Helicobacter py roli, by its presence in the human digestive system, can lead to a number of pathological changes. In the course of development and worsening of the abnormalities, a number of diseases may appear that pose a direct threat to human health and life, including gastric ulcer cancer and MALT lymphoma outside the gastrointestinal tract. Infection with the bacteria most often occurs in childhood, when the first pathological changes in the mucosa are already visible.
Table of contents:
- Gastrointestinal functions
- Pathologies of the gastric mucosa
- Helicobacter pyroli infection
- Bacteria
- Lesions caused by Helicobacter pyroli
Thehuman dig estive system is a system composed of components such as the mouth, oesophagus, stomach, small intestine, large intestine, and the organs connected to it, such as the digestive glands - salivary glands, pancreas and liver. The primary tasks of the human gastrointestinal tract include the absorption of nutrients, vitamins, mineral salts and water ingested with food, which is accomplished through the action of neurohormonal regulation [1].
Activities of the digestive system
The gastrointestinal system, as a complex system of interrelated organs, has the task of supplying the human body with all the necessary elements through digestion and absorption of substances supplied with food. Consequently, it can be described from many different angles and perspectives. Among the activities performed by the digestive system, it can be described from the point of view of its motility, the secretion of substances by means of which it performs its function of breaking down food into absorbable components and thus enabling the digestive process, and from the point of view of the excretion of all unnecessary components of the food supplied. It is through the proper functioning of the gastrointestinal tract that the body is supplied with all the necessary nutritional elements, thus allowing for their optimal utilisation [1].
Pathologies of the gastric mucosa
Numerous pathologies can be encountered within the gastric mucosa that interfere with the function of the digestive system. Among other things, inflammation of the mucosa is a cause of disorders and dysfunctions against this background. Mucositis itself is understood as all pathologies occurring on the gastric mucosa, but is not a separate disease entity. Changes occurring in the gastric mucosa can be caused by a number of factors, including infections or immune inflammation. They can also be expected as a result of damage to the mucosa (in which case we speak of haemorrhagic or biliary gastropathy). The inflammation manifests itself through dyspeptic symptoms, which are one of the most common reasons for presenting to the doctor when there are gastric problems [2].
The range of dyspeptic symptoms includes complaints of epigastric pain, a feeling of fullness after a meal, nausea, vomiting, rapid satiety and concomitant weight loss, as well as bothersome and chronic belching after meals [3].
Inflammation can have a variety of causes and aetiologies - they can be caused by infection, but also by non-infectious agents - with Helicobacter pyroli cited as the most common cause of infection and associated gastric mucosal problems. These organisms are a potent pathogen that was first described in the 1980s by researchers B. J. Marshall and J. R. Warren, who were awarded the Nobel Prize in 2005 for linking H. pyroli to gastritis and peptic ulcer disease [2].
Helicobacter pyroli infection
Infection with this microorganism is cited as one of the most common causes of death from gastric cancer in people worldwide, but H. py roli has also been linked to the development of peptic ulcer disease and diseases of other organs in the human body.
Infection is most common during early childhood, and the microorganism itself tends to persist in the body throughout life, but this does not change the fact that infection can occur at any age. H. pyroli is the cause of numerous gastrointestinal complaints, leading to the development of peptic ulcer disease, gastric cancer or contributing to the formation of MALT lymphoma outside the gastrointestinal tract. The way in which the infection progresses and the development of individual diseases depends not only on the type of strain being dealt with, but also on the patient's age, state of health and lifestyle [4].
Stomach, photo: panthermedia
Bacteria
Helicobacter pyroli are a group of Gram-negative bacteria with a spiral, rod-shaped structure, the shape of which usually takes the letter U or S. The length of the entire bacterium usually closes to a maximum size of 5 μm and a width of 0.5-1 μm.
Three morphological forms of bacteria can be distinguished - rod-shaped (spiral), granular (coccoid), and granular forms of dying bacteria, with the predominant form being rod-shaped bacteria, which can be virulent or infectious [4].
The most commonly colonised site, however, is the pyloric mucosa of the stomach, although cases of bacteria have also been observed in the duodenum, oesophagus, dental plaque or faecal samples [4].
Lesions caused by Helicobacter pyroli
As infection with this bacterium is widespread (up to 90% of people in developed countries), it is necessary to investigate and control the changes that occur when H. pyroli is present in the gastric mucosa.
The study described in the paper Morphological changes of the mucosa in children with chronic gastric and duodenal disease and infection with cytotoxic strains of >>Helicobacter pyroli<< bacteria [5], was conducted on a group of 75 children aged between 10 and 18 years diagnosed with gastric and duodenal disease associated with the presence of H. pyroli. The changes occurring in the study group were assessed according to the type of bacterial strain.
According to the results reported in the above-mentioned paper, in the study group, those children infected with the CagA (+) strain showed active and profound gastroduodenitis more often than those with the CagA (-) strain. The authors of the research work, by means of morphological studies, also observed both qualitative and quantitative changes in the patients' mucosa, from which they conclude that the presence of the bacteria influences the formation of numerous lesions.
In the mucosa, the presence of glandular epithelial metaplasia (a change from multilayered epithelium to a homogenised epithelium), fibrosis and lymphoplasmacytic inflammatory infiltrates of a diffuse nature were observed. Dysmorphic and exfoliative lesions also appeared in the samples. Increased vascular fragility and thrombotic metaplasia were also noted [5].
The authors of the study indicate the site where the most frequent lesions occur: this is the gastric mucosal area.
However, in the majority of children with the CagA (-) strain, inactive and superficial inflammation prevailed, in a situation where the number of inflammation-lesioned cells was doubled in children with the CagA (+) strain. A similar situation applied to the presence of infiltrates, which were observed much more frequently in children with the CagA (+) strain than in those with CagA (-) [5].
To summarise the observations of the authors of this study, it is possible to speak of the influence of the presence of the bacteria on the state of the mucosa of children infected with the bacterium. Undoubtedly, the resulting lesions are pathological and provide the basis for the development of other life-threatening conditions.