Abstract: Through the research on the structure of gastric mucosa in patients with Helicobacter pylori (Hp) positive and negative duodenal ulcer, the effects of Hp infection and duodenal ulcer on the structure of duodenal mucosa were investigated. Five cases of duodenal mucosa in patients with Hp-positive and Hp-negative duodenal ulcer were selected. The 16S rRNA gene amplicon sequencing was used to detect the proportion of Hp colonization in duodenal mucosa. Structural analysis was performed. Results showed that, the number of species in the Hp-positive mucosa of patients with duodenal ulcer was significantly higher than that of Hp-negative mucosa (P<0.05), but the difference in microbial diversity was not statistically significant. Except Hp, Prevotella and Neisseria were also the dominatnt flora.  The content of Leptotrichia was significantly different between the two groups (P<0.05). Results indicated that, Hp does not become the only dominant bacteria after infection of duodenal mucosa, but increases the number of species in the duodenal mucosa. And it has little effect on the microbial diversity and has a certain influence on the flora structure. Leptotrichia may be involved in the development of ulcers.

Key words: flora structure, Helicobacter pylori infection, duodenal ulcer, flora diversity

摘要： 通过研究幽门螺杆菌（Helicobacter pylori，Hp）阳性和阴性十二指肠溃疡患者胃黏膜菌群结构，探讨 Hp 感染及十二指肠溃疡的发生对十二指肠黏膜菌群结构的影响。选取 Hp 感染阳性和 Hp 阴性的十二指肠溃疡患者的十二指肠黏膜各 5 例，采用 16S rRNA 基因扩增子测序方法检测十二指肠黏膜中 Hp的定植比例，并进行菌群结构分析。十二指肠溃疡患者 Hp感染阳性粘膜中菌群物种数目明显多于 Hp阴性粘膜（P<0.05），但菌群多样性的差异不具有统计学意义。十二指肠溃疡黏膜中除 Hp为优势菌群外，还有普雷沃氏菌属（Prevotella）和奈瑟菌属（Neisseria）。纤毛菌属（Leptotrichia）的含量在两组间存在明显差异（P<0.05）。结果表明，Hp 感染十二指肠黏膜后没有成为唯一的优势菌，反而增加了十二指肠黏膜内的菌群物种数目，对菌群结构有一定的影响，但对菌群多样性的影响不大；纤毛菌属（Leptotrichia）等可能与溃疡的发生有关。

关键词: 菌群结构, 幽门螺杆菌感染, 十二指肠溃疡, 菌群多样性