Digestive Enzymes

Digestion begins in the mouth with salivary amylase, which converts starch into maltose, maltotriose, and alpha-dextrin (10). Then in the stomach, pepsin breaks down proteins into peptides, while gastric and lingual lipases convert triacylglycerols into fatty acids, diacylglycerols, and monoacylglycerols (10). The resulting chyme (food that has undergone gastric digestion) then passes through the pylorus into the small intestine, where the partially digested macronutrients are further broken down into fully absorbable nutrients (10).

 

The following table shows the main types of digestive enzymes found in the brush border of the small intestine and their functions (10):

Enzyme	What it breaks down
Alpha-dextrinase	Alpha-dextrin into glucose
Maltase	Maltose into glucose
Sucrase	Sucrose into glucose and fructose
Lactase	Lactose into glucose and galactose
Enterokinase	Trypsinogen into trypsin
Peptidases (aminopeptidase and dipeptidase)	Peptides and dipeptides into amino acids and peptides
Nucleosidases and phosphatases	Nucleotides into nitrogenous bases, pentoses, and phosphates

All the mechanical and chemical processes that take place along the digestive tract serve to process food into a form that can pass through the epithelial cells of the mucosa and into the bloodstream and lymphatic vessels (10). However, some people don’t naturally produce enough of certain digestive enzymes, making it difficult for their bodies to digest and absorb certain nutrients. This can lead to the presence of partially digested food in the gut, causing gastrointestinal symptoms.

 

Certain health conditions, such as exocrine pancreatic insufficiency (EPI), can interfere with the production of digestive enzymes. EPI occurs when the pancreas is unable to produce enough digestive enzymes (5).

 

Enzyme differences are also involved in lactose intolerance. In some individuals, the mucosal cells of the small intestine do not produce enough lactase (1, 10). Lactose then goes undigested, causing fluid retention in the stool and being fermented by bacteria, which produces gas (1, 10). Symptoms of undigested lactose include diarrhea, abdominal cramps, bloating and flatulence (1, 10).

There are a number of enzyme supplements available on the market. For specific medical conditions like EPI, healthcare providers can establish medical protocols incorporating such supplements. Many over-the-counter digestive enzymes are also available for managing gastrointestinal symptoms, but there is often little scientific evidence of their effectiveness.

 

Lactase is one of the enzyme supplements that does have scientifically proven benefits (7, 9). It is available in drop and tablet form and helps increase lactose tolerance in lactose-intolerant individuals (7, 9).

 

Another supplement with scientifically demonstrated benefits is alpha-galactosidase, the enzyme that breaks down galacto-oligosaccharides (GOSs) into simple sugars (2, 11). When the body fails to produce it, unabsorbed GOSs travel to the colon and are fermented by intestinal bacteria, causing gastrointestinal symptoms (2, 11).

 

There are also combined enzymes proven to help digest certain FODMAPs. FODZYME® enzyme blend is a supplement made of three enzymes that break down fructans, GOSs, and lactose (3, 8). It’s taken as a powder added to food just before consuming to help improve tolerance (3, 8).

 

There are also xylose isomerase supplements available for people with fructose malabsorption or intolerance (4, 6). It’s taken before consuming any source of fructose—apples, pears, mangoes, honey, asparagus, bell peppers, wheat, candy, soft drinks, etc.

 

Science-based enzyme supplement	Name brands
Lactase	Lactaid®, Lacteeze®
Alpha-galactosidase	Beano®, Gas Stop Enzyme Formula (Renew Life®), AORzymes (AOR®)
Three-enzyme blend (fructan hydrolase, alpha-galactosidase, lactase)	FODZYME®
Xylose isomerase	Fructaid®

 

Although there are enzyme supplements that can help manage digestive symptoms, patients should seek a clinical evaluation before using them.

Enzyme supplement use is of interest in certain specific clinical contexts for managing symptoms of gastrointestinal conditions such as lactose intolerance and certain FODMAP intolerances. However, a clinical nutritional assessment should always be performed to identify any potential food intolerances (FODMAPs, added fats, histamines, etc.) and assess the eating context (chewing, how fast meals are consumed, etc.) before a patient starts using any such supplements.