An interventional study of Experimental arm: probiotic and Placebo in Irritable Bowel Syndrome (IBS), sponsored by University of Bari. Recruiting at 3 sites in Italy. Open to participants aged 4 Years to 18 Years. Per ClinicalTrials.gov, last updated 2026-10-08.
Sponsored by University of Bari · Not applicable, Interventional, and Treatment
What is this study about? This clinical study aims to investigate whether a specific combination of probiotics-Lactobacillus rhamnosus GG and Lactobacillus plantarum 299V-can help children and adolescents with Irritable Bowel Syndrome (IBS). IBS is a common digestive condition in children, causing abdominal pain, bloating, and changes in bowel habits (either diarrhoea, constipation, or alternating between the two). These symptoms can seriously affect a child's daily life and wellbeing.
The study is coordinated by the University of Bari, in collaboration with the University of Udine, and led by Prof. Ruggiero Francavilla.
Why is this study being done? Although probiotics are increasingly used in IBS, solid scientific evidence in children is still limited. This study will assess whether the chosen probiotic mix improves symptoms, bowel habits, and quality of life in young people with IBS. It will also investigate how the probiotics affect gut bacteria (microbiota) and the chemicals produced by the body (metabolomics), to better understand how these changes might help relieve symptoms.
Who can take part? Children and adolescents aged 4 to 18 years with a diagnosis of IBS (based on international Rome IV criteria) who experience abdominal pain on a daily basis.
Children with other significant medical conditions, recent surgery, or ongoing infections, as well as those taking antibiotics or other probiotics shortly before the study, cannot participate.
How does the study work? The study is a randomised, double-blind, placebo-controlled trial, meaning that some children will receive the probiotic drops, and others will receive placebo drops (which do not contain probiotics), and neither the participants nor the doctors will know who is receiving which treatment. This is the best way to test whether the probiotics really work.
Each participant will be involved in the study for about 14 weeks, divided into:
A 2-week "run-in" period to confirm eligibility.
An 8-week treatment period (probiotic or placebo).
A 4-week follow-up.
The probiotics/placebo are taken as 20 drops once daily for 8 weeks.
Throughout the study, children and parents will be asked to keep a daily diary of abdominal pain and bowel habits, and to complete validated questionnaires on symptom severity and quality of life. Stool and urine samples will also be collected at different time points to analyse changes in gut bacteria and body metabolism.
What are the aims of the study?
Primary aim:
To see whether the probiotics reduce abdominal pain by at least 30% compared to the start of the study.
Secondary aims:
To check if bowel habits improve (stool consistency and frequency).
To assess improvements in quality of life.
To analyse whether the probiotics cause positive changes in gut bacteria and metabolic profiles.
To ensure that the treatment is safe and well-tolerated.
What are the possible risks and benefits? The probiotic mixture used in this study has been studied in children before and is generally considered safe. The study includes careful monitoring for any side effects.
Participants may or may not experience an improvement in symptoms. However, the information gained from the study will help doctors better understand how probiotics work in IBS and may benefit future patients.
What are participants' rights? Participation is voluntary, and families may withdraw their child from the study at any time, without affecting the child's medical care. The study has been approved by an independent ethics committee and complies with all European and Italian regulations regarding research in children.
All personal data and medical information will be treated confidentially and securely, in accordance with privacy laws.
Where is the study taking place? The study is being conducted at the Paediatric Gastroenterology Unit of the University of Bari Aldo Moro and the Paediatric Unit of the University of Udine. These centres are national referral centres for children with gastrointestinal problems.
Who is funding and organising the study? The study is sponsored and conducted by the University of Bari. The probiotic and placebo products are provided by Dicofarm S.p.A., who also ensures that the placebo and probiotic products look and taste the same to maintain the study's blinding.
Irritable Bowel Syndrome (IBS) is one of the most prevalent functional gastrointestinal disorders in children and adolescents, with an estimated global prevalence ranging from 6% to 14% depending on diagnostic criteria used. IBS is characterized by chronic abdominal pain and altered bowel habits, including diarrhea, constipation, or mixed patterns, in the absence of identifiable structural or biochemical abnormalities. These symptoms significantly impair the quality of life, school performance, and psychosocial well-being of affected individuals.
