背景:粪便微生物群移植(FMT)和粪便病毒移植(FVT,无菌过滤的供体粪便)已有效治疗复发性艰难梭菌感染,可能是通过噬菌体介导的肠道微生物组的调节。然而,像捐赠者变异性这样的挑战,昂贵的筛查,再加上对病原体转移的担忧(包括具有FMT或FVT的真核病毒)阻碍了它们在治疗不太急性的疾病中的更广泛的临床应用。
方法:为了克服这些挑战,我们开发了方法来扩大FVT的临床应用,同时保持疗效和安全性。具体来说,我们采用了以下方法:(1)恒化发酵复制噬菌体FVT供体成分并去除真核病毒(FVT-ChP),(2)溶剂-洗涤剂处理灭活包膜病毒(FVT-SDT),和(3)用于抑制RNA病毒复制的吡喃酮-Y处理(FVT-PyT)。我们评估了这些处理过的FVT在艰难梭菌感染小鼠模型中的功效,并将其与未经处理的FVT(FVT-UnT)进行比较。FMT,和盐水。
结果:FVT-SDT,FVT-UnT,与FMT相比,FVT-ChP降低了达到人道终点的小鼠的发生率(分别为0/8、2/7和3/8),FVT-PyT,和盐水(分别为5/8、7/8和5/7),并显着降低了定居艰难梭菌细胞的负荷和相关的毒素A/B水平。有可能消除艰难梭菌定植,用FVT-SDT治疗的八只小鼠中有七只qPCR检测为阴性。相比之下,所有其他处理显示艰难梭菌的持续存在。此外,结果得到了肠道微生物组变化的支持,盲肠细胞因子水平,和组织病理学发现。FMT/FVT治疗后对病毒植入的评估和宿主-噬菌体相关性分析表明,噬菌体的转移可能是与治疗功效相关的重要促成因素。
结论:这项概念验证研究表明,FVT的特定修饰有望解决与供体变异性和感染风险相关的挑战。两种策略导致治疗显著限制小鼠中艰难梭菌定植,随着溶剂/去污剂处理和供体噬菌体的恒化器繁殖成为有希望的方法。视频摘要。
BACKGROUND: Fecal microbiota transplantation (FMT) and fecal virome transplantation (FVT, sterile filtrated donor feces) have been effective in treating recurrent Clostridioides difficile infections, possibly through bacteriophage-mediated modulation of the gut microbiome. However, challenges like donor variability, costly screening, coupled with concerns over pathogen transfer (incl. eukaryotic viruses) with FMT or FVT hinder their wider clinical application in treating less acute diseases.
METHODS: To overcome these challenges, we developed methods to broaden FVT\'s clinical application while maintaining efficacy and increasing safety. Specifically, we employed the following approaches: (1) chemostat-fermentation to reproduce the bacteriophage FVT donor component and remove eukaryotic viruses (FVT-ChP), (2) solvent-detergent treatment to inactivate enveloped viruses (FVT-SDT), and (3) pyronin-Y treatment to inhibit RNA virus replication (FVT-PyT). We assessed the efficacy of these processed FVTs in a C. difficile infection mouse model and compared them with untreated FVT (FVT-UnT), FMT, and saline.
RESULTS: FVT-SDT, FVT-UnT, and FVT-ChP reduced the incidence of mice reaching the humane endpoint (0/8, 2/7, and 3/8, respectively) compared to FMT, FVT-PyT, and saline (5/8, 7/8, and 5/7, respectively) and significantly reduced the load of colonizing C. difficile cells and associated toxin A/B levels. There was a potential elimination of C. difficile colonization, with seven out of eight mice treated with FVT-SDT testing negative with qPCR. In contrast, all other treatments exhibited the continued presence of C. difficile. Moreover, the results were supported by changes in the gut microbiome profiles, cecal cytokine levels, and histopathological findings. Assessment of viral engraftment following FMT/FVT treatment and host-phage correlations analysis suggested that transfer of phages likely were an important contributing factor associated with treatment efficacy.
CONCLUSIONS: This proof-of-concept study shows that specific modifications of FVT hold promise in addressing challenges related to donor variability and infection risks. Two strategies lead to treatments significantly limiting C. difficile colonization in mice, with solvent/detergent treatment and chemostat propagation of donor phages emerging as promising approaches. Video Abstract.