H pylori antigen stool vs H pylori antibody in serum which one is better?

H. pylori Stool Antigen Test

• What it detects: Active infection (current presence of the bacteria).
• Use case: Ideal for diagnosis and for checking if treatment was successful.
• Accuracy: Very good sensitivity and specificity.
• Sample: Stool.
• Best for: Diagnosing active infection, especially if symptoms like gastritis or ulcers are present.

H. pylori Antibody Test (Serology)

• What it detects: Past or present exposure to H. pylori (antibodies in blood).
• Use case: Can show if a person has ever been exposed, but cannot distinguish between past and current infection.
• Accuracy: Lower clinical usefulness compared to stool antigen or breath test.
• Sample: Blood.
• Best for: Historical exposure — but not very useful for active infection diagnosis.

Which one is better?

• For current diagnosis and treatment monitoring, stool antigen is much better.
• For screening in populations with high exposure, antibody test can be considered — but it’s not ideal for individual diagnosis.