鱼腥草共附生细菌组成及其对小鼠肠道菌群的影响

Symbiotic Bacteria Composition of Houttuynia cordata and Effect of Houttuynia cordata on Gut Microbiota of Mice

【目的】了解鱼腥草共附生细菌的组成,以及小鼠食用新鲜鱼腥草对其肠道菌群的影响,为探明鱼腥草的药用价值及其相关机制提供参考。【方法】采用高通量测序技术对鱼腥草进行共附生细菌16S rRNA基因测序;试验组和对照组小鼠分别用鱼腥草(试验组)和生理盐水(对照组)连续灌胃20 d,在灌胃前和停止灌胃7 d后分别采集试验组与对照组小鼠粪便进行细菌16S rRNA基因高通量测序分析。【结果】鱼腥草共附生细菌的优势菌门为变形菌门(Proteobacteria)、拟杆菌门(Bacteroidetes)和放线菌门(Actinobacteria),其相对丰度分别为85.45%、10.52%和1.63%。试验组中,灌胃后与灌胃前相比,小鼠粪便菌群中变形菌门(Proteobacteria)、拟杆菌门(Bacteroidetes)和放线菌门(Actinobacteria)的相对丰度并未增加;菌群多样性的Shannon指数显著增高。灌胃后,试验组较对照组小鼠粪便菌群结构有显著差异,在门分类水平上,试验组厚壁菌门/拟杆菌门(Firmicutes/Bacteroidetes)显著高于对照组。【结论】新鲜鱼腥草能增加小鼠肠道菌群的多样性以及调节小鼠肠道菌群结构;鱼腥草对小鼠肠道菌群的调节作用主要是通过调节厚壁菌门/拟杆菌门(Firmicutes/Bacteroidetes)的比值实现。

【Objective】The symbiotic bacteria composition of Houttuynia cordata was known and the effect of fresh H.cordata on gut microbiota of mice was studied to provide a reference for understanding the medicinal value and related mechanism of H.cordata.【Method】The 16S rRNA gene of the symbiotic bacteria of H.cordata was sequenced by the high-throughput sequencing technique.Mice in the test and control groups were respectively given a gavage of fresh H.cordata(test group)and normal saline(CK)for 20 d continuously and then the 16S rRNA gene of the bacteria in the feces of test and control groups collected before gavage and on 7 d after stopping gavage was sequenced by the high-throughput sequencing technique.【Result】The dominant bacteria phyla of H.cordata symbiotic bacteria were Proteobacteria,Bacteroidetes and Actinobacteria.The relative abundance of Proteobacteria,Bacteroidetes and Actinobacteria was 85.45%,10.52%and 1.63%respectively.There was no increase of the relative abundance of Proteobacteria,Bacteroidetes and Actinobacteria in the fecal microbiota before and after gavage in the test group but Shannon index of bacteria diversity increased significantly.There was a significant difference in the fecal bacteria community structure after gavage between test and control groups.The Firmicutes/Bacteroidetes of the test group was significantly higher than the control group at the phylum level.【Conclusion】The fresh H.cordata could increase the diversity of gut microbiota and adjust the structure of gut microbiota in mice.The regulating effect of H.cordata on the gut microbiota was implemented by adjusting the Firmicutes/Bacteroidetes ratio.