Hao Zikai, Zhu Yinzhen, Fu Yuming, Yang Jianlou, Meng Chen, Dong Chen, Liu Hong
Beijing Advanced Innovation Centre for Biomedical Engineering, Beihang Universitygrid.64939.31, Beijing, China.
State Key Laboratory of Software Development Environment, School of Computer Science and Engineering, Beihang Universitygrid.64939.31, Beijing, China.
Microbiol Spectr. 2022 Apr 27;10(2):e0025422. doi: 10.1128/spectrum.00254-22. Epub 2022 Mar 7.
The long-term exposure to enclosed environments may lead to chronic stress in crewmembers and affect their physical and mental state. Salivary microbiome and biomarkers of immune function are increasingly used in human health research. The "Lunar Palace 365" project, which was a 370-day, multicrew, enclosed experiment carried out in a ground-based bioregenerative life support system platform named Lunar Palace 1 (LP1). We investigated the temporal dynamics of the salivary microbiota and cytokines in the third phase of the "Lunar Palace 365" experiment, including 1 month before entering LP1 and 1 month after leaving Lp1. Results reveal no regular temporal change pattern in these parameters (highly abundant phyla and genera) during the experiment. Although the crewmembers' oral microbiota temporally changed, it recovered quickly after the study subjects left the enclosed environment. The levels of IL-6, IL-10, and TNF-α in crewmembers' saliva decreased after leaving the normal environment for the enclosed environment, indicating that their oral inflammatory response level was reduced. There were significant individual differences in crewmembers' salivary microbiota, however, the shared living space reduced these differences. Moreover, air microbiota might have also played a significant role in reducing the individual differences. In summary, the enclosed environment did not result in persistent changes in human salivary microbiota and oral immunity. This study provides some insights for studying the effect of enclosed controlled environments on human immunity and microbiome. Long-term exposure to space environments may influence the human microbiome, the human immune system, and the intricate balance between the two, causing impaired immunity and increased disease susceptibility. It was previously believed that the main potential factors of long-term spaceflight on human health were microgravity and radiation. However, the effects of long-term enclosed environments on human health were unclear. Bioregenerative life support systems (BLSS) is a good experimental model for studying the effects of enclosed environments on human systemic microbiota and immune disorders. We monitored the microbiota and cytokines in the saliva of crewmembers before they entered BLSS, during their stay in BLSS, and after leaving BLSS. The results indicated long-term closed environment will not cause persistent changes in human salivary microbiota and immunity.
长期暴露于封闭环境可能导致机组人员出现慢性应激，并影响他们的身心健康状态。唾液微生物群和免疫功能生物标志物在人类健康研究中的应用越来越广泛。“月宫365”项目是在一个名为月宫一号（LP1）的地面生物再生生命支持系统平台上进行的为期370天的多乘员封闭实验。我们在“月宫365”实验的第三阶段调查了唾液微生物群和细胞因子的时间动态变化，包括进入LP1前1个月和离开LP1后1个月。结果显示，在实验期间，这些参数（高丰度的门和属）没有规律的时间变化模式。虽然机组人员的口腔微生物群随时间发生了变化，但在研究对象离开封闭环境后，它很快就恢复了。机组人员唾液中的白细胞介素-6（IL-6）、白细胞介素-10（IL-10）和肿瘤坏死因子-α（TNF-α）水平在从正常环境进入封闭环境后有所下降，这表明他们的口腔炎症反应水平降低了。机组人员的唾液微生物群存在显著的个体差异，然而，共同的生活空间减少了这些差异。此外，空气微生物群可能在减少个体差异方面也发挥了重要作用。总之，封闭环境并未导致人类唾液微生物群和口腔免疫力的持续变化。本研究为研究封闭控制环境对人类免疫力和微生物群的影响提供了一些见解。长期暴露于太空环境可能会影响人类微生物群、人类免疫系统以及两者之间的复杂平衡，导致免疫力受损和疾病易感性增加。以前人们认为长期太空飞行对人类健康的主要潜在因素是微重力和辐射。然而，长期封闭环境对人类健康的影响尚不清楚。生物再生生命支持系统（BLSS）是研究封闭环境对人类全身微生物群和免疫紊乱影响的良好实验模型。我们监测了机组人员在进入BLSS之前、在BLSS停留期间以及离开BLSS之后唾液中的微生物群和细胞因子。结果表明，长期封闭环境不会导致人类唾液微生物群和免疫力的持续变化。
