Irritable Bowel SyndromeNCT07722572
Low-FODMAP vs Lactose-Gluten-Free Diet in Patients With Irritable Bowel Syndrome
A study testing Low-FODMAP Diet and Lactose- and Gluten-Free Diet in people with Irritable Bowel Syndrome, run by Antalya Bilim University at 1 site in Turkey (Türkiye).
Trial summary
Irritable bowel syndrome (IBS) is a common functional gastrointestinal disorder that substantially affects quality of life. Dietary therapy is considered one of the primary treatment approaches; however, the optimal sequence of dietary interventions remains unclear. Read more about this study
- Who is it for?
- Ages 18 to 64 years
- Conditions the study is for
- Irritable Bowel Syndrome
- What is being tested?
- Low-FODMAP Diet and Lactose- and Gluten-Free Diet
- Type of treatment
- Lifestyle or therapy programme
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 72 participants
- Where
- 1 siteTurkey (Türkiye)
- Study dates
- 1 Sep 2020to 20 Jan 2022
- Phase
- Interventional
- Are there results?
- None posted in the registry
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 64 years
- All sexes
- No healthy volunteers
- Adult
Who may be able to join
- Adults aged 18-64 years.
- Diagnosis of Irritable Bowel Syndrome according to the Rome III criteria.
- Ability and willingness to comply with the dietary intervention.
- Written informed consent provided.
Who cannot join
- Pregnancy or lactation.
- Diabetes mellitus.
- Organic gastrointestinal disease.
- Current follow-up for cardiologic, neurologic, oncologic, or psychiatric disorders.
- Following a therapeutic diet within 1 month before enrollment.
Trial locations and contacts
1 site in 1 country.
Turkey (Türkiye)1 site
Istanbul University-Cerrahpaşa, Cerrahpaşa Faculty of Medicine, Department of Gastroenterology
Istanbul
About this study
Official title: Comparative Effects of Low-FODMAP and Lactose-Gluten-Free Diets on Gastrointestinal Symptoms and Mental Health in Irritable Bowel Syndrome: A Randomized Crossover Trial
Irritable bowel syndrome (IBS) is a common functional gastrointestinal disorder that substantially affects quality of life. Dietary therapy is considered one of the primary treatment approaches; however, the optimal sequence of dietary interventions remains unclear. This randomized crossover trial was designed to compare the effects of a low-FODMAP diet and a lactose-free, gluten-free diet on gastrointestinal symptoms, psychological status, anthropometric measurements, and biochemical parameters in adults with IBS. Participants were randomly assigned to one of two dietary sequences, with each intervention lasting four weeks and separated by a one-week washout period. Outcomes were assessed using validated symptom and psychological questionnaires together with anthropometric and biochemical measurements before and after each intervention period.
Read the detailed description
This randomized crossover trial was designed to evaluate the comparative effects of a low-FODMAP diet and a lactose- and gluten-free diet in adults with irritable bowel syndrome (IBS). Participants were randomly assigned to one of two dietary sequences, with each intervention lasting 4 weeks and separated by a 1-week washout period. Gastrointestinal symptoms, psychological outcomes, anthropometric measurements, and biochemical parameters were assessed before and after each intervention period.
- Conditions
- Irritable Bowel Syndrome
- Being tested
- Low-FODMAP Diet, Lactose- and Gluten-Free Diet
- Keywords
- Anxiety, Irritable Bowel Syndrome, Diet, FODMAPs, Lactose-free and gluten-free diet
- Medical subject headings
- Irritable Bowel Syndrome, Anxiety Disorders
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Low-FODMAP DietBehavioural
Participants followed a low-FODMAP diet for 4 weeks under the supervision of a dietitian.
