Digestive Enzyme Types Explained: Protease Lipase Amylase and What Each One Does

Digestive Enzyme Types Explained: Protease Lipase Amylase and What Each One Does

By Dr. Onikepe Adegbola, MD PhD — Johns Hopkins-trained physician-scientist and founder of Casa de Sante

The Major Enzymes

Proteases (Protein Digestion)

• What they do: Break the peptide bonds in protein molecules → progressively smaller peptides → individual amino acids ready for absorption.
• Types: Pepsin (stomach, activated by acid), trypsin and chymotrypsin (pancreatic, work in small intestine), peptidases (brush border enzymes, final breakdown).
• Why you need them: Incomplete protein digestion → large peptide fragments reach the colon → bacterial fermentation → gas, bloating. Also: undigested proteins may cross a permeable gut barrier → immune reactions.
• Signs of insufficiency: Feeling heavy after protein-rich meals, excessive gas after meat/eggs/dairy, slow recovery from exercise (amino acids needed for muscle repair).

Lipase (Fat Digestion)

• What it does: Breaks down triglycerides → free fatty acids + monoglycerides → absorbed through intestinal wall.
• Requires bile: Bile emulsifies fat globules (makes them smaller) → increased surface area for lipase to work. Without adequate bile (gallbladder removal, liver disease), lipase alone isn't enough.
• Why you need it: Fat malabsorption → steatorrhea (pale, floating, foul-smelling stools), fat-soluble vitamin deficiency (A, D, E, K), essential fatty acid deficiency, bloating after fatty meals.
• Signs of insufficiency: Greasy stools, stools that float, feeling sick after fatty food, visible oil droplets in toilet water.

Amylase (Starch Digestion)

• What it does: Breaks down starch (complex carbohydrate) → maltose → glucose. Digestion begins in the mouth (salivary amylase) and continues in the small intestine (pancreatic amylase).
• Why you need it: Undigested starch reaching the colon → rapid bacterial fermentation → gas, bloating, diarrhea. This is the mechanism behind carbohydrate intolerance.
• Signs of insufficiency: Bloating after bread/pasta/rice/potatoes, excessive flatulence after starchy meals, feeling tired after carb-heavy meals (poor glucose availability).

Specialized Enzymes

Alpha-Galactosidase (Bean/Legume Digestion)

• Breaks down galacto-oligosaccharides (GOS) — the specific FODMAP in beans, lentils, chickpeas, and some vegetables (broccoli, Brussels sprouts).
• Humans do NOT produce alpha-galactosidase. We literally cannot digest GOS on our own. That's why beans cause gas in EVERYONE, not just IBS patients.
• This is the enzyme in Beano and similar products. A game-changer for patients who want to eat legumes.

Lactase (Dairy Sugar Digestion)

• Breaks down lactose (milk sugar) → glucose + galactose. Most of the world's adult population produces insufficient lactase (lactose intolerance is the biological norm).
• Supplemental lactase allows dairy consumption for lactose-intolerant individuals. Must be taken WITH the dairy product, not before or after.

Cellulase (Plant Fiber Digestion)

• Breaks down cellulose (the structural fiber in plant cell walls). Humans produce ZERO cellulase.
• This is why raw vegetables are harder to digest than cooked ones (cooking softens cellulose). Supplemental cellulase improves digestion of raw vegetables and salads.

Invertase (Sugar Digestion)

• Breaks down sucrose (table sugar) → glucose + fructose. Supports the brush border enzyme sucrase.

Why Broad-Spectrum Supplements Outperform Single Enzymes

• Every meal contains protein, fat, AND carbohydrates. Taking just protease or just lipase addresses only one component.
• Meals with mixed macronutrients (which is most real food) require all three major enzyme categories working simultaneously.
• Adding specialized enzymes (alpha-galactosidase, lactase, cellulase) extends coverage to the specific problem foods (beans, dairy, raw vegetables) that single-enzyme products miss.
• The most effective digestive enzyme supplements combine ALL of these in a single capsule — mimicking the comprehensive enzyme cocktail that your pancreas is supposed to produce.