Helicobacter pylori is a bacterium commonly found on the human stomach lining. Infection with Helicobacter pylori is an important risk factor for inflammation, ulcers, and cancer of the stomach and intestines. Helicobacter pylori colonization can be controlled by oral antibiotics.
What is Helicobacter pylori?
Helicobacter pylori is a rod-shaped bacterium that can colonize the human stomach. With an incidence of approximately 50%, Helicobacter pylori infection is one of the most common chronic bacterial infections. Click to enlarge. Helicobacter pylori is a gram-negative rod-shaped bacterium that colonizes the human stomach. It is by far the most important human pathogen of the genus Helicobacter. The name Helicobacter pylori is derived from the spiral appearance of the bacteria and the pylorus. The bacterium has flagella for locomotion and special adhesive structures for nesting. Helicobacter pylori was discovered in 1983 by Australian researchers Robin Warren and Barry Marshall. However, the bacterium’s far-reaching clinical significance did not become apparent until the following decade. In 2005, the discoverers of Helicobacter pylori were awarded the Nobel Prize in Medicine.
Significance and function
In Western countries, about 20% of all 40-year-olds are infected with Helicobacter pylori. The prevalence increases with age, so that it is already 50% in 60-year-olds. In developing countries, much higher infection rates are found. Overall, 30%-50% of the world’s population is considered infected. It is thus one of the most common chronic bacterial infections of all. The bacterium probably enters the stomach by the fecal-oral route via contaminated water or food. Oral-oral and gastro-oral routes of infection (e.g., contact with infected vomit) are also discussed. Once in the vestibule, Helicobacter pylori can spread throughout the gastric mucosa by means of its flagella. It has two mechanisms at its disposal to protect itself from the antibacterially effective gastric acid: First, it nests within or below the mucus layer with which the gastric mucosa protects itself from its acidic secretion. Secondly, Helicobacter pylori uses the enzyme urease to break down urea into ammonia and carbon dioxide. The basic ammonia neutralizes the stomach acid and raises the pH value in the immediate vicinity of Helicobacter pylori. In addition to urease, the bacterium has other enzymes and cytotoxins that attack the epithelial cells of the stomach and increase gastric juice production. If the gastric mucosal barrier is additionally attacked by other factors such as drugs, alcohol or stress, ulcers develop, especially in the area of the gastric portal and the duodenum. It is not known that Helicobacter pylori has a positive function in the human organism. The human immune system is unable to eliminate the germ. Therefore, if left untreated, Helicobacter pylori infection persists for life.
Diseases
Infection with Helicobacter pylori may be inconspicuous if the gastric mucosa is intact and resistant. However, the bacterium is considered the most important risk factor for the development of gastritis and gastric or duodenal ulcers. Type B gastritis (bacterial form) is caused by Helicobacter pylori in 90% of cases. In the case of gastric ulcers, around 75%, and in the case of duodenal ulcers, as many as 100% of all cases are attributed to the pathogen. In the case of chronic stomach complaints, tests for Helicobacter pylori infestation are therefore now routinely performed. The most reliable way of detecting the presence of Helicobacter pylori is to take an endoscopic biopsy followed by histological examination. In the tissue sample, the urease in particular can be detected by the easily performed Helicobacter urease test. Non-invasive methods include a breath test and antibody detection in serum or stool. However, antibody tests are more suitable for epidemiological investigations and less for acute clinical diagnosis. If Helicobacter pylori is detected in a patient, antibiotic therapy can completely eradicate the colonization. So-called triple therapy or quadruple therapy are common. Antibiotics are combined with proton pump inhibitors and, in the case of quadruple therapy, with bismuth salts.Radical clearance makes sense, since Helicobacter pylori promotes the development of cancer in the long term. The WHO has classified Helicobacter pylori as a first-order carcinogen since 1994. The bacterium is considered an important risk factor for gastric carcinomas and MALT lymphomas (cancers of mucosa-associated lymphoid tissue). For some time, research has also been conducted on vaccines against Helicobacter pylori.