Lactose- and Gluten-Free DietBehavioural
Participants followed a lactose- and gluten-free diet for 4 weeks under the supervision of a dietitian.
| Study group | Role | What they receive |
|---|---|---|
| Low-FODMAP → Lactose- and Gluten-Free Diet | Experimental | Participants received the low-FODMAP diet for 4 weeks, followed by a 1-week washout period and then the lactose- and gluten-free diet for 4 weeks. Receives: Behavioral: Low-FODMAP Diet; Behavioral: Lactose- and Gluten-Free Diet |
| Lactose- and Gluten-Free Diet → Low-FODMAP | Experimental | Participants received the lactose- and gluten-free diet for 4 weeks, followed by a 1-week washout period and then the low-FODMAP diet for 4 weeks. Receives: Behavioral: Low-FODMAP Diet; Behavioral: Lactose- and Gluten-Free Diet |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change in Irritable Bowel Syndrome Symptom Severity Score (IBS-SSS)
Change in Irritable Bowel Syndrome Symptom Severity Score (IBS-SSS). The IBS Symptom Severity Score assessed the severity of IBS symptoms based on four questions, scoring between 0 and 100 points for each symptom. A total score of 75-174 points indicated mild IBS, 175-299 points indicated moderate IBS, and >300 points indicated severe IBS.
Measured: Baseline, Week 4, and Week 9
Secondary outcomes (4)
Change in Gastrointestinal Symptom Rating Scale (GSRS) score
Change in gastrointestinal symptom severity assessed using the Gastrointestinal Symptom Rating Scale (GSRS). The GSRS assessed gastrointestinal symptoms based on 15 items categorized into five subdimensions: abdominal pain, reflux, diarrhea, indigestion, and constipation. The scale measures symptom severity over the past week, with higher scores indicating more severe symptoms.
Measured: Baseline, Week 4, and Week 9
Change in Hospital Anxiety and Depression Scale (HADS) score
Change in anxiety and depression symptoms assessed using the Hospital Anxiety and Depression Scale (HADS). The HADS is a 14-question scale that identifies anxiety and depression risks. The scale is divided into two subscales, one for anxiety and one for depression, with scores ranging from 0 to 21. Scores between 0-7 are considered normal, 8-10 borderline, and ≥11 indicates anxiety and/or depression.
Measured: Baseline, Week 4, and Week 9
Change in body weight
Change in body weight measured in kilograms.
Measured: Baseline, Week 4, and Week 9
Change in body mass index
Change in body mass index (BMI), calculated as weight in kilograms divided by height in meters squared.
Measured: Baseline, Week 4, and Week 9
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted23 Jul 2026
- Study start1 Sep 2020
- Primary completion25 Nov 2021
- Study completion20 Jan 2022
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Irritable Bowel SyndromeStudies 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 N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Crossover
- Model description
- Participants were randomized to two crossover sequences. Each participant received both dietary interventions (low-FODMAP diet and lactose- and gluten-free diet) for 4 weeks each, separated by a 1-week washout period.
- Masking
- None (open label)
- Enrolment
- 72 participants (actual)
Sponsor and investigators
- Lead sponsor
- Antalya Bilim University
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Hatice Kübra Aras, Principal investigator, Antalya Bilim University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07722572
- Sponsor's protocol ID
- 2020/034
- Status last verified
- Jul 2026
- First submitted
- 16 Jul 2026
- Last updated
- 23 Jul 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 23 Jul 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Comparative Effects of Low-FODMAP and Lactose-Gluten-Free Diets on Gastrointestinal Symptoms and Mental Health in Irritable Bowel Syndrome: A Randomized Crossover Trial
- ClinicalTrials.gov ID
- NCT07722572
- Acronym / sponsor ID
- 2020/034
- Conditions
- Irritable Bowel Syndrome
- Keywords
- Anxiety, Irritable Bowel Syndrome, Diet, FODMAPs, Lactose-free and gluten-free diet
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 72 participants (actual)
- Lead sponsor
- Antalya Bilim UniversityUniversity, hospital or other
- Study start
- 1 Sep 2020 (actual)
- Primary completion
- 25 Nov 2021 (actual)
- Study completion
- 20 Jan 2022 (actual)
- First posted
- 23 Jul 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.
Irritable bowel syndrome (IBS) is a common functional gastrointestinal disorder that substantially affects quality of life. Dietary therapy is considered one of the primary treatment approaches; however, the optimal sequence of dietary interventions remains unclear. This randomized crossover trial was designed to compare the effects of a low-FODMAP diet and a lactose-free, gluten-free diet on gastrointestinal symptoms, psychological status, anthropometric measurements, and biochemical parameters in adults with IBS. Participants were randomly assigned to one of two dietary sequences, with each intervention lasting four weeks and separated by a one-week washout period. Outcomes were assessed using validated symptom and psychological questionnaires together with anthropometric and biochemical measurements before and after each intervention period.
