Helicobacter pylori, better known as H. pylori, a bacterium that lives in our stomach and duodenum, being responsible for most common chronic bacterial infection in humans.
The H. pylori has been recognized in all the world's populations and individuals of all ages. Conservative estimates suggest that over 50% of the world population has the stomach colonized by these bacteria.
The H. pylori is a bacterium that has an amazing ability to survive in one of the harshest environments in our body, the stomach, which features are extremely acidic, with a pH below 4. The acidity of the stomach is one of the defense mechanisms of the body against bacteria that are ingested along with food. There are few living things that can survive in such acid environment. However, H. pylori has a few "tricks" that evolution allowed it to adapt to such hostile environment.
The bacterium produces substances that neutralize acids, forming a kind of protective cloud around it, allowing it to be locomova within the stomach until it finds a point to settle. In addition to this protection, the H.pylori can overcome the mucus barrier that the stomach has to protect itself from the acidity, clinging to the mucosa, the mucous area below where the acidity is much less intense. Therefore, besides producing substances against acidity, H. pylori can penetrate to such places of the stomach where the environment is less aggressive.
The mode of transmission of H. pylori is not yet fully known. We know that transmission can occur from an infected person to a healthy person through contact with vomit or feces, the latter usually in the form of contaminated food or water.
Humans appear to be the principal reservoir of the bacteria, however, H.pylori has been isolated from other primates, sheep and domestic cats, suggesting that their transmission to humans could occur.
The contaminated water, especially in developing countries, often serves as a source of bacteria. The H.pylori can remain viable in water for several days. Even in countries without universal sanitation, most children are infected before 10 years and the prevalence in the adult population becomes greater than 80%. In developed countries like the United States and Europe, contamination in children is rare, but the transmission is common in adulthood, where over 50% of the population over age 60 years is infected.
When a family member is infected with Helicobacter pylori, the risk of transmission to their children and other members is very high. This transmission is common even in homes with hygienic conditions, which puts in doubt whether the transmission always occurs by the feces / vomit. Transmission through saliva is not yet proven. The H. pylori can be found in the mouth, especially in dental plaque, but its concentration seems to be too low to be broadcast. A fact that speaks against this form of transmission is that dentists do not have higher infection rates than other traders who deal constantly with saliva and bacterial plaque.
As has been mentioned earlier in this article, the H.pylori often becomes lodged in the wall of the stomach just below the protective layer of mucus. This layer is essential for protecting the stomach, preventing the hydrochloric acid impairs its mucosa. The problem is that the H. pylori produces a number of enzymes, some of them directly irritant to the stomach cells, other active against the mucous layer by making it weaker, leaving the stomach wall unprotected against the acid content. These actions cause inflammation of the stomach lining, leading to gastritis and in some cases, to the formation of peptic ulcers and even tumors.
Helicobacter pylori diseases
To summarize, the presence of Helicobacter pylori causes damage in the stomach and duodenum, thus being associated with a higher risk of:
The vast majority of patients infected by H. pylori do not present any symptom or complication. There are strains of bacteria more aggressive and they are more indolent, which partly explains the occurrence of symptoms in only a few infected people. Importantly Helicobacter pylori itself does not cause symptoms. Patients infected with H. pylori complain of gastritis or peptic ulcers caused by bacteria. In these cases the most common symptoms are:
Helicobacter pylori symptoms
Pain or discomfort, burning usually in the upper abdomen
If the patient does not have gastritis or ulcers, the mere presence of H. pylori cannot be responsible for symptoms such as stomachaches. Just as an example, studies show that only 1 in every 14 patients complaining of burning stomach without gastritis or ulcer on endoscopy, improve with treatment for H. pylori.
The H. pylori also appears to be responsible for the appearance of recurrent ulcers in some patients, but this association is not yet proven.
Currently there are several methods to diagnose the presence of the bacterium Helicobacter pylori. However, more important than diagnosing the bacterium is knowing what to search. As in some places up to 90% of the population presents itself contaminated by bacteria, tests will be positive in almost everyone. Therefore, it makes sense to request research H.pylori in people without specific complaints.
Formerly of H.pylori research was done only with endoscopy biopsies from the stomach. Nowadays there are non-invasive tests, through faeces, blood or breath. However, in patients who complain of stomach pains, endoscopy is important to assess the condition of the stomach, also serving for the diagnosis of gastritis, ulcers or tumors. Therefore, many of the diagnoses of Helicobacter pylori are still made by endoscopy, biopsy and by urease test. The non-invasive tests are eventually used more after treatment in order to confirm elimination of bacteria.
Patients younger than 55 years who present with complaints of stomach burning, no signs that may indicate a tumor or active ulcers (bleeding, anemia, early satiety, unexplained weight loss, recurrent vomiting, family history of gastrointestinal cancer ...) can undergo a noninvasive test, seeking treatment if they are positive for H. pylori. Endoscopy is indicated only if there is no improvement in symptoms with treatment.
We know that the majority of the population is infected by H. pylori, but only a tiny part of developing stomach cancer. Thus, we can conclude that H. pylori increases the risk of cancer, but it is not the only factor. Therefore, treatment is not indicated against Helicobacter pylori to everyone who has the bacteria. Only patients with a family history of gastric cancer should worry about the presence of asymptomatic H. pylori. In these cases even if the patient does not present any symptoms, the research and treatment of the bacteria are indicated in order to eradicate it.
The H. pylori is related to the appearance of a particular type of lymphoma stomach, called the MALT. The relationship is so strong that the treatment of this tumor is done with antibiotics and eradication of the bacteria leads to a cure of this malignancy.
Recently, the indications for treatment of H.pylori were expanded, encompassing groups that until recently were not routinely treated. The current indications for treatment of Helicobacter pylori are:
Patients on long-term therapy with NSAIDs, which have gastrointestinal bleeding and / or peptic ulcers
Treatment of H. pylori is usually done with three drugs for 7 to 14 days with a proton pump inhibitor (omeprazole, lansoprazole or pantoprazole) + two antibiotics such as clarithromycin and amoxicillin or metronidazole and clarithromycin.
After 4 weeks from the end of treatment, the patient can perform the noninvasive tests to confirm the elimination of bacteria.
