沙门菌感染后0至5岁婴幼儿肠道微生物群落

The intestinal microflora of infants aged 0-5 years after Salmonella infection

目的比较0至5岁沙门菌感染和健康婴幼儿的肠道菌群分布特点,研究沙门菌感染导致的婴幼儿肠道菌群微生态失调情况,为腹泻病的发病机制和防治提供微生态学理论依据。方法采集9例沙门菌腹泻婴幼儿(腹泻组)与11例健康婴幼儿(健康组)的粪便样本,通过16S扩增子测序分析肠道菌群的多样性,并比较2组样本的群落结构差异,研究沙门菌对婴幼儿肠道微生态的影响。结果腹泻组婴幼儿粪便样本的Shannon指数显著低于健康组(2.2611 vs 4.0699,t=-4.8920,P=0.0010),Simpson指数也显著低于健康组(0.5629 vs 0.8733,t=-3.7210,P=0.0060)。腹泻组婴幼儿粪便样本的变形菌门(Proteobacteria)丰富度显著高于健康组(t=0.0357,P=0.0092),而厚壁菌门(Firmicutes)和拟杆菌门(Bacteroidetes)丰富度显著低于健康组(t=0.1154,P=0.0446;t=0.0357,P=0.0070)。腹泻组婴幼儿粪便样本的人类疾病(human diseases)功能的基因丰富度显著高于健康组(t=0.1315,P=0.0260),而新陈代谢(metabolism)功能和生物体系统(organismal systems)功能的基因丰富度显著低于健康组(t=0.0991,P=0.0098;t=0.1429,P=0.0463)。结论沙门菌降低了婴幼儿肠道菌群的多样性,改变了肠道菌群的群落结构,并调控机体功能的基因表达。细菌性腹泻与病原菌侵袭、肠道微生态失衡及机体功能密切相关。

Objective To compare the distribution characteristics between intestinal flora in infants with Salmonella diarrhea and healthy infants aged 0-5 years,analyze the impact of Salmonella on intestinal microecology of infants,and provide a microecological theoretical basis for the pathogenesis,prevention and treatment of diarrhea.Methods Fecal samples of 9 infants with Salmonella diarrhea(diarrhea group)and 11 healthy infants(control group)were collected.The differences in intestinal flora diversity and community structure between the two groups were analyzed through 16 S amplicon sequencing.Results Compared with the control group,the Shannon index(2.2611 vs 4.0699,t=-4.8920,P=0.0010)and Simpson index(0.5629 vs 0.8733,t=-3.7210,P=0.0060)in the diarrhea group were significantly lower;The abundance of Proteobacteria was higher(t=0.0357,P=0.0092),while those of Firmicutes(t=0.1154,P=0.0446)and Bacteroidetes were lower(t=0.0357,P=0.0070);The abundance of human disease function gene was higher(t=0.1315,P=0.0260),and that of metabolic function gene(t=0.0991,P=0.0098)and organismal system function gene were lower(t=0.1429,P=0.0463).Conclusion Salmonella has reduced the diversity,changed the community structure of intestinal flora,and regulated the expression of body function genes.Bacterial diarrhea is closely related to pathogen invasion,intestinal microecological imbalance and body function.