Abstract Several studies have indicated that the oral and gut microbiota may exhibit differences in patients with cirrhosis. Less is known about the microbiota in the stomach, which is located between the oral cavity and the intestinal tract. In this study, the gastric mucosal microbiota of patients with liver cirrhosis and controls were analyzed with 16S ribosomal RNA (rRNA) pyrosequencing. Cirrhotic patients had significantly lower Helicobacter pylori (H. pylori) infection rates, as confirmed by both the histological method and the pyrosequencing method. In H. pylori-negative subjects, gastric bacterial communities of healthy and cirrhosis cohorts were clustered into four clusters based on bacterial compositions: Cluster_1 and Cluster_2 (mostly cirrhosis), Cluster_3 (mostly healthy), and Cluster_4 (around half of each). Compositional and functional differences were observed among these different clusters. At the genus level, Cluster_1 and Cluster_2 showed enrichment of Neisseria and Streptococcus, respectively. Functionally, Cluster_2 was characterized as depleted of genetic information processing, as well as of modules related to glycan biosynthesis and metabolism. Patients in Cluster_2 had more severe gastrointestinal symptoms and a higher rate of previous endoscopic variceal ligation (EVL) therapy than patients in other clusters. Our findings suggest that the colonization of both H. pylori and non-H. pylori is influenced in liver cirrhosis. Although the H. pylori-negative gastric mucosal microbiota showed considerable heterogeneity, associations between specific gastric microbiota and clinical characteristics could be observed. Previous EVL therapy might lead to a distinct structure of the gastric mucosal microbiota, thus aggravating the gastrointestinal symptoms in H. pylori-negative cirrhotic patients.

中文翻译：

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肝硬化患者胃黏膜微生物群的特征及其与胃肠道症状的关系

摘要 多项研究表明，肝硬化患者的口腔和肠道微生物群可能存在差异。对位于口腔和肠道之间的胃中的微生物群知之甚少。在本研究中，使用 16S 核糖体 RNA (rRNA) 焦磷酸测序分析了肝硬化患者和对照组的胃粘膜微生物群。经组织学方法和焦磷酸测序方法证实，肝硬化患者的幽门螺杆菌 (H. pylori) 感染率显着降低。在幽门螺杆菌阴性受试者中，健康和肝硬化队列的胃细菌群落根据细菌组成分为四个集群：Cluster_1 和 Cluster_2（主要是肝硬化）、Cluster_3（主要是健康）和 Cluster_4（各占一半左右）。在这些不同的簇中观察到了组成和功能的差异。在属水平上，Cluster_1 和 Cluster_2 分别显示了奈瑟菌和链球菌的富集。在功能上，Cluster_2 的特征是缺乏遗传信息处理，以及与聚糖生物合成和代谢相关的模块。Cluster_2 中的患者比其他集群中的患者具有更严重的胃肠道症状和更高的内窥镜静脉曲张结扎术 (EVL) 治疗率。我们的研究结果表明 H. pylori 和非 H. pylori 的定植。幽门螺杆菌在肝硬化中受到影响。尽管幽门螺杆菌阴性胃粘膜微生物群表现出相当大的异质性，但可以观察到特定胃微生物群与临床特征之间的关联。