

I find that remarkable considering the fact that astronauts would eat high protein foods to minimize their bowel movements because the human body will efficiently absorb highly bioavailable proteins and fat (e.g. from animal sources) it consumes. Considering human feces are 75% water and the remaining 25% are primarily bacterial biomass and plant matter, my guess is the carnivores you know have just started the diet and have upset their stomachs with the sudden change.
What about Rumble? GN is on there and directly supportable.