Recruitment was slow and disrupted by COVID-19.

Challenges in the treatment of Helicobacter pylori (H. pylori) include increasing antimicrobial resistance and patient's low tolerance to some regimens. Lactobacillus johnsonii (L. johnsonii) and Immunoglobulin Y (IgY) have been shown to decrease the amount and activity of H. pylori in human stomach and can increase patient's tolerance. We conduct a single-center double-masked randomized controlled trial to evaluate the effectiveness of GastimunHp Plus (a product combining L. johnsonii and IgY) in improving the clearance of H. pylori after six to eight weeks of treatment and side effects of H. pylori treatment. H. pylori is tested by C13- or C14-urea breath test.

Inclusion Criteria:

• Diagnosed with gastritis, duodenitis, or peptic ulcer.
• Tested positive with Helicobacter pylori using C13- or C14-urea breath test or urease test.
• Indicated for Helicobacter pylori eradication.

Exclusion Criteria:

• Suspected malignant lesions.
• Children under 10 years of age; pregnant or lactating women.
• Allergic to chicken egg.

The investigational product (IP) is compared with a placebo. The IP and placebo are manufactured by the sponsor and then sent to the trial pharmacist. They are only different in a number in the package label, and only the sponsor knows which number is the IP and will call them "product I" and "product II". This labelling is not revealed to the study team, the trial pharmacist, and the biostatistician.

In the random number sequences generated by the biostatistician, the study numbers will be allocated to either "product I" or "product II". The trial pharmacist is responsible for making product bags using study numbers and allocation given by the biostatistician. The product bags are transferred to the study team. In this way, the study team and patients are completely masked to the allocation.