Dr. Luca Covotta, expert in General Surgery in Avellino , explains what repercussions the infection of Helicobacter pylori can have on the health of our stomach
Helicobacter pylori infection: what is it?
It is an infection that affects the mucous membrane of the stomach caused by a Gram-negative microaerophilic bacterium called Helicobacter pylori (Hp). This bacterium, discovered by Warren and Marshall in 1983, commonly lives in the stomach where it manages to survive thanks to its two specific abilities:
- The production of a substance (enzyme) called “urease” which reduces gastric acidity;
- Penetration into the innermost and less acidic layer of the gastric mucosa thanks to its helical shape from which it takes its name.
Is it a very common infection?
According to epidemiological data, the incidence of this infection is linked more to the socio-economic state than to the geographical area. In industrialized countries, for example, this infection:
- It concerns 20% of people under 40 and 50% of over 60;
- It is rare in children;
- It has a higher impact in the case of a low socio-economic status;
- It can increase in areas with a large immigration flow.
In developing countries, however, HP affects about 80% of the adult population and affects about 10% of children aged between 2 and 8 years.
What can be caused by?
Currently, according to current knowledge, man is the only “container” of this bacterium , which is most likely transmitted via the oral (eg direct contact, saliva), or fecal-gold (HP has been found both in saliva than in the stool) or by means of intermediate vehicles (e.g. ingestion of contaminated water, polluted vegetables, etc.).
What causes it to the stomach?
Although in most people the presence of the bacterium in the stomach does not cause acute consequences, in some it can lead to the formation of acute gastritis and duodenal ulcer. The major problem of Hp infection is that it can induce chronic inflammation of the gastric mucosa over the years, this could lead to the disappearance of gastric glandular cells (atrophy). Sometimes, these glands can be the subject of intestinal metaplasia, that is to say, they are replaced by glandular structures normally present in other areas of the digestive tract. This cascade of events is called “Correa Cascade”.
What is an intestinal metaplasia?
The metaplasia framework can be divided into three types:
- Type I (complete intestinal): all the enzymes normally contained in the intestinal mucosa are present and the metaplastic cells have strong similarity with those of the small mucous membrane, with shorter and rounded villi and with the permanence in some areas of the gastric glands;
- Type II (incomplete intestinal): there is only a limited amount of intestinal enzymes in which the goblet cells secrete exclusively N-acetylsialomucins and neutral mucins, while the sulphomucins are almost completely absent;
- Type III (incomplete colic): total subversion of the glandular structure represented by colic-type goblet cells. Goblet cells secrete large quantities of sulfomucine. This type of metaplasia is the most dangerous one in which the cellular atypia present fully meet the criteria of mild dysplasia, confirming the sequence: chronic gastritis, intestinal metaplasia, dysplasia, gastric carcinoma of the intestinal type.
Hp infection has also been implicated for MALT (Mucosa Associated Lymphoid Tissue) lymphoma, a rare form of a tumor that affects the cells of the immune system and affects the stomach wall.
What does the diagnosis consist of?
The diagnosis of Helicobacter pylori infection is made with different tests. Non-invasive tests include:
- The Breath Urea Test (breath test): certainly the most reliable (sensitivity and specificity 94-98%). It involves the administration of radioactively labeled urea to the patient in order to measure how much CO2 is emitted on exhalation. This gas represents the metabolic product of the bacterium in the presence of urea;
- The bacterium antigen research test in the stool: there is a better sensitivity of tests with monoclonal antibodies compared to polyclonal ones (respectively around 90% and 96%);
- Serological tests (sensitivity and specificity 80% -95%): these tests allow us to identify the presence of IgG antibodies in the blood, specifically directed against this infection.
Invasive tests, on the other hand, require endoscopic examination and the collection of biological samples and obviously represent those with a greater sensitivity and specificity (almost 100%):
- Histological examination: the sample is sent by microbial culture to the laboratory;
- Rapid urease test: the sample is put in contact with a liquid containing urea and the presence of the urease-producing bacterium induces a change in the color of the liquid.
What does the therapy involve?
The therapy is entrusted to drugs that reduce the acid secretion of the stomach (Proton Pump Inhibitors) and association of different antibiotics. Unfortunately, HP is easily transmitted, so it is possible that the infection occurs again, even following therapy.
Is it possible to prevent Helicobacter pylori infection?
Excluding the most important risk factors (smoking, alcohol, chronic intake of NSAIDs), the only ways to prevent this infection are:
- Follow appropriate hygiene rules, washing your hands thoroughly before touching or eating food and after using the toilet;
- Eat safe, properly washed and / or cooked food;
- Drink drinking water or, if you are unsure of drinking, bottled water.