What are Digestive Enzymes and How do they Work? An Overview of Human Digestive Enzymes

Page content

What are Digestive Enzymes?

Human digestive enzymes assist the body in breaking down food. There are many different enzymes that work in our oral cavity, stomach and small intestine, as one enzyme can’t break down all types of food stuffs. Faulty enzyme reactions may contribute to health issues such as bloating, food allergies, nausea and stomach disorders.

Oral Digestive Enzymes

The salivary amylase is an enzyme responsible for breaking down starches into sugar. This enzyme is present in saliva, where the process of digestion actually begins. Food that is high in starch and low in sugar, such as potatoes, taste sweet while chewing, because the digestion process is already beginning. Other digestive enzymes present in the oral cavity are lipase, trypsin and sucrase.

Stomach Digestive Enzymes

Pepsin is produced by the stomach gastric pit, and is responsible for breaking protein into peptides. When the digestion process starts, gastrin (which is a hormone) triggers the release of this digestive enzyme from the stomach lining. Pepsin is stored in the body so it’s only released when the body needs it. After the pepsin has broken down the food, the gelatinase, gastric amylase, and gastric lipase enzymes are released, degrading the proteoglycans in meat, starches and fat.

Small Intestine Enzymes

The majority of digestive activity occurs in the small intestines. Steapsin is part of a group of digestive enzymes called lipases. These digestive enzymes are found in the pancreatic juices and digest vegetable oils and animal fat. First food is broken down by the oral digestive enzymes, and once the pepsin is released, stepsin takes over, further digesting the food. Then the food is moved into the small intestine for further digestion. Steapsin is responsible for turning fatty acids and glycerol.

How do Enzymes Work?

Enzymes are catalysts and as such they speed up chemical reactions. They are proteins that break up food so that its nutrients can be absorbed by the body and waste products can be directed towards the exit. Food macromolecules are essentially broken down into their component parts i.e. proteins will be broken down into amino acids.

An enzyme works by binding to a specific substrate, in this case food. It has a binding site that the substrate molecules will fit into - this is called the active site. Enzymes work best under specific temperature and acidic conditions. When temperature increases so does the rate of reactions, however above 45 degrees Celsius the enzyme will denature.

Combating Incomplete Digestion

If you think you suffer from incomplete digestion, there are diet adjustments you can make to optimize the usage of your digestive enzymes. Some people recommend drinking lemon water to boost digestive juices in the mouth. Others advise taking B complex vitamins as well as suggesting adding a teaspoon of apple cider vinegar to a glass of warm water before eating to encourage digestive acids.