Infection

The transmission path of Helicobacter pylori is not conclusively clarified. The possibility of oral-oral and faecal-oral transmission by excretion of the bacterium in stool and reabsorption by other persons, e.g. from water, is being discussed. Contaminated food also provides a source of absorption.

The germ initially colonizes its main reservoir in humans, the lower part of the stomach (antrum), moves forward in a directed manner by means of small, elongated membrane protuberances (flagella), which are made of spiral-shaped protein threads and function like a propeller, and spreads via the mouth of the stomach (cardia) and the stomach body (corpus). This colonization of the gastric mucosa can take decades. The stomach environment is protected against bacteria by the aggressive gastric acid.

Helicobacter pylori is able to survive for a short time in the acidic gastric juice due to some adaptation mechanisms. Just long enough for the bacterium to attach itself to the epithelial cells of the gastric mucosa with special adhesive structures, so-called adhesins, and then penetrate into them and nestle in the mucus, which protects the stomach from self-digestion and, for this reason, the bacterium from gastric acid. This is a prerequisite for Helicobacter pylori caused gastritis.

Inflammatory cells enter the tissue. The clinical picture is called chronic active gastritis. –>

Transmission

The infection with the Helicobacter pylori bacterium is considered contagious, but not the clinical picture of gastritis caused by Helicobacter pylori. It is assumed with great certainty that the transmission in most of the affected persons has already taken place in childhood, when the immune system is not yet sufficiently powerful to fight the germ. Likewise, the route of transmission itself, in addition to age at transmission, is still the subject of current research.

It is suspected that transmission is by mouth-to-mouth contact or through the faeces of people who harbour it in their stomach and then excrete it together with the digested food. For example, mouth-to-mouth transmission would typically occur by putting the child’s pacifier or spoon in the mouth. Transmission through faeces would mean that it is sufficient for an infection to occur if the person concerned does not wash his hands sufficiently after going to the toilet, allowing the germ to adhere to his hands and then enter the digestive tract of other people through contact with food or direct oral contact.

There it can then settle down and be transmitted again to other people through the same mechanism by excretion with the faeces. A transmission of the animals has been ruled out so far. In Germany alone, bacterial colonization can be proven in many millions of people.

It is assumed that worldwide about 50% of the population is affected. The rate of infection varies greatly according to age, geographical aspects, ethnicity and social class (i.e. housing situation, income, occupation). Once infected, Helicobacter pylori colonizes the entire stomach mucosa and often roams around unnoticed for decades. Helicobacter pylori only causes symptoms in about 10% of infected people, and in an even smaller number of cases, irritation of the mucous membrane cells triggers gastritis.