Respiratory syncytial virus (RSV) is the number one cause of lower respiratory tract infections in infants. There are still no vaccines or specific antiviral therapies against RSV, mainly due to the inadequate understanding of RSV pathogenesis. Recent data suggest a role for gut microbiota community structure in determining RSV disease severity. Our objective was to determine the gut microbial profile associated with severe RSV patients, which could be used to help identify at-risk patients and develop therapeutically protective microbial assemblages that may stimulate immuno-protection. We enrolled 95 infants from Le Bonheur during the 2014 to 2016 RSV season. Of these, 37 were well-babies and 58 were hospitalized with RSV. Of the RSV infected babies, 53 remained in the pediatric ward (moderate) and 5 were moved to the pediatric intensive care unit at a later date (severe). Stool samples were collected within 72 h of admission; and the composition of gut microbiota was evaluated via 16S sequencing of fecal DNA. There was a significant enrichment in S24_7, Clostridiales, Odoribacteraceae, Lactobacillaceae, and Actinomyces in RSV (moderate and severe) vs. controls. Patients with severe RSV disease had slightly lower alpha diversity (richness and evenness of the bacterial community) of the gut microbiota compared to patients with moderate RSV and healthy controls. Beta diversity (overall microbial composition) was significantly different between all RSV patients (moderate and severe) compared to controls and had significant microbial composition separating all three groups (control, moderate RSV, and severe RSV). Collectively, these data demonstrate that a unique gut microbial profile is associated with RSV disease and with severe RSV disease with admission to the pediatric intensive care unit. More mechanistic experiments are needed to determine whether the differences observed in gut microbiota are the cause or consequences of severe RSV disease.

中文翻译：

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婴儿肠道菌群的改变与呼吸道合胞病毒疾病的严重程度有关。

呼吸道合胞病毒（RSV）是婴儿下呼吸道感染的第一大原因。仍然没有针对RSV的疫苗或特异性抗病毒治疗，主要是由于对RSV发病机理的了解不足。最近的数据表明肠道微生物群落结构在确定RSV疾病严重程度中的作用。我们的目标是确定与严重RSV患者相关的肠道微生物谱，可用于帮助识别高危患者并开发可激发免疫保护作用的治疗性微生物组合。在2014年至2016年的RSV季节，我们招募了95名Le Bonheur的婴儿。其中37例是好孩子，58例因RSV住院。在受RSV感染的婴儿中，53例仍留在儿科病房（中度），5例后来转移到儿科重症监护室（严重）。入院72小时内收集粪便样品；通过粪便DNA的16S测序评估肠道菌群的组成。与对照相比，RSV（中度和重度）中的S24_7，梭菌，奥德杆菌科，乳杆菌科和放线菌显着富集。与中度RSV和健康对照组相比，严重RSV疾病患者的肠道菌群的α多样性（细菌群落的丰富度和均匀度）略低。与对照组相比，所有RSV患者（中度和重度）的Beta多样性（总体微生物组成）均存在显着差异，并且将所有三组（对照组，中度RSV，和严重的RSV）。总体而言，这些数据表明，进入小儿重症监护室时，独特的肠道微生物特征与RSV疾病和严重的RSV疾病有关。需要更多的机械实验来确定肠道菌群中观察到的差异是否是严重RSV疾病的原因或后果。