CHARACTERIZATION OF THE ROLE OF THE SMALL INTESTINAL MICROBIOTA IN THE PATHOGENESIS OF ENVIRONMENTAL ENTERIC DYSFUNCTION IN UNDERNOURISHED CHILDREN AND MOTHERS

小肠微生物群在营养不良儿童和母亲环境性肠功能障碍发病机制中的作用特征

• 批准号: 10554100
• 负责人: Clara Kao
• 金额: $ 5.16万
• 依托单位: WASHINGTON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-02-01 至 2025-01-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10554100
• 关键词: 5 year old; Adult; Affect; Age; Area; Bacteria; Bangladesh; Bangladeshi; Biological; Biopsy; Body mass index; Cells; Child; Childhood; Chronic; Chronology; Clinical; Collection; Communities; Consumption; DNA; Development; Diet; Dietary Intervention; Disease; Duodenum; Enteral; Epithelium; Esophagogastroduodenoscopy; Etiology; Experimental Models; Exposure to; Family; Female of child bearing age; Functional disorder; Gene Expression Profiling; Generations; Germ-Free; Gnotobiotic; Goals; Growth; Histologic; Histopathology; Immune; Immune response; Immunoassay; Impairment; Incidence; Inflammatory; Inflammatory Infiltrate; Inflammatory Response; Intervention; Intestinal Content; Intestines; Lamina Propria; Length; Locales; Malnutrition; Measurement; Modeling; Mothers; Mucous Membrane; Mus; Nature; Nuclear RNA; Outcome; Output; Participant; Pathogenesis; Pathology; Phenotype; Plasma; Plasma Proteins; Play; Pre-Clinical Model; Preclinical Testing; Prevention; Protein Deficiency; Proteins; Proteome; Research Personnel; Ribosomal DNA; Risk; Role; Sampling; Sanitation; Shotgun Sequencing; Slum; Small Intestines; Structure; Surface; Technology; Testing; Therapeutic; Time; Tissues; Villus; Woman; World Health Organization; aptamer; aspirate; bacterial community; candidate identification; cohort; community transmission; experimental study; fecal microbiota; follow-up; global health; gut microbiota; improved; insight; intergenerational; long-term sequelae; member; microbial; microbial community; microbiota; microorganism; mouse model; multiple omics; neurodevelopment; novel; offspring; pre-clinical; prevent; pup; recruit; reproductive; technology platform; therapeutic target; therapy development; transcriptome sequencing; transmission process

ABSTRACT Worldwide, one in five children under five years of age manifests undernutrition as impaired linear growth, or stunting. Stunting, defined as having a length-for-age z-score (LAZ) < -2, is associated with poor developmental outcomes, including impaired neurodevelopment and immune responses. Furthermore, stunting and its long- term sequelae persist across generations, contributing to an intergenerational cycle of undernutrition. Existing nutritional interventions fail to substantially improve stunting, highlighting the need to (i) better understand other factors contributing to stunting and (ii) focus clinical efforts towards treating maternal undernutrition in order to break the cycle of intergenerational undernutrition. In recent years, a subclinical disorder called environmental enteric dysfunction (EED) has been suggested to contribute to 45% of childhood stunting globally. EED is an inflammatory enteropathy localized to the small intestine; it is characterized histologically by loss of villi and absorptive surface area, epithelial barrier dysfunction, and an immunoinflammatory infiltrate in the lamina propria. While the pathogenesis of EED is poorly understood, researchers have postulated a role for enteric microorganisms. However, the small intestinal microbiota remains largely understudied, in part due to challenges in gaining access to samples. Moreover, few experimental models of EED exist, none of which account for the intergenerational nature of undernutrition. I hypothesize that perturbations in the small intestinal microbiota play a causal role in the pathogenesis of EED and consequently undernutrition that persists across generations. To test this hypothesis, the first aim of this proposal will use gnotobiotic mice to characterize the transmissibility of enteropathy and growth faltering by the small intestinal microbiota of Bangladeshi children and women with evidence of EED based on histopathology of their duodenal biopsies. Collections of sequenced bacterial strains, cultured from duodenal aspirates obtained from these stunted children and malnourished women (BMI<18.5 kg/m2) will be introduced into young germ-free mice. I will characterize host pathology by performing immune cell profiling, protein immunoassays, and transcriptional profiling (whole tissue and single cell). Microbial community structure will be quantified by shotgun sequencing of community DNA, and expressed community functions by microbial RNA- Seq. In parallel, I will establish a novel model of intergenerational undernutrition by introducing these microbia l communities into germ-free dams and assessing the pathology in dams and their pups. The second aim will test prevention and/or treatment of enteropathy in the gnotobiotic mouse models through introduction of duodenal bacterial communities derived from healthy Bangladeshi women (with normal BMI). Prevention or amelioration of enteropathy by duodenal bacterial communities from healthy women will allow further identification of taxa that may promote or reduce pathology. These experiments will provide a pre-clinical test of the role of the small intestinal microbiota in the pathogenesis of EED and could result in identification of therapeutic targets for EED.

摘要 在全世界，五岁以下儿童中有五分之一表现为营养不良，表现为线性生长受损， 发育不良发育迟缓，定义为年龄别身高z评分（LAZ）<-2，与发育不良有关。 结果，包括受损的神经发育和免疫反应。此外，发育迟缓及其长期- 长期后遗症持续几代人，造成营养不良的代际循环。现有 营养干预措施未能实质性改善发育迟缓，突出表明需要（i）更好地了解其他 （二）将临床工作重点放在治疗产妇营养不良上， 打破营养不良的代际循环。近年来，一种被称为环境性疾病的亚临床疾病 肠功能障碍（EED）被认为是全球45%的儿童发育迟缓的原因。EED是一种 局限于小肠的炎性肠病;其组织学特征是绒毛的丧失， 吸收表面积、上皮屏障功能障碍和椎板中的免疫炎症浸润 propria。虽然EED的发病机制知之甚少，但研究人员已经假设肠上皮细胞在EED中的作用。 微生物的然而，小肠微生物群在很大程度上仍然没有得到充分研究，部分原因是挑战 获取样本此外，存在很少的EED实验模型，其中没有一个能解释EED的原因。 营养不良的代际性质。 我推测，小肠微生物群的扰动在发病机制中起着因果作用 EED和因此持续几代人的营养不良。为了验证这一假设，第一个 本提案的目的是使用无菌小鼠来表征肠病和生长的传播性 孟加拉国儿童和妇女的小肠微生物群步履蹒跚，EED的证据基于 十二指肠活检的组织病理学。从十二指肠培养的测序细菌菌株的集合 将从这些发育迟缓的儿童和营养不良的妇女（BMI<18.5 kg/m2）中抽取 变成了无菌的小白鼠我将通过免疫细胞分析，蛋白质分析， 免疫测定和转录谱分析（全组织和单细胞）。微生物群落结构将是 通过群体DNA的鸟枪测序进行定量，并通过微生物RNA表达群体功能- Seq.与此同时，我将通过介绍这些微生物， 社区的无菌母鼠，并评估母鼠及其幼崽的病理学。第二个目标将测试 通过引入十二指肠给药预防和/或治疗非细菌性小鼠模型中的肠病 来自健康孟加拉国妇女（BMI正常）的细菌群落。预防或改善 健康女性十二指肠细菌群落对肠病的影响将有助于进一步鉴定 可以促进或减少病理学。这些实验将提供一个临床前测试的作用小 肠道微生物群在EED发病机制中的作用，并可能导致EED治疗靶点的鉴定。