H. pylori Deep Dive – Part 1: The Basics

Written By Kirsty Groves

H. pylori 101: what it is, how common it is, symptoms to watch for, and the smartest way to test

You’ve probably heard of Helicobacter pylori - often shortened to H. pylori - in the context of ulcers. But this spiral-shaped bacterium is far more common than most people realise, and it can quietly influence digestive comfort and long-term stomach health. In this primer, I’ll cover what H. pylori is, how widespread it is, typical (and not-so-typical) symptoms, and how testing works, so you’re ready for the focused posts to follow on reflux/bloating, histamine-type reactions, cholesterol, and blood sugar.

What exactly is H. pylori?

H. pylori lives in the stomach lining. Many people acquire it in childhood and carry it for years. In some, it’s relatively quiet; in others, it causes gastritis (stomach lining inflammation) and can lead to peptic ulcers. Long-term, untreated infection increases the risk of more serious outcomes (including a form of stomach cancer), which is why identifying and treating confirmed infection matters. Guidance from both European and US expert groups view H. pylori as a treatable infectious disease—eradication (treatment) plus proof of cure is the modern standard.(1)

Image: Pixabay

How common is it?

Globally, H. pylori remains common, though prevalence has been falling in many regions over recent decades:

  • A large 2024 review of data from 111 countries estimated ~44% of adults carried H. pylori in 2015–2022 (higher in some regions, lower in others).(2)

  • Earlier work suggested roughly 4.4 billion people were infected worldwide in 2015. Prevalence varies widely by country and living conditions.(3)

In practical terms, if you’ve grown up or spent long periods in higher-prevalence regions, or if H. pylori runs in the family, your likelihood is higher.

How is it transmitted?

Most infections occur in childhood, likely via close contact (oral–oral or faecal–oral routes) in households. Good hygiene and safe food/water handling help reduce the spread. (I’ll keep the focus here on what to do next rather than the “how” of transmission.)

Image: Unsplash

What symptoms can it cause?

Many people have no obvious symptoms. When H. pylori does cause trouble, it commonly shows up as:

  • Upper-abdominal discomfort or pain

  • Nausea, bloating, early fullness, belching

  • Disturbed hunger and appetite

  • Recurrent or persistent “indigestion” (dyspepsia)

  • Peptic ulcer disease (duodenal or gastric ulcers), sometimes with bleeding

You might also notice iron-deficiency anaemia that’s hard to explain, or B12 deficiency in some cases. H. pylori’s relationship with reflux/GERD is complex and varies between individuals (I’ll unpack this in the reflux/bloating post). If you recognise yourself in several of these, testing can be worthwhile.(1)

Red flags: when to seek medical care urgently

If you have unintentional weight loss, black stools, vomiting that won’t settle, difficulty swallowing, severe anaemia, or a strong family history of gastric cancer, please speak with your GP promptly. These signs warrant medical evaluation. (Testing for H. pylori may still be part of the work-up, but the priority is safety.)

Who should consider testing?

You don’t need to test everyone, but it’s reasonable (and often recommended) to test for H. pylori if you have:

  • Ongoing dyspepsia/upper-GI symptoms without a clear cause

  • A history of peptic ulcer disease (past or present)

  • Unexplained iron-deficiency anaemia

  • A first-degree relative with gastric cancer, or personal risk factors tied to higher prevalence

  • Situations where H. pylori could be an upstream contributor (e.g., you’ll see in this series how it may intersect with cholesterol, blood glucose, histamine-type sensitivity, and bloating/reflux)

European (Maastricht VI/Florence) and US (ACG) guidance align on testing and treating confirmed infection, followed by test-of-cure to make sure the bacterium is gone.(1,4)

The smartest way to test (and avoid false negatives)

For most adults, non-invasive tests are accurate, straightforward, and preferred:

  1. Urea Breath Test (UBT) – highly sensitive and specific for active infection.(5)

  2. Stool antigen test – choose a validated monoclonal assay for best accuracy.(6)

Important: To keep results accurate, time your test correctly:

  • Pause PPIs for ~2 weeks beforehand.

  • Avoid antibiotics and bismuth for ~4 weeks beforehand.

  • These same washouts apply before the test-of-cure (the follow-up test proving eradication).

  • H2 blockers or antacids are usually fine during the washout (check with your clinician).(4)

When might endoscopy be used? If you have alarm features, are older with new-onset symptoms, or your doctor needs to check for ulcers/bleeding, endoscopy with biopsy may be recommended. Otherwise, UBT or stool antigen testing is typically enough.

If you test positive: what treatment looks like

Because antibiotic resistance has risen in many countries, current guidance often recommends 7-day bismuth quadruple therapy (combinations including a PPI + bismuth + tetracycline + metronidazole) when antibiotic susceptibility isn’t known. In general, clarithromycin-based regimens are avoided unless susceptibility testing shows they’ll work. After completing therapy, eradication is often confirmed using UBT or stool antigen at least 4 weeks later (observing the medication washouts noted above).(4,7)

A nutritional therapist can support you with symptom-friendly nutrition during therapy (smaller meals, tolerable gentle fibres, possibly specific supplements), and with a short, structured post-antibiotic gut-care plan once treatment finishes. This is never a substitute for antibiotics, but it can make the process more comfortable and aid the important post-infection recovery and repair phase.

What about prevention and recurrence?

Good hygiene, safe food/water practices, and avoiding unnecessary antibiotics are practical ways to reduce risk. Encouragingly, recurrence after successful eradication is relatively low in many regions (often ~1% per year), though this varies with local factors.(4)

Additionally, some evidence-based approaches may enhance eradication therapy, minimise the risk of re-infection, and support gastric and digestive health. Sulforaphane in broccoli, mastic gum, and live microbial supplements, such as Saccharomyces boulardii, have all demonstrated positive effects.(8,9)

Image: Mastic gum

Where this series goes next

This introductory piece sets the stage for a few “H. pylori x [topic]” posts where we’ll unpack possible systemic ripple effects - always balancing curiosity with caution:

  • H. pylori & GI disturbances: when it’s the culprit behind dyspepsia/ulcers, and the nuanced relationship with reflux/bloating.

  • H. pylori & histamine/sensitivities: how mast cells and immune signalling might be involved.

  • H. pylori & cholesterol: emerging links with less favourable lipid profiles (association ≠ causation).

  • H. pylori & blood glucose/insulin resistance: what the data suggest and where it’s still unclear.

 

FAQs

Is H. pylori always harmful?
Not always. Some people never develop symptoms. But because it can cause ulcers and is a known risk factor for stomach cancer, confirmed infection is generally treated and then retested to ensure it’s gone.(3)

Can I just do a blood test for antibodies?
Antibody tests can’t reliably tell you if the infection is current (antibodies linger). For diagnosing active infection or confirming cure, UBT or stool antigen tests are preferred.(3)

Will treating H. pylori fix my reflux or cholesterol?
Not necessarily. Some people notice improvements (especially in dyspepsia/ulcer-type symptoms); others won’t. We’ll explore the reflux and cholesterol questions in upcoming posts with a balanced, evidence-based lens.

 

Kirsty Groves - registered nutritional therapist at Revolution Nutrition

Work with me

If this article has struck a chord, I can help you decide whether H. pylori testing makes sense for you. If you discover, or already know that you are H. pylori-positive, I can support you through treatment with a personalised nutrition plan.

Kirsty Groves
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