HELICOBACTER PYLORI (H. PYLORI)

Helicobacter pylori (H. pylori) is a spiral-shaped bacterium that infects the stomach lining and is one of the most common chronic infections worldwide. Estimations are that more than half the worlds population have H, Pylori present in their gut, but only 10% to 20% of people infected will develop symptoms of peptic ulcers, and a very small percentage will develop gastric cancer.

H. pylori is a leading cause of gastritis, peptic ulcers, and plays a major role in the development of stomach cancer if untreated.

At its core, H. pylori damages the stomach’s mucosal barrier, allowing acid to injure the underlying cells and tissue, leading to chronic inflammation and, in some cases, ulceration or malignancy. The cause of infection is typically through oral-oral or faecal-oral routes (contaminated food, water, or saliva), and infection often occurs in childhood, persisting lifelong if untreated.

1. Mucosal damage as H. pylori weakens the protective mucus layer of the stomach, exposing tissues to acid.

2. Inflammatory Response as H. pylori triggers chronic immune activation, leading to inflammation and tissue injury.

3. Toxin production as some strains produce toxins (e.g., CagA, VacA) that increase the risk of ulcers and cancer.

• Upper abdominal pain/burning that worsens when stomach is empty.
• Bloating and a general indigestion feeling.
• Nausea which may come and go.
• Loss of appetite, which is sometimes associated with weight loss.
• Frequent burping due to excess stomach gas.
• Black/tarry stools (melena) in less than 10% of cases. Is a red flag for bleeding ulcers caused by H. pylori.

Because H. pylori causes chronic injury to the stomach lining, it can lead to several serious complications if left untreated:

• Peptic Ulcers – H. pylori is the leading cause of both stomach and duodenal ulcers, resulting from mucosal erosion due to acid exposure.
• Gastritis – Chronic inflammation of the stomach lining can cause long-term pain, indigestion, and lead to mucosal atrophy.
• Stomach (Gastric) Cancer – persistent H. pylori infection increases the risk of developing gastric adenocarcinoma, particularly if the infection causes long-term atrophic gastritis.

The Urea Breath Test is a first-line test for identifying an active infection and is highly definitive and non-invasive.

Stool Antigen Test is an alternative to the urea breath test and is accurate.

Endoscopy with Biopsy (Rapid Urease Test, Histology) is the gold standard test if there are suspected ulcers, severe symptoms, or cancer risk suspected.

Triple Therapy (2 antibiotics + PPI) directly kills H. pylori and heals gastritis/ulcers but does lead to microbiome disruption.

Quadruple Therapy (2 antibiotics + PPI + bismuth) is highly effective if triple therapy fails but does lead to microbiome disruption.

Sequential Therapy (changing antibiotics during treatment) helps overcome antibiotic resistance.

In the early 1980s, two Australian doctors, Dr. Barry Marshall and Dr. Robin Warren, made a groundbreaking discovery. They found that a tiny spiral-shaped bacterium called Helicobacter pylori (H. pylori) was present in the stomach lining of many patients with gastritis and stomach ulcers. At the time, doctors believed stress, spicy food, or excess acid caused ulcers — no one thought bacteria could survive in the harsh, acidic stomach.

To prove their theory, Dr. Marshall famously drank a beaker full of H. pylori, making himself sick with gastritis — and showing that the bacteria could directly cause stomach inflammation and ulcers. Their discovery revolutionised medicine, leading to new treatments that cured ulcers with antibiotics, rather than just managing symptoms with acid blockers.

In 2005, Barry Marshall and Robin Warren were awarded the Nobel Prize in Physiology or Medicine for their discovery of “the role of Helicobacter pylori in gastritis and peptic ulcer disease.”