In collaboration with NASA, researchers have investigated what happens in astronauts' stomachs. By analysing blood from astronauts on the ISS, they discovered that during spaceflight, protein ferments to a greater degree than normal.
It can also happen on Earth and is linked to food staying longer in the intestines.
"The lack of gravity in space probably causes food to move more slowly through the gut, which may help explain constipation in astronauts. This is consistent with our seeing signs of increased protein fermentation," says Jan Stanstrup at the University of Copenhagen and one of the study authors, in a press release.
