Digestive Enzymes


Products classified as digestive enzymes help facilitate digestion, the absorption of nutrients, maintenance of proper pH in the gastrointestinal tract, and act as a barrier against invasion of pathological organisms. There are seven basic types of digestive enzymes. Also, there are various sub-classifications within some of these groups, and each type of enzyme has a specific activity and functions best within a specific pH range. The basic enzymes and their related functions are as follows: amylase digests starches, cellulase digests fibers, lactase digests dairy products, lipases digest fats, oils and triglycerides, maltase digests starch and grains, proteases digest proteins and sucrase digests sugars.

Some enzymes are extracted from animal sources such as the pancreas, liver and stomach of cattle or pigs. Examples of animal enzymes include oxbile, trypsin, chymotrypsin, rennin, pepsin, and pancreatin. Other digestive enzymes are derived from plants such as bromelain from pineapple and papain from papaya.

Hydrochloric acid, which is produced in the parietal glands in the lining of the stomach, is necessary for the digestion of proteins. Although hydrochloric acid is not an enzyme, it is required to convert pepsinogen to pepsin for the digestion of proteins. Betaine hydrochloride, which is a form of hydrochloric acid that is derived from beets, is a source of hydrochloric acid that is commonly referred to and utilized as a digestive enzyme product. For the purposes of this monograph, hydrochloric acid and its related products will be considered as digestive enzymes.

More recently, a large percentage of the digestive enzymes being used in commercial products are produced from fungi and bacteria using fermentation processes. In the dietary supplement industry, these products are called plant-based digestive enzymes to distinguish them from enzymes from animal sources. Actually, calling these products plant enzymes is incorrect because fungi and bacteria are not plants, but this terminology has been accepted and is being used. One of the claims for these plant-based digestive enzyme products is that they function at a pH range from 2 to 12, which means they are effective in the acidic environment of the stomach as well as the more alkaline environment of the small intestines.

Digestive enzymes work within a specific pH range. For example, agents such as betaine hydrochloride, bromelain and papain, which digest proteins, function primarily in the stomach where the environment needs to be fairly acidic. Pancreatic enzymes exert their digestive effects in the small intestines where the pH is more alkaline. Plant-based digestive enzyme products reportedly function over a wider pH range (pH 2 to 12), which enables them to function in both the stomach and the small intestine environment.

Impaired digestive function can produce many symptoms and is associated with a wide variety of clinical conditions such as gas, bloating, heartburn, indigestion, malabsorption disorders, malnutrition, dysbiosis, leaky gut, diarrhea, constipation, lactose intolerance, food allergies, celiac disease, etc. However, there is a disappointing lack of scientific studies regarding the use of digestive enzyme products in the treatment of health conditions. The use of digestive enzymes to treat symptoms and clinical conditions associated with digestive problems comes mostly from clinical observations, anecdotal comments, and manufacturer’s product claims. Even though there is a lack of scientific research to verify the effectiveness of digestive enzymes, these products have become quite well accepted and are commonly used.

Dosage Info

Dosage Range

Not applicable because dosages vary widely due to different clinical conditions, patient’s individual responses, and different types of digestive enzyme products available.

Most Common Dosage

Not applicable because dosages vary widely due to different clinical conditions, patient’s individual responses, and different types of digestive enzyme products available.

Dosage Forms

Tablets, capsules, and powders.

Adult RDI

None established

Adult ODA

None established

Active Forms

There are many different types of digestive enzymes and digestive enzyme products. Examples of substances in digestive enzyme products include proteases such as bromelain and papain, lipase, amylase, lactase, cellulase, pancreatin, and betaine hydrochloride.


Small amounts of some digestive enzymes may be absorbed from the intestinal tract into systemic circulation. However, most digestive enzymes are not systemically absorbed, but rather function within the gastrointestinal tract.

Toxicities & Precautions


Digestive enzyme products are considered safe when used in accordance with proper dosing guidelines.

