In a new study published in the journal npj Microgravity, scientists and astronauts conducted experiments with human cells and pathogens to see how the two would change and interface differently in a low-gravity environment. The researchers used the microbial species salmonella typhimurium to infect human cells in controlled experiments on Earth and on the International Space Station.

Chia-Yi Hou of Changing America writes the researchers found that there were changes in RNA and protein expression in the human cells in a microgravity environment. They also found that salmonella was able to cause the human cells to upregulate — increase the rate or level of — expression of compounds that would help fight an infection in both cells that were inflight and on the ground.

Inflight cells upregulated genes that were associated with inflammation, one of the human body’s mechanisms for fighting pathogens. Other genes that are related to virulence or stress regulators were also upregulated in the cells in space compared to the cells on the ground.