Digestive Enzymes

Reading Time: 12 minutes

Elisabeth Phillips PhD and Antony Haynes BA, RNT explore the role and nature of digestive enzymes, to unlock some of the mystery around their role in human health and supplementation.


Digestive enzymes catalyse (cause or accelerate (a reaction) by acting as a catalyst) the breakdown of food in the mouth and gut so nutrients are released and can be absorbed across the intestinal barrier into the blood stream. Therefore, one of the main functions of digestive enzymes is to increase the bioavailability of nutrients.

Digestive enzymes are produced in your saliva and as exocrine (a gland that secretes a substance out through a duct) secretions from the pancreas, released via pancreatic juices into the duodenum by specific hormonal signals during the consumption of food. The environment in which digestive enzymes function, as well as the availability of energy, is key to their synthesis and activity. This means the health of the digestive tract, including structure and function of the gastric and intestinal mucosa; pH and composition of gut microbiota all play critical roles in the process of digestion.

Causes of Digestive Enzyme Deficiency

There are many reasons why we do not make enough of our own digestive enzymes. Poor enzyme production can lead to problems of nutrient insufficiency, and even deficiency, resulting in a whole host of health problems.

One of the main reasons for reduced output of digestive enzymes is poor exocrine pancreatic function. The causes of Exocrine Pancreatic Insufficiency (EPI) are very diverse ranging from:

  • Problems with the endocrine part of the pancreas such as insulin dysregulation from diet high in refined carbohydrates and diabetes
  • Gall stones that block the bile duct and reduce/halt the flow of pancreatic juices (biliary stasis)
  • Poor function of the Sphincter of Oddi that controls release of bile and pancreatic juices from the bile duct into the small intestines
  • Alcohol abuse
  • Micronutrient deficiency
  • Protein deficiency
  • Diets high in refined carbohydrates causing hypoglycemia, insulin resistance and diabetes
  • High calorie intake
  • Too little or too much exercise

Other factors that greatly impact on digestive enzyme output include:

  • Foods or drinks that promote intestinal inflammation including coffee, alcohol, sugar, highly processed foods
  • Individual food sensitivities like gluten, dairy, corn, soy etc.
  • Chronic GI infection or inflammation
  • Repeated antibiotic exposure, which affects gut microbiota, digestive and liver health
  • Physical, emotional or psychological stress, which reduces pancreatic digestive enzyme output, as well as affecting many other areas of digestive function and health
  • Smoking
  • Pregnancy, which places extra demands on the body’s energy requirements
  • Ageing, which leads to a decline in pancreatic and digestive function

Symptoms of Digestive Enzyme Insufficiency

There are many symptoms relating to digestive enzyme insufficiency. Let’s face it, if you are not absorbing all the essential nutrients from your diet then there could be no end to the potential impact on your health!

Symptoms of digestive enzyme insufficiency are normally first apparent in the gut. Symptoms may appear for a day or even a week, and may include:

  • Bloating
  • Flatulence
  • Abdominal pain or discomfort
  • Irritable bowel type symptoms
  • Diarrhoea
  • Constipation
  • Gut microbiota dysbiosis
  • Undigested food in the stools
  • Stools that float (steatorrhea)
  • Feeling full after only a few mouthfuls
  • Food allergies and intolerances

In some, the lack of enzymes can become a chronic insufficiency. The wider impact of digestive enzyme deficiency on health includes:

  • Obesity
  • Allergies and poor immune function
  • Depression and anxiety
  • Premenstrual Syndrome
  • Fatigue
  • Autoimmune conditions such as coeliac disease
  • Ulcerative colitis and Crohn’s disease

It’s important to bear in mind that as we age, or indeed experience chronic sub optimal health, our digestive function deteriorates. The general medical trend is often to view common acute digestive symptoms such as heartburn and indigestion as an excess stomach acid (hyperchlorydria). Antacid or proton pump inhibitor medications are frequently prescribed to reduce levels or production of stomach acid. In fact, over £4.2 m was spent in September 2016 on omeprazole (PPI) prescriptions by GP surgeries in England alone![1] This is one of the highest-level prescribing trends of any drug by GPs in England. Many of these medications are also widely available in high street chemists and supermarkets after self-diagnosis, potentially encouraged by widespread TV and magazine adverts promoting the ease in combatting the symptoms rather than addressing the underlying causes.

Stomach acid is needed to activate endogenous digestive enzymes, properly digest food and release nutrients (especially calcium, magnesium, iron, Vitamin C, Vitamin B12 and folate) and importantly to protect against pathogens. This means that reducing or blocking its production has potential knock on effects for other digestive processes and health in general. Research from Professor Mullins at the Johns Hopkins School of Complementary Medicines suggests that biliary issues (pooling of bile in the stomach) may well contribute to up to 75% of cases of where patients complain of acid stomach or reflux. This suggests the need for bile flow support agents rather than digestive enzymes alone

The appropriate use of enzymes in the ageing population may well help prevent nutrient deficiencies and even inflammatory conditions.

Digestive Enzymes Supplements

Supplemental digestive enzymes can originate from three different sources: animals, plants and microbes.

Animal-sourced enzymes include pancreatin, pepsin, trypsin and chymotrypsin. Pancreatin is still often used by practitioners and usually includes most of the enzymes necessary for digestion of proteins, fats and carbