人工肠道菌群的构建及其移植技术对溃疡性结肠炎的治疗作用

Transplantation of artificial gut microbiota which uses defined culturable gut microbial consortia has shown promising effect to re-built the gut microbial ecosystem of patients and is considered as the next-generation microbiota therapeutics for diseases associated with microbiota dysbiosis in the gut. Ulcerative colitis (UC) is a disease with gut microbiota as a pivotal factor in its etiology. In the present study, we will target UC to study the development methods of gut artificial microbiota. UC patients will be recruited and the patients with significant microbiota dysbiosis will be selected for fecal microbiota transplantation (FMT) treatment. The composition of microbiota before and post treatment will be compared to monitor the colonization and re-establishment of the new microbial ecosystem. Through co-relation analysis of gut microbiome data with clinical and inflammatory parameters, the functional bacteria which play key roles during disease remission will be identified; using habitat-stimulating media, the functional and predominant species from the healthy donor will be isolated and mixed into different bacteria combinations. Those cultured "cocktails" will be acclimated to propagate steadily in vitro. The artificial microbiota will be transferred to germfree mice to test its safety. This is an novel attempt to introduce microbiota theory and techniques to ulcerative colitis therapy and will also provide important guidance to other disease therapies. Compared with traditional fecal transplantation, artificial microbiota transplantation is much easier to be standardized and manipulated in clinical practice.

用人工肠道菌群代替粪便进行移植来重建患者的肠道微生态系统，是应用粪菌移植技术治疗肠道菌群紊乱相关疾病的发展趋势。溃疡性结肠炎（UC）的发病机制中肠道菌群发挥了重要作用，本课题拟以该病为切入点，摸索人工肠道菌群的构建方法。筛选UC患者，选择肠道菌群严重失衡的患者进行粪菌移植治疗，对比治疗前后肠道微生物组的变化，探讨肠道中菌群的定植和重建规律；对肠道菌群元基因组学和临床数据、炎症指标进行关联分析，鉴定在疾病转归过程中发挥重要作用的肠道细菌成员；设计“生境模拟”培养体系厌氧分离健康供体肠道中的优势菌和功能菌，依据兼顾“功能和多样性”原则，在体外组合、配伍成不同的细菌组合物，驯化使其在体外稳定传代；应用无菌小鼠检测细菌组合物的安全性。该课题是将微生态理论和技术应用于UC治疗的科学创新，将克服传统粪菌移植技术难以标准化、规模化的缺陷，有望在UC治疗领域取得重要突破，同时为其它肠道菌群相关疾病的治疗提供依据和借鉴。

用人工肠道菌群代替粪便进行移植来重建患者的肠道微生态系统，是应用粪菌移植技术治疗肠道菌群紊乱相关疾病的发展趋势，这就需要对粪菌移植中的关键功能细菌进行鉴定。溃疡性结肠炎（UC）的发病机制中肠道菌群发挥了重要作用，本课题完成了15例中、重度溃疡性结肠炎患者的粪菌移植治疗以及90天的随访，基于Mayo评分的临床检测显示，FMT后90天，15名患者中有13人临床改善，其中8人达到临床缓解，FMT治疗效果显著。患者的CRP、血沉、IL-6等指标也显著下降。我们分析了患者在菌群移植前后的肠道菌群组成，检测到属于Bacteroides、Faecalibacterium、Bifidobacterium、Blautia、Roseburia等属以及Lachnospiraceae纲的一些短链脂肪酸产生菌在患者肠道中成功定植，这些菌的定植与患者移植后改善的临床指标相关。在此基础上，采用能较好模拟肠道营养组成的培养体系，我们分离得到了4种Bifidobacterium菌株、2种Faecalibacterium属菌株和一些潜在的新菌株。我们在患者肠道中也分离出一株嗜胆酸盐细菌Bilophila wadsworthia，该菌可导致正常SPF小鼠出现低度的系统炎症。我们还摸索建立了一种健康供体肠道菌群的人工驯化方法，可使供体中的Faecalibacterium、Blautia、Ruminococcus、Bifidobacterium、Roseburia等细菌数量较好地维持，而机会致病菌减少。综上，该课题是将微生态理论和技术应用于UC治疗的科学创新，有望在UC治疗领域取得重要突破，同时为其它肠道菌群相关疾病的治疗提供依据和借鉴。