■胃肠道(GI)微生物群是一个复杂而动态的生态系统,其组成和功能受许多内部和外部因素的影响。总的来说,个体GI微生物群组成似乎相当稳定,但可能受到环境暴露的极端变化的影响。迄今为止,没有系统的文献综述来考察极端环境条件的影响,比如严格的隔离和禁闭,胃肠道微生物群。
■我们进行了系统评价,以检查隔离和封闭环境对人类胃肠道微生物群的影响。文献检索是根据PRISMA标准使用PubMed进行的,WebofScience和Cochrane图书馆。相关研究是根据暴露于孤立和封闭环境而确定的,通常也是抗原受限的,至少28天,并根据微生物群分析方法(基于培养或分子的方法)和隔离栖息地(空间,空间或微重力模拟,如MARS-500或自然隔离,如南极洲)。微生物的丰度变化,评估了响应隔离的α多样性和群落结构。
■无论研究栖息地如何,40个不同属的丰度变化不一致,主要在菌门(以前的Firmicutes)中进行了报道。总的来说,研究的异质性很高。通过区分微生物区系分析方法或根据隔离生境进行分组都不可能减少异质性。阿尔法多样性非特异性进化,尽管部分收敛,但微生物群落结构仍然不同。暴露后GI生态系统恢复到基线水平,显示出与实验长度无关的弹性。
■就优势分类群的多样性和相对丰度而言,隔离和封闭的环境对GI微生物群组成具有相当大的影响。然而,由于样本量相当小的研究数量有限,重要的是要谨慎地得出一个深入的结论,结果应被视为初步趋势。在极端环境下规划未来项目时,应考虑菌群失调和相关疾病的风险。
■https://www.crd.约克。AC.英国/普华永道/,标识符CRD42022357589。
UNASSIGNED: The gastrointestinal (GI) microbiota is a complex and dynamic ecosystem whose composition and function are influenced by many internal and external factors. Overall, the individual GI microbiota composition appears to be rather stable but can be influenced by extreme shifts in environmental exposures. To date, there is no systematic literature
review that examines the effects of extreme environmental conditions, such as strict isolation and confinement, on the GI microbiota.
UNASSIGNED: We conducted a systematic
review to examine the effects of isolated and confined environments on the human GI microbiota. The literature search was conducted according to PRISMA criteria using PubMed, Web of Science and Cochrane Library. Relevant studies were identified based on exposure to isolated and confined environments, generally being also antigen-limited, for a minimum of 28 days and classified according to the microbiota analysis method (cultivation- or molecular based approaches) and the isolation habitat (space, space- or microgravity simulation such as MARS-500 or natural isolation such as
Antarctica). Microbial shifts in abundance, alpha diversity and community structure in response to isolation were assessed.
UNASSIGNED: Regardless of the study habitat, inconsistent shifts in abundance of 40 different genera, mainly in the phylum Bacillota (formerly Firmicutes) were reported. Overall, the heterogeneity of studies was high. Reducing heterogeneity was neither possible by differentiating the microbiota analysis methods nor by subgrouping according to the isolation habitat. Alpha diversity evolved non-specifically, whereas the microbial community structure remained dissimilar despite partial convergence. The GI ecosystem returned to baseline levels following exposure, showing resilience irrespective of the experiment length.
UNASSIGNED: An isolated and confined environment has a considerable impact on the GI microbiota composition in terms of diversity and relative abundances of dominant taxa. However, due to a limited number of studies with rather small sample sizes, it is important to approach an in-depth conclusion with caution, and results should be considered as a preliminary trend. The risk of dysbiosis and associated diseases should be considered when planning future projects in extreme environments.
UNASSIGNED: https://www.crd.york.ac.uk/prospero/, identifier CRD42022357589.