Study Gut Dysbiosis in Anemic Preterm Infants Using a Multiomics Approach

项目总结/摘要 该提案详细介绍了一项纵向前瞻性研究，以确定粪便微生物群和宿主的变化 早产儿出现严重贫血时，具体目标是确定红细胞压积 (Hct)与肠道生态失调相关的阈值以及贫血发展如何影响微生物群和宿主 使用多组学方法进行交互。这项转化研究将提供临床相关信息， 可能会改变贫血的临床管理，这是早产儿的常见疾病。 所有早产儿都有贫血的风险，这种风险随着出生体重和胎龄的降低而增加。 超过50%的极低出生体重（VLBW，<1500 g）婴儿需要输血来治疗贫血 但缺乏研究证据来指导临床医生何时输血以实现最佳健康结果。 早产儿贫血与炎症、肠道生态失调和肠道损伤有关， 发病率和死亡率，如坏死性小肠结肠炎。贫血的严重程度也决定了 结果。最近，贫血与肠道生态失调有关，其特征在于， 早产儿中革兰氏阴性变形菌和较低的细菌多样性，这种关系值得 进一步调查我们的初步数据表明，变形菌丰度与总细菌 贫血组与对照组相比，毒力因子的丰度明显增高。 对脆弱的早产儿进行侵入性手术或生物标本采集是一项挑战， 调查或粪便含有丰富的肠道细菌、细菌和人体代谢产物的信息 这可以为肠道微生物群的变化以及微生物群之间的相互作用提供重要的见解， 和主机。一个多组学的方法，使用宏基因组学，元蛋白质组学和代谢组学数据一起将 揭示肠道炎症和损伤与严重贫血相关的潜在机制。实现我们 我们将执行以下目标：1）进行一项纵向研究的VLBW婴儿谁发展严重 贫血（Hct ≥ 25%），以确定微生物组模式和贫血相关生态失调的预测因子，以及2） 比较粪便多组学特征（宏基因组学、元蛋白组学、代谢组学和生物标志物）， 贫血婴儿（Hct> 25%）和非贫血婴儿（Hct >30%），以确定肠道微生物群的变化 组成和功能，以及宿主反应。我们利用一个大型队列的370+ VLBW婴儿从一个正在进行的 入组，以提供本提案所需的样本量。16 S rRNA V4区域将用于计算 细菌微生物组组成和比较生物统计学分析以及 将针对目标1进行临床和微生物组研究。粪便宏基因组学、元蛋白组学、代谢组学和 生物标志物将用于lasso惩罚混合效应逻辑回归和网络分析， 贫血组和对照组之间的相互作用和比较。

Project Summary/Abstract This proposal details a longitudinal prospective study to define the changes in stool microbiota and host responses as severe anemia develops in preterm infants. The specific goals are to determine the hematocrit (Hct) threshold associated with gut dysbiosis and how anemia development influences the microbiota and host interactions using a multiomics approach. This translational study will provide clinical-relevant information that can potentially change the clinical management of anemia, a common condition in preterm infants. All preterm infants are at risk for anemia and this risk increases with lower birth weight and gestational age. Greater than 50% of very low birth weight (VLBW, <1500 g) infants require a blood transfusion to treat anemia but there is a lack of research evidence to guide clinicians when to transfuse to achieve optimal health outcomes. Anemia in preterm infants has been associated with inflammation, gut dysbiosis, and gut injury with high morbidity and mortality such as necrotizing enterocolitis. The severity of anemia also determined the severity of the outcomes. Recently, anemia has been linked to intestinal dysbiosis characterized by increased proportion of gram-negative Proteobacteria and lower bacterial diversity in preterm infants and this relationship warrants further investigation. Our preliminary data showed that Proteobacterial abundance correlated with total bacterial virulence factors and higher virulence factor abundance was found in anemic group compared to control group. It is a challenge to subject vulnerable preterm infants to invasive procedures or biospecimen collection for research purposes. Stool holds abundance information on gut bacteria, bacterial and human metabolic products that can provide critical insights into the changes in the gut microbiota and the interaction between microbiota and host. A multiomics approach using metagenomics, metaproteomics, and metabolomics data altogether will reveal the potential mechanisms of gut inflammation and injury associated with severe anemia. To achieve our goals, we will perform the following aims: 1) conducting a longitudinal study of VLBW infants who develop severe anemia (had Hct ൑ 25%) to define the microbiome pattern and predictors of anemia associated dysbiosis and 2) compare stool multiomics profiles (metagenomics, metaproteomics, metabolomics, and biomarkers) between anemic (had Hct ൑ 25%) and non-anemic infants (Hct >30%) to identify the changes in gut microbiota composition and function, and host response. We leverage a large cohort of 370+ VLBW infants from an ongoing enrollment to provide the required sample size for this proposal. 16S rRNA V4 region will be used to compute bacterial microbiome composition and comparative biostatistical analyses and survival analysis models of clinical, and microbiome will be performed for aim 1. Stool metagenomics, metaproteomics, metabolomics, and biomarkers will be used in lasso penalized mixed-effects logistic regression and network analysis to identify the interactions and compare between anemic and control groups for aim 2.