免疫学: 現在の研究

抽象的な

Role of Gastric Microbiota in H. Pylori. Infection: A Hero or a Villain?

Fateme Davarani

Gastric cancer is known as the second leading cause of cancer death. H.pylori is classified as a group 1 human carcinogen by the international agency of research on cancer. Gastric microbiome is proved to be affected by H.pylori infection. Molecular methods and approaches for microbiome have increased the interest of studying the role of gastric microbiota in health and disease. Several studies have claimed the “mask changing” behavior of gastric microbiota in H.pylori infection which may cause more complications. Also, there are huge amount of studies that suggest using probiotics instead of antibiotic treatment in gastric infection. Although in vitro and animal model studies suggest anticancer effects of probiotics, results are controversial in human models. There are some investigations suggest the negative role of probiotics in gastric cancer. In this study, we will observe gastric microbiome and probiotics differently, compare the hero/villain role of these microbes in critical gastric condition and will discuss novel studies that we willing to do if opportunities are available in a professional environment.

Microbiome can show a different face

Das et al studied positive and negative interactions between microbiome and H.pylori and believed that microbiome is suspected to play a role in diseases caused by H.pylori. On the other hand, presence of H.pylori modulates interactions between various microbial genera. H.pylori abundance may influence or be influenced by gastric microbiota. We must notice that these interaction patterns can be used in identification of microbial genera which can help to restore harmony in gastric microbial community. In H.pylori infection, increase of gastric environment pH leads to best growth condition for microbes that are incapable of growing in normal environment. This may cause microbial bloom and outnumbering H.pylori. So adding new microbial genera (probiotics) in this critical situation may cause further new diseases in long term.

Gastric microbiota contains fungi and yeasts in addition to bacteria. Fungal colonization is common among patients with gastric ulcer. In this critical situation, microbiota changes its positive role to negative role and increases the risk of infection in addition to cancer.

So it is important to consider gastric microbiota as our ally we shouldn’t underestimate, because it changes the mask in case of complications and makes the process of healing even harder.

Engstrand et al Claimed that changes in gastric pH or antibiotic treatment can cause noticeable shift in stomach microbiota and can lead to disease. They believe that the role of gastric microbiota is unclear in diseases. They also found that oral microbiota was more stable than intestinal microbiota in antibiotic treatment. So in H.pylori infection this stable oral microbiota may find a way to stomach, where pH has increased due to the infection and colonized there. This may cause further diseases.