Irritable Bowel Syndrome (IBS)Phase 1SIMPACTNCT07882953
SIMBA in Irritable Bowel Syndrome (IBS)
A Phase 1 study testing Rifaximin (drug) and fluid biopsy capsule in people with Irritable Bowel Syndrome (IBS) and Microbiome, run by University of Calgary at 1 site in Canada.
Trial summary
This study is intended to characterize longitudinal changes in the small intestinal microbiome following rifaximin treatment in participants with Irritable Bowel Syndrome (IBS) over a 12 week period. Read more about this study
- Who is it for?
- Ages 18 to 65 years
- Conditions the study is for
- Irritable Bowel Syndrome (IBS), Microbiome
- What is being tested?
- Rifaximin (drug) and fluid biopsy capsule
- Type of treatment
- Pill or oral medicine, Medical device
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 180 participants
- Where
- 1 siteCanada
- Study dates
- Nov 2026to Sep 2028
- Phase
- Phase 1
- 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
- Age 18-65 years at the inclusion of the study, both female and male subjects.
- Provide informed consent to participate in study; willing and able to comply with study procedures.
- Able to swallow a capsule sized 25mm length and 9mm width (i.e. large dose omega 3 pill).
- Willing to maintain their diet and physical activity levels during the study.
- Participants with a confirmed or suspected diagnosis of Irritable Bowel Syndrome (IBS) meeting or presenting with symptoms consistent with Rome V criteria for one of the following subtypes: IBS-C, IBS-M, or IBS-D.
- Baseline weekly average of worst daily (in past 24 hours) abdominal bloating score of >= 3.0 on a 0-to-10-point scale.
Who cannot join
- Non-English speaking.
- Regular use of probiotics, prebiotics or synbiotics (including food and drinks containing added probiotics and/or probiotic yogurts with live, active cultures, or kefir) within 1 month prior to screening. Non-probiotic fortified yogurt is acceptable. Potential participants may be eligible once a 1-month washout is completed.
- Stimulant laxative use (includes bisacodyl/Dulcolax, senna/Senekot, cascara, or fiber supplements) is allowed if it is kept unchanged in the week prior to the SIMBA capsule ingestion. Osmotic laxatives (polyethylene glycol (PEG; other trade names), milk of magnesia, lactulose), stool softeners (docusate; other trade names) or secretagogues (linaclotide/Constella, plecanatide/Trulance, tenapanor/Ibsrela should not be used within 7 days of taking the SIMBA capsules.
- Use of oral or intravenous antibiotics or antifungal medications (except topical antibiotics or antifungals) within the previous 12 weeks. This includes rifaximin.
- Use of medications known to affect gastrointestinal motility, including but not limited to prokinetics (including domperidone, metoclopramide, prucalopride), anticholinergics, opioids, GLP-1 receptor agonists, secretagogues (linaclotide, plecanatide, tenapenor), cholestyramine, colchicine, and methyldopa, unless permitted by protocol.
- Chronic use of salicylates, aspirin (ASA), corticosteroids, nonsteroidal anti-inflammatory drugs (NSAIDs), misoprostol or other medications known to affect small intestinal mucosal integrity, as determined by the Principal Investigator.
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- Current smoker or use of tobacco, nicotine, or cannabis products including vapes, gums, gummies, or other ingestible or inhaled formats.
- Alcohol consumption >21 units per week, alcohol abuse, or illicit drug use.
- Currently dieting for weight loss or following a low-carbohydrate diet.
- Participation in another clinical trial within 30 days prior to enrollment.
- Known allergy or hypersensitivity to rifaximin.
- Pregnancy, lactation, planned pregnancy during the study period, or unwillingness to use an approved method of contraception if of childbearing potential.
- Major surgery within the previous 3 months.
