When you eat a meal, your body gets to work digesting it using enzymes. The job of these substances is to break up the food into particles that can be absorbed by your body. Several of these enzymes -- amylase, lipase and proteases -- are produced in an inactive form in the pancreas, an organ in your abdomen. They are activated when they are secreted into the part of the intestine located just beyond the stomach -- the duodenum.
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Amylase is an enzyme produced by your body that helps break down starches and complex sugars -- carbohydrates -- in your food. Most of the amylase in your body is made by the pancreas, but a small amount is made by the glands that produce your saliva. Salivary amylase begins the digestion of carbohydrates in your mouth, breaking them down into simple sugars that can be absorbed. It accompanies the food into your stomach where it continues its work. Once the food leaves your stomach, amylase produced in the pancreas and secreted into the intestines takes over the digestion of carbohydrates.
The job of the digestive proteases is to break down the proteins in your food into their building blocks -- amino acids. Examples of digestive proteases are trypsin, chymotrypsin and elastase. Each is responsible for breaking down a different part of the protein. Once the proteins have been broken down into amino acids, some of them are absorbed into the bloodstream. Other amino acids play a role in increasing the secretion of pancreatic enzymes and slowing the emptying of your stomach so that you feel full.
Lipase is also secreted by your pancreas and is responsible for digesting fat from the food you eat. Most of the fat in food is in the form of triglycerides, which cannot be absorbed from your intestine. Lipase works with bile, a substance made by your liver and stored in your gallbladder. Bile helps ingested fat form small globules of triglycerides, which lipase breaks down into their building blocks -- fatty acids. Fatty acids are absorbed into the bloodstream, where they again form triglycerides. These are delivered to organs such as the liver, where they are used to store energy.
Exocrine Pancreatic Insufficiency
Exocrine pancreatic insufficiency refers to a deficiency of the digestive enzymes amylase, lipase and proteases. It can be caused by a variety of conditions, ranging from chronic inflammation -- known as chronic pancreatitis -- to cystic fibrosis, celiac disease, previous surgery and tumors. When the pancreas cannot make enough amylase, lipase and proteases, the body cannot adequately absorb carbohydrates, fats and proteins. This leads to weight loss, abdominal pain and bloating, diarrhea with fatty stools, vitamin deficiencies and malnutrition. Exocrine pancreatic insufficiency is treated with dietary restriction, vitamin supplementation and synthetic enzymes.
REFERENCES & RESOURCES
- The Exocrine Pancreas; Stephen J. Pandol
- National Nutrition: Amylase
- University of Maryland Medical Center: Lipase
- Proteases: Structure and Function; Klaudia Brix and Walter Stöcker
- Cleveland Clinic: Triglycerides
- Modern Nutrition in Health and Disease, 10th Edition; Maurice Edward Shils, et al.
- World Journal of Gastroenterology: Exocrine Pancreatic Insufficiency in Adults: A Shared Position Statement of the Italian Association for the Study of the Pancreas
- National Institute of Diabetes and Digestive and Kidney Diseases: Your Digestive System and How it Works