Six food elimination diet in functional dyspepsia
| ISRCTN | ISRCTN14638935 |
|---|---|
| DOI | https://doi.org/10.1186/ISRCTN14638935 |
| Sponsor | Clinic of Internal Medicine-Gastroenterology, Jessenius Faculty of Medicine in Martin, Comenius University |
| Funder | Clinic of Internal Medicine-Gastroenterology, University Hospital Martin, Jessenius Faculty of Medicine in Martin, Comenius University, Slovakia |
- Submission date
- 22/10/2025
- Registration date
- 16/01/2026
- Last edited
- 16/01/2026
- Recruitment status
- No longer recruiting
- Overall study status
- Completed
- Condition category
- Digestive System
Plain English summary of protocol
Background and study aims
Functional dyspepsia is a common digestive condition that affects about 10 to 15 percent of people worldwide. It causes symptoms like bloating, stomach discomfort, feeling full quickly, and nausea, which can seriously affect quality of life. There is currently no cure. Some recent research suggests that certain foods might trigger an abnormal immune response in people with this condition. This study is investigating whether removing six specific foods—milk, wheat, soy, eggs, nuts, and seafood—from the diet for four weeks can help improve symptoms and provide useful biological information through blood, stool, and urine tests.
Who can participate?
Adults aged 18 and over who have been diagnosed with functional dyspepsia can take part. Healthy volunteers are also welcome. People cannot participate if they have active cancer, other digestive diseases like ulcers or inflammatory bowel disease, serious health conditions, are pregnant or breastfeeding, have known allergies to any of the six foods being removed, or have taken antibiotics or probiotics in the last three months.
What does the study involve?
Each participant will be involved for four weeks. At the start, they will have a medical check-up, complete symptom questionnaires, and provide blood, stool, and urine samples. Then, for four weeks, they will follow a diet that excludes milk, wheat, soy, eggs, nuts, and seafood. They can contact the study team by phone or email if needed. At the end of the four weeks, they will repeat the questionnaires and provide another set of samples. The team will also check that everything went safely.
What are the possible benefits and risks of participating?
Participants may experience relief from symptoms like bloating and nausea. The study may also help researchers better understand how diet affects this condition and could lead to more personalized dietary advice in the future. Risks are minimal. Changing the diet may be challenging and could temporarily worsen symptoms. Giving blood may cause minor discomfort or bruising. Overall, the diet is temporary and generally well tolerated.
Where is the study run from?
The study is being conducted at the Department of Internal Medicine – Gastroenterology, University Hospital Martin, Jessenius Faculty of Medicine, Comenius University, in Martin, Slovakia.
When is the study starting and how long is it expected to run for?
Who is funding the study?
Clinic of Internal Medicine-Gastroenterology, University Hospital Martin, Jessenius Faculty of Medicine in Martin, Comenius University, Slovakia.
Who is the main contact?
Dr Peter Liptak, peter.liptak@uniba.sk
Contact information
Public, Scientific, Principal investigator
Clinic of Internal Medicine-Gastroenterology
University Hospital Martin
Jessenius Faculty of Medicine in Martin, Comenius University
Martin
03601
Slovakia
 ORCID ID |
0000-0001-8257-8567 |
|---|---|
| Phone | +421434203266 |
| peter.liptak@uniba.sk |
Study information
| Primary study design | Interventional |
|---|---|
| Study design | Single center interventional non randomised trial |
| Secondary study design | Non randomised study |
| Scientific title | The impact of a six food elimination diet on clinical symptoms and metabolomic parameters in patients with functional dyspepsia compared to healthy volunteers |
| Study acronym | FunDiet |
| Study objectives | Hypothesis: The six-food elimination diet alleviates symptoms of functional dyspepsia without inducing significant alterations in the individuals’ metabolic profile. |
| Ethics approval(s) |
1. Approved 07/12/2022, Independent Ethics Committee at the Jessenius Faculty of Medicine, Comenius University in Martin (Department of Public Health Jessenius School of Medicine, Comenius University Malá Hora 4B, Martin, 036 01, Slovakia; +421 43 2633604; jana.mahutova@uniba.sk), ref: EK 72/2022 2. Approved 28/06/2023, Independent Ethics Committee at the Jessenius Faculty of Medicine, Comenius University in Martin (Department of Public Health Jessenius School of Medicine, Comenius University Malá Hora 4B, Martin, 03601, Slovakia; +421 43 2633604; jana.mahutova@uniba.sk), ref: EK 38/2023 |
| Health condition(s) or problem(s) studied | Patients with functional dyspepsia presenting with postprandial distress syndrome, epigastric pain syndrome, or an overlap of both subtypes |
| Intervention | Intervention type: Dietary modification Intervention description: Implementation of a six-food elimination diet excluding dairy, wheat, soy, eggs, nuts, and seafood for 4 weeks. Duration of intervention: 4 weeks (30 days) Adherence support: Clinitian consultation, food diary |
| Intervention type | Behavioural |
| Primary outcome measure(s) |
Dyspeptic symptom burden assessed by validated questionnaires (PAGI-SYM, PHQ-15, PAGI-QoL,WHOQOL-BREF) at baseline and after 30 days of dietary intervention |
| Key secondary outcome measure(s) |
Metabolic parameters from blood, urine, and stool (assessed by Nuclear Magnetic Resonance (NMR) spectroscopy metabolomic analysis) at baseline and after 30 days of dietary intervention |
| Completion date | 31/12/2025 |
Eligibility
| Participant type(s) | Healthy volunteer, Patient |
|---|---|
| Age group | Mixed |
| Lower age limit | 18 Years |
| Upper age limit | 75 Years |
| Sex | All |
| Target sample size at registration | 30 |
| Key inclusion criteria | For patients: 1. Age ≥ 18 years 2. Diagnosed functional dyspepsia (Rome IV criteria) 3. Absence of acute somatic disease 4. Absence of chronic metabolic disease For healthy volunteers: 1. Age ≥ 18 years 2. Absence of symptoms of DGBI 3. Absence of acute somatic disease 4. Absence of chronic metabolic disease |
| Key exclusion criteria | 1. Active malignancy (except long-term remission) 2. Severe metabolic or endocrine disease (e.g. decompensated diabetes, untreated hypothyroidism) 3. Pregnancy 4. Age < 18 years 5. Inability to attend follow-up visit |
| Date of first enrolment | 05/02/2023 |
| Date of final enrolment | 01/12/2025 |
Locations
Countries of recruitment
- Slovakia
Study participating centre
Martin
03601
Slovakia
Results and Publications
| Individual participant data (IPD) Intention to share | Yes |
|---|---|
| IPD sharing plan summary | Available on request |
| IPD sharing plan | The datasets generated during and/or analysed during the curret study will be available upon request from Peter Liptak (email:peter.liptak@uniba.sk) |
Editorial Notes
14/11/2025: Trial's existence confirmed by Independent Ethics Committee at the Jessenius Faculty of Medicine, Comenius University in Martin.
