Table_1_Necrotizing Enterocolitis and Intestinal Microbiota: The Timing of Disease and Combined Effects of Multiple Species.XLS

Background: The purpose of this study was to investigate the relationship between intestinal microbiota and necrotizing enterocolitis (NEC).Methods: 16S rRNA gene sequencing was used to compare the microbial composition of feces. The first sample was collected within 48 h after birth, then once per week until the NEC diagnosis, and finally 1–2 weeks after treatment or 28 days after birth.Results: The alpha diversity of the microbiota in the NEC group was higher than that in the control group. Beta diversity analysis showed that the control group had a higher similarity at the onset of NEC, while the NEC group was distributed in subgroups. Linear discriminant analysis effect size and taxonomic composition analyses indicated that the abundance of Bacteroides and Actinobacteria in NEC infants at birth was much higher than that in the control group, and this trend continued until NEC occurred. At this time, Rhizobiales, Dysgonomonas, Ochrobactrum, Ralstonia, Pelomonas, Acinetobacter, etc., were also more abundant in NEC infants. The upregulated different metabolic pathways in the NEC group were mainly concentrated on degradation/utilization/assimilation, biosynthesis, and generation of precursor metabolites and energy.Conclusions:1. The microbial community differs according to the time of NEC diagnosis (bounded by 20 days).2. No single microorganism is related to NEC, and the combined effect of multiple species is of great significance in the occurrence of NEC. Premature infants are easily affected by bacteria living in the environment, and compared with ordinary premature infants, NEC infants have a higher abundance of waterborne bacteria. Therefore, attention should be paid to the contamination of water sources and various ventilator pipelines for premature infants hospitalized in the neonatal intensive care unit.3. An in-depth study of the mode of microbial colonization in premature infants combined with the different functions of various metabolic pathways involved in different microorganisms may be able to identify the cause of NEC.

背景：本研究旨在探讨肠道菌群与坏死性小肠结肠炎（NEC）之间的关系。方法：采用16S rRNA基因测序技术比较粪便的微生物组成。首次样本于出生后48小时内采集，之后每周采集一次，直至NEC诊断，最后在治疗后的1-2周或出生后28天进行采集。结果：NEC组的微生物群α多样性高于对照组。β多样性分析显示，对照组在NEC发病初期具有更高的相似性，而NEC组则分布在多个亚组中。线性判别分析效应大小和分类组成分析表明，NEC新生儿出生时拟杆菌和放线菌的丰度远高于对照组，且这一趋势持续至NEC发生。此时，根瘤菌目、变形杆菌属、黄杆菌属、拉尔斯顿菌属、多胞菌属、不动杆菌属等在NEC新生儿中也更为丰富。NEC组上调的不同代谢途径主要集中在降解/利用/同化、生物合成以及前体代谢物和能量的生成。结论：1. 微生物群落随NEC诊断时间（限于20天内）而有所不同。2. 没有任何单一微生物与NEC相关，多种物种的联合作用在NEC的发生中具有重大意义。早产儿易受环境细菌的影响，与普通早产儿相比，NEC新生儿的水生细菌丰度更高。因此，应关注新生儿重症监护病房中早产儿的供水源和各种呼吸机管道的污染。3. 深入研究早产儿微生物定植模式以及不同微生物所涉及的不同代谢途径的功能差异，可能有助于识别NEC的成因。