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.

The objective of the Rodent Research-6 (RR-6) study was to evaluate muscle atrophy in mice during spaceflight and to test the efficacy of a novel therapeutic to mitigate muscle wasting. The experiment involved an implantable subcutaneous nanochannel delivery system (nDS; between scapula) which delivered the drug formoterol (FMT; a selective xce xb22 adrenoceptor agonist) over the course of time. To this end a cohort of forty 32-weeks-old female C57BL/6NTac mice were either sham operated or implanted with vehicle or treatment-filled nDS launched in two Transporters (20 mice per Transporter) on SpaceX-13 on December 15 2017. They were transferred to Rodent Habitats onboard the International Space Station (ISS) and maintained in microgravity for 29 days (N=20 Live Animal Return Spaceflight [LAR FLT]) or >50 days (N=20 ISS Terminal Spaceflight [ISS-T FLT]). After 29 days the 20 LAR FLT animals were returned live to back to Earth on January 13 2018. After splashdown the animals were ambulatory on-ground for ~4 days until all subjects were processed during one day of dissections. There were two Basal (BSL) groups of animals sacrificed (LAR BSL & ISS-T BSL; N=20; 40 animals; ~36 weeks old) at Kennedy Space Center (KSC; 12/9/17). LAR BSL animals were dissected and samples were collected upon euthanasia. A Ground Control (GC) group LAR GC mimicked the LAR FLT group which was housed at KSC then shipped alive to Novartis xe2 x80 x99s Facilities where both the LAR FLT and LAR GC groups were processed (~41 weeks old; 1/16/18). All were anesthetized with isoflurane blood samples were obtained by closed-chest cardiac puncture and the animals were euthanized by exsanguination and thoracotomy. The 20 ISS-T FLT mice were anesthetized via intraperitoneal injection of ketamine/xylazine/acepromazine over the course of a four days of dissections (2/6/18 until 2/9/18; 53-56 days after launch; 44 weeks old at time of on-orbit dissections). Blood samples and euthanasia were conducted the same as LAR groups. Following blood draw and hind limb dissection the ISS-T FLT animal carcasses were wrapped in aluminum foil placed in a ziploc bag and placed in storage at -80 xcb x9aC or colder until return. The ISS-T Ground Control (ISS-T GC) (at KSC) followed the same euthanasia timeline methods and preservation. The final processing of frozen ISS-T FLT frozen ISS-T GC and frozen 0-day ISS-T BSL animals were completed at Houston Methodist Research Institute in Houston TX (5/21/18 until 5/24/18). GeneLab received feces from only sham treated animals (no drug treated animals) from the following groups. FLT: LAR (n=9) ISS-T (n=7); GC: LAR (N=7) ISS-T (N=9); BSL: LAR (n=7) ISS-T (n=9). DNA was extracted and analyzed by sequencing using a variety of different targeted and un-targeted metagenome profiling assays.

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.

Presented here is the environmental microbiome study of the International Space Station surfaces. The environmental samples were collected with the polyester wipes from eight different locations in the ISS during two consecutive sampling sessions (three months apart). The specific objective was to unveil the pool of genes for each location during two separate sessions to learn of functional and metabolic diversity of microorganisms in the ISS. The International Space Station (ISS) as a closed built environment has its own environmental microbiome which is shaped by microgravity radiation and limited human presence. The microbial diversity associated with ISS environmental surfaces was investigated during this study. Polyester wipes and contact slides were used for sampling of eight various surface locations on the ISS at different time periods. The samples were retrieved and analyzed immediately upon the return to the Earth (via Soyuz TMA-14M or Dragon capsule from SpaceX). After surface sample collection contact slides containing nutrient media for the growth of bacteria and fungi were incubated at 25 xcb x9aC. The polyester wipes were processed to measure microbial burden (R2A Blood Agar and Potato Dextrose Agar) and recover cultivable bacteria as well as fungi. Subsequently viable microbial burden was assessed using Adenosine Triphosphate (ATP) assay and quantitative polymerase chain reaction (PCR) methods after propidium monoazide (PMA) treatment. The 16S-tag and metagenome analyses were used to elucidate viable microbial diversity. The cultivable bacterial population yield from the polyester wipes was very high (5 to 7-logs) when compared with the contact slides (102 to 103 CFU/m2). The PMA-qPCR analysis showed considerable variation of viable bacterial population (105 to 109 16S rDNA gene copies/m2) among locations sampled. Unlike contact slides polyester wipes cover much larger sample surface (~1 m2) and produce much more reliable results of the microbial diversity of the ISS covering both cultivable and non-cultivable species. The cultivable total and viable microbial diversity was determined utilizing state-of-the art molecular techniques. The implementation of the PMA assay before DNA extraction allowed distinguishing viable microorganisms which is crucial for determining their role to the crew health the ISS maintenance and the general knowledge of the closed environmentally controlled built systems.

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-10 Mission (RR-10) was to investigate how spaceflight affects the cellular and molecular mechanisms of normal bone tissue regeneration in space. To this end, ten (10) 14-15 weeks-old female B6129SF2/J Wild Type (WT), and ten (10) 14-15 weeks-old female B6;129S2-Cdkn1atm1Tyj/J (p21-null) mice received a pre-flight subcutaneous injection of the bone marker (Alizarin Red), and were then delivered to the ISS aboard SpaceX-21. At 7 days before euthanasia, all 20 mice received an intraperitoneal (IP) injection with a bone formation marker (Calcein). At 48 +/- 2 hours before euthanasia, all 20 mice received an IP injection with a second dose of Calcein as well as a cell proliferation marker (BrdU). Then, following 28-29 days in microgravity, the Flight mice were euthanized. Following removal of hindlimbs, carcasses were wrapped in aluminum foil, preserved in the CryoChiller, and stored at -80 C or colder until return to Earth. In addition to the Flight group, three ground control groups were also part of the study: Basal (representing the pre-launch state), Vivarium (standard vivarium housing for the same duration of time as flight), and Ground (flight habitat in the International Space Station Environment Simulator, ISSES). Twenty mice (10 of each strain) were included in each of these control groups (except Vivarium which included 12 of each strain). These were treated, euthanized and processed on the same schedule and in the same manner as the flight samples. At the end of RR-10 experiment, all frozen carcasses were partially thawed and fecal pellets were removed and preserved by flash freezing in LN2. DNA was extracted, shotgun metagenome libraries generated, and libraries sequenced (target 10 M clusters at PE 250 bp). This dataset features WT samples from the Flight (n=3), Ground (n=5), Basal (n=10) and Vivarium groups (n=12), as well as p21-null samples from Flight (n=5), Ground (n=5), Basal (n=10) and Vivarium groups (n=12).

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).

In an on-going Microbial Observatory experimental investigation on the International Space Station (ISS) multiple bacterial isolates of Biosafety Level 2 (BSL-2) were isolated and identified. The antibiotic susceptibility pattern was tested in these BSL-2 isolates for the following antibiotics: cefazolin ciprofloxacin cefoxitin erythromycin gentamycin oxacillin penicillin rifampin tobramycin and many of the BSL-2 isolates showed multiple drug resistance. Among these isolates 21 strains were chosen for whole genome sequencing (WGS) for a possible lead to develop appropriate countermeasures. In addition the genomic data would enable to determine the influence of microgravity on the pathogenicity and virulence in the BSL-2 microorganisms.