Space travel is associated with continuous low-dose-rate exposure to high Linear Energy Transfer (LET) radiation. Pathophysiological manifestations after low-dose radiation exposure are strongly influenced by non-cytocidal radiation effects including microbiome and cellular gene expression. Using a mouse model for exposure to high LET radiation we observed substantial changes in the composition and functional potential of the microbiome. These were paralleled by changes in the abundance of multiple metabolites which were related to the enzymatic activity of the altered metagenome by means of metabolic network modeling. There was a complex dynamic in microbial and metabolic composition at different radiation doses suggestive of transient dose-dependent interactions between microbial ecology and signals from the host s cellular damage repair processes. Functional shifts included features associated with dysbiosis at the onset of chronic inflammatory responses which could prMouse fecal microbiome after exposure to high LET radiatione-dispose space travelers to systemic long-term health risks.

We report how high and low linear energy transfer (LET) radiation microgravity and elevated dietary iron affect colon microbiota (determined by 16S rDNA pyrosequencing) and colon function. Three independent experiments were conducted: 1) fractionated low LET gamma radiation (137Cs 3 Gy RAD) high Fe diet (IRON) (650 mg/kg diet) and a combination of low LET gamma radiation and high Fe diet (IRON+RAD) in male Sprague-Dawley rats; 2) high LET 38Si particle exposure (0.050 Gy) 1/6 G partial weight bearing (PWB) and a combination of high LET38Si particle exposure and PWB in female BalbC/ByJ mice; and 3) 13 d spaceflight in female C57BL/6 mice. For each experiment the colon was resected and feces removed for microbial sequencing analysis on a Roche 454 Genome Sequencer FLX Titanium instrument (Microbiome Core Facility Chapel Hill NC) using the GS FLX Titanium XLR70 sequencing reagents and protocols. Analysis of amplicon sequencing data was carried out using the QIIME pipeline. Low LET radiation high iron diet and spaceflight increased Bacteroidetes and decreased Firmicutes. Low LET radiation high Fe diet and spaceflight did not significantly affect diversity or richness or elevate pathogenic genera. Spaceflight increased Clostridiales and decreased Lactobacillales and similar trends were observed in the experiment using a ground-based model of microgravity suggesting altered gravity may affect colonic microbiota. Microbiota characteriztion in these models is a first step in understanding the impact of the space environment on intestinal health.

Data were generated as part of a NASA-funded study (Turek F (PI) et al. Effects of Spaceflight on Gastrointestinal Microbiota in Mice: Mechanisms and Impact on Multi-System. NASA NRA: NRA NNH14ZTT002N). As part of the study we requested and received samples from RR1. We generated 16S rRNA gene amplicon sequence data from DNA extracted from fecal samples and compared these data to similar data generated on shuttle mission STS-135 and from ground-based studies of radiation. We assessed effect of flight conditions and radiation.

Data were generated as part of a NASA-funded study (Turek F (PI) et al. Effects of Spaceflight on Gastrointestinal Microbiota in Mice: Mechanisms and Impact on Multi-System. NASA NRA: NRA NNH14ZTT002N). As part of the study, we requested and received samples from RR1. We generated 16S rRNA gene amplicon sequence data from DNA extracted from fecal samples, and compared these data to similar data generated on shuttle mission STS-135 and from ground-based studies of radiation. We assessed effect of flight conditions and radiation.

The objective of the Rodent Research-9 (RR-9) mission was to use mice to understand the molecular basis of phenomena that affect astronauts during long-duration spaceflight particularly visual impairment and joint tissue degradation. To this end a flight group (FLT) of 10-week-old male C57BL/6J mice was launched from Kennedy Space Center (KSC) on 8/14/2017 and housed in Rodent Habitats on the ISS for 33 days before being returned alive to Earth. After splashdown in the Pacific Ocean the animals were transported to Loma Linda University (LLU) for testing euthanasia and dissection on 9/18/2018. A Basal Control (BSL) was housed in standard cages at Kennedy Space Center (KSC) and euthanized one day after launch of the FLT animals (8/15/2017). Ground Control (GC) and Vivarium Control (VIV) studies were planned to commence at KSC approximately one-week after the conclusion of the flight experiments. However all the GC and VIV mouse studies at KSC had to be cancelled due to Hurricane Irma and potential adverse effects on the animal housing facility. The GC and VIV studies were therefore rescheduled and begun in May 2018. The GC was euthanized and dissected 6/18/2018 - 6/20/2018 while the VIV was euthanized and dissected 6/22/2018 - 6/23/2018. Because this resulted in a different cohort of mice being used for the GC and VIV controls as compared to the flight (FLT) and basal (BSL) groups two cohort controls were included in the study. The first Cohort Control 1 (CC_C1) was from the same cohort as the FLT and BSL animals and was sacrificed and dissected 4 days after the FLT group (9/22/2017). The second Cohort Control 2 (CC_C2) was from the same cohort as the GC and VIV animals and was sacrificed and dissected 2-8 days after the GC and VIV groups (6/24/2018 - 6/26/2018). The CC_C1 and CC_C2 groups were housed in standard cages and fed standard chow in contrast to all other groups which received Rodent Foodbars. To clarify the connections between treatment groups and animal cohorts the following group abbreviations are used in the sample metadata: Flight (FLT_C1); Basal (BSL_C1); Ground Control (GC_C2); Vivarium Control (VIV_C2) Cohort Control 1 (CC_C1); Cohort Control 2 (CC_C2). Fecal pellets were isolated directly from mice during dissection and preserved by flash freezing in liquid nitrogen before stored at -80 C. DNA was then extracted shotgun metagenomic libraries generated and libraries sequenced (target 10 M clusters at PE 250 bp). Metagenomic data was generated from the following groups: Basal Control (n=5) Ground Control (n=5) Vivarium Control (n=5) Cohort Control 1 (n=5) Cohort Control 2 (n=5) Flight (n=5).

The MARS500 project the longest ground-based space simulation ever provided us with a unique opportunity to trace the crew microbiota over 520 days of isolated confinement such as that faced by astronauts in real long-term interplanetary space flights and after returning to regular life for a total of 2 years.

Mice were flown onboard STS-135 and returned to Earth for analysis. Livers were collected within 3-4 hours of landing and snap frozen in liquid nitrogen. Samples were shipped to UCI Genomics High Throughput Facility for analysis.

Mice were flown onboard STS-135 and returned to Earth for analysis. Cerebellums were collected within 3-4 hours of landing and snap frozen in liquid nitrogen. Samples were shipped to UCI Genomics High Throughput Facility for analysis.

Here we present a whole-genome survey of the murine transcriptomic response to physiologically-relevant radiation doses 2 and 8 Gy. There are 18 distinct biological samples here. Mice were exposed to ionizing radiation (Cesium-138 source) and whole blood was collected by cardiac puncture 6 hours post treatment. Doses were 0 (7 samples) 2 (5 samples) and 8 (6 samples) gy.

The MARS500 project the longest ground-based space simulation ever provided us with a unique opportunity to trace the crew microbiota over 520 days of isolated confinement such as that faced by astronauts in real long-term interplanetary space flights and after returning to regular life for a total of 2 years.