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

Prospective Randomized Controlled Proof-of-concept Trial to Investigate the Effects of STW 5-II on Duodenal Mucosa and Symptoms in Functional Dyspepsia

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.

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

Exclusion 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

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