Keeping your house clean can be challenging. Consider what it would be like to have several people confined to a small space on the International Space Station (ISS). You might think that keeping that environment perfectly clean and sterile would ensure the astronauts’ health. That is not necessarily the case. Excessive cleanliness on the International Space Station may cause health problems.
According to a new study, the ISS may be more sterile than it should be. Microbes can be beneficial to our health, and research indicates that low microbial diversity on the ISS may be contributing to immune dysfunction, skin rashes, and other inflammatory issues. The new study suggests that introducing more Earth microbes may help prevent astronaut health problems.
For the study, astronauts were asked to swab 803 surfaces on the ISS and return the samples to Earth for analysis. The returned samples contained chemicals from cleaning products and disinfectants, as well as microbes. Researchers examined how the bacteria and chemicals interacted. Particularly important were the dining, food-prep, and toilet areas.
Microbes in our natural Earth environments may help strengthen our health and resistance to infections and skin problems. We have millions of microbes on our skin and in our gut that are not harmful and actually help us digest our food and fight diseases. While on Earth, we have beneficial microbes all around us, but excessive cleanliness on the International Space Station may not be entirely positive. The researchers suggested introducing microbes from Earth to give a more natural balance without posing any health risks to the astronauts.
Sanitized living spaces may not be as healthy as we think. There are far more microbes on planet Earth than there are people, and we can be thankful that God has placed them here for the benefit of life.
— Roland Earnst © 2026
Reference: Discovermagazine.com