Warner Barbara B, Deych Elena, Zhou Yanjiao, Hall-Moore Carla, Weinstock George M, Sodergren Erica, Shaikh Nurmohammad, Hoffmann Julie A, Linneman Laura A, Hamvas Aaron, Khanna Geetika, Rouggly-Nickless Lucina C, Ndao I Malick, Shands Berkley A, Escobedo Marilyn, Sullivan Janice E, Radmacher Paula G, Shannon William D, Tarr Phillip I
Department of Pediatrics, Washington University in St Louis School of Medicine, St Louis, MO, USA.
Department of Medicine, Washington University in St Louis School of Medicine, St Louis, MO, USA.
Lancet. 2016 May 7;387(10031):1928-36. doi: 10.1016/S0140-6736(16)00081-7. Epub 2016 Mar 9.
Gut bacteria might predispose to or protect from necrotising enterocolitis, a severe illness linked to prematurity. In this observational prospective study we aimed to assess whether one or more bacterial taxa in the gut differ between infants who subsequently develop necrotising enterocolitis (cases) and those who do not (controls).
We enrolled very low birthweight (1500 g and lower) infants in the primary cohort (St Louis Children's Hospital) between July 7, 2009, and Sept 16, 2013, and in the secondary cohorts (Kosair Children's Hospital and Children's Hospital at Oklahoma University) between Sept 12, 2011 and May 25, 2013. We prospectively collected and then froze stool samples for all infants. Cases were defined as infants whose clinical courses were consistent with necrotising enterocolitis and whose radiographs fulfilled criteria for Bell's stage 2 or 3 necrotising enterocolitis. Control infants (one to four per case; not fixed ratios) with similar gestational ages, birthweight, and birth dates were selected from the population after cases were identified. Using primers specific for bacterial 16S rRNA genes, we amplified and then pyrosequenced faecal DNA from stool samples. With use of Dirichlet multinomial analysis and mixed models to account for repeated measures, we identified host factors, including development of necrotising enterocolitis, associated with gut bacterial populations.
We studied 2492 stool samples from 122 infants in the primary cohort, of whom 28 developed necrotising enterocolitis; 94 infants were used as controls. The microbial community structure in case stools differed significantly from those in control stools. These differences emerged only after the first month of age. In mixed models, the time-by-necrotising-enterocolitis interaction was positively associated with Gammaproteobacteria (p=0·0010) and negatively associated with strictly anaerobic bacteria, especially Negativicutes (p=0·0019). We studied 1094 stool samples from 44 infants in the secondary cohorts. 18 infants developed necrotising enterocolitis (cases) and 26 were controls. After combining data from all cohorts (166 infants, 3586 stools, 46 cases of necrotising enterocolitis), there were increased proportions of Gammaproteobacteria (p=0·0011) and lower proportions of both Negativicutes (p=0·0013) and the combined Clostridia-Negativicutes class (p=0·0051) in infants who went on to develop necrotising enterocolitis compared with controls. These associations were strongest in both the primary cohort and the overall cohort for infants born at less than 27 weeks' gestation.
A relative abundance of Gammaproteobacteria (ie, Gram-negative facultative bacilli) and relative paucity of strict anaerobic bacteria (especially Negativicutes) precede necrotising enterocolitis in very low birthweight infants. These data offer candidate targets for interventions to prevent necrotising enterocolitis, at least among infants born at less than 27 weeks' gestation.
National Institutes of Health (NIH), Foundation for the NIH, the Children's Discovery Institute.
肠道细菌可能易引发坏死性小肠结肠炎，也可能起到预防作用，坏死性小肠结肠炎是一种与早产相关的严重疾病。在这项前瞻性观察研究中，我们旨在评估随后发生坏死性小肠结肠炎的婴儿（病例组）和未发生该病的婴儿（对照组）肠道中一种或多种细菌类群是否存在差异。
我们在2009年7月7日至2013年9月16日期间纳入了主要队列（圣路易斯儿童医院）中出生体重极低（1500克及以下）的婴儿，并在2011年9月12日至2013年5月25日期间纳入了次要队列（科赛尔儿童医院和俄克拉荷马大学儿童医院）中的婴儿。我们前瞻性地收集了所有婴儿的粪便样本，然后将其冷冻。病例定义为临床病程符合坏死性小肠结肠炎且X线片符合贝尔2期或3期坏死性小肠结肠炎标准的婴儿。在确定病例后，从总体人群中选择胎龄、出生体重和出生日期相似的对照婴儿（每个病例1至4名；非固定比例）。使用针对细菌16S rRNA基因的引物，我们对粪便样本中的粪便DNA进行扩增，然后进行焦磷酸测序。通过狄利克雷多项分析和混合模型来处理重复测量数据，我们确定了与肠道细菌群体相关的宿主因素，包括坏死性小肠结肠炎的发生情况。
我们研究了主要队列中122名婴儿的2492份粪便样本，其中28名婴儿发生了坏死性小肠结肠炎；94名婴儿作为对照。病例组粪便中的微生物群落结构与对照组粪便中的显著不同。这些差异仅在出生后第一个月后出现。在混合模型中，坏死性小肠结肠炎与时间的交互作用与γ-变形菌纲呈正相关（p = 0.0010），与严格厌氧菌尤其是梭杆菌纲呈负相关（p = 0.0019）。我们研究了次要队列中44名婴儿的1094份粪便样本。18名婴儿发生了坏死性小肠结肠炎（病例组），26名是对照组。将所有队列的数据合并（166名婴儿，3586份粪便，46例坏死性小肠结肠炎）后，与对照组相比，发生坏死性小肠结肠炎的婴儿中γ-变形菌纲的比例增加（p = 0.0011），梭杆菌纲和梭杆菌纲与梭杆菌纲合并类别的比例均降低（p = 0.0013和p = 0.0051）。这些关联在主要队列和总体队列中对于胎龄小于27周出生的婴儿最为明显。
在出生体重极低的婴儿中，γ-变形菌纲（即革兰氏阴性兼性杆菌）相对丰度较高，严格厌氧菌（尤其是梭杆菌纲）相对较少，这在坏死性小肠结肠炎之前出现。这些数据为预防坏死性小肠结肠炎的干预措施提供了候选靶点，至少对于胎龄小于27周出生的婴儿是如此。
美国国立卫生研究院（NIH）、NIH基金会、儿童发现研究所。
