Table_2_Fecal Bile Acids Profile of Crewmembers Consuming the Same Space Food in a Spacecraft Simulator.pdf

Introduction: Recently, bile acids (BAs) are increasingly being considered as unique metabolic integrators and not just for the cholesterol metabolism and absorption of dietary lipids. Human BAs profiles are evolved to be individual under different environmental, dietary, and inherited factors. Variation of BAs for crewmembers from freshly prepared kitchen diets to wholly prepackaged industrial foods in a ground-based spacecraft simulator has not been clearly interpreted.
Methods: Three crewmembers were confined in a docked spacecraft and supplied with 7 days periodic wholly prepackaged industrial foods for 50 days. Fecal samples were collected before entry in the spacecraft simulator and after evacuation. Determination of 16 kinds of BAs was carried out by high-performance liquid chromatography tandem mass spectrometry method.
Results: Bile acids metabolism is sensitive to diet and environment transition from freshly prepared kitchen diets in the canteen to wholly prepackaged industrial foods in a ground-based spacecraft simulator, which is also specific to individuals. A significant positive relationship with a coefficient of 0.85 was found for primary BAs as chenodeoxycholic acid (CDCA) and cholic acid (CA), and a significantly negative relationship with a coefficient of −0.69 for secondary BAs as lithocholic acid (LCA) and deoxycholic acid (DCA).
Discussion: The profile of BA metabolism of individuals who share the same food in the same environment appears to be unique, suggesting that the inherent ability of different individuals to adapt to diet and environment varies. Since the transition from the free diet in open space to whole prepackaged space food diet in a space station simulator causes the variations of BAs pool in an individual manner, assessment of BA metabolic profiles provides a new perspective for personalized diet design, astronaut selection and training, and space flight diet acclimatization.

引言：近年来，胆汁酸（bile acids, BAs）日益被视为独特的代谢整合因子，而非仅参与胆固醇代谢与膳食脂质吸收。人体胆汁酸谱会因不同环境、膳食及遗传因素而呈现个体差异。目前对于在地面航天器模拟器中，航天员从厨房现制膳食转为全预包装工业食品时的胆汁酸变化，尚未得到清晰阐释。
方法：3名航天员被安置于对接航天器内，在50天周期内以7天为循环供应全预包装工业食品。分别在进入航天器模拟器前及撤离后采集粪便样本。采用高效液相色谱串联质谱法对16种胆汁酸进行定量检测。
结果：胆汁酸代谢对膳食与环境的转变极为敏感：从食堂现制厨房膳食转为地面航天器模拟器中的全预包装工业食品时，该代谢变化同样具有个体特异性。其中初级胆汁酸鹅脱氧胆酸（chenodeoxycholic acid, CDCA）与胆酸（cholic acid, CA）的相关系数达0.85，呈显著正相关；次级胆汁酸石胆酸（lithocholic acid, LCA）与脱氧胆酸（deoxycholic acid, DCA）的相关系数为-0.69，呈显著负相关。
讨论：在相同环境、摄入相同膳食的前提下，个体的胆汁酸代谢谱仍呈现独特性，这表明不同个体对膳食与环境的内在适应能力存在差异。鉴于在空间站模拟器中，从开放式自由膳食转为全预包装航天食品膳食会以个体特异性方式改变胆汁酸池，因此对胆汁酸代谢谱的评估可为个性化膳食设计、航天员选拔与训练以及航天膳食适应提供全新视角。