Is the International Space Station Too Clean? Scientists Explore the Surprising Impact on Space Research

The International Space Station (ISS) may be too sterile for the astronauts living there. A recent study suggests that a little more dirt could actually be beneficial.

Astronauts on the ISS often face health issues like immune problems and skin disorders. Researchers think this might be due to the lack of microbial diversity on the station compared to Earth.

The microbes present mostly come from human sources, which means the environment is quite different from what we’d find in nature. This raises an interesting idea: if astronauts could introduce more natural microbes, it might improve their health.

To illustrate this, researchers liken it to gardening. Studies show that handling healthy soil can enhance our immune systems. Rob Knight from UC San Diego noted that being in a confined space without outside microbial input leads to a buildup of just our own microbes, rather than exposing astronauts to a variety of healthy ones.

In the study, scientists worked with astronauts to swab 803 surfaces aboard the ISS—significantly more than in previous studies. They created detailed 3D maps that showed where these samples were taken and what types of microbes were present.

The findings revealed that most of the microbes came from human skin, and cleaning chemicals were also visible across the station. The microbial community on the ISS was far less diverse than on Earth, resembling that of sterile environments like hospitals.

This unique microbial and chemical environment has been documented in a paper titled “The International Space Station Has a Unique and Extreme Microbial and Chemical Environment Driven by Use Patterns,” published in the journal Cell.