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Study of the Impact of Long-term Space Travel on the Astronaut's Microbiome (Microbiome)
Principal Investigator
Research Area:
Species Studied
Scientific Name: Homo sapiens Species: Human

The human microbiome, the collection of microbes that live in and on the human body, plays an important role in human health contributing to the processing and absorption of nutrients in the human body, and plays a protective role by competing for resources with pathogenic organisms. Changes in the dynamic or composition of the human microbiome may lead to altered human metabolic function or pave the way for the colonization of the human body by opportunistic pathogenic microorganisms. It is known that factors such as stress, diet, and an impaired immune system can trigger changes in the human microbiota, increasing the risk of contracting a disease. The goal of the experiment was to determine how the composition of the human microbiome changes during long-term space exploration and to evaluate its potential impact on a crewmember’s health. This is a retrospective study using data from Functional Immune Alterations, Latent Herpesvirus Reactivation, Physiological Stress and Clinical Incidence Onboard the International Space Station (Functional_Immune) and The Effects of Long-Term Exposure to Microgravity on Salivary Markers of Innate Immunity (Salivary_Markers). Some microbial species from the human microbiome have a beneficial or protective effect on health; the loss of these species can lead to an altered metabolic function and, in conjunction with reduced immune response, may increase the chance of infection by opportunistic pathogens. By sampling the microbiome of astronauts on earth while in peak physical health and during subsequent times of stress, including long-term exposure to microgravity, g-forces, radiation and changes in health status, the investigators aimed to define signatures of human response to a variety of relevant aspects of space travel.

This study had the following objectives:

  1. Characterize and investigate the changes occurring in the prokaryotic and viral microbiome of astronauts from key body sites before, during, and after a space mission.
  2. Assess astronaut immune function before, during, and after the space mission.
  3. Identify associations between changes in the astronaut’s microbiome and relevant metadata.

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Immune system
Virus activation

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Data Information
Data Availability
Archive is complete. Data sets are not publicly available but can be requested.
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Epstein-Barr Virus (EBV) DNA, saliva
Functional annotation
Immunoglobulin A (IgA)
Immunoglobulin G (IgG)
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Mission/Study Information
Mission Launch/Start Date Landing/End Date Duration
Expedition 36 05/13/2013 09/10/2013 166 days
Expedition 37 09/10/2013 11/10/2013 61 days
Expedition 38 11/10/2013 03/10/2014 120 days
Expedition 40 05/13/2014 09/10/2014 133 days
Expedition 41 09/10/2014 11/09/2014 29 days
Expedition 42 11/10/2014 03/11/2015 121 days
Expedition 43 03/11/2015 06/10/2015 91 days
Expedition 44 06/10/2015 09/11/2015 93 days
Expedition 45 09/11/2015 12/11/2015 91 days
Expedition 46 12/11/2015 03/02/2016 82 days
Expedition 47 03/02/2016 06/18/2016 108 days

Human Research Program (HRP) Human Research Roadmap (HRR) Information
Crew health and performance is critical to successful human exploration beyond low Earth orbit. The Human Research Program (HRP) investigates and mitigates the highest risks to human health and performance, providing essential countermeasures and technologies for human space exploration. Risks include physiological and performance effects from hazards such as radiation, altered gravity, and hostile environments, as well as unique challenges in medical support, human factors, and behavioral health support. The HRP utilizes an Integrated Research Plan (IRP) to identify the approach and research activities planned to address these risks, which are assigned to specific Elements within the program. The Human Research Roadmap is the web-based tool for communicating the IRP content.

The Human Research Roadmap is located at:

+ Click here for information of how this experiment is contributing to the HRP's path for risk reduction.

Additional Information
Managing NASA Center
Johnson Space Center (JSC)
Responsible NASA Representative
Johnson Space Center LSDA Office
Project Manager: Jessica Keune
Institutional Support
National Aeronautics and Space Administration (NASA)
Alternate Experiment Name
Proposal Date
Proposal Source
2010 Crew Health NNJ10ZSA003N