Fecal analysis for Helicobacter pylori

At the moment, Helicobacter pylori is recognized as one of the most commonly diagnosed infections affecting humans. The name of this pathogenic microbe literally translates as "a spiral-shaped bacterium living in the pyloric (lower) segment of the stomach." The microorganism belongs to anaerobic Gram-negative motile bacteria that settle among the folds of the gastric mucosa. Among the many ways to diagnose their presence in the digestive tract is the analysis of feces for Helicobacter pylori. This research procedure is simple, therefore, it is often prescribed for children, the elderly and seriously ill patients.

Reliability of the results of the analysis of feces for Helicobacter pylori

To determine the presence of Helicobacter pylori, several types of tests are involved - in particular, a stool or blood test.

Fecal analysis for Helicobacter pylori refers to qualitative studies, that is, indicates the presence or absence of a bacterial agent in the digestive tract, without an exact count. Diagnosis is performed in laboratory and clinical conditions, using the polymerase chain reaction technique. The reliability of the results is considered quite high - about 95%. Considering this, as well as ease of execution, the study is often recommended for most patients with suspected gastritis, stomach ulcers, etc. [1]

Indications for the procedure of the stool test for Helicobacter pylori

Fecal analysis for Helicobacter pylori can be prescribed to any patient who complains of pain and discomfort in the epigastric zone. More precisely, the reason for the appointment of the study is most often:

• discomfort in the upper abdomen after eating;
• regular and unpleasant belching;
• periodically disturbing heartburn;
• difficulty in swallowing food;
• increased gas formation, impaired digestion of food;
• regular bouts of nausea, vomiting;
• frequent change of periods of diarrhea and constipation;
• loss of appetite, food aversion, cachexia;
• blood in stool or vomit.

These signs do not always indicate the presence of Helicobacter pylori in the feces. However, analysis is a way to help confirm or refute the presence of an infection, which will fundamentally affect the treatment of the disease. 

Preparation

How accurate the result of the analysis of feces for Helicobacter pylori will be depends not only on the quality of laboratory diagnostics, but also on how clearly the patient follows the stages of preparation for diagnosis.

Here's how to pass feces for Helicobacter:

• four weeks before the proposed analysis, you should stop taking any antimicrobials;
• in three days, you need to delete from the diet the so-called “tinting” foods, which include beets, dark grapes, chokeberry, etc.;
• 3-4 days before the study, you need to stop taking laxatives, activated charcoal.

How to collect feces for Helicobacter?

• Feces for analysis are separated into a special container, which can be found in a pharmacy or asked directly at the laboratory;
• for adequate diagnosis, it will be enough if the container is filled by 1/3 or 1/2 of the volume;
• do not remove feces from the toilet, as it may contain traces of cleaning products and detergents.

How to store feces for Helicobacter?

Feces for analysis should preferably be taken to the laboratory immediately after collection. If necessary, it can be stored for no more than 10-12 hours in a refrigerator, in a tightly sealed container, in a temperature range from +2 to +8°C. [2]

Technique of the stool test for Helicobacter pylori

There are several methods to determine the presence of Helicobacter pylori in the digestive tract.

An analysis of a qualitative nature helps to find out whether there is such a bacterium in the body at all. The method of polymerase chain reaction - PCR feces for Helicobacter - is performed in the laboratory. Experts point to the high accuracy of diagnosis: more than 90%.

Feces for antigen to Helicobacter are given for analysis by immunochromatographic method with monoclonal antibodies. Bacterial antigens in the patient's body provoke the development of an immune response: we are talking about the production of antibodies (they are also called immunoglobulins). Such a study is also qualitative: it can be prescribed, in particular, to those people who have been in close contact with patients suffering from gastrointestinal pathologies.

When a patient is contacted, the doctor can prescribe several different tests at the same time - for example, feces for Helicobacter pylori, hemotest, examination of the contents of the stomach, etc. This is necessary in order to clearly determine the diagnosis and prescribe the correct therapeutic measures.

ELISA of feces for Helicobacter is performed within one working day, but urgently the result can be obtained in two hours. The method is based on the principle of thin layer chromatography and consists in the antigen-antibody reaction in the corresponding biomaterial. Diagnosis is carried out using specific test strips, cassettes or panels. [3]

Normal performance

Helicobacter pylori refers to microbes that settle on the mucous membranes of the gastric tissues: microorganisms cling to the villous epithelium and become a provoking factor in the development of 85% of ulcerative lesions of the stomach and duodenum. It is desirable to examine stool samples in case of recurrence of the disease, however, there are no special requirements for the timing of the analysis. For the study, feces of any consistency are suitable.

Analysis indicators can be reflected in only two options: bacterium (+) or (-). An apparatus for fecal analysis for Helicobacter pylori is not required. [4]

Raising and lowering of values

There is nothing difficult in interpreting the resultant values of fecal analysis for Helicobacter pylori, since most often only two final options are indicated on the laboratory form:

• the result is negative - the bacteria Helicobacter pylori was not detected;
• the result is positive - the bacterium Helicobacter pylori is present.

An increase and decrease in values takes place if the patient's venous blood is taken for the study. Fecal analysis is just a qualitative diagnosis, without counting the probable number of pathogenic microorganisms.

Positive stool test for Helicobacter pylori

It should not be assumed that a positive stool test for Helicobacter directly indicates the presence of pathologies of the stomach and duodenum 12. It often happens that the carrier of the infection is completely healthy, because it has a genetic immunity to the bacteria: this means that the microorganisms are simply not able to linger on the gastric mucosa.

Situations are considered clinically significant when the presence of Helicobacter is associated with symptoms characteristic of chronic inflammation of the duodenum or stomach ulcers.

However, regardless of the severity of the clinical picture, a positive stool test for Helicobacter pylori should be the reason for prescribing eradication (anti-Helicobacter pylori) treatment.