Eating seems simple: you chew, you swallow, you get the nutrients. Behind the scenes, though, a whole team of enzymes is working to take that meal apart so your body can use it. Here's how they break it down.
What are digestive enzymes?
Enzymes are proteins that speed up chemical reactions. Digestive enzymes are the ones that break large food molecules, like starches, proteins and fats, into pieces small enough to pass through the wall of your small intestine and into your bloodstream.
Each enzyme is specialized. Amylase works on starch, proteases work on protein and lipase works on fat. Your body makes them in your mouth, stomach, pancreas and small intestine, and each one works best in its own part of the digestive tract.
How does digestion work, step by step?
Here's the route a meal takes, based on the National Institutes of Health's overview of the digestive system.
1. It starts in your mouth
Chewing breaks food into smaller pieces and mixes it with saliva, which contains amylase to start breaking down starch. Your mouth even gets a head start: just seeing, smelling or imagining food can make you salivate.
2. Then your stomach
Your stomach churns food with stomach acid (hydrochloric acid) and enzymes, mainly pepsin, which begins breaking down protein. The acid isn't an enzyme itself; it creates the conditions pepsin needs to work.
3. Then your small intestine
This is where most digestion and absorption happens. Your pancreas releases a juice full of enzymes, including amylase, proteases such as trypsin, and lipase, which digest carbohydrates, proteins and fats. Your liver makes bile, which is stored in your gallbladder and helps break fat into small droplets so lipase can reach it. Enzymes on the lining of the small intestine, such as lactase, finish the job.
The nutrients are then absorbed through the intestinal wall. Whatever isn't digested moves on to the large intestine, where gut bacteria ferment some of it, producing gas along the way.
What are the main types of digestive enzymes?
- Amylase breaks starches into sugars.
- Proteases (such as pepsin and trypsin) break proteins into smaller peptides and amino acids.
- Lipase breaks fats (triglycerides) into fatty acids and monoglycerides.
- Lactase breaks lactose, the sugar in milk, into glucose and galactose.
What other enzymes are in digestive supplements?
Many supplements also include enzymes from plants and microbes. Some are well studied; for others the evidence is thin.
- Papain comes from papaya and breaks down protein. In a small placebo-controlled study, a papaya preparation eased constipation and bloating in people with ongoing digestive complaints.
- Bromelain comes from pineapple and also breaks down protein. It has been studied for a range of uses, including digestion, mostly in small studies.
- Alpha-galactosidase breaks down the complex carbohydrates in beans. In a placebo-controlled trial, it reduced gas and flatulence after a bean-heavy meal.
- Cellulase, hemicellulase, xylanase, pectinase and beta-glucanase break down different parts of plant cell walls and fiber. Humans don't make these enzymes. Supplement makers include them to help release nutrients from plant foods, but human evidence for them is limited.
How do I know if I have enough digestive enzymes?
Most people make plenty. The clearest exception is lactose intolerance: many adults make less lactase as they get older, and lactose then causes gas, bloating or diarrhea. Our article on lactose intolerance and gut health covers this in detail.
When the pancreas doesn't make enough enzymes, a condition called exocrine pancreatic insufficiency (EPI), the signs include fatty, greasy stools, diarrhea, weight loss, bloating, excess gas and vitamin deficiencies. EPI is a medical condition. It needs a diagnosis and prescription pancreatic enzymes from a doctor, not an over-the-counter supplement.
See your doctor if you notice oily or floating stools, unexplained weight loss, ongoing diarrhea or pain. Occasional gas and fullness after a big meal, on the other hand, are normal.
Can a digestive enzyme supplement help?
For some people and some meals, yes. In a double-blind study, healthy adults who took pancreatic enzymes with a large, high-fat meal had less bloating, gas and fullness afterward. Lactase taken with dairy reduced symptoms in people with lactose intolerance. Researchers continue to explore plant- and microbe-derived enzyme blends, though the evidence is still developing.
One important limit: enzyme supplements don't make gluten safe for people with celiac disease. The treatment for celiac disease is a gluten-free diet.
If heavy meals tend to leave you burping, bloated or uncomfortably full, our Break It Down capsules combine 15 plant-based enzymes with 1 billion probiotics. Read how and when to take digestive enzymes to get the most from them, and how enzymes and probiotics work together.
