An interventional study of LL1500 and Placebo Capsule in IBS-D (Diarrhea-predominant), IBS (Irritable Bowel Syndrome) and Functional Diarrhea, sponsored by Szeged University. Recruiting at 1 site in Hungary. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-11-04.
Sponsored by Szeged University · Not applicable, Interventional, and Treatment
The goal of this clinical trial is to learn whether a probiotic supplement can improve symptoms and quality of life in adults with diarrhea-predominant irritable bowel syndrome (IBS-D) or functional diarrhea (FD). These conditions can cause frequent loose stools, abdominal discomfort, and a lower quality of life.
The main questions this study aims to answer are:
Researchers will compare the probiotic supplement with a placebo to see whether the probiotic improves symptoms and quality of life.
Participants will:
The study will follow each participant for 6 months. Researchers hope the results will help determine whether this probiotic is a useful treatment option for people living with IBS-D or functional diarrhea.
1,116 studies on the registry are indexed under Irritable Bowel Syndrome; 208 are open to participants now.
This study's planned enrollment of 100 is above the median of 70 across 896 interventional studies indexed under Irritable Bowel Syndrome.
Browse Irritable Bowel Syndrome studies →Szeged University is the lead sponsor of 56 studies on the registry; 8 are open to participants now.
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Participants randomized to this arm will receive LL1500, a probiotic supplement containing Lactobacillus rhamnosus and Lactobacillus plantarum, once daily for 3 months, followed by crossover to matching placebo for an additional 3 months under double-blind conditions.
Dietary Supplement: LL1500 · Other: Placebo Capsule
Participants randomized to this arm will receive matching placebo once daily for 3 months, followed by crossover to LL1500, a probiotic supplement containing Lactobacillus rhamnosus and Lactobacillus plantarum, for an additional 3 months under double-blind conditions.
Dietary Supplement: LL1500 · Other: Placebo Capsule
LL1500 is an oral probiotic supplement administered once daily as a gelatin capsule. Each capsule contains lyophilized Lactobacillus rhamnosus and Lactobacillus plantarum, providing at least 7.5 × 10⁹ colony-forming units (CFU) of each bacterial strain. Participants will receive LL1500 for a 3-month treatment period.
Matching oral placebo administered once daily as a gelatin capsule containing inactive excipients and no live bacterial strains. Participants will receive placebo for a 3-month treatment period.
Irritable Bowel Syndrome Quality of Life (IBS-QOL) Total Score at 3 Months
IBS-specific quality of life assessed using the Irritable Bowel Syndrome Quality of Life (IBS-QOL) questionnaire. The IBS-QOL contains 34 items and yields a total score ranging from 0 to 100, with higher scores indicating better quality of life. The outcome measure is the change in total IBS-QOL score from baseline to 3 months.
Time frame: Three months after enrollment
Irritable Bowel Syndrome Quality of Life (IBS-QOL) Total Score at 6 Months
IBS-specific quality of life assessed using the Irritable Bowel Syndrome Quality of Life (IBS-QOL) questionnaire. The IBS-QOL contains 34 items and yields a total score ranging from 0 to 100, with higher scores indicating better quality of life. The outcome measure is the change in total IBS-QOL score from baseline to 6 months.
Time frame: Six months after enrollment
Mean Daily Stool Frequency at 3 Months
Mean number of bowel movements per day recorded by participants. The outcome measure is the change in average daily stool frequency from baseline to 3 months. Lower values indicate fewer bowel movements.
Time frame: Three months after enrollment
Mean Daily Stool Frequency at 6 Months
Mean number of bowel movements per day recorded by participants. The outcome measure is the change in average daily stool frequency from baseline to 6 months. Lower values indicate fewer bowel movements.
Time frame: Six months after enrollment
Mean Bristol Stool Form Scale Score at 3 Months
Stool consistency assessed using the Bristol Stool Form Scale, which ranges from Type 1 (hard stools) to Type 7 (watery stools). Types 3 to 5 are considered normal stool consistency. The outcome measure is the change in mean Bristol Stool Form Scale score from baseline to 3 months.
Time frame: Three months after enrollment
Mean Bristol Stool Form Scale Score at 6 Months
Stool consistency assessed using the Bristol Stool Form Scale, which ranges from Type 1 (hard stools) to Type 7 (watery stools). Types 3 to 5 are considered normal stool consistency. The outcome measure is the change in mean Bristol Stool Form Scale score from baseline to 6 months.
Time frame: Six months after enrollment
Defecation Pain Visual Analog Scale (VAS) Score at 3 Months
Pain during defecation assessed daily using a Visual Analog Scale (VAS). Scores range from 0 to 10, where 0 indicates no pain and 10 indicates the worst imaginable pain. The outcome measure is the change in mean daily VAS score from baseline to 3 months.
Time frame: Three months after enrollment
Defecation Pain Visual Analog Scale (VAS) Score at 6 Months
Pain during defecation assessed daily using a Visual Analog Scale (VAS). Scores range from 0 to 10, where 0 indicates no pain and 10 indicates the worst imaginable pain. The outcome measure is the change in mean daily VAS score from baseline to 6 months.
Time frame: Six months after enrollment
Treatment-Emergent Adverse Events
Number of participants experiencing any adverse event reported during treatment with either the probiotic supplement or placebo. Adverse events will be collected throughout study participation.
Time frame: From enrollment through 6 months
Plan to share: Yes
No publications or documents are linked to this record.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
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