Probiotic treatment for patients with small intestinal bacterial overgrowth

The Safety And Efficacy Of A Probiotic Intervention On Lactulose Hydrogen Breath Test-Positive Patients And Related Gastrointestinal Symptoms

NA · Nimble Science Ltd. · NCT06317441

This study is testing if a new probiotic can help people with small intestinal bacterial overgrowth feel better by reducing symptoms like bloating and discomfort.

Quick facts

PhaseNA
Study typeInterventional
Enrollment105 (estimated)
Ages18 Years to 65 Years
SexAll
SponsorNimble Science Ltd. (industry)
Drugs / interventionsradiation
Locations1 site (Calgary, Alberta)
Trial IDNCT06317441 on ClinicalTrials.gov

What this trial studies

This clinical trial aims to evaluate the safety and efficacy of a probiotic formulation in patients diagnosed with small intestinal bacterial overgrowth (SIBO). Participants will be randomly assigned to receive either one of two doses of the probiotic or a placebo over a two-month period. The study will assess changes in gastrointestinal symptoms, gut microbiota, and the incidence of SIBO through various evaluations conducted at baseline, mid-intervention, and at the end of the intervention. The primary focus is on the probiotic's effects on abdominal bloating, distension, and other related gastrointestinal symptoms.

Who should consider this trial

Good fit: Ideal candidates are adults aged 18-65 with a diagnosis of functional abdominal bloating, functional diarrhea, or irritable bowel syndrome with diarrhea, who have tested positive for SIBO.

Not a fit: Patients with constipation-predominant irritable bowel syndrome or those with a history of significant gastrointestinal disease may not benefit from this study.

Why it matters

Potential benefit: If successful, this study could provide a new therapeutic option for patients suffering from SIBO and related gastrointestinal symptoms.

How similar studies have performed: Previous studies have shown promising results with probiotic interventions for gastrointestinal conditions, suggesting potential for success in this approach.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

1. Aged 18-65 years old at the inclusion of the study, both female and male subjects.
2. Signed Informed Consent; willing and able to comply with study procedures.
3. Willing to maintain their diet and physical activity levels during the study.
4. Able to swallow a size-00 capsule (23mm length and 9mm width).
5. Participants with at least one of the following Rome IV diagnoses: FABD, functional diarrhea, IBS-M, or IBS-D.
6. Baseline weekly average of worst daily (in past 24 hours) abdominal bloating/distension score of \>= 3.0 on a 0-to-10-point scale.
7. Participants with abnormal LHBT following the North American Consensus recommendations (A rise in hydrogen of ≥20 ppm by 90 min).

Exclusion Criteria:

1. History of less than three (3) bowel movements per week.
2. With the diagnosis of IBS-C.
3. 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.
4. Persons with central venous catheters.
5. History of known structural gastrointestinal abnormalities such as structures or fistulas leading to mechanical obstruction.
6. Known history abdominal radiation treatment.
7. 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.
8. 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.
9. Organic motility disorder, including gastroparesis, intestinal pseudo-obstruction, systemic sclerosis, Ogilvie's syndrome.
10. Celiac disease (treated or untreated).
11. 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.
12. Cancer diagnosis or treatment within the past year (non-melanoma skin cancers are acceptable).
13. Gastrointestinal inflammatory diseases, including ulcerative colitis, Crohn's disease, microscopic colitis.
14. Participants with IBS presenting with alarm symptoms such as: rectal bleeding, unexplained weight loss, iron deficiency anemia, and nocturnal symptoms,
15. 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
16. Epilepsy diagnosis.
17. 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.
18. History of oropharyngeal dysphagia, or other swallowing disorder with a risk of capsule aspiration.
19. Antibiotic use (except for topical use) ≤ 12 weeks prior to screening. Potential participants may be eligible once a 12-week washout is completed.
20. 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.
21. Any prior Fecal Microbiota Transplantation.
22. Pregnant or breastfeeding.
23. Planning to become pregnant.
24. Alcohol or drug abuse.
25. Allergy to the components present in the probiotic and placebo capsules.
26. Are non-English speaking.
27. Are scheduled for an MRI at any time during the study. Potential participants may be eligible to participate once their MRI procedure is completed.

Where this trial is running

Calgary, Alberta

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.

View on ClinicalTrials.gov →

Conditions: Small Intestinal Bacterial Overgrowth, SIBO, Functional abdominal bloating and distension, Functional Diarrhea, Irritable Bowel Syndrome with Diarrhea, Irritable Bowel Syndrome, Abdominal Bloating, IBS

Last reviewed 2026-05-15 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.