system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5:Gravity aids us in our digestion. However, in space, how is food digested? Does it float around in your digestive system?
gpt
Remember

>Gravity ***aids*** us in our digestion.

Which means there are other ways to move food down the digestive system. The answer is muscles. Food in your mouth is pushed to the stomach by muscles in the lining of the tube between mouth and your stomach. Then, in your stomach the digested food is pushed again into your intestines. While in the intestines it is pushed all the way to the, well, to the end.

As a simple experiment, try drinking water while standing on your head. You will be amazed that you can indeed swallow the water. You could even eat a full meal on your head and you would have no problem getting your food where it belongs.

Also your digestive system, when empty, isn't just full of open space where food can float around inside like you see on cartoons. Your stomach shrinks down as food passes from it and can expand as much as 50x in size! But when empty your stomach isn't just a gallon of empty air.