I believe many such enzymes are taken in an enteric coating, which prevents the denaturation of the enzymes by protecting them in the stomach and subsequently dissolving outside of the stomach releasing the enzymes.
Admittedly Maximum living's claims that their pancreatic enzymes work
with stomach acid gives me pause for thought although the fact that they contain cellulose and magnesium stearate would be consistent with enteric coating.
TTFN,
WK