end of intervention (week 8), and follow-up (week 12) compared to baseline.
Investigation how the microbiome and SIBO associate with each other though bacterial population analyses.
Time frame: Through study completion, an average of 1 year
Change in SIBO positivity rate
Time frame: Through study completion, an average of 1 year
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 30 Sep 2026.
- Individual participant dataSharing planned: No. Select data with be shared with the participants
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Probiotic in people with Small Intestinal Bacterial Overgrowth and SIBO, run by Nimble Science Ltd. at 1 site in Canada.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 7 inclusion and 30 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: under way, not looking for participants, as of the sponsor's last update on 30 Sep 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Canada. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Change in bloating/distension severity (time frame: From baseline to end of intervention (week 8).). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 30 Sep 2026.