The same principle applies with tablets for indigestion. Using the tablets causes the natural enzymes to shut down or off. So a pickle a day works better.
Sorry....but digestive enzyme tablets do not cause your body to produce less or shut down enzymatic process. If that was the case, then foods would cause the same thing, since many have enzymes still intact. What cause improper enzyme function is low hydrochloric acid, which happens with age. The low acid levels prevent proper titration, which is the locomotion which allows enzymes to reach the location of the body in need.
If you are talking about the purple pill, it works by inhibiting hydrochloric acid. It does not turn off enzyme production. It does, turn off enzyme production. However, it will cause malabsorption of nutrients and dispiosis of the gut, because HCL is necessary for healthy gut flora and nutrient absorption from food, specifically, magnesium and the amino acid L-Taurine, both of which are deficient in the older population. Interestingly, the three most common ailments in the elderly is AFIB, osteoporosis, and sleep disorders. All of which are strongly related to such deficiencies. As for proteolytic or systemic enzymes: we all have a finite supply and when they are, they are gone. The higher your enzyme load, the faster they are depleted. Enzymes supplements help to reduce the load, thus sparing our natural enzyme production.