Combined Effects of Simulated Microgravity, Low Pressure and Noise Environment on the Intestinal Flora of C57BL/6 Mice

Abstract Background: The composition and function of intestinal microbial communities are important for human health. However, these intestinal floras are sensitive to changes in the environment. Adverse changes to intestinal flora can affect the health of astronauts in complex space environments, resulting in difficulties of implementing space missions.Results: Under the influence of different space environmental factors, the species composition at the phylum and genus level were significantly affected by the combined effects environment. Furthermore, screening was conducted to identify biomarkers that could be regarded as environmental markers. And there have also been some noticeable changes in the function of intestinal floras. Moreover, the antibiotic resistance genes (ARGs) were also found to be differently expressed under different environmental conditions.Conclusion: The combined effects environment could significantly affect the species composition, function and the expression of ARGs of intestinal flora which may provide a theoretical basis for space medical supervision and healthcare. Meanwhile, these changes require more attention because they may induce diseases that may further affect performance during space missions.