Probiotics and Biomarkers in Irritable Bowel Syndrome

NCT07584278 | Recruiting

• 1 other identifier: BIO-IBS 2025-04788-01-805801
• Study Type: interventional
• Target: 252
• Locations: 1 country
• Sites: 1

Brief Summary

The goal of this double-blind parallel-arm randomized controlled trial is to learn if a probiotic supplement (containing a new strain derived from L. reuteri DSM 17938) alters outcomes related to symptom severity and transit time in adults with irritable bowel syndrome (IBS). The main question it aims to answer is: Does the probiotic alter IBS symptom severity? Researchers will compare the probiotic to a placebo (a lookalike substance that contains no probiotic) to see if the probiotic works to alter outcomes. Participants will: Be randomized to either take the probiotic supplement or placebo supplement daily for 12 weeks. Visit the lab for 4 study visits (visit 1: screening and informed consent; visit 2: randomization, data collection, beginning the intervention; visit 3: end of intervention and data collection; visit 4: 3 month post intervention follow up and data collection). Provide biological samples (blood, stool, saliva, urine) Complete questionnaires

Conditions

Irritable Bowel Syndrome (IBS)

Keywords

probiotic; irritable bowel syndome; ibs symptom severity; oro-anal transit time; randomized controlled trial

Outcome Measures

Primary Outcomes (1)

• IBS symptom severity (IBS-Symptom-Severity-Score)

  * Between group differences (intervention vs control) in mean IBS-SSS scores from baseline to end of intervention. * Proportion of responders (decrease in IBS-SSS over greater than or equal to 50 points from baseline to end of intervention) between arms * Proportion of greater responders (decrease in IBS-SSS scores greater than or equal to 100 points from baseline to end of intervention) between arms

  Screening (15-60 days pre-intervention), baseline (day 0 of intervention), during intervention (days 14, 28, 42, 56, 70), end of intervention (day 84), 3 month follow up post intervention

Secondary Outcomes (8)

• Gastrointestinal Symptom Rating Scale- IBS (GSRS-IBS)

  Screening (15-60 days pre-intervention), baseline (day 0 of intervention), during intervention (days 14, 28, 42, 56, 70), end of intervention (day 84), 3 month follow up post intervention

• General global assessment: satisfactory adequate relief of symptoms from baseline to end of intervention between arms

  During intervention (days 14, 28, 42, 56, 70), end of intervention (day 84)

• General global assessment: worst pain over the last 24 hours, intervention group vs placebo group reduced between baseline and end of intervention between arms

  During intervention (days 14, 28, 42, 56, 70), end of intervention (day 84)

• IBS-quality of life (IBS-QoL)

  Baseline (day 0 of intervention), during intervention (days 14, 28, 42, 56, 70), end of intervention (day 84), 3 month follow up post intervention

• Work Productivity and Activity Impairment:IBS (WPAI:IBS)

  Baseline (day 0 of intervention), during intervention (days 14, 28, 42, 56, 70), end of intervention (day 84), 3 month follow up post intervention

Other Outcomes (10)

• ROME V

  Baseline (day 0 of intervention), during intervention (days 14, 28, 42, 56, 70), end of intervention (day 84), 3 month follow up post intervention

• Validation of the measurement of oro-anal transit time using sweetcorn vs radiopaque markers

  Baseline to end of intervention (12 weeks)

• Fecal samples

  Baseline (day 0 of intervention), during intervention (days 14, 28, 42, 56, 70), end of intervention (day 84), 3 month follow up post intervention

Study Arms (2)

Intervention

EXPERIMENTAL

Adults with IBS who have been randomized to receive the intervention

Other: Probiotic Supplementation (Lactobacillus Reuteri)

Control

PLACEBO COMPARATOR

Adults with IBS who have been randomized to receive the placebo

Other: Placebo Supplementation

Interventions

Placebo Supplementation OTHER

A placebo supplement that is identical to the probiotic in formulation and packaging except that the probiotic bacteria is not present.

Control

Probiotic Supplementation (Lactobacillus Reuteri) OTHER

Probiotic using a new strain derived from L. reuteri.

Intervention

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Diagnosed with IBS according to ROME V criteria
• IBS-SSS greater than or equal to 75
• Adult over 18 years old
• BMI 18.5-35 kg/m2
• Able to understand the participant information sheet and willing to comply with the study protocol
• Able to give informed consent
• Able to complete the Swedish questionnaires

You may not qualify if:

• History of any gastroenterology disease including coeliac disease, heart, liver, neurological, or current psychiatric disease, diabetes, any surgery to the abdomen that affects intestinal function (not including cholecystectomy, appendectomy, ceasarean section).
• The use of opioids 1 month prior to screening and throughout the study
• The use of probiotic supplements from 14days before randomization and during the study (not including foods with probiotic components)
• Consumption of antibiotics 3 months prior to screening and throughout the study
• The start of any new drugs that affect the gastrointestinal tract or symptoms within the last month before the start of the study. As well as the start of new diets of psychological therapy as treatment for IBS symptoms.
• Participation in any medical research during the last month
• Clinically relevant lab abnormalities at the time of screening (fecal calprotectin greater than or equal to 150 ug/g as absolute cutoff. If calprotectin is between 50 - 150ug/g the decision is made on clinical judgement)
• Pregnancy, plan to become pregnant during the study, breastfeeding
• alcohol consumption \>14 units per week
• Use of recreational active drugs during 1 month before screening or during the study
• Use of medication that primarily affects bowel function, transit time, stool consistency 2 weeks before the intervention or during the 12 week intervention period

Sponsors & Collaborators

• Sahlgrenska University Hospital: lead

Study Sites (1)

Mag-tarmlab, Sahlgrenska University Hospital

Gothenburg, 413 45, Sweden

RECRUITING

MeSH Terms

Conditions

Irritable Bowel Syndrome

Condition Hierarchy (Ancestors)

Colonic Diseases, Functional; Colonic Diseases; Intestinal Diseases; Gastrointestinal Diseases; Digestive System Diseases

Study Officials

• Magnus Simren, MD PHD

  Göteborg University

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Magnus Simren, MD, PhD

CONTACT

0046313428107; magnus.simren@medicine.gu.se

MagTarmlab office

CONTACT

0046313428107; magtarmlab.su@vgregion.se

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: DOUBLE
• Who Masked: PARTICIPANT, INVESTIGATOR
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Professor

Study Record Dates

• First Submitted: April 22, 2026
• First Posted: May 13, 2026
• Study Start: April 28, 2026
• Primary Completion (Estimated): April 1, 2031
• Study Completion (Estimated): May 1, 2031
• Last Updated: May 13, 2026

Record last verified: 2026-05

Data Sharing

• IPD Sharing: Will not share

Locations

SE (1)