Overview
The Helicobacter pylori (H. pylori) Test is performed to detect the presence of H. pylori, a spiral-shaped bacterium that lives in the stomach and upper part of the small intestine. This bacterium can weaken the stomach lining, leading to chronic gastritis, peptic ulcers, and—in long-standing cases—an increased risk of stomach cancer.
H. pylori infection is extremely common worldwide, especially in regions with poor sanitation or contaminated food and water. Many people may carry this bacterium for years without symptoms, which is why testing becomes important for individuals experiencing persistent digestive issues.
The test is typically done to diagnose an active infection, confirm whether the bacteria have been eradicated after treatment, and evaluate the cause of long-term digestive symptoms.
How H. pylori Enters and Behaves in the Body
H. pylori is not produced naturally by the human body. It enters from outside sources such as:
- Contaminated food
- Contaminated water
- Direct contact (saliva, utensils, close household interaction)
Once inside the body, the bacterium settles in the stomach lining (mucosa). Its spiral shape helps it burrow into the protective mucus layer, making it hard for the immune system to remove. It produces enzymes like urease, which neutralize stomach acid and allow the bacteria to survive in the acidic stomach environment.
Why the H. pylori Test Is Important
Testing for H. pylori is medically important for several reasons:
✔ 1. Detecting Infection Early
It identifies H. pylori, one of the most common causes of stomach irritation and ulcers.
✔ 2. Preventing Serious Complications
Early detection reduces the risk of:
- Stomach ulcers
- Bleeding ulcers
- Chronic gastritis
- Gastric cancer
✔ 3. Guiding Treatment
Accurate detection helps doctors prescribe appropriate antibiotics and acid-reducing medicines.
✔ 4. Confirming Treatment Success
The test is also used after therapy to ensure the bacterium is fully removed.
Causes of Low or Negative H. pylori Levels
A negative test result usually indicates:
✔ No current infection
There is no active H. pylori in the stomach.
✔ Medication interference
Recent use of:
- Antibiotics
- Proton pump inhibitors (PPIs) like omeprazole
- Bismuth medications
can suppress bacteria and cause false-negative results.
✔ Testing too soon after treatment
H. pylori needs time to regrow after therapy if treatment failed. Testing too early can give wrong results.
Symptoms of Low/Negative Levels
Low or negative levels do not cause symptoms themselves. However, if symptoms still exist, the cause may be:
- GERD (acid reflux)
- Stress
- Poor eating habits
- Gastritis from other causes
- Medication irritation
A negative result simply means H. pylori is not responsible.
Causes of High or Positive H. pylori Levels
High or positive test results indicate:
✔ Active H. pylori infection
The bacterium is currently present in the stomach.
✔ Reinfection
In some cases, infection can return after successful eradication.
✔ Chronic, untreated infection
Long-term infection leads to continuous irritation and ulcer risk.
Symptoms When H. pylori Levels Are High
H. pylori itself does not cause symptoms directly, but the damage it creates leads to:
- Burning stomach pain (especially on an empty stomach)
- Bloating
- Nausea or vomiting
- Excessive burping
- Loss of appetite
- Unexplained weight loss
- Indigestion
- Acid discomfort
Severe symptoms (due to ulcers):
- Blood in vomit
- Black or tar-like stools
- Severe abdominal pain
These require immediate medical attention.
Reference Ranges for H. pylori Test
Reference ranges depend on the test type:
1. Urea Breath Test
- Negative: No H. pylori detected
- Positive: Active infection present
2. Stool Antigen Test
- Negative: No active infection
- Positive: Active infection present
3. Blood Antibody Test
- Negative: No antibodies or very early infection
- Positive: Past or present infection
(Not preferred for diagnosis because antibodies stay for years.)
4. Biopsy Test (via endoscopy)
- Direct detection from stomach lining
- Gold-standard test in complex cases
Sample Types Used
Different sample types are used depending on the test:
- Breath sample (Urea Breath Test)
- Stool sample (Stool Antigen Test)
- Blood sample (Antibody Test)
- Tissue sample (Biopsy during endoscopy)
Test Preparation
✔ For Urea Breath Test
- Stop PPIs (like omeprazole) for 2 weeks
- Stop antibiotics for 4 weeks
- Do the test on an empty stomach
✔ For Stool Antigen Test
- Avoid PPIs or antibiotics
- Collect a fresh stool sample
✔ For Blood Antibody Test
- No fasting required
- Not recommended for confirming eradication
✔ For Biopsy
- Requires fasting (as advised) before endoscopy
When to Consult a Doctor
Seek medical advice if you experience:
- Persistent stomach pain
- Burning pain relieved by eating
- Unexplained weight loss
- Black stools or vomiting blood
- Nausea, bloating, or frequent burping
- Poor appetite
- Long-term gastritis symptoms
- If symptoms return after treatment
You should also consult a doctor if you have:
- History of stomach ulcers
- Family history of stomach cancer
- Severe acid reflux not improving with medication
Important Word Explanations
- H. pylori: A spiral-shaped bacterium that infects the stomach.
- Gastritis: Inflammation of the stomach lining.
- Peptic Ulcer: A sore in the stomach or upper intestine.
- Urea Breath Test: A test where H. pylori breaks down urea into CO₂ detected in breath.
- Stool Antigen Test: Detects H. pylori proteins in stool.
- Biopsy: Tissue sample taken during endoscopy.
- PPI: Proton pump inhibitor, a medicine that reduces stomach acid.
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