How to Use An H Pylori Test to Diagnose and Treat

Helicobacter pylori infection is common worldwide and a prevalent cause of gastritis, peptic ulcer disease, and gastric cancer. As such, accurate diagnosis and effective eradication of identified infections are critical in ensuring long-term gastrointestinal health. Diagnosing H. pylori infection may feel daunting, given the multiple avenues of testing available. This article will discuss the various testing options, how to choose the best one, and considerations to explore when making H. pylori treatment decisions.

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Understanding H. pylori Infection

Helicobacter pylori (H. pylori) is a bacterium that primarily resides in the stomach lining, and its infection is a prevalent and significant clinical concern. H. pylori affects the body by colonizing the mucous layer of the stomach, where it can disrupt the protective barrier and induce inflammation, called gastritis. The inflammatory response can lead to common symptoms such as abdominal pain, bloating, nausea, and, in some cases, vomiting. Additionally, H. pylori infection is a major risk factor for developing peptic ulcers, which are open sores that form on the inner lining of the stomach or the upper part of the small intestine. (3) 

The complications of H. pylori infection extend beyond ulcers and gastritis. It is also linked to an increased risk of stomach cancer, particularly in individuals with long-term, untreated infections. The bacterium achieves its persistence in the stomach by evading the immune system and adapting to the acidic environment, making it challenging to eradicate without specific antibiotic therapy. (3, 8)

H. pylori infection is widespread globally, with prevalence rates varying by geographical region, socioeconomic factors, and age. It is estimated that three-quarters of the world's population may carry the bacterium. Retrospective studies have reported lower prevalence rates in younger people, high-income countries, and countries with universal healthcare. Transmission is thought to occur mainly through oral-oral or fecal-oral routes, often during childhood. (3) 

Indications for H. pylori Testing

The American College of Gastroenterology (ACG) has proposed that the following groups of people be tested for H. pylori infection:

• All patients with active and past history of peptic ulcer disease (PUD), low-grade gastric mucosa-associated lymphoid tissue (MALT) lymphoma, or history of endoscopic resection of early gastric cancer 
• Patients under age 60 with uninvestigated dyspepsia and no alarm features (vomiting, bleeding, anemia, abdominal mass, unintended weight loss, and difficulty swallowing). Dyspepsia refers to symptoms of upper abdominal pain, burning, fullness after eating, and heartburn. (15) 
• Patients on long-term low-dose aspirin therapy 
• Patients initiating long-term treatment with a non-steroidal anti-inflammatory drug (NSAID)
• Patients with unexplained iron deficiency anemia (IDA)
• Adults with idiopathic thrombocytopenic purpura (ITP)

Ninety percent of patients with H. pylori infection are asymptomatic. If present, symptoms are related to gastritis or PUD and may include abdominal pain, nausea, vomiting, dyspepsia, loss of appetite, frequent burping, and bloating.

Types of H. pylori Tests

There are four ways in which H. pylori infection can be diagnosed:

Urea Breath Test

The urea breath test is the most accurate non-invasive testing method for diagnosing H. pylori infection, with specificity and sensitivity approaching 100%. The test involves the patient collecting a baseline breath sample after fasting for at least one hour, swallowing a urea-containing solution, and collecting a second breath sample 15 minutes later. Breath carbon dioxide levels are measured and compared to determine the presence of infection. Patients should discontinue antimicrobials, proton pump inhibitors (PPIs), and bismuth compounds at least two weeks before testing to prevent false negative test results. The urea breath test can also be used as a test of cure and should be performed 4-6 weeks after completing H. pylori eradication therapy. (9, 16) 

Stool Antigen Test

A stool antigen test, such as the H. Pylori Antigen test by Doctor's Data, measures immunogenic proteins in a stool sample associated with H. pylori to diagnose infection. While this testing method is slightly less accurate than the urea breath test, it is cheaper. Patients should discontinue antimicrobials, PPIs, and bismuth preparations at least two weeks before testing. The stool antigen test can also be used as a test of cure after a patient has completed H. pylori eradication therapy. (8, 9)

Serologic Antibody Test

Serologic antibody testing, such as the H. Pylori (IgG) blood test by Alletess Medical Laboratory, measures immune proteins specific to H. pylori. This testing option is least preferred because it is the least accurate and cannot distinguish between an active and past infection. It may be recommended as an alternative testing method for patients who are unable to stop taking PPIs or antibiotics, but it should never be used as a test of cure. (9)

Endoscopy

An upper endoscopy is a medical procedure in which a flexible tube with a light and camera, called an endoscope, is used to visualize the upper gastrointestinal tract. Endoscopy with biopsy is recommended to investigate gastrointestinal symptoms in patients 55 years or older or with alarm symptoms. Histological staining with or without a rapid urease test can be performed on the biopsy to diagnose infection. (9)

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Interpreting H. pylori Test Results

Positive H. pylori urea breath and stool antigen tests indicate an active infection. A positive serological antibody test means that IgG antibodies are detectable in the serum, but this can indicate a past or active infection. Rarely, false positives can occur on the urea breath test in the presence of other urease-producing pathogens in the stomach. (18) 

