Eighty percent of our immune system is in the gut. This makes sense when one considers that the digestive tract is technically outside the body. That is, it is a hollow tube into which we put food that we will digest and absorb through the walls of our intestines into our bodies. It is only once we have absorbed the food through the intestines that, technically-speaking, it is inside us. Since part of the immune system’s function is to protect us from the outside world, it’s no wonder then why so much of the immune system is clustered around the digestive tract.

When our digestion is working properly, and food gets broken down into the smallest possible particles, our immune system does not react. However, if we are not producing enough digestive enzymes, or if we are genetically predisposed to react to certain proteins in foods (e.g., gluten), our immune system becomes active and can cause a whole host of problems, including gas, bloating, abdominal discomfort, autoimmune disease, brain fog, eczema and dermatitis.

Digestive enzymes are the work-horses of our gastrointestinal system. They are complex proteins that break down the food we eat into smaller particles that we can absorb. They work optimally at specific temperature and pH (a measurement of the strength of acid). There are three classes of digestive enzymes: proteolytic enzymes needed to digest protein, lipases needed to digest fat , and amylases needed to digest carbohydrates. A lack of digestive enzymes leads to malnutrition and can also cause autoimmune reactions anywhere in the body.

Carbohydrate digestion begins in the mouth with the production of saliva. Saliva contains the enzyme alpha-amylase, which begins the breakdown of sugars such as starch. Once food enters the stomach, hydrochloric acid deactivates alpha-amylase while activating pepsin, which is produced in the stomach. Pepsin begins the digestion of proteins. Hydrochloric acid in the stomach is responsible for activating the enzymes produced in that organ. A lack of hydrochloric acid, or low hydrochloric acid production in the stomach, is the cause for decreased digestive enzyme activation in some people. If low acid production is suspected, your doctor might consider directly testing the amount of acid you’re producing, or prescribe a trial of oral hydrochloric acid supplementation. Alternatively, some natural remedies exist to help people increase their production of stomach acid.

As the food travels from the stomach to the small intestine, the acidity decreases, and the pancreas secretes other enzymes that become activated. These include proteolytic enzymes (digest proteins), lipase (digests fat), amylase (digests carbohydrates). Without these enzymes food particles remain too large to be absorbed properly. When the particles are too large and they pass through the intestinal lining, they can be detected by the immune system as foreign. The immune system then becomes activated and attacks the partially digested proteins in the food. This causes an inflammation in the gut, and the intestines become damaged.

When they’re damaged, gaps can develop between the cells in the intestines, allowing even more undigested food particles to get through the gut wall and activate the immune system. Until this cycle is stopped through proper nutrition and treatments (e.g., by taking digestive enzymes and other remedies to heal and strengthen the lining of the gut), damage continues. And if these immune complexes enter the blood stream, they can settle out in distant organs such as joints and the skin, and cause arthralgia (joint pain) and eczema. Improving digestion is part of a holistic approach to treating a wide range of diseases.

If your doctor recommends supplementing with digestive enzymes, it’s important to only take enzymes that will survive the acid environment of the stomach as they travel to the small intestines where they’re needed most. These “acid-stable” enzymes will be the most beneficial. Plant-based digestive enzymes, such as bromelain, tend to be acid-stable. Bromelain is a proteolytic enzyme isolated from the pineapple plant (Ananas comosus), and was discovered in 1957. Bromelain activity is measured in GDUs (gelatin curdling units) or MCUs (milk curdling units). The dosage of bromelain as a digestive aid is 6,000 GDU or 9,000 MCU taken with meals. Since bromelain digests proteins, a full-spectrum digestive enzyme formula will also contain acid-stable lipases and amylases for digesting fat and carbohydrates, respectively.