To keep space travellers safe, NASA researchers are taking steps to fight fungus as prolonged stay in closed habitats that may one day be used to explore other planets might be stressful for inhabitants and thus lead to decreased immune response, making people more vulnerable to opportunistic pathogens like fungi.
Human presence in closed habitats is associated with changes in the composition of the fungal community -- the mycobiome -- that grows on surfaces inside the habitat, according to a study published in the journal Microbiome.
"Our study is the first report on the mycobiome of a simulated habitat meant for the future human habitation of other planets. We used the Inflatable Lunar/Mars Analog Habitat (ILMAH), a unique, simulated closed environment that mimics the conditions found on the International Space Station and possible human habitats on other planets," said Kasthuri Venkateswaran, Senior Research Scientist at the NASA Jet Propulsion Laboratory, and corresponding author of the study.
"We showed that the overall fungal diversity changed when humans were present," Venkateswaran said.
The primary goal of the ILMAH was to understand the physiological, psychological, and behavioral changes in humans in a confined environment.
Three student crews were housed inside the ILMAH for 30 days. In order to determine which fungal species were present and how the composition of the mycobiome changed during human habitation, samples collected at various time points in a 30-day period were characterised.
The researchers found that certain kinds of fungi -- including known pathogens that can colonise the human body and cause allergies, asthma and skin infections -- increased in number while humans were living inside the ILMAH.
"Fungi are extremophiles that can survive harsh conditions and environments like deserts, caves or nuclear accident sites, and they are known to be difficult to eradicate from other environments, including indoor and closed spaces," Venkateswaran said.
"Characterising and understanding possible changes to, and survival of, fungal species in environments like the ILMAH is of high importance since fungi are not only potentially hazardous to the inhabitants but could also deteriorate the habitats themselves," Venkateswaran said.
Knowing how fungal communities change in the presence of humans is thus necessary for the development of appropriate countermeasures to maintain habitats like the ILMAH or the ISS and to protect the health of the people who live there.