Detailed description
This randomized crossover trial was designed to evaluate the comparative effects of a low-FODMAP diet and a lactose- and gluten-free diet in adults with irritable bowel syndrome (IBS). Participants were randomly assigned to one of two dietary sequences, with each intervention lasting 4 weeks and separated by a 1-week washout period. Gastrointestinal symptoms, psychological outcomes, anthropometric measurements, and biochemical parameters were assessed before and after each intervention period.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- None (open label)
- Number of arms
- 2
- Model description
- Participants were randomized to two crossover sequences. Each participant received both dietary interventions (low-FODMAP diet and lactose- and gluten-free diet) for 4 weeks each, separated by a 1-week washout period.
| Arm | Type | Receives |
|---|---|---|
| Low-FODMAP → Lactose- and Gluten-Free Diet | Experimental | Behavioral: Low-FODMAP Diet, Behavioral: Lactose- and Gluten-Free DietParticipants received the low-FODMAP diet for 4 weeks, followed by a 1-week washout period and then the lactose- and gluten-free diet for 4 weeks. |
| Lactose- and Gluten-Free Diet → Low-FODMAP | Experimental | Behavioral: Low-FODMAP Diet, Behavioral: Lactose- and Gluten-Free DietParticipants received the lactose- and gluten-free diet for 4 weeks, followed by a 1-week washout period and then the low-FODMAP diet for 4 weeks. |
Who may qualify
- Ages
- 18 to 64 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult
Key inclusion criteria (4 listed)
- Adults aged 18-64 years.
- Diagnosis of Irritable Bowel Syndrome according to the Rome III criteria.
- Ability and willingness to comply with the dietary intervention.
- Written informed consent provided.
Key exclusion criteria (5 listed)
- Pregnancy or lactation.
- Diabetes mellitus.
- Organic gastrointestinal disease.
- Current follow-up for cardiologic, neurologic, oncologic, or psychiatric disorders.
- Following a therapeutic diet within 1 month before enrollment.
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 |
|---|---|---|
| Low-FODMAP DietParticipants followed a low-FODMAP diet for 4 weeks under the supervision of a dietitian. | Behavioural | Lactose- and Gluten-Free Diet → Low-FODMAP, Low-FODMAP → Lactose- and Gluten-Free Diet |
| Lactose- and Gluten-Free DietParticipants followed a lactose- and gluten-free diet for 4 weeks under the supervision of a dietitian. | Behavioural | Lactose- and Gluten-Free Diet → Low-FODMAP, Low-FODMAP → Lactose- and Gluten-Free Diet |
Primary outcome
Change in Irritable Bowel Syndrome Symptom Severity Score (IBS-SSS)
Time frame: Baseline, Week 4, and Week 9
Change in Irritable Bowel Syndrome Symptom Severity Score (IBS-SSS). The IBS Symptom Severity Score assessed the severity of IBS symptoms based on four questions, scoring between 0 and 100 points for each symptom. A total score of 75-174 points indicated mild IBS, 175-299 points indicated moderate IBS, and >300 points indicated severe IBS.
4 secondary outcomes
Change in Gastrointestinal Symptom Rating Scale (GSRS) score
Time frame: Baseline, Week 4, and Week 9
Change in Hospital Anxiety and Depression Scale (HADS) score
Time frame: Baseline, Week 4, and Week 9
Change in body weight
Time frame: Baseline, Week 4, and Week 9
Change in body mass index
Time frame: Baseline, Week 4, and Week 9
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 23 Jul 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. This study is not recruiting at the moment.
Hatice Kübra Aras principal investigator
Antalya Bilim University
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Low-FODMAP Diet and Lactose- and Gluten-Free Diet in people with Irritable Bowel Syndrome, run by Antalya Bilim University at 1 site in Turkey (Türkiye).
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 4 inclusion and 5 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: finished, as of the sponsor's last update on 23 Jul 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 Turkey (Türkiye). 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.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Change in Irritable Bowel Syndrome Symptom Severity Score (IBS-SSS) (time frame: Baseline, Week 4, and Week 9). 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 23 Jul 2026; AzTrials last refreshed its copy on 7 Nov 2026.