粪便移植中细菌的存活情况：哪些细菌能够存活？

Bacterial viability in faecal transplants: Which bacteria survive?

机构信息

The South Australian Health and Medical Research Institute (SAHMRI), Adelaide, South Australia, Australia; The SAHMRI Microbiome Research Laboratory, School of Medicine, Flinders University, Bedford Park, South Australia, Australia; Department of Infectious Diseases, Royal Adelaide Hospital, Adelaide, South Australia, Australia.

出版信息

EBioMedicine. 2019 Mar;41:509-516. doi: 10.1016/j.ebiom.2019.02.023. Epub 2019 Feb 19.

DOI:10.1016/j.ebiom.2019.02.023

PMID:30796005

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC6444077/

Abstract

BACKGROUND

The therapeutic potential of faecal microbiota transplantation (FMT) is under investigation for a range of inflammatory conditions. While mechanisms of benefit are poorly understood, most models rely on the viability of transplanted microbes. We hypothesised that protocols commonly used in the preparation of faecal transplants will substantially reduce the number, diversity and functional potential of viable microbes.

METHODS

Stools from eight screened donors were processed under strict anaerobic conditions, in ambient air, and freeze-thawed. Propidium monoazide (PMA) sample treatment was combined with quantitative PCR, 16S rRNA gene amplicon sequencing and short-chain fatty acid (SCFA) analysis to define the viable microbiota composition and functional potential.

FINDINGS

Approximately 50% of bacterial content of stool processed immediately under strict anaerobic conditions was non-viable. Homogenisation in ambient air or freeze-thaw reduced viability to 19% and 23% respectively. Processing of samples in ambient air resulted in up to 12-fold reductions in the abundance of important commensal taxa, including the highly butyrogenic species Faecalibacterium prausnitzii, Subdoligranulum variable, and Eubacterium hallii. The adverse impact of atmospheric oxygen exposure on the capacity of the transplanted microbiota to support SCFA biosynthesis was demonstrated by significantly reduced butyrate and acetate production by faecal slurries processed in ambient air. In contrast, while reducing overall levels of viable bacteria, freeze-thaw did not significantly alter viable microbiota composition.

INTERPRETATION

The practice of preparing material for faecal transplantation in ambient air profoundly affects viable microbial content, disproportionately reducing the abundance of anaerobic commensals and the capacity for biosynthesis of important anti-inflammatory metabolites. FUND: This work was supported by the South Australian Health and Medical Research Institute. LP is supported by a scholarship from the Flinders Foundation. GR is supported by a Matthew Flinders Research Fellowship.

摘要

背景

粪便微生物群移植（FMT）的治疗潜力正在针对一系列炎症性疾病进行研究。虽然其获益机制尚未完全阐明，但大多数模型都依赖于移植微生物的存活能力。我们假设，在制备粪便移植物时常用的方案会大大减少有活力的微生物的数量、多样性和功能潜力。

方法

从八位筛选出的供体中采集的粪便样本在严格的厌氧条件下，在大气环境中，以及冻融条件下进行处理。将吖啶橙（PMA）样品处理与定量 PCR、16S rRNA 基因扩增子测序和短链脂肪酸（SCFA）分析相结合，以确定有活力的微生物群落组成和功能潜力。

结果

立即在严格厌氧条件下处理的粪便中约有 50%的细菌含量是非有活力的。在大气环境中均质化或冻融处理分别将其有活力性降低到 19%和 23%。在大气环境中处理样本会导致包括高度丁酸产生菌粪拟杆菌（Faecalibacterium prausnitzii）、可变副拟杆菌（Subdoligranulum variable）和真杆菌属（Eubacterium hallii）在内的重要共生菌的丰度降低 12 倍。大气氧暴露对移植菌群支持 SCFA 生物合成能力的不利影响通过在大气环境中处理的粪便悬浮液中显著减少丁酸盐和乙酸盐的产生来证明。相比之下，尽管冻融处理降低了整体有活力细菌水平，但并未显著改变有活力微生物群落的组成。