Differences in Gastric Microbiota in Patients Who Were Infected Between CagA Positive and Negative Helicobacter Pylori

Status

Enrolling by invitation

Phases

Study type

Interventional

Source

ClinicalTrials.gov

Registry ID

NCT06785922

Enrollment

Registered

2025-01-21

Start date

2025-01-12

Completion date

2026-12-31

Last updated

2025-01-21

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

CagA, Gastric Cancer, Gastric Microbiota, Helicobacter Pylori

Keywords

Gastric microbiota, Helicobacter pylori, CagA, Gastric cancer

Brief summary

The goal of this clinical trial is to study the differences in gastric microbiota (Diversity index) between patients who were infected with CagA-positive Helicobacter pylori and CagA-negative Helicobacter pylori. The main question it aims to answer are: The effect of Helicobacter pylori typing (CagA status) on gastric microbiota, what is the different? Patients indicated for EGD at Siriraj Endoscopic Center will undergo a Helicobacter pylori test (Rapid urease test) If the result is positive, a stomach biopsy for gastric microbiota testing and CagA antibody testing will be conducted. Then, the patients will be divided into two groups: CagA-positive Helicobacter pylori and CagA-negative Helicobacter pylori. To compare the differences in gastric microbiota in terms of species and biodiversity, as well as endoscopic results, etc.

Interventions

PROCEDUREStomach biopsy for gastric microbiota

Stomach biopsy for gastric microbiota testing (16S RNA sequencing)

Study design

Allocation

NON_RANDOMIZED

Intervention model

PARALLEL

Primary purpose

BASIC_SCIENCE

Masking

NONE

Eligibility

Sex/Gender

ALL

Age

18 Years to No maximum

Healthy volunteers

Inclusion criteria

* Patients aged over 18 with an indication for EGD * Helicobacter pylori infection (Rapid urease test positive)

Exclusion criteria

* Severe comorbidities: poorly controlled DM, ESRD, decompensated cirrhosis, Malignancy * BMI ≤ 23 kg/m2 * Receiving medications that affect the gastric microbiota include Antibiotics, probiotics, or bismuth within 4 weeks, PPI within 2 weeks, NSAIDs or Metformin within 2 weeks * History of cholecystectomy or proximal small bowel surgery

Design outcomes

Primary

Measure	Time frame	Description
The differences in gastric microbiota (Diversity index)	On the 1 day of EGD	Diversity index: Shannon index, Simpson index

Secondary

Measure	Time frame	Description
Microbiota composition	On the 1 day of EGD	Prevalence of microbiota species
Endoscopic finding	During the EGD	Endoscopic finding was described by investigators
Pathological finding	Within 2 week after EGD	Pathological finding was described by pathologist

Countries

Thailand

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026