Shifts in the Gastrointestinal Metabolome During Clostridium difficile Infection

艰难梭菌感染期间胃肠道代谢组的变化

基本信息

批准号：
8908026
负责人：
Casey Michelle Theriot
金额：
$ 12.37万
依托单位：
NORTH CAROLINA STATE UNIVERSITY RALEIGH
依托单位国家：
美国
项目类别：
财政年份：
2013
资助国家：
美国
起止时间：
2013-09-30 至 2017-08-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8908026
关键词：
Address Affect Amino Acids Antibiotic Therapy Antibiotic-Associated Colitis Antibiotics Bile Acids Bioinformatics Biological Biological Markers Carbohydrates Clostridium difficile Communicable Diseases Communities Complex Core Facility Data Data Analyses Development Dipeptides Disease Educational workshop Ensure Environment Equipment Ethics Future Gastrointestinal Diseases Gastrointestinal tract structure Germination Goals Grant Growth Health Health Care Costs Human In Vitro Indigenous Infection Intestines Knowledge Lead Learning Mass Spectrum Analysis Mediating Medicine Mentors Mentorship Metabolic Methodology Methods Mission Morbidity - disease rate Mus Nonesterified Fatty Acids Nutrient Outcome Pathogenesis Physiological Play Predisposition Preparation Process Production Public Health Research Research Design Research Personnel Research Project Grants Resistance Resources Role Sampling Studies Scientist Staging Techniques Technology Testing Therapeutic Therapeutic Intervention Toxin Training base career gastrointestinal gut microbiota improved innovation instrument interest liquid chromatography mass spectrometry mass spectrometer metabolomics microbiome mortality mouse model novel prevent programs statistics success

项目摘要

DESCRIPTION (provided by applicant): Clostridium difficile infection (CDI) is the leading cause of antibiotic-associated colitis and is responsible for significant morbidity, mortality and increased healthcare costs. Despite the significance of CDI, there are major gaps in our understanding of the pathogenesis of this infection. Antibiotics disrupt the indigenous gut microbiota, reducing resistance to C. difficile colonization. However, our knowledge of how the gut microbiota confers resistance to CDI is rudimentary, presenting a significant roadblock to improving preventative and therapeutic approaches against this infection. My long-term goal is to understand how the gastrointestinal tract microbiota mediates colonization resistance against C. difficile. The overall objective of this application is to define metabolites associated with changes in the gut microbiota that contribute to C. difficile colonization and pathogenesis. Using an untargeted metabolomics approach, we have shown that the intestinal environment of antibiotic-treated mice was characterized by major shifts in metabolic profiles. Following antibiotic administration, we detected increases in primary bile acids, carbohydrates, and amino acids and decreased free fatty acids, secondary bile acids and dipeptides; reflecting the diminished metabolic activity of the gut microbiome. Subsequently, we demonstrated that C. difficile could utilize many of these metabolites for in vitro germination and growth. The central hypothesis is that the availability of specific nutrients that support C. difficile growth in the gt after antibiotic treatment is responsible for the observed decrease in colonization resistance. The rationale for the proposed research is that understanding the role the gastrointestinal metabolome plays in C. difficile pathogenesis has the potential to improve preventative and therapeutic approaches for this infection. Guided by strong preliminary data, this hypothesis will be tested by pursuing two specific aims: 1) Identify metabolites in the gastrointestinal tract that contribute to C. difficile colonization and pathogenesis; and 2) Determine the physiological concentrations of gut metabolites that modulate C. difficile pathogenesis. Under the first specific aim, we will use an untargeted metabolomics approach to identify candidate biomarkers from the murine gastrointestinal tract prior to CDI and during different stages of infection. Under the second specific aim, we will use a targeted metabolomics approach to confirm and quantitate metabolites that were significantly affected in specific aim 1, prior to CDI and during different stages of infection. We will also use in vitro studies to confirm their role in C. difficile germination, growth and toxin production. The approach is innovative, because we are using new mass spectrometry technology in a different way, to help solve important biological questions that will improve public health. The proposed research is significant, because it will lead to the identification of novel biomarkers and potential targets for therapeutic interventions to prevent or treat CDI. My overall career goal is to establish an independent research career bridging the field of metabolomics and biomedical infectious diseases, with emphasis on understanding Clostridium difficile pathogenesis. My long-term research interests have always included studying the impact of disease and how it impacts human health. With the advent of "omics" technologies complex communities, including the gastrointestinal tract, can be defined. The expertise and co-mentorship of both Dr. Vincent Young and Dr. Charles Burant ensures success of this research project and my continued success a research scientist. The combined resources that my mentors and collaborators share will allow me access to mouse models of C. difficile infection and the Metabolomics Core Facility, which includes access to state of the art mass spectrometry equipment and trained experts in metabolomics. Finally, these studies will provide me with the opportunity to learn the methodologies related to the emerging field of metabolomic profiling, including the design of studies, sample preparation, metabolite extraction and analysis by the latest mass spectrometer based methods and the processes of data analysis and bioinformatics interpretation of the acquired data. The mentorship plan detailed in this proposal and further didactic coursework in ethics, bioinformatics, statistics, and workshops on metabolomics will help me to become an independent researcher in the field of biomedical infectious diseases and metabolomics.

