## Blood tests reveal why astronauts get constipated in space ## Astronauts’ gut bacteria shift within weeks of entering space, potentially revealing why constipation is so common in microgravity. Constipation is a familiar problem for astronauts, but scientists have not fully understood why spending time in space can disrupt normal digestion. New research from the University of Copenhagen, conducted in collaboration with NASA, offers a possible explanation. Scientists analyzed blood samples from 52 astronauts who spent months aboard the International Space Station and found signs that the…