The pathophysiology of IBS remains multifactorial and incompletely understood. Emerging evidence suggests that disturbances in the gut-brain axis play a critical role, with bidirectional signaling pathways involving the enteric nervous system, central nervous system, and endocrine components. Additionally, alterations in the intestinal microbiota-commonly termed dysbiosis-have been implicated as potential contributors to IBS pathogenesis. Reduced microbial diversity and imbalances in beneficial versus pathogenic bacterial populations have been observed in pediatric IBS patients. Concurrently, immune dysregulation with low-grade mucosal inflammation and altered immune responses may exacerbate symptoms.
The use of probiotics has emerged as a promising therapeutic strategy for managing IBS.
In this context, Lactobacillus rhamnosus GG is one of the most extensively studied probiotics, demonstrating efficacy in improving abdominal pain, stool consistency, and microbial composition in pediatric IBS. Similarly, Lactobacillus plantarum 299V has been associated with a reduction in bloating, improvement in stool frequency, and normalization of gut microbiota in adults.
Despite promising preliminary results, robust, high-quality evidence supporting the efficacy of thiscombination in pediatric IBS remains limited, highlighting the need for further investigation.
To address this a large double blind randomized clinical trial including advanced analytical techniques, such as fecal microbiota profiling via 16S rRNA sequencing and urinary metabolomic analysis, provide a unique opportunity to explore the mechanistic underpinnings of probiotic action. Microbiota profiling allows for the identification of specific bacterial taxa changes associated with symptom improvement, while metabolomics can reveal alterations in gut microbial metabolites, such as short chain fatty acids (SCFAs), that may mediate therapeutic effects.
1,116 studies on the registry are indexed under Irritable Bowel Syndrome; 208 are open to participants now.
This study's planned enrollment of 124 is above the median of 70 across 896 interventional studies indexed under Irritable Bowel Syndrome.
Browse Irritable Bowel Syndrome studies →University of Bari is the lead sponsor of 76 studies on the registry; 12 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.
62 children will take the product under study based on 20 drops containing L. Rhamnosus GG 12 × 10\^9 CFU plus L. Plantarum 299V. 12 × 10\^9 CFU per day for 8 weeks
Dietary Supplement: Experimental arm: probiotic
62 children will take a carbohydrate-based control product (maltodextrin)
Dietary Supplement: Placebo
a dietary supplement containing L. Rhamnosus GG 1x1010 CFU plus L. Plantarum 299V. 1x1010 CFU
Placebo (maltodextrine)
VAS visual analogue scale 0-10
Treatment success defined as decrease of abdominal pain severity of at least 30% from baseline (measured with VAS).
Time frame: BASELINE AND AFTER 8 WEEKS OF TREATMENT
Bristol Stool Form Scale
Stool consistency improvement measured with Bristol Stool Form Scale (≥1 Bristol Stool Form Scale to a higher number average consistency at the last week of trial compared with baseline for IBS-D or lower number for IBS-C) between baseline and end of treatment in the two groups
Time frame: BASELINE AND AFTER 8 WEEKS OF TREATMENT
Change in Quality of life
Change in Quality of life as assed by Pediatric Quality of Life Inventory 4.0 between baseline and end of treatment in the two groups
Time frame: BASELINE AND AFTER 8 WEEKS OF TREATMENT
Irritable Bowel Syndrome Symptom Severity Score
Change in IBS severity as measured by the Irritable Bowel Syndrome Symptom Severity Score (IBS-SSS) between baseline and end of treatment in the two groups
Time frame: BASELINE AND AFTER 8 WEEKS OF TREATMENT
Microbiota
Changes in the microbiota composition as well as changes in the fecal and urinary metabolomic profiles between baseline and end of treatment in the two groups
Time frame: BASELINE AND AFTER 8 WEEKS OF TREATMENT
Plan to share: Undecided
Started Oct 2025 (actual). Primary completion is estimated for Jun 2027, 20 months after the start.
Of 305 non-industry interventional studies with no phase under Irritable Bowel Syndrome, half reached primary completion within 21 months of starting (the median), counting those still running; a quarter within 9 and three quarters within 40. This study's planned 20 months is close to that.
Counting every sponsor, half of 357 studies reached it within 19 months; a quarter within 9 and three quarters within 38.
Since we started tracking on Sep 25, 2026, the dates moved once, on Oct 8, 2026: start Sep 2025 → Oct 2025, primary completion Dec 2026 → Jun 2027 and completion Jun 2027 → Oct 2027.
Earlier changes are on the record history on ClinicalTrials.gov ↗
How these figures are worked out, and which studies are left out of them.
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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Studies of the drug tested here: Probiotic
University of Bari