Each food has the enzymes and probiotics necessary for proper early stages of digestion ... ain't God smart?? The digestive system makes more ... example, insulin is an enzyme. If you use Rx insulin instead of correcting the problem in the body, the pancreas makes less insulin.
When I was a kid, if you went in for abdominal surgery of any sort, they went ahead and took out your appendix, considering it a useless organ (we have NO useless organs). The appendix is the incubator of friendly flora, you literally will grow your own if you are eating plenty of raw, fresh fruits and veggies.