描述（由申请人提供）：艰难梭菌感染 (CDI) 是抗生素相关性结肠炎的主要原因，是造成显着发病率、死亡率和医疗费用增加的原因。尽管 CDI 具有重要意义，但我们对这种感染发病机制的理解仍存在重大差距。抗生素会破坏本地肠道微生物群，降低对艰难梭菌定植的抵抗力。然而，我们对肠道微生物群如何赋予 CDI 抵抗力的了解还很初级，这为改善这种感染的预防和治疗方法带来了重大障碍。我的长期目标是了解胃肠道微生物群如何介导艰难梭菌的定植抵抗力。本申请的总体目标是确定与肠道微生物群变化相关的代谢物，这些代谢物有助于艰难梭菌定植和发病机制。使用非靶向代谢组学方法，我们发现接受抗生素治疗的小鼠肠道环境的特征是代谢谱发生重大变化。施用抗生素后，我们检测到初级胆汁酸、碳水化合物和氨基酸增加，而游离脂肪酸、次级胆汁酸和二肽减少；反映肠道微生物组代谢活动减弱。随后，我们证明艰难梭菌可以利用许多这些代谢物进行体外萌发和生长。中心假设是抗生素治疗后支持艰难梭菌生长的特定营养物质的可用性是观察到的定植抗性下降的原因。这项研究的基本原理是，了解胃肠道代谢组在艰难梭菌发病机制中所起的作用有可能改善这种感染的预防和治疗方法。在强有力的初步数据的指导下，该假设将通过追求两个具体目标来检验：1）识别胃肠道中的代谢物有助于艰难梭菌定植和发病机制； 2) 确定调节艰难梭菌发病机制的肠道代谢物的生理浓度。根据第一个具体为了实现这一目标，我们将使用非靶向代谢组学方法来识别 CDI 之前和感染不同阶段的小鼠胃肠道中的候选生物标志物。在第二个具体目标下，我们将使用有针对性的代谢组学方法来确认和定量在 CDI 之前和感染不同阶段在具体目标 1 中受到显着影响的代谢物。我们还将利用体外研究来确认它们在艰难梭菌发芽、生长和毒素产生中的作用。这种方法是创新的，因为我们正在以不同的方式使用新的质谱技术来帮助解决改善公众健康的重要生物学问题。拟议的研究意义重大，因为它将导致识别新的生物标志物和预防或治疗 CDI 的治疗干预的潜在目标。我的总体职业目标是建立一个连接代谢组学和生物医学传染病领域的独立研究生涯，重点是了解艰难梭菌的发病机制。我的长期研究兴趣一直包括研究疾病的影响以及它如何影响人类健康。随着“组学”技术的出现，可以定义包括胃肠道在内的复杂群落。 Vincent Young 博士和 Charles Burant 博士的专业知识和共同指导确保了该研究项目的成功以及我作为研究科学家的持续成功。我的导师和合作者共享的综合资源将使我能够获得艰难梭菌感染的小鼠模型和代谢组学核心设施，其中包括最先进的质谱设备和训练有素的代谢组学专家。最后，这些研究将为我提供学习与代谢组学分析新兴领域相关的方法的机会，包括研究设计、样品制备、代谢物提取和通过最新的基于质谱仪的方法进行分析以及数据分析和处理的过程。对获得的数据进行生物信息学解释。本提案中详细介绍的指导计划以及伦理学、生物信息学、统计学和代谢组学研讨会的进一步教学课程将帮助我成为生物医学传染病和代谢组学领域的独立研究员。