Pilot Study of a Gastric String Test Combined With a Rapid Antigen Assay for Helicobacter Pylori Detection

This single-center, open-label, prospective pilot study aims to evaluate the feasibility, safety, and preliminary diagnostic performance of a minimally invasive gastric string sampling device combined with a rapid antigen assay for the detection of Helicobacter pylori infection. A total of 40 participants with documented \^13C-urea breath test (UBT) results will be enrolled, including 30 UBT-positive and 10 UBT-negative participants. All participants will undergo gastric mucus collection using a disposable string sampling device, followed by H. pylori rapid antigen testing. The primary objective is to assess the diagnostic sensitivity and specificity of the investigational test using \^13C-UBT as the reference standard. The secondary objective is to explore the correlation between the semi-quantitative test-line (T-line) color intensity of the rapid antigen assay and the corresponding UBT delta-over-baseline (DOB) values.

Inclusion Criteria: 1. Adults aged 18-75 years. 2. Completed a 13C-urea breath test (UBT) within 28 days prior to enrollment, with documented test results. 3. Able to understand the study procedures and willing to provide written informed consent. Exclusion Criteria: 1. History of dysphagia, esophageal stricture, or gastrointestinal obstruction. 2. Use of antibiotics, bismuth-containing agents, or proton pump inhibitors (PPIs) within 4 weeks prior to enrollment, as these medications may affect H. pylori antigen detection.