目的 通过比较健康人群、幽门螺杆菌（HP）感染患者、非酒精性脂肪性肝病（NAFLD）患者以及HP感染合并NAFLD患者的肠道菌群变化特点，探讨NAFLD合并HP患者肠道菌群特征及作用机制。 方法 选取河南科技大学第二附属医院2023年3月1日—2024年4月30日收治的NAFLD患者19例（NAFLD组）、HP感染患者19例（HP组）、NAFLD合并HP感染患者19例（NAFLD合并HP组），另选取健康体检者20例作为对照。留取粪便标本，提取标本的总DNA，进行PCR扩增，通过16S rDNA测序，分析4组人群肠道菌群特征及差异性。计量资料多组间比较采用方差分析，计数资料多组间比较采用χ²检验。菌群物种之间差异性分析采用Mann-Whitney U检验或Kruskal-Wallis H检验。 结果 NAFLD合并HP组与其他3组相比，肠道菌群丰富度有降低趋势。NAFLD合并HP组与NAFLD组相比、NAFLD组与健康对照组相比，菌群分布具有明显差异性（P值均<0.05）。在门水平上，NAFLD合并HP组占前3位的物种分别为厚壁菌门（59.94%）、变形菌门（17.00%）、放线菌门（14.75%），相比于其他3组，变形菌门占比增加，放线菌门占比减少。在属水平上，NAFLD合并HP组的前5位优势菌属分别为Bifidobacterium、Streptococcus、Escherichia-Shigella、Agathobacter、Ruminococcus gnavus_group。与NAFLD组相比，NAFLD合并HP组Streptococcus、Veillonella、Rothia的丰度升高，Dialister、Ruminococcus toraues_group的丰度降低。与HP组相比，NAFLD合并HP组Collinsella、Subdoligranulum、Catenibacterium、Porphyromonas的丰度降低，而Citrobacter、Olsenella的丰度升高，物种差异性分析均具有统计学意义（P值均<0.05）。 结论 NAFLD合并HP感染患者的肠道菌群发生相应变化，这些菌群可能是HP感染促进NAFLD发生、发展的肠道微生态因素。

Objective To investigate the features and mechanism of action of intestinal flora in patients with nonalcoholic fatty liver disease （NAFLD） and Helicobacter pylori （HP） infection by comparing the changes in intestinal flora between the healthy population，the patients with HP infection，the patients with NAFLD，and the patients with NAFLD and HP infection. Methods This study was conducted among the 19 patients with NAFLD （NAFLD group），19 patients with HP infection （HP group），and 19 patients with NAFLD and HP infection （NAFLD+HP group） who were admitted to The Second Affiliated Hospital of Henan University of Science and Technology from March 1，2023 to April 30，2024，and 20 individuals undergoing physical examination were enrolled as control group. Fecal samples were collected，total DNA was extracted for PCR amplification，and 16S rDNA sequencing was performed to compare the features of intestinal flora between the four groups. An analysis of variance was used for comparison of continuous data between multiple groups，and the chi-square test was used for comparison of categorical data between multiple groups. The Mann-Whitney U test or the Kruskal-Wallis H test was used for comparison of the species in intestinal flora. Results The NAFLD+HP group showed a tendency of reduction in flora abundance compared with the other three groups. There was a significant difference in flora distribution between the NAFLD+HP group and the NAFLD group and between the NAFLD group and the control group （P<0.05）. At the phylum level，the top three species in the NAFLD+HP group were Firmicutes （59.94%），Proteobacteria （17.00%），and Actinobacteria （14.75%），with an increase in the proportion of Proteobacteria and a reduction in the proportion of Actinobacteria compared with the other three groups. At the genus level，the top five dominant bacteria in the NAFLD+HP group were Bifidobacterium，Streptococcus，Escherichia-Shigella，Agathobacter，and Ruminococcus gnavus_group. Compared with the NAFLD group，the NAFLD+HP group had increases in the abundance of Streptococcus，Veillonella，and Rothia and reductions in the abundance of Dialister and Ruminococcus toraues_group. Compared with the HP group，the NAFLD+HP group had reductions in the abundance of Collinsella，Subdoligranulum，Catenibacterium，and Porphyromonas and increases in the abundance of Citrobacter and Olsenella （all P<0.05）. Conclusion Patients with NAFLD and HP infection have changed in intestinal flora. These flora may be the intestinal microecological factors for HP infection in promoting the development and progression of NAFLD.