False negative test results can occur with the urea breath and stool antigen tests if the patient has recently taken antibiotics, bismuth compounds, PPIs, and sucralfate before testing. These medications can suppress H. pylori activity, making the tests less accurate. To prevent false negatives, it is recommended that patients discontinue antibiotics and bismuth compounds for at least four weeks and PPIs and sucralfate for at least two weeks before testing. Similarly, following H. pylori eradication therapy, the urea breath or stool antigen test should be performed at least four weeks after completing treatment. An advantage of the serological antibody test is that the accuracy is not affected by the use of these medications. (16, 18) 

Treatment Strategies Post-Diagnosis

Treatment is recommended for any patient diagnosed with H. pylori infection. Conventional treatment regimens include combinations of 2-3 antibiotics with a PPI taken for periods ranging from 10-14 days. Outlined below are standard first-line therapies recommended for H. pylori eradication (1):  

• Clarithromycin triple therapy: PPI, clarithromycin, and amoxicillin* for 14 days. 
• Bismuth quadruple therapy: PPI or histamine-2 receptor antagonist, bismuth, tetracycline, and metronidazole for 10-14 days
• Concomitant therapy: PPI, clarithromycin, amoxicillin, and metronidazole or tinidazole for 10-14 days

*Metronidazole can be used as an alternative to amoxicillin for patients with penicillin allergy.

Clarithromycin triple therapy should not be utilized in areas with documented high clarithromycin resistance rates. Clarithromycin triple therapy is 90% effective in eradicating clarithromycin-sensitive H. pylori; however, the eradication rate decreases to 22% when clarithromycin triple therapy is used to treat clarithromycin-resistant H. pylori strains. (1)

Monitoring and Follow-Up Testing

Based on ACG clinical guidelines, testing to prove H. pylori eradication should be performed using a urea breath test, stool antigen test, or biopsy at least four weeks after completing treatment. Confirming eradication through post-treatment testing is crucial for several reasons. First and foremost, H. pylori has exhibited a propensity for developing antibiotic resistance, and treatment failure can occur due to this resistance. Follow-up testing helps identify cases where the infection persists despite treatment, allowing for the prompt adjustment of therapeutic strategies. Additionally, asymptomatic carriers may still harbor the bacteria even after treatment completion, contributing to the risk of recurrence, potential complications, and spread of infection. In the absence of follow-up testing, the success of H. pylori treatment remains uncertain, emphasizing the necessity of this post-treatment assessment in clinical practice. (1)

Patient Education and Management

Patient education plays a pivotal role in the comprehensive management of H. pylori infection, encompassing not only the understanding of the prescribed treatment regimen but also emphasizing the significance of adherence and the implementation of lifestyle modifications. Clear communication regarding the antibiotic regimen, including the names, dosages, and duration of medications, is crucial for preventing treatment failure and the development of antibiotic resistance.

Moreover, patient education extends beyond pharmaceutical interventions to include lifestyle modifications that can positively impact the management of H. pylori infection. Counseling on dietary choices, such as avoiding spicy foods and irritants, can contribute to symptom relief and support the healing process. Educating patients about the potential recurrence of infection and the importance of follow-up testing post-treatment enhances their awareness and promotes long-term health. Clear communication encourages a collaborative approach between healthcare providers and patients, fostering a sense of responsibility and engagement in managing H. pylori infection. Ultimately, an informed patient is better equipped to actively participate in their care, leading to improved treatment outcomes and a reduced risk of complications associated with H. pylori infection.

Challenges in H. pylori Management

There are increasing numbers of patients with H. pylori infections resistant to antibiotics. A multicenter European survey conducted between 2008 and 2009 reported resistant rates of 35% for metronidazole, 17.5% for clarithromycin, and 14% for levofloxacin. Functional medicine tests are available to help providers optimize eradication rates. For example, the GI-MAP comprehensive stool test by Diagnostic Solutions includes H. pylori antibiotic-resistance genes. This allows healthcare providers to make informed treatment decisions, selecting antibiotic agents that are most effective against the specific strains detected. 

The most common side effects of H. pylori eradication therapy are associated with antibiotic use, including symptoms like nausea, abdominal pain, and diarrhea. Growing evidence suggests that Lactobacillus and Bifidobacterium probiotics help reduce these side effects and improve patient compliance with therapy. Additional evidence suggests an inhibitory effect of these probiotic strains on H. pylori, increasing cure rates in those who used probiotics as adjuvant therapy in H. pylori treatment protocols. (1)

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How to Use An H Pylori Test: Key Takeaways

Adopting a comprehensive approach to H. pylori management is imperative for accurate diagnosis and effective treatment. Understanding when to utilize the appropriate H. pylori tests, such as the urea breath test, antigen test, or serological test, is crucial in confirming the presence of the infection and guiding tailored therapeutic strategies. Treatment decisions should consider antibiotic resistance patterns and the patient's medical history, and follow-up testing post-treatment is essential to confirm eradication and prevent potential complications. Embracing this comprehensive model, which encompasses accurate diagnosis, effective treatment, patient education, and diligent follow-up care, promotes optimal outcomes and long-term gastrointestinal health.