动物实验,肠道细菌 z-bo 2020-09-04 403

　　The latest research jointly published by Tiffani Jones and Karen Guillemin of the University of Oregon shows that Helicobacter pylori, the O toxin-related gene protein A (cagA), changes the number of intestinal flora of fruit flies. Can cause various diseases. Bacteria living in human intestines can usually keep humans healthy, but destroying this microbiota can cause disease. Certain microbial infections can destroy the intestinal flora, but it is not clear how this destruction occurs and whether it causes disease.

　　Study In this new study, Jones and her colleagues used Drosophila melanogaster to observe the effects of Helicobacter pylori infection, which can lead to human stomach cancer. They speculated that the protein cagA related to Helicobacter pylori destroyed the gut flora of fruit flies and caused disease. To test their hypothesis, the researchers used gene editing technology to design a fruit fly intestine that expresses cagA without being infected with Helicobacter pylori. Therefore, we can analyze the specific role of cagA in Helicobacter pylori infection. They found that in the intestines of fruit flies, cagA can cause excessive growth of intestinal wall cells, which strengthens the immune system and produces a response related to Helicobacter pylori infection. However, cagA-expressing fruit flies cultured under sterile conditions did not show these symptoms, indicating the importance of the gut flora. In fact, further studies have shown that cagA expression is related to the destructive intestinal flora of Drosophila. Contact with cagA expressing fruit flies will cause the destruction of the same bacterial flora as normal fruit flies. This is enough to cause the same cell proliferation and the same symptoms as the immune response of genetically modified flies. Together, these findings indicate that cagA can indirectly cause disease by changing the intestinal flora. The harmful effects of Helicobacter pylori and other bacteria with similar functions can be reduced by adjusting the balance of intestinal flora. The author explains: "Our research first shows that bacterial virulence factors (such as cagA) can cause disease by changing the symbiotic flora."

　　"This study also shows that the symbiotic flora may be related to the regulation of Helicobacter pylori on gastric cancer."