Protein is arguably one of the more essential macronutrients when it comes to diet. It helps with muscle and bone synthesis, as well as assists in regulating hormones and enzymes. 

As soon as a protein source is ingested, it begins the breakdown process in your mouth, but the biggest part of protein digestion is in your stomach and small intestine with enzymes called protease and hydrochloric acid. 

Protein goes for a ride before it is digested and absorbed into the bloodstream. Go on its journey with us as we explain as simply as we can, how protein gets digested and absorbed to build and support your body. 

What is protein?

Protein is not just what we consume, but what we are made of. We have protein in our hair, bones, skin, and of course throughout our bodies in muscles and tissues. Amino acids are what make up proteins and are something that our body can actually make on its own. 

The tricky part in the amino acid building is that we need 20 different amino acids and our bodies can only make up about 11 of those, leaving us without 9. This is where food comes in, as we will get the remaining amino acids from high-protein foods like dairy, poultry, fish, and red meats. 

Where does protein digestion begin?

Protein digestion begins in the stomach. The start of breakdown begins in the mouth through the enzymes in your saliva but will begin to be digested once it enters the stomach. Your mouth will still play a role in the digestion process when chewing your food thoroughly, creating more surface area to be broken down faster. 

Once the protein reaches your stomach it begins the breakdown into simpler amino acids to be absorbed into the body. The end of the road for protein will be in the small intestine, from there it will travel to the liver and be distributed throughout the body as needed.

How does protein get absorbed?

Your small intestine is where all of the protein gets absorbed. The protein is broken down further into 3 categories: tripeptides, dipeptides, and amino acids. Once broken down, they get transported using energy from our body into the bloodstream. 

Once absorbed into the bloodstream and taken to the liver, Healthyeating, reports that it can then be incorporated into new protein, distributed to muscles and tissues, and stored to be used as energy.  

How do the enzymes play a part?

Enzymes’ role in the body is to digest and create energy from the food that it is digesting. There are hundreds of enzymes in our body, each with a very specific function. For example, lipase breaks down fat, carbohydrase breaks down carbs, and lactase breaks down lactose. 

In our case, we are talking about protease, this enzyme is responsible for the breakdown of protein to create amino acids. The rate at which protease breaks down proteins will be dependent on their biological value (BV). A whey protein powder will have a higher BV than meat, because of the added digestive enzymes and the liquid form it is usually consumed in. 

When the enzymes do not need to break down the protein as much it is faster for that protein to be absorbed into the bloodstream. 

Final thoughts

Protein is an important macronutrient, and if you would ask me it is THE most important one. As you can see there is a lot that goes into the breakdown and absorption of protein. Keeping a healthy gut is essential for the enzymes to do their job and distribute protein correctly and efficiently.