- Any significant medical condition that, in the opinion of the Principal Investigator or Qualified Investigator, could interfere with study participation, intervention, or outcome assessment, including:
- Renal disease
- Gastrointestinal disorders (includes inflammatory bowel disease, celiac disease (treated or untreated), any eosinophilic gastrointestinal disorder, microscopic colitis)
- Autoimmune disease (including Rheumatoid arthritis, lupus, scleroderma)
- Metabolic disease (type 1 diabetes is excluded. Controlled Type 2 diabetes may be acceptable per investigator's discretion)
- Cardiovascular or vascular disease
- Respiratory disease (COPD, home oxygen use is excluded. Mild asthma (prn puffer use) may be acceptable)
- major mental health disorder
- Hyperthyroidism (whether controlled or not). Controlled hypothyroidism is allowable
- Prior fecal microbiota transplantation, less than a year before study enrollment.
- Cancer diagnosis or treatment within the past year (except non-melanoma skin cancer).
- Concomitant Supplements Participants taking supplements that are judged by the investigators not to interfere with study outcomes (e.g., vitamins, omega-3 fatty acids, creatine monohydrate) may continue use, provided the dose remains unchanged throughout the study, are not taken within 6 hours on either side of capsule ingestion, and no new supplements are introduced unless medically recommended.
- Pregnancy Assessment Females of childbearing potential will be assessed for pregnancy risk through self-report. A urine β-hCG test will be required if pregnancy status is uncertain. Participants who become pregnant during the study will discontinue the study medication immediately and notify the investigators.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Canada1 site
University of Calgary, Foothills Campus
Calgary, Alberta, T2N 4Z6
Lynn Wilsack, MSc, 403 592-5045, lwilsack@ucalgary.ca
Gwen Duytschaever, PhD, gwen@nimblesci.com
About this study
Official title: Advancing Nimble Science's SIMBA GI Data Platform for Clinically Actionable Insights From the Small Intestine in Irritable Bowel Syndrome to Deliver Personalized Treatment
This study is intended to characterize longitudinal changes in the small intestinal microbiome following rifaximin treatment in participants with Irritable Bowel Syndrome (IBS) over a 12 week period.
Read the detailed description
The goal of this open-label interventional trial is to evaluate the changes in the small intestinal microbiome in a population of 180 adults with irritable bowel syndrome (IBS) over a twelve week period. The study will compare microbiome data collected with the SIMBA capsule before, during and after treatment, along with qualitative questionnaires.
- Conditions
- Irritable Bowel Syndrome (IBS), Microbiome
- Being tested
- Rifaximin (drug), fluid biopsy capsule
- Medical subject headings
- Irritable Bowel Syndrome
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Rifaximin (drug)Drug
Open label
fluid biopsy capsuleDevice
Collection of a fluid biopsy from the small intestine via ingestible capsule
| Study group | Role | What they receive |
|---|---|---|
| Irritable Bowel Syndrome - Diarrhea | Active comparator | As confirmed by diagnosis and/or Principal Investigator assessment and measured via patient response to validated questionnaires Receives: Drug: Rifaximin (drug); Device: fluid biopsy capsule |
| Irritable Bowel Syndrome - Constipation | Active comparator | As confirmed by diagnosis and/or Principal Investigator assessment and measured via patient response to validated questionnaires Receives: Drug: Rifaximin (drug); Device: fluid biopsy capsule |
| Irritable Bowel Syndrome - Mixed | Active comparator | As confirmed by diagnosis and/or Principal Investigator assessment and measured via patient response to validated questionnaires Receives: Drug: Rifaximin (drug); Device: fluid biopsy capsule |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change in small intestinal microbiome composition
Difference in small intestinal microbiome composition (Community Distance Index) within participant
Measured: Baseline and 4 weeks post end of treatment
Secondary outcomes (4)
Change in Abdominal Pain Severity (VAS-IBS)
Change in participant's abdominal pain sub-score measured using the Visual Analogue Scale for Irritable Bowel Syndrome (VAS-IBS)
Measured: Baseline and 4 weeks post end of treatment
Difference in Dominant Microbial Composition Index Among IBS Rome V Subtypes
Dominant microbial composition index will be developed using shotgun metagenomic sequencing and metabolome analysis of capsule samples for each IBS sub-type (D, C and M) by collating sample results for participants by study arm. This microbial composition index for each arm will be described and differences compared.
