Study of the composition and functional effects of gut microbiota in children infected with norovirus

Norovirus is the leading cause of sporadic cases and outbreaks of viral gastroenteritis. The gut microbiota plays important roles in energy and immune homeostasis of the gastrointestinal tract. The aim of this study was to investigate the composition and functional effects of gut microbiota in children infected with norovirus.Stool samples were collected from 31 children infected with norovirus and 25 healthy children. The gut microbiota was analyzed by 16S rRNA gene sequencing, followed by composition analysis, difference analysis, random forest model prediction analysis, correlation network analysis, functional and phenotype prediction analysis.Gut microbiota in children infected with norovirus was characterized by decreased species richness and diversity. Veillonella was dominant gut microbiota specie in norovirus infection. Rothia/Clostridium_sensu_stricto_1 and Romboutsia was respectively the most significantly increased and decreased gut microbiota specie in norovirus infection. Interestingly, Romboutsia, Turicibacter, Agathobacter, Eubacterium_hallii, Dorea, Blautia_obeum, Peptostreptococcaceae, Terrisporobacter and Odoribacter_splanchnicus were potential diagnostic biomarkers for norovirus infection. There was a positive interaction between Faecalibacterium, Blautia, Subdoligranulum, Eubacterium_hallii_group, Fusicatenibacter, Agathobacter, Roseburia and Dorea. Functionally, secondary metabolites biosynthesis, transport and catabolism, selenocysteine lyase and peroxiredoxin were the most significantly increased functional compositions of gut microbiota in norovirus infection. While, sn-glycerol-1-phosphate dehydrogenase and fermentation were the most significantly decreased functional compositions in norovirus infection group. Phenotype analysis showed that Contains_Mobile_Elements (contributed by Enterococcus_faecium) and Anaerobic (contributed by Bifidobacterium) was respectively the highest and lowest level of phenotypes in gut microbiota of norovirus infection.

诺如病毒（Norovirus）是引发散发性病毒性胃肠炎病例与暴发的首要致病原。肠道菌群（gut microbiota）在胃肠道的能量稳态与免疫稳态中发挥关键作用。本研究旨在探究诺如病毒感染儿童的肠道菌群组成及其功能效应。研究人员收集了31例诺如病毒感染儿童与25例健康儿童的粪便样本，采用16S rRNA基因测序技术对肠道菌群进行分析，依次开展组成分析、差异分析、随机森林模型预测分析、关联网络分析以及功能与表型预测分析。诺如病毒感染儿童的肠道菌群以物种丰富度与多样性降低为典型特征。韦荣球菌属（Veillonella）是该感染状态下的优势肠道菌群物种。罗氏菌属/狭义梭菌簇1（Rothia/Clostridium_sensu_stricto_1）与罗姆布茨菌属（Romboutsia）分别是诺如病毒感染中丰度显著升高与降低最显著的肠道菌群物种。值得注意的是，罗姆布茨菌属、图里巴菌属（Turicibacter）、阿加特杆菌属（Agathobacter）、霍氏真杆菌（Eubacterium_hallii）、多雷菌属（Dorea）、obeum型布劳特氏菌（Blautia_obeum）、消化链球菌科（Peptostreptococcaceae）、土孢杆菌属（Terrisporobacter）以及内脏气味杆菌（Odoribacter_splanchnicus）均可作为诺如病毒感染的潜在诊断生物标志物。粪杆菌属（Faecalibacterium）、布劳特氏菌属（Blautia）、亚硫酸盐还原杆菌属（Subdoligranulum）、霍氏真杆菌群（Eubacterium_hallii_group）、梭形杆菌属（Fusicatenibacter）、阿加特杆菌属、罗斯伯里菌属（Roseburia）与多雷菌属之间存在正向相互作用。在功能层面，次生代谢产物的生物合成、转运与分解代谢，硒半胱氨酸裂解酶以及过氧化物氧还蛋白是诺如病毒感染组肠道菌群中丰度显著升高的核心功能组分；而sn-甘油-1-磷酸脱氢酶（sn-glycerol-1-phosphate dehydrogenase）与发酵作用则是该感染组中丰度显著降低的核心功能组分。表型分析结果显示，携带移动元件表型（Contains_Mobile_Elements，由粪肠球菌Enterococcus_faecium介导）与厌氧表型（Anaerobic，由双歧杆菌属Bifidobacterium介导）分别为诺如病毒感染儿童肠道菌群中表型水平最高与最低的表型。