Response to Low Shear Modeled Microgravity Indicates Translation of Lactobacillus acidophilus ATCC 4356 Benefits to Spaceflight

The introduction of generally recognized as safe (GRAS) probiotic microbes into the spaceflight food system has the potential for use as a safe, non-invasive, daily countermeasure to crew microbiome and immune dysregulation. However, the microgravity effects on the stress tolerances and genetic expression of probiotic bacteria must bedetermined to confirm translation of strain benefits and to identify potential for optimization of growth, survival, and strain selection for spaceflight. The work presented here demonstrates the translation of characteristics of a GRAS probiotic bacteria to a microgravity analog environment. Lactobacillus acidophilus ATCC 4356 was grown in the low shear modeled microgravity (LSMMG) orientation and the control orientation in the rotating wall vessel (RWV) to determine the effect of LSMMG on the growth, survival through stress challenge, and gene expression of the strain. No differences were observed between the LSMMG and control grown L. acidophilus, suggesting that the strain will behave similarly in spaceflight and may be expected to confer Earth-based benefits.

将一般认为安全 (Generally Recognized As Safe, GRAS) 的益生菌微生物引入航天食品系统，有望作为一种安全、非侵入性的日常干预手段，用于改善乘员微生物组失调与免疫功能异常。然而，为验证菌株益处的可转化性，并明确航天应用中优化菌株生长、存活及筛选的潜力，必须明确微重力对益生菌应激耐受性与基因表达的影响。本研究所开展的工作证实了一株GRAS益生菌的特性可适配微重力模拟环境。本研究将嗜酸乳杆菌ATCC 4356分别置于低剪切模拟微重力 (Low Shear Modeled Microgravity, LSMMG) 组与对照组的旋转壁式生物反应器 (Rotating Wall Vessel, RWV) 中培养，以探究LSMMG对该菌株生长、应激挑战下的存活能力及基因表达的影响。结果显示，LSMMG培养组与对照组的嗜酸乳杆菌未观察到显著差异，表明该菌株在太空环境中亦能表现出类似的特性，有望保留其在地球环境下的有益功效。