It's harder to poop in space. Scientists may finally know why

Astronauts have long struggled with constipation in space. Now, scientists may finally understand why.A new study of 52 astronauts who lived aboard the International Space Station (ISS) suggests that microgravity may slow the movement of food through the intestines, changing how gut bacteria break down nutrients. The findings could ultimately help researchers develop dietary strategies to keep astronauts' digestive systems running smoothly during future missions to the moon and Mars — whil