There two types of enzymes: Digestive enzymes and systemic enzymes.
Digestive enzymes play a major role in the digestion of food. Secreted naturally along the upper gastrointestinal tract, digestive enzymes help the body break down food so nutrients can be absorbed into the bloodstream. Specific digestive enzymes help the body break down certain food elements. For example, the enzyme protease acts on protein, amylase on carbohydrates, cellulase on fiber, lipase on fat and lactase on dairy sugar.
While the body produces its own digestive enzymes, it may not be enough to completely break down cooked or processed foods. Raw foods contain their own natural enzymes that activate in the acidic environment of the stomach. During cooking and processing, these natural enzymes are destroyed. Fortunately, digestive enzyme supplements can replace destroyed enzymes, resulting in fewer digestive problems (indigestion, gas and bloating) and a more complete release and absorption of food nutrients.
Systemic enzymes, also called proteolytic enzymes, help support the immune system and help the body with normal inflammatory processes. Systemic enzymes containing select blends of acidic, alkaline and neutral proteases have been shown to reduce pain, swelling and redness associated with inflammatory conditions. They are a safe alternative to Nonsteroidal Anti-Inflammatory Drugs (NSAIDs), which have been linked to adverse side effects.
Enzymes, Inc. uses a proprietary blend of proteases called pHysioProtease™ in many of its vegetarian-based systemic products. In a recent study, pHysioProtease™ was evaluated with three commercially-available protease blends recommended for systemic use. The results revealed that pHysioProtease™ provided significantly more systemic enzyme activity per dose.
Source: Enzyme supplements for indigestion and inflammation