Study of the Impact of Long-Term Space Travel on the Astronauts' Microbiome (Microbiome) - 07.29.14
ISS Science for Everyone
Science Objectives for Everyone
The Microbiome experiment investigates the impact of space travel on both the human immune system and an individual’s microbiome (the collection of microbes that live in and on the human body at any given time). To monitor the status of the crewmembers' microbiome and immune system and their interaction with the unique environment of the International Space Station (ISS), we will take periodic samples from different parts of the body and the surrounding ISS environment. As part of this study, the likelihood and consequences of alterations in the microbiome due to extreme environments, and the related human health risk, will be assessed.
Science Results for Everyone
Johnson Space Center, Human Research Program, Houston, TX, United States
Sponsoring Space Agency
National Aeronautics and Space Administration (NASA)
Human Exploration and Operations Mission Directorate (HEOMD)
Earth Benefits, Scientific Discovery, Space Exploration
ISS Expedition Duration
March 2013 - Ongoing
Previous ISS Missions
- This research is needed to determine how long-duration space flight may affect the human microbiome and, in consequence, human health.
- Various samples will be collected from ISS crewmembers before, during, and after their missions to the ISS to determine how microgravity, the ISS environment and diet affect their stress levels, immune system function and microbiome.
- This research can help predict how long-term space travel may impact the human microbiome and human health.
The goal of the experiment is 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. 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. This experiment will elaborate the notion of the microbiome as harbingers or sentinels to monitor a variety of aspects of the human host, including associations with health status, environmental stress, and exposure to space conditions. 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, we will be able to define signatures of human response to a variety of relevant aspects of space travel. This experiment will characterize the prokaryotic and viral microbiome from various body sites of nine crewmembers who travel to space at several time points before, during, and after a space mission. Also, the crewmembers’ immune function and stress levels will be assessed before, during, and after the missions by analyzing saliva samples for reactivated latent viruses and cortisol levels as well as cytokines from blood samples. Finally, the microbiome and immune function data collected will be correlated with other measured metadata including crewmember health and hygiene as well as environmental factors (such as temperature and humidity) that will be documented in conjunction with the subject swab sessions.
During a mission to space, astronauts are subject to many stressful conditions (g-forces, radiation, microgravity, anxiety, etc.) that can have a negative impact on their health. Several studies have demonstrated that space travel affects the astronauts’ immune systems and have shown some evidence suggesting that changes in their microbiomes occur as well. Because the human microbiome plays a key role in human health, it is important to assess the effect of long duration space exploration on the microbial population that inhabits the human body. This study will carry out a thorough evaluation of how long-term space travel impacts the human microbiome and ultimately human health, and it will form the basis for further studies towards the design of therapies to mitigate any microbiome changes or related health issues found as a result of this project. Therefore, this study has the potential to lower the risks to human health for future space explorations.
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/or playing a protective role (for example) by competing for resources with pathogenic organisms. Changes in the dynamics 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 product of this study will be an assessment of the likelihood and consequences of alterations in the microbiome due to extreme environments, and the related human health risk.
Findings from this study could be used to benefit people on earth that live and work in extreme environments. Other potential applications of this study could be to further research in preliminary detection of diseases, alterations in metabolic function, and immune system deficiency.
A total of 9 subjects are required for this investigation.
For six-month missions, in-flight sessions are planned on flight day (FD) 7 (±7 days), FD90 (±7 days), and R-14 ((±7 days) for subject swabs, gastrointestinal samples (optional), and saliva samples. The optional gastrointestinal sample must be collected from the first bowel movement after the subject swabs are collected. Blood collection sessions are planned on FD7 (±7 days) and R-1, and ISS surface swabs and perspiration collection are planned on FD7 (±7 days) and R-14 (±7 days). Potable water collection is scheduled once per increment, but must be collected within 2 weeks before returning to the ground.
For one-year missions, in-flight sessions are planned on FD7 (±7 days), FD90 (±7 days), FD180 (±15 days) and R-30 (±30 days) for subject swabs and gastrointestinal samples (optional). The optional gastrointestinal sample must be collected from the first bowel movement after the subject swabs are collected. Blood collection sessions are planned on FD7 (±7 days), FD180 (±15 days), FD240 (±15 days) and R-1. ISS surface swabs and perspiration collection are planned on FD7 (±7 days) and R-30 (±30 days). Saliva samples are planned on FD7 (±7 days), FD90(±7 days), FD180 (±15 days), FD240 (±15 days), and R-30 (±30 days). Potable water collection is scheduled once per increment, but must be collected within 2 weeks before returning to the ground.
Subject swabs of the forehead, left and right forearm, left and right nares, and oral cavity along with four saliva samples will be collected using sterile swab devices, salivettes, and gloves. Gastrointestinal samples (optional) will also be collected using a modified, sterile swab device and gloves following the first bowel movement after the subject swabs are collected. In conjunction with the subject swab/gastrointestinal/saliva sampling, ISS surface swabs will be taken from ISS module locations used throughout a normal crew day. ISS surface swabs will be collected from the crewmember’s sleeping quarters, exercise equipment, handheld microphone, Cupola knob, and two air vents located within frequently used ISS modules using a swabbing device. The crewmember will also collect a 400ml (minimum) water sample from the Potable Water Dispenser (PWD) once during the increment. Whole body perspiration collection will use sterile swab devices. Four and a half ml of blood will be collected on FD7 using blood collection hardware from the HRF Supply Kit and will be processed using the Refrigerated Centrifuge. Ten ml of blood will be collected on R-1 (also on FD180 and FD240 for a yearlong mission), but those samples will not be centrifuged. All samples, except for blood samples collected after FD7 and water, will be frozen in MELFI for later return. Blood samples collected after FD7 and water samples will remain at ambient temperature and will return on the Soyuz. Lastly, an Environmental Health and Hygiene survey will be completed as part of the subject swab sessions to document metadata including astronaut health and hygiene, and environmental factors, such as temperature and humidity, will be collected via ECLSS for subject swab, ISS surface swab and perspiration sample collection sessions.
Ground Based Results Publications
Nickerson CA, Ott CM, Wilson JW, Ramamurthy R, Pierson DL. Microbial Responses to Microgravity and Other Low-Shear Environments. Microbiology and Molecular Biology Reviews. 2004; 68(2): 345-361.
Wilson JW, Ott CM, Quick L, Davis R, Honer zu Bentrup K, Crabbe A, Richter E, Sarker SF, Barrila J, Porwollik S, Cheng P, McClelland M, Tsaprailis G, Radabaugh T, Hunt A, Shah M, Nelman-Gonzalez MA, Hing SM, Parra MP, Dumars P, Norwood KL, Bober R, Devich J, Ruggles AD, CdeBaca A, Narayan S, Benjamin J, Goulart C, Rupert M, Catella LA, Schurr MJ, Buchanan K, Morici L, McCracken J, Porter MD, Pierson DL, Smith SM, Smith SM, Mergeay M, Mergeay M, Leys N, Stefanyshyn-Piper HM, Gorie D, Nickerson CA. Media Ion Composition Controls Regulatory and Virulence Response of Salmonella in Spaceflight. PLOS ONE. 2008; 3(12). DOI: 10.1371/journal.pone.0003923.
JCVI: Astronaut Microbiome