Where is cellulose digested?

Answer 1

Cellulose is not particularly digestible by the human digestive tract and tends to pass thorugh as roughage. Herbivorous animals called ruminants (deer, sheep, camals, etc.) can digest cellulose through bacterial action in one or more of the four sections of their stomach.

Answer 2

Cellulose cannot be digested by humans any more, because it's too tough to be broken down by enzymes. Tens of thousands of years ago, however, humans were predominantly herbivore, so they had a large appendix (like rabbits and other plant-eaters) which contained bacteria to "ferment" and break-down the substance. As humans evolved, though, we became more reliant on meat, and so the appendix lost its function. Now, any cellulose passes straight through our digestive system, and out as faeces.

Answer 3

It is fermented in the cecum and further digested in the ascending colon