菌群与新生儿疾病

Microbiota and neonatal diseases

菌群与人类健康和疾病密切相关，新生儿菌群受许多因素的影响。本文主要概述了本课题组在菌群与新生儿疾病关系方面的初步探索：新生儿呼吸机相关性肺炎致病菌以群体形式即生物膜形式致病；新生儿口咽部常寄居的链球菌通过自身诱导因子-2起辅助致病菌作用；新生儿坏死性小肠结肠炎肠壁及粪便中变形菌门相对丰度升高而厚壁菌门相对丰度降低，与短链脂肪酸合成不足进而调节性T细胞分化不足有关；新生儿早发败血症时经验性使用抗生素1周可明显降低肠道菌群多样性，易于损伤肠道自然防御屏障；剖宫产儿肠道拟杆菌属含量明显不足，健康平衡的肠道菌群迟迟不能建立。

Microbiota is closely related to human health and diseases, while it is affected by many factors in neonates. We summarized our primary research on gut microbiota and the associated neonatal diseases. Pathogenic bacteria may cause neonatal ventilator associated pneumonia （VAP） by the form of biofilms. Straptococcus spp., commonly seen in neonatal oropharynx, facilitate pathogenic process through secretion of autoinducer-2 （AI-2）. Significantly increased Proteobacteria and decreased Firmicutes in gut tissues and feaces in neonates with necrotizing enterocolitis （NEC） are associated with deficiency of short chain fatty acids （SCFAs） and impaired differentiation of regulatory T cells （Treg）. One-week empirical antibiotic therapy for neonatal early-onset septicemia may remarkably affect the diversity of gut microbiota in early life, which is likely to damage the intestinal mucosal barrier. Obvious deficiency of intestinal Bacteroides in newborns born abdominally will delay the establishment of a healthy and balanced intestinal flora.