The ISS is too sterile: more "dirt" could improve crew health
The most comprehensive analysis of samples from the ISS suggests that it is far too sterile. More natural microbes could reduce the number of diseases.
The ISS from the outside
(Image: NASA)
The International Space Station (ISS) is too sterile, and more microbes from nature could possibly ensure that astronauts fall ill there less often. This is the result of the most comprehensive analysis to date of samples taken from surfaces on board the space station, reports the University of California, San Diego. Most of the microbes found in the samples came from human skin, and many chemicals from cleaning products and disinfectants were also detected. The human outpost in space is therefore most similar to hospitals and isolated habitats, and therefore not particularly healthy.
As sterile as a hospital
As Rodolfo Salido's research group now explains, astronauts on board the ISS often suffer from immune disorders, skin rashes and inflammatory diseases. To find out whether this is due to the sterility of the environment, they analyzed samples taken from over 800 locations in the ISS – more than 100 times as many as in previous studies. This enabled them to create a three-dimensional map of the microbiome on board the space station. The microbes were actually able to identify where food is prepared on the ISS or where the toilets are located. Overall, however, the diversity was significantly lower than in terrestrial habitats.
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Overall, the ISS lacked the free-living microbes that are found on Earth in soil and water, for example. If these microbes and the environments in which they occur are deliberately brought to the ISS, this could be beneficial to the health of the crew without compromising hygiene, the team writes. This refers to the proven positive effects of gardening on health. The point is that people there no longer "stew in their own filth", as is the case in such a closed environment where no healthy sources of microbes can penetrate from outside.
Overall, the research group does not just want their findings to be seen as important for the operation of the ISS. "If we really want life to thrive outside of Earth, we can't just send a small part of the tree of life into space and hope that everything will be fine," says Salido. We need to think about what useful companions we can give astronauts in order to develop ecosystems that are sustainable and useful for everyone. The research has now been published in the journal Cell.
(mho)
