According to a recent publication in Scientific Reports, the way we view space-grown food, such as lettuce and other leafy greens, may need to be reconsidered. While it is crucial to provide astronauts with necessary nutrients during their time in space, these plants are apparently more vulnerable to bacteria like salmonella, as per the study. The research was led by scientists from the University of Delaware and raises concerns about the potential use of space-grown food in deep space exploration missions, such as NASA’s future manned mission to Mars.
If the findings hold true and space-grown leafy greens are more prone to bacterial contamination, this could pose a serious threat to astronauts as more of them are sent into space over the next few decades. 
NASA astronaut Kate Rubins harvesting radishes on board the ISS. Image source: NASA While it’s not possible to directly test how plants grow in microgravity on Earth, the researchers utilized specialized equipment to simulate the weightless environment found on the International Space Station, which also provides insights into how humans would live in space.
Tech. Entertainment. Science. Your inbox. Sign up for the most interesting tech & entertainment news out there. By signing up, I agree to the Terms of Use and have reviewed the Privacy Notice. When using this weightless system to deceive the plants into thinking they are not in a gravity environment, the researchers discovered that lettuce was more likely to have open stomata, which are tiny pores in the leaves and stems that typically close when a plant senses a need to protect itself. These stomata usually close when faced with stressors like bacteria. However, the researchers observed that when exposed to weightless environments like those in space, the stomata did not close, making the plant susceptible to bacteria. Given that bacteria are likely to be present on the ISS and other space environments, this presents a significant challenge for space-grown food, particularly if other plants exhibit similar characteristics in a weightless setting. Perhaps researchers can find a way to stimulate the stomata to function even in a weightless environment. Nonetheless, consuming any type of leafy green grown in space could pose a significant risk for astronauts.
