The Effects of STW 5-II on Duodenal Mucosa and Symptoms in Functional Dyspepsia

NCT ID: NCT07198243

Last Updated: 2025-09-30

Basic Information

• Recruitment Status: NOT_YET_RECRUITING
• Clinical Phase: PHASE4
• Total Enrollment: 100 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2025-09-30
• Study Completion Date: 2028-12-01

Brief Summary

The goal of this clinical trial is to find out whether a herbal medicine called STW 5-II can help improve gut health and symptoms in adults recently diagnosed with functional dyspepsia (FD)-a condition that causes frequent stomach discomfort, especially after eating.

The main questions it aims to answer are:

Can STW 5-II reduce certain immune cells (eosinophils) in the gut lining? Can it improve symptoms like severe postprandial fullness, bloating, epigastric pain, and improve quality of life?

Researchers will compare STW 5-II to a placebo to see if it helps reduce gut inflammation and ease symptoms.

Participants will:

Take either STW 5-II or a placebo for 8 weeks Provide small samples of gut tissue (via endoscopy) Answer questions about their symptoms and daily life An optional 4-week treatment with STW 5-II will follow for all participants.

Conditions

Functional Dyspepsia

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: PARALLEL
• Primary Study Purpose: TREATMENT
• Blinding Strategy: QUADRUPLE

Study Groups

Placebo

Functional dyspepsia patients taking the matching placebo for 8 weeks.

Group Type: PLACEBO_COMPARATOR

Placebo

Intervention Type: DRUG

Matching placebo will be a solution for oral intake, administered as 20 droplets in liquids, three times daily during 8 weeks. Recommended time of ingestion is just before or with meals. Patients and study staff are blinded for the intervention.

STW 5-II

Functional dyspepsia patients taking STW 5-II, the active product for the treatment of FD.

Group Type: EXPERIMENTAL

STW 5-II

Intervention Type: DRUG

STW 5-II is an herbal medicinal product for the symptomatic treatment of functional dyspepsia with main symptoms such as epigastric pain, epigastric burning, postprandial fullness and early satiation, but often also loss of appetite, excessive belching and heartburn. STW5-II consists of six herbal extracts: bitter candy tuft, camomile flower, caraway fruit, melissa leaf, peppermint leaf, and licorice root.

STW 5-II will be a solution for oral intake, for the treatment of FD, administered as 20 droplets in liquids, three times daily during 8 weeks. Recommended time of ingestion is just before or with meals. Patients and study staff are blinded for the intervention

Interventions

STW 5-II

STW 5-II is an herbal medicinal product for the symptomatic treatment of functional dyspepsia with main symptoms such as epigastric pain, epigastric burning, postprandial fullness and early satiation, but often also loss of appetite, excessive belching and heartburn. STW5-II consists of six herbal extracts: bitter candy tuft, camomile flower, caraway fruit, melissa leaf, peppermint leaf, and licorice root.

STW 5-II will be a solution for oral intake, for the treatment of FD, administered as 20 droplets in liquids, three times daily during 8 weeks. Recommended time of ingestion is just before or with meals. Patients and study staff are blinded for the intervention

Intervention Type: DRUG

Placebo

Matching placebo will be a solution for oral intake, administered as 20 droplets in liquids, three times daily during 8 weeks. Recommended time of ingestion is just before or with meals. Patients and study staff are blinded for the intervention.

Intervention Type: DRUG

Eligibility Criteria

Inclusion Criteria

• Patients ≥18 years newly to be treated with an FD/PDS diagnosis (Rome IV clinical criteria).
• Newly to be treated patients are defined as patients currently not on any ongoing treatment for FD (including OTC medication) for the last 2 weeks. Medications such as PPI or others that may affect GI function and symptom should be stopped prior the trial (min 4 weeks). See list of forbidden medication.
• Male or female using contraception or postmenopausal
• Witnessed written informed consent
• Capable to understand and comply with the study requirements

• Patients ≥18 years newly to be treated with an FD/PDS diagnosis (Rome IV clinical criteria).
• Newly to be treated patients are defined as patients currently not on any ongoing treatment for FD (including OTC medication) for the last 2 weeks. Medications such as PPI or others that may affect GI function and symptom should be stopped prior the trial (min 4 weeks). See list of forbidden medication.
• Male or female using contraception or postmenopausal
• Witnessed written informed consent
• Capable to understand and comply with the study requirements

Exclusion Criteria

• Major active somatic or psychiatric condition that may explain dyspeptic symptoms (stable dose of single antidepressant allowed for psychiatric indication, no limitation for other indications) Predominant symptoms of gastro-esophageal reflux disease (GERD) or irritable bowel syndrome (IBS)
• Chronic ppi use. No PPI use for at least the prior 4 weeks before entering the trial- History of major abdominal surgery (except for appendectomy, cholecystectomy or splenectomy)
• History or presence of diabetes mellitus type 1 & type 2, coeliac disease or inflammatory bowel disease
• Active malignancy
• Known HIV, HBV or HCV infection
• Significant alcohol use (>10 units/weeks)
• Females pregnant or lactating
• Hypersensitivity against ingredients of STW 5-II or placebo (see annex)
• Abnormal baseline laboratory blood values

• Minimum Eligible Age: 18 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

Universitaire Ziekenhuizen KU Leuven

OTHER

Sponsor Role: lead

Responsible Party

Responsibility Role: SPONSOR

Principal Investigators

Jan Tack, MD, PhD

Role: PRINCIPAL_INVESTIGATOR

Universitaire Ziekenhuizen KU Leuven

Locations

University Hospitals Leuven / UZLeuven

Leuven, , Belgium

Countries

Belgium

Central Contacts

Jan Tack, MD, PhD

Role: CONTACT

jan.tack@kuleuven.be

+32 16 34 47 75

Facility Contacts

CTC UZLeuven

Role: primary

ctc@uzleuven.be

+32 16 34 19 98

Other Identifiers

2025-521141-24-00

Identifier Type: CTIS

Identifier Source: secondary_id

S70188

Identifier Type: -

Identifier Source: org_study_id