Functions in the Body

Clinical Applications


Pancreatic diseases are a frequent cause of dyspepsia and in these cases, the use of pancreatic enzyme supplementation can be useful. (1)


Administration of pancreatic enzymes resulted in a significant reduction of bloating associated with the ingestion of high calorie, high fat meals. (2)

Cystic fibrosis

Patients with cystic fibrosis generally have pancreatic enzyme insufficiency causing fat malabsorption. Administration of pancreatic enzyme supplements helps improve fat absorption in these patients. (3) , (4) , (5)


Administration of pancreatic enzymes resulted in a significant reduction of gas following the ingestion of high calorie, high fat meals. (6)

Lactose Intolerance

Individuals who are lactose intolerant do not produce enough lactase to properly digest milk and dairy products. Lactase-containing enzyme products help people reduce the symptoms associated with this condition. (7) Adding a few drops of lactase to a quart of milk and allowing it to stand overnight substantially reduces the amount of lactose present. Chewing lactase-containing tablets reportedly helps people digest solid lactose-containing foods.


The use of pancreatic enzyme supplements is very effective in reducing the amount of fecal fat loss in HIV patients with fat malabsorption. (8)


The use of pancreatic enzymes helps reduce nutrient malabsorption problems in patients with chronic pancreatitis. (9)


Administration of enteric coated pancreatic enzyme supplements caused a significant reduction in fecal weight and fat excretion in patients with steatorrhea. (10)

Symptoms and Causes of Deficiency

It is generally believed that aging results in a gradual reduction in individual’s ability to secrete gastric hydrochloric acid (11) and pancreatic enzymes (12) for digestive purposes.

Dietary Sources

Digestive enzymes in commercial products come from several sources. Some come from the organs of animals, some such as papain and bromelain come from plants, and many are produced from fungi and bacteria via fermentation processes.


  1. View Abstract: Worning H. Exocrine pancreatic function in dyspepsia. Digestion. 1987;37(Suppl 1):3-13.
  2. View Abstract: Suarez F, Levitt MD, Adshead J, Barkin JS. Pancreatic supplements reduce symptomatic response of healthy subjects to a high fat meal. Dig Dis Sci. Jul1999;44(7):1317-21.
  3. View Abstract: Santini B, Antonelli M, Battistini A, et al. Comparison of two enteric coated microsphere preparations in the treatment of pancreatic exocrine insufficiency caused by cystic fibrosis. Dig Liver Dis. Jun2000;32(5):406-11.
  4. View Abstract: Littlewood JM, Wolfe SP. Control of malabsorption in cystic fibrosis. Paediatr Drugs. May2000;2(3):205-22.
  5. View Abstract: Ritz MA, Fraser RJ, Di Matteo AC, et al. Evaluation of the 13C-triolein breath test for fat malabsorption in adult patients with cystic fibrosis. J Gastroenterol Hepatol. Apr2004;19(4):448-53.
  6. View Abstract: Suarez F, Levitt MD, Adshead J, Barkin JS. Pancreatic supplements reduce symptomatic response of healthy subjects to a high fat meal. Dig Dis Sci. Jul1999;44(7):1317-21.
  7. View Abstract: Ramirez FC, Lee K, Graham DY. All lactase preparations are not the same: results of a prospective, randomized, placebo-controlled trial. Am J Gastroenterol. Apr1994;89(4):566-70.
  8. Carroccio A, Guarino A, Zuin G, et al. Efficacy of oral pancreatic enzyme therapy for the treatment of fat malabsorption in HIV-infected patients. Aliment Pharmacol Ther. Oct2001;15(10):1619-25.
  9. View Abstract: Layer P, Keller J. Pancreatic enzymes: secretion and luminal nutrient digestion in health and disease. J Clin Gastroenterol. Jan1999;28(1):3-10.
  10. View Abstract: Lankisch PG, Lembcke B, Kirchhoff S, et al. Therapy of pancreatogenic steatorrhea. Comparison of 2 acid-protected enzyme preparations. Dtsch Med Wochenschr. Jan1988;113(1):15-7.
  11. View Abstract: Korkuschko OW, Kotko DN. Peculiarities of unconditioned and conditioned reflex stimuli effects on secretory function of gastric glands in elderly and senile people. Aktuelle Gerontol. Jun1976;6(6):305-10.
  12. View Abstract: Laugier R, Bernard JP, Berthezene P, Dupuy P. Changes in pancreatic exocrine secretion with age: pancreatic exocrine secretion does decrease in the elderly. Digestion. 1991;50(3-4):202-11.