Thompson Robert S, Hopkins Shelby, Kelley Tel, Wilson Christopher G, Pecaut Michael J, Fleshner Monika
Department of Integrative Physiology, University of Colorado Boulder, Boulder, CO 80301, USA.
Center for Neuroscience, University of Colorado Boulder, Boulder, CO 80301, USA.
Nutrients. 2025 Jul 24;17(15):2417. doi: 10.3390/nu17152417.
BACKGROUND/OBJECTIVES: Environmental stressors, including spaceflight and altered gravity, can negatively affect the symbiotic relationship between the gut microbiome and host health. Dietary prebiotics, which alter components of the gut microbiome, show promise as an effective way to mitigate the negative impacts of stressor exposure. It remains unknown, however, if the stress-protective effects of consuming dietary prebiotics will extend to chronic altered-gravity exposure.
Forty female C57BL/6 mice consumed either a control diet or a prebiotic diet containing galactooligosaccharides (GOS) and polydextrose (PDX) for 4 weeks, after which half of the mice were exposed to 3 times the gravitational force of Earth (3g) for an additional 4 weeks. Fecal microbiome samples were collected weekly for 8 weeks, sequenced, and analyzed using 16S rRNA gene sequencing. Terminal physiological endpoints, including immune and red blood cell characteristics, were collected at the end of the study.
The results demonstrate that dietary prebiotic consumption altered the gut microbial community structure through changes to β-diversity and multiple genera across time. In addition, consuming dietary prebiotics reduced the neutrophil-to-lymphocyte ratio (NLR) and increased red blood cell distribution width (RDW-CV). Importantly, the prebiotic diet prevented the impacts of altered-gravity on β-diversity and the bloom of problematic genera, such as and . Furthermore, several prebiotic diet-induced genera-level changes were significantly associated with several host physiological changes induced by 3g exposure.
These data demonstrate that the stress-protective potential of consuming dietary prebiotics extends to environmental stressors such as altered gravity, and, potentially, spaceflight.
背景/目的：包括太空飞行和重力改变在内的环境应激源会对肠道微生物群与宿主健康之间的共生关系产生负面影响。膳食益生元可改变肠道微生物群的组成部分，有望成为减轻应激源暴露负面影响的有效方法。然而，食用膳食益生元的应激保护作用是否会延伸至长期重力改变暴露，目前尚不清楚。
40只雌性C57BL/6小鼠连续4周食用对照饮食或含有低聚半乳糖（GOS）和聚葡萄糖（PDX）的益生元饮食，之后将一半小鼠再暴露于3倍地球重力（3g）环境中4周。在8周内每周采集粪便微生物群样本，进行测序，并使用16S rRNA基因测序进行分析。在研究结束时收集包括免疫和红细胞特征在内的终末生理指标。
结果表明，食用膳食益生元通过随时间改变β多样性和多个菌属，改变了肠道微生物群落结构。此外，食用膳食益生元降低了中性粒细胞与淋巴细胞比率（NLR），并增加了红细胞分布宽度（RDW-CV）。重要的是，益生元饮食可防止重力改变对β多样性和问题菌属（如……和……）大量繁殖的影响。此外，几种由益生元饮食引起的菌属水平变化与3g暴露诱导的几种宿主生理变化显著相关。
这些数据表明，食用膳食益生元的应激保护潜力可延伸至重力改变等环境应激源，甚至可能延伸至太空飞行应激源。
