Effect of PPIs on Stool DNA Test for H. Pylori

Effect of Proton Pump Inhibitors on Stool DNA Detection of Helicobacter Pylori: A Prospective Clinical Study

This prospective, self-controlled clinical study aims to evaluate the impact of proton pump inhibitor (PPI) use on the accuracy of stool DNA testing for Helicobacter pylori (H. pylori) and to assess the applicability of this test in patients receiving PPI therapy. Patients requiring long-term PPI treatment and meeting the inclusion criteria were enrolled. After at least four weeks of PPI therapy, a stool DNA test was performed, along with collection of gastric mucosal samples via gastroscopy for tissue PCR, histology, and rapid urease testing, as well as H. pylori antibody detection. Subsequently, PPI treatment was discontinued for four weeks, after which a 13C-urea breath test and a repeat stool DNA test were conducted. By comparing the sensitivity, specificity, and consistency of stool DNA testing before and after PPI discontinuation, this study aims to characterize the interference of PPIs with the test results, thereby providing evidence to support improvements in H. pylori diagnostic methods.

Study Overview

• Status: Recruiting
• Conditions: Helicobacter Pylori Infection
• Intervention / Treatment: Drug: Proton Pump Inhibitor Discontinuation

• Study Type: Observational
• Enrollment (Estimated): 25

Contacts and Locations

• Study Contact: Name: Hong Lu, MD; Phone Number: +86-13611958022; Email: hlu@sjtu.edu.cn

Study Locations

• China
  • Shanghai Municipality
    • Shanghai, Shanghai Municipality, China, 200127
      • Recruiting
      • Renji Hospital, School of Medicine, Shanghai Jiao Tong University
      • Contact: Hong Lu; Phone Number: +86-13611958022; Email: hlu@sjtu.edu.cn

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

Patients aged 18-80 years requiring PPI therapy for gastritis or peptic ulcer disease, with no prior H. pylori eradication therapy, and confirmed H. pylori infection (≥2 positive among antibody, histology, and RUT). Exclusion criteria include pregnancy, lactation, acute gastrointestinal bleeding, subtotal gastrectomy, severe organ dysfunction, recent antibiotic use (within 4 weeks), substance abuse, and conditions affecting compliance or safety. All participants provide written informed consent.

Description

Inclusion Criteria:

• Male or female patients aged 18-80 years;
• No prior H. pylori eradication therapy;
• Patients requiring proton pump inhibitor (PPI) therapy in the near future due to gastritis, peptic ulcer disease, or other indicated conditions;
• Patients with at least two positive results among H. pylori antibody test, histology, and rapid urease test (RUT);
• Provision of signed informed consent and being informed of the specific study protocol.

Exclusion Criteria:

• Prior H. pylori eradication therapy;
• Pregnant or lactating women;
• Acute gastrointestinal bleeding;
• History of subtotal gastrectomy;
• Severe dysfunction of vital organs (heart, liver, kidney, lungs, etc.) or congenital diseases, such as class IV cardiac insufficiency, liver failure, uremia, respiratory failure, hemophilia, Wilson's disease, etc.;
• Refusal of enrollment by the guardian or the patient;
• Alcohol and/or drug abuse (addiction or dependence), or poor compliance as judged by the investigator;
• Individuals without legal capacity or with impaired insight;
• Abnormal neurological signs on physical examination;
• Use of oral antibiotics with bactericidal activity against H. pylori within 4 weeks.

Study Plan

How is the study designed?

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in Diagnostic Sensitivity and Specificity of Stool DNA Test Before and After PPI Discontinuation	The sensitivity and specificity of stool DNA testing for Helicobacter pylori detection will be assessed under two conditions: (1) after at least 4 weeks of continuous proton pump inhibitor (PPI) therapy, and (2) after a 4-week PPI washout period. The reference standard comprises gastric mucosal biopsy results (histology, tissue PCR, and rapid urease test) combined with H. pylori antibody testing during the PPI-on phase, and 13C-urea breath test during the PPI-off phase. The primary outcome is the difference in sensitivity and specificity between the two conditions.	Assessed at two time points: at baseline (after ≥4 weeks of PPI use) and at 4 weeks after PPI discontinuation

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Inter-Method Agreement Among Diagnostic Tests	The level of agreement (kappa coefficient) among stool DNA test, gastric biopsy-based methods (histology, PCR, RUT), H. pylori antibody test, and 13C-urea breath test. This outcome assesses the overall concordance of diagnostic results across different testing modalities under varying PPI conditions.	Baseline (for comparisons involving biopsy-based methods and serology) and 4 weeks after PPI discontinuation (for comparisons involving UBT)

Collaborators and Investigators

• Sponsor: Shanghai Jiao Tong University School of Medicine

Study record dates

Study Major Dates

• Study Start (Actual): May 1, 2025
• Primary Completion (Estimated): May 1, 2026
• Study Completion (Estimated): May 1, 2026

Study Registration Dates

• First Submitted: March 31, 2026
• First Submitted That Met QC Criteria: March 31, 2026
• First Posted (Actual): April 7, 2026

Study Record Updates

• Last Update Posted (Actual): April 7, 2026
• Last Update Submitted That Met QC Criteria: March 31, 2026
• Last Verified: March 1, 2026

More Information

Terms related to this study

• Keywords: Helicobacter pylori; Proton pump inhibitors; Stool DNA Testing
• Other Study ID Numbers: rjyg20260331

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No