Helicobacter Pylori – Debunking the Myth of a Sterile Stomach


Bacteria is omnipresent in the world, even in unthinkable locations like inside our bellies. Besides feeling grossed out, you may be wondering how could any bacteria survive the highly acidic environment. Turns out that back in the 1970s, many Western doctors also bought this myth of a sterile stomach. As a result, patients were usually misdiagnosed, and this proved to be potentially fatal when gastric ulcers paved the path for cancerous tumours. It was after the Nobel-winning discovery of Helicobacter pylori by Prof Barry Marshall and Prof Robin Warren, only then the revolutionary wheels of gastroenterological medicine started turning into what we have today.

Electron micrograph of H. pylori waving its flagella
Electron micrograph of H. pylori waving its flagella (Source: Wiki Commons)

Amongst the genus of Helicobacter, H. pylori is the most widely studied strain, notorious for causing infections in the lower digestive tract. Like many pathogens, H. pylori dwelled in contaminated sources like faeces, and could be transferred into our stomach due to unhygienic practices, such as not washing hands with soap before eating.

Upon infiltration, H. pylori propels with its tail-like flagella, and quickly burrows itself deep within the inner mucus lining. From there, it is safe from acid digestion, since acid reacts poorly with the glycophospholipids floating above the mucus. H. pylori is then in a good position to infect the sea-bed layer of epithelial cells beneath the mucus.

H. pylori infection of the stomach.
H. pylori’s mode of infection into the host’s gastric epithelium (Source: Wiki Commons)

A common symptom is the formation of peptic ulcers near the pylorus (hence its name Pylori), or the stomach’s lower opening leading to the duodenum. After infection, H. pylori would secrete proteins which induce gastritis, the inflammation of the stomach lining. The protective mucus lining could be thinned out, and acid production will increase due to excessive irritation. The lower stomach’s epithelium is now more susceptible to be digested by gastric acid.

Peptic Ulcer (Source: Wikimedia Commons)
Gastric ulcer in lower stomach (Source: Wiki Commons)

Over time, the damaged cells swell due to inflammation and form gastric ulcers. Symptoms of acid reflux and abdominal pain will be intensified, coupled with a higher risk of tumour development. Ulcers may also manifest inside the duodenum, first segment of the small intestine. With innumerable delicate capillaries in the proximity, duodenal ulcers could pose serious risks of systemic infections and fatal internal bleeding. At this stage, a doctor would really be your new best friend.

Standard treatments for H. pylori infections go beyond a simple antibiotic prescription. To minimise chances for H. pylori to develop antibiotic resistance, 2 classes of antibiotics are often used, together with a proton pump inhibitor (PPI). As its name said, PPIs restrict proton (H+) supply to the upper stomach lining, reducing acid production. Besides alleviating acid-related symptoms and allowing ulcers to heal faster, the milder environment is also more conducive for certain antibiotics to work their magic. While other advanced therapies are beginning to take root, this treatment protocol, known as “triple therapy”, have since stood the test of time.

While Helicobacter is known to be indigenous to more than 50% of the current world’s population, most strains are non-pathogenic and their dormancy calls for little medical concern. With proper hygiene habits and affordable healthcare in most countries, H. pylori should pose fewer worries to us in the years to come.