Measured: Baseline and 4 weeks post end of treatment
Change in Antimicrobial Resistance Gene Burden and Microbial Antimicrobial Resistance
Characterize intrinsic antimicrobial resistance (AMR) profiles of microbial species and subspecies identified in small intestinal samples via shotgun sequencing, measured through copy numbers of NCBI AMRFinder+ genome annotations.
Measured: Baseline and 4 weeks post end of treatment
Predictive Accuracy of Baseline Multi-Omic Features for Clinical Response to Rifaximin
Microbiome feature selection and documentation (p-Values, effect size) based on Linear Mixed Effect modelling of clinical response. Model performance metrics (e.g., discrimination, calibration, and predictive accuracy) for predicting clinical response to rifaximin using baseline clinical characteristics and small intestinal multi-omic features measured via shotgun sequencing and metabolomic analysis.
Measured: Baseline and 4 weeks post end of treatment
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted20 Oct 2026
- Study startNov 2026 (estimated)
- Primary completionDec 2027 (estimated)
- Study completionSep 2028 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Irritable Bowel Syndrome (IBS)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 1
- Primary purpose
- Basic science
- Allocation
- Non-randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 180 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University of Calgary
- Sponsor type
- University, hospital or other
- Collaborators
- Nimble Science Ltd., Genome Alberta
- Responsible party
- Sponsor
- Investigators
- Christopher N Andrews, MD MSc, Principal investigator, University of Calgary
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07882953
- Sponsor's protocol ID
- 26-1476
- Acronym
- SIMPACT
- Status last verified
- Oct 2026
- First submitted
- 6 Oct 2026
- Last updated
- 20 Oct 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 20 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Advancing Nimble Science's SIMBA GI Data Platform for Clinically Actionable Insights From the Small Intestine in Irritable Bowel Syndrome to Deliver Personalized Treatment
- ClinicalTrials.gov ID
- NCT07882953
- Acronym / sponsor ID
- SIMPACT / 26-1476
- Conditions
- Irritable Bowel Syndrome (IBS), Microbiome
- Phase
- Phase 1
- Study type
- Interventional
- Recruitment status
- Not yet recruiting
- Enrolment
- 180 participants (estimated)
- Lead sponsor
- University of CalgaryUniversity, hospital or other
- Collaborators
- Nimble Science Ltd., Genome Alberta
- Study start
- Nov 2026 (estimated)
- Primary completion
- Dec 2027 (estimated)
- Study completion
- Sep 2028 (estimated)
- First posted
- 20 Oct 2026 (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.
This study is intended to characterize longitudinal changes in the small intestinal microbiome following rifaximin treatment in participants with Irritable Bowel Syndrome (IBS) over a 12 week period.
Detailed description
The goal of this open-label interventional trial is to evaluate the changes in the small intestinal microbiome in a population of 180 adults with irritable bowel syndrome (IBS) over a twelve week period. The study will compare microbiome data collected with the SIMBA capsule before, during and after treatment, along with qualitative questionnaires.
Study design
- Primary purpose
- Basic science
- Allocation
- Non-randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 3
| Arm | Type | Receives |
|---|---|---|
| Irritable Bowel Syndrome - Diarrhea | Active comparator | Drug: Rifaximin (drug), Device: fluid biopsy capsuleAs confirmed by diagnosis and/or Principal Investigator assessment and measured via patient response to validated questionnaires |
| Irritable Bowel Syndrome - Constipation | Active comparator | Drug: Rifaximin (drug), Device: fluid biopsy capsuleAs confirmed by diagnosis and/or Principal Investigator assessment and measured via patient response to validated questionnaires |
| Irritable Bowel Syndrome - Mixed | Active comparator | Drug: Rifaximin (drug), Device: fluid biopsy capsuleAs confirmed by diagnosis and/or Principal Investigator assessment and measured via patient response to validated questionnaires |
Who may qualify
- Ages
- 18 to 65 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (6 listed)
- Age 18-65 years at the inclusion of the study, both female and male subjects.
