According to the landmark NASA Twins Study, extended spaceflight will change your poop.
Astronaut Scott Kelly spent a year on the International Space Station, while his twin brother, Mark, stayed on earth. During Scott’s stay in space, the brothers provided researchers with blood and saliva samples, eye sonograms, cheek swabs, cognitive tests and fecal matter.
After analyzing and comparing thousands of data samples, researchers found that the diversity of Scott Kelly’s gut bacteria did not change. However, he experienced two major shifts in his microbiome – or the collection of organisms in the intestines that help regulate a variety of bodily processes.
When in orbit, Scott’s gut microbes shifted significantly from the kinds that researchers found when living on earth. When he returned to earth, within months, his microbiome shifted once again back to its “normal” state.
“We cannot send humans to Mars without knowing how spaceflight affects the body, including the microbes traveling with humans to Mars,” said Fred Turek, PhD, professor at the Weinberg College of Arts and Sciences. “And we need to know sooner rather than later. The plan is to send people to Mars in 2035, so we cannot wait until 2033 to gain this information.”
NASA believes this study provides critical information indicating that spaceflight isn’t likely to permanently harm human bodies.