One would think that astronauts’ living quarters in space need to be perfectly sterilized, but it turns out that creating a "dirtier" environment with more microbes from Earth may boost their health.
New research has shown that the International Space Station (ISS) is overly sterile, and while this may not sound like an issue, it carries some surprising consequences; the sterile nature of the station has led to a low diversity of microbes, which could be what is causing astronauts to develop health complications like immune dysfunction, skin rashes, and other inflammatory conditions while in space.
A study recently published in the journal Cell analyzed samples that were collected by astronauts, finding inadequate microbial diversity compared to human-occupied environments on Earth. Introducing environmental microbes from Earth into the ISS, the study suggests, may help stave off health problems that are often experienced by the astronauts living there.
Analyzing Bacteria on the ISS
In the study, researchers called on astronauts to swab 803 different surfaces on the ISS, which gathered 100 times more samples than previous surveys have examined. The samples returned to Earth, where they were analyzed to determine the presence of bacterial species and chemicals. The researchers then constructed 3D maps that displayed where each sample was found on the station and how the bacteria and chemicals might be interacting.
The results, detailed in a statement, showed that human skin was the primary source of microbes in the ISS and that chemicals from cleaning products and disinfectants were present all throughout the station. Certain microbial communities were also present in different areas of the station — the dining and food prep areas contained more food-associated microbes, while the space toilet contained more urine- and fecal-associated microbes and metabolites.
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The Benefits of Microbes
The ISS, however, is missing microbes from natural environments that bolster human health. Most microbes — which live all around us and even populate our own skin and gut — aren’t out to harm humans; many actually provide health benefits like helping to digest food into nutrients and fighting diseases. Being in nature can support the positive growth of one’s microbiome, the community of microorganisms that coexist with us and live inside our bodies.
Compared to natural environments on Earth, where beneficial microbes reside in soil and water, the ISS lacks diverse microbial communities. The samples were more akin to those found in industrialized, isolated environments like hospitals and closed habitats.
The researchers claim that introducing microbes from Earth could potentially reinforce the microbial community on the ISS without posing any hygienic risks to astronauts.
“Future built environments, including space stations, could benefit from intentionally fostering diverse microbial communities that better mimic the natural microbial exposures experienced on Earth, rather than relying on highly sanitized spaces,” said co-first author Rodolfo Salido of the University of California, San Diego.
Keeping Astronauts Healthy
Future studies will be geared toward the detection of pathogenic (or disease-spreading) microbes and signals of human health from environmental metabolites, small molecules that are products of cellular metabolism. An enhanced understanding of these factors will help scientists decide how to move forward, potentially encouraging healthier living spaces for astronauts and people working in similarly sterile places here on Earth.
“If we really want life to thrive outside Earth, we can't just take a small branch of the tree of life and launch it into space and hope that it will work out,” said Salido. “We need to start thinking about what other beneficial companions we should be sending with these astronauts to help them develop ecosystems that will be sustainable and beneficial for all.”
Read More: Microbes Can Colonize Space, Produce Drugs, and Create Energy
Article Sources
Our writers at Discovermagazine.com use peer-reviewed studies and high-quality sources for our articles, and our editors review for scientific accuracy and editorial standards. Review the sources used below for this article:
National Acadamies. Are all microbes dangerous?
Jack Knudson is an assistant editor at Discover with a strong interest in environmental science and history. Before joining Discover in 2023, he studied journalism at the Scripps College of Communication at Ohio University and previously interned at Recycling Today magazine.