- Provide informed consent to participate in study; willing and able to comply with study procedures.
- Able to swallow a capsule sized 25mm length and 9mm width (i.e. large dose omega 3 pill).
- Willing to maintain their diet and physical activity levels during the study.
- Participants with a confirmed or suspected diagnosis of Irritable Bowel Syndrome (IBS) meeting or presenting with symptoms consistent with Rome V criteria for one of the following subtypes: IBS-C, IBS-M, or IBS-D.
Key exclusion criteria (26 listed)
- Non-English speaking.
- Regular use of probiotics, prebiotics or synbiotics (including food and drinks containing added probiotics and/or probiotic yogurts with live, active cultures, or kefir) within 1 month prior to screening. Non-probiotic fortified yogurt is acceptable. Potential participants may be eligible once a 1-month washout is completed.
- Stimulant laxative use (includes bisacodyl/Dulcolax, senna/Senekot, cascara, or fiber supplements) is allowed if it is kept unchanged in the week prior to the SIMBA capsule ingestion. Osmotic laxatives (polyethylene glycol (PEG; other trade names), milk of magnesia, lactulose), stool softeners (docusate; other trade names) or secretagogues (linaclotide/Constella, plecanatide/Trulance, tenapanor/Ibsrela should not be used within 7 days of taking the SIMBA capsules.
- Use of oral or intravenous antibiotics or antifungal medications (except topical antibiotics or antifungals) within the previous 12 weeks. This includes rifaximin.
- Use of medications known to affect gastrointestinal motility, including but not limited to prokinetics (including domperidone, metoclopramide, prucalopride), anticholinergics, opioids, GLP-1 receptor agonists, secretagogues (linaclotide, plecanatide, tenapenor), cholestyramine, colchicine, and methyldopa, unless permitted by protocol.
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 |
|---|---|---|
| Rifaximin (drug)Open label | Drug | Irritable Bowel Syndrome - Constipation, Irritable Bowel Syndrome - Diarrhea, Irritable Bowel Syndrome - Mixed |
| fluid biopsy capsuleCollection of a fluid biopsy from the small intestine via ingestible capsule | Device | Irritable Bowel Syndrome - Constipation, Irritable Bowel Syndrome - Diarrhea, Irritable Bowel Syndrome - Mixed |
Primary outcome
Change in small intestinal microbiome composition
Time frame: Baseline and 4 weeks post end of treatment
Difference in small intestinal microbiome composition (Community Distance Index) within participant
4 secondary outcomes
Change in Abdominal Pain Severity (VAS-IBS)
Time frame: Baseline and 4 weeks post end of treatment
Difference in Dominant Microbial Composition Index Among IBS Rome V Subtypes
Time frame: Baseline and 4 weeks post end of treatment
Change in Antimicrobial Resistance Gene Burden and Microbial Antimicrobial Resistance
Time frame: Baseline and 4 weeks post end of treatment
Predictive Accuracy of Baseline Multi-Omic Features for Clinical Response to Rifaximin
Time frame: Baseline and 4 weeks post end of treatment
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 20 Oct 2026.
- Individual participant dataSharing planned: No
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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.
Christopher N Andrews, MD MSc principal investigator
University of Calgary
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 1 study testing Rifaximin (drug) and fluid biopsy capsule in people with Irritable Bowel Syndrome (IBS) and Microbiome, run by University of Calgary 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 6 inclusion and 26 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: opening soon, as of the sponsor's last update on 20 Oct 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.
What does this phase mean?
Phase 1 studies test a treatment in a small group of people for the first time or in a new way, mainly to check safety and find the right dose.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
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?
Contact Lynn Wilsack, MSc (403 592-5045, lwilsack@ucalgary.ca), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Change in small intestinal microbiome composition (time frame: Baseline and 4 weeks post end of treatment). 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 20 Oct 2026.