Section of Oral Biology, Division of Oral Biology and Medicine, School of Dentistry, University of California, Los Angeles, Los Angeles, CA 90095, USA; Department of Microbiology, The Forsyth Institute, Cambridge, MA 02142, USA.
Department of Periodontics, School of Dentistry, University of Washington, Seattle, WA 98195, USA.
Cell Rep. 2023 May 30;42(5):112299. doi: 10.1016/j.celrep.2023.112299. Epub 2023 Apr 19.
Understanding the axis of the human microbiome and physiological homeostasis is an essential task in managing deep-space-travel-associated health risks. The NASA-led Rodent Research 5 mission enabled an ancillary investigation of the gut microbiome, varying exposure to microgravity (flight) relative to ground controls in the context of previously shown bone mineral density (BMD) loss that was observed in these flight groups. We demonstrate elevated abundance of Lactobacillus murinus and Dorea sp. during microgravity exposure relative to ground control through whole-genome sequencing and 16S rRNA analyses. Specific functionally assigned gene clusters of L. murinus and Dorea sp. capable of producing metabolites, lactic acid, leucine/isoleucine, and glutathione are enriched. These metabolites are elevated in the microgravity-exposed host serum as shown by liquid chromatography-tandem mass spectrometry (LC-MS/MS) metabolomic analysis. Along with BMD loss, ELISA reveals increases in osteocalcin and reductions in tartrate-resistant acid phosphatase 5b signifying additional loss of bone homeostasis in flight.
理解人类微生物组的轴和生理动态平衡是管理深空旅行相关健康风险的一项重要任务。美国宇航局领导的啮齿动物研究 5 号任务使人们能够在先前观察到飞行组中出现的骨密度（BMD）损失的背景下，对肠道微生物组进行辅助研究，其中涉及微重力（飞行）与地面对照的不同暴露。通过全基因组测序和 16S rRNA 分析，我们证明了在微重力暴露期间，乳酸杆菌和 Dorea sp. 的丰度相对于地面对照升高。L. murinus 和 Dorea sp. 具有产生代谢物、乳酸、亮氨酸/异亮氨酸和谷胱甘肽的特定功能分配基因簇，这些代谢物在微重力暴露的宿主血清中升高，如通过液相色谱-串联质谱（LC-MS/MS）代谢组学分析所示。与 BMD 损失一起，ELISA 揭示了骨钙素的增加和抗酒石酸酸性磷酸酶 5b 的减少，这意味着飞行中骨动态平衡的进一步丧失。
