The objective of the study is to investigate the efficacy and safety of an argon plasma-based therapy - HEAPE - in treating H. pylori infections during endoscopic procedures. By filling the stomach with sodium chloride solution that is treated with APC (PAL), the Investigators hypothesize a significant reduction in H. pylori. The use of PAL instead of direct application of APC allows for a broader and more homogeneous application throughout the stomach and a faster procedure time, as the fluid bypasses the thermal effects typically associated with higher electrical power settings and focuses on the bactericidal action of PAL. It is a procedure that does not involve thermal ablation of the stomach lining. Thus, side effects should be expected to be as low as possible. Two different PAL generation modalities will be compared in this study: 1. HEAPE direct: This modality is the direct generation of PAL in the stomach. The stomach is filled with sodium chloride solution which is then treated with APC. With HEAPE direct a potential decrease of reactive species is avoided, as the treatment happens directly at the intended location in the H. pylori infected stomach. 2. Pre-HEAPE: This modality features the treatment of sodium chloride with APC outside of the patient in a sterile container. After the APC treatment, the generated PAL is administered into the stomach with a syringe through the working channel of the endoscope. Pre-HEAPE allows an easier handling of the APC probe as the treatment of the sodium chloride solution can be done without an endoscope. To evaluate the immediate effect of this novel treatment approach the metabolic activity of H. pylori will be assessed using a urea breath test (UBT) before and after treatment. A reduction in H. pylori levels can be detected by a reduction in urease activity in the breath test. After the HEAPE procedure, patients are treated with antibiotics (best practice) as they would be under normal circumstances. Four weeks after treatment, another UBT is performed to determine if H. pylori has been eradicated or if additional antibiotic treatment is indicated. This two-arm, randomized, pilot, single-center, prospective clinical study is designed to evaluate the safety, tolerability and proof of concept that PAL has the ability to eradicate or reduce the bacterial load of H. pylori in humans.