Identification of Intestinal Bacteria Protective against C. Difficile Colitis

鉴定可预防艰难梭菌结肠炎的肠道细菌

• 批准号: 8023787
• 负责人: ALEXANDER KHORUTS
• 金额: $ 22.65万
• 依托单位: UNIVERSITY OF MINNESOTA
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-01-01 至 2012-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8023787
• 关键词: Adult; Antibiotic Therapy; Antibiotics; Bacteria; Bioinformatics; Birth; Case Study; Clinical; Clostridium difficile; Colitis; Colon; Complementarity Determining Regions; Computing Methodologies; DNA Sequence; Data; Dependency; Disease; Drug Formulations; Elements; Ensure; Environment; Esthetics; Exotoxins; Exposure to; Feces; Foundations; Functional disorder; Funding; Future; Gastrointestinal Diseases; Gastrointestinal tract structure; Goals; Grant; Growth; Human; Individual; Infection; Institution; Intestines; Lead; Life; Medical; Metagenomics; Metronidazole; Molecular; Patients; Performance; Play; Preparation; Probiotics; Procedures; Public Health; Recurrence; Recurrent disease; Refractory; Role; Sampling; Specific qualifier value; Staging; Study Subject; System; Therapeutic; Time; Transplantation; Vancomycin; Work; commensal microbes; conventional therapy; disorder control; microbial; microbial host; microbiome; microorganism; microorganism interaction; mortality; next generation; prevent; programs; rRNA Genes; reconstitution; restoration; success

DESCRIPTION (provided by applicant): Clostridium difficile associated disease (CDAD) is a major growing public health problem. The growth of C. difficile bacteria in the colon is thought to be inhibited by normal constituents of the mutualist bacteria flora. Therefore, the major trigger for the C. difficile infection is exposure to antibiotics which alter the composition of the normal intestinal microbiota. About 20% of patients with CDAD fail conventional therapy with antibiotics and develop recurrent disease. A significant fraction of these patients develop life-long dependency on antibiotics and often dysfunction of their gastrointestinal tract. Other patients develop fulminant disease, which is associated with high mortality rate. The protective role of the normal intestinal flora is supported by clinical success of bacteriotherapy by way of fecal transplantation. In this procedure the intestinal tracts of patients with recurrent CDAD are inoculated with fecal material from healthy donors. We had recently demonstrated in a case report that this procedure indeed is associated with establishment of donor bacteria in the recipient's colon. However, fecal transplantation is not widely available because of practical and aesthetic considerations. Our long-term goal is to develop a standardized, easy-to- administer formulation of colonic bacteria that can efficiently treat patients with CDAD. In this proposal we will use massively parallel pyrosequencing of hypervariable regions from SSU rRNA genes to characterize the composition of fecal material from patients with recurrent CDAD and their donors. In this exploratory work we will obtain critical data in pursuit of the following specific aims: 1) Determine the composition and diversity of the patient fecal microbiome before and after bacteriotherapy, 2) Determine the rate of recolonization and stability of the fecal microbiome following bacteriotherapy, and 3) Determine if a fecal sample from a single donor can be preserved and later used to restore normal bowel functioning to several CDAD patients. The data obtained from the first aim will form the foundation for future extension of this work requiring more patients. The results will allow us to perform power calculations to determine the number of patients needed in such studies to obtain more definitive results. Bacteriotherapy of patients with CDAD represents a unique opportunity to study establishment of new microflora in an adult patient. The data obtained from the second aim will lay the foundation into future studies that will be further investigate host- microbial interactions in this unique clinical situation. Finally, the third aim represents the first step toward our ultimate goal and has the potential to significantly reduce the complexity of the pursuit for the signature of healthy, protective colonic microflora. PUBLIC HEALTH RELEVANCE: Clostridium difficile is the major known cause of antibiotic associated disease, and represents a growing problem. We are normally protected against this infection by normal bacteria that live in our intestines. Antibiotics used in medical practice weaken this protection. A significant fraction of patients with this infection cannot be treated by conventional treatments, which also involve antibiotics. Our ultimate goal is to develop a standardized formulation of protective bacteria. In this grant we will make critical initial steps toward this goal by studying composition of intestinal bacteria in patients undergoing fecal transplantation for C. difficile infection refractory to conventional treatment.

描述（由申请人提供）：艰难梭菌相关疾病（CDAD）是一个日益严重的主要公共卫生问题。结肠中艰难梭菌的生长被认为受到共生菌群正常成分的抑制。因此，艰难梭菌感染的主要触发因素是接触改变正常肠道微生物群组成的抗生素。大约 20% 的 CDAD 患者使用抗生素进行常规治疗失败并出现复发性疾病。这些患者中有很大一部分对抗生素产生终生依赖，并且常常出现胃肠道功能障碍。其他患者会发展为暴发性疾病，死亡率很高。通过粪便移植进行细菌治疗的临床成功证明了正常肠道菌群的保护作用。在此过程中，复发性 CDAD 患者的肠道接种了来自健康捐赠者的粪便材料。我们最近在一份病例报告中证明，这一过程确实与受体结肠中供体细菌的建立有关。然而，出于实用和美观的考虑，粪便移植并未广泛应用。我们的长期目标是开发一种标准化、易于管理的结肠细菌制剂，能够有效治疗 CDAD 患者。在本提案中，我们将使用 SSU rRNA 基因高变区的大规模并行焦磷酸测序来表征复发性 CDAD 患者及其供体的粪便物质的成分。在这项探索性工作中，我们将获得关键数据，以实现以下具体目标：1）确定细菌治疗前后患者粪便微生物组的组成和多样性，2）确定细菌治疗后粪便微生物组的再定植率和稳定性，以及3）确定是否可以保存来自单个供体的粪便样本，并在以后用于恢复几位 CDAD 患者的正常肠道功能。从第一个目标获得的数据将为这项工作的未来扩展（需要更多患者）奠定基础。结果将使我们能够进行功效计算，以确定此类研究所需的患者数量，以获得更明确的结果。 CDAD 患者的细菌治疗为研究成年患者新微生物群落的建立提供了独特的机会。从第二个目标获得的数据将为未来的研究奠定基础，进一步研究这种独特的临床情况下宿主-微生物的相互作用。最后，第三个目标代表了我们实现最终目标的第一步，并且有可能显着降低追求健康、保护性结肠微生物群特征的复杂性。 公共卫生相关性：艰难梭菌是抗生素相关疾病的主要已知病因，并且是一个日益严重的问题。通常，我们肠道中的正常细菌可以保护我们免受这种感染。医疗实践中使用的抗生素削弱了这种保护作用。很大一部分患有这种感染的患者无法通过传统疗法进行治疗，传统疗法也涉及抗生素。我们的最终目标是开发保护性细菌的标准化配方。在这笔资助中，我们将通过研究接受粪便移植治疗传统治疗难治性艰难梭菌感染的患者的肠道细菌组成，为实现这一目标迈出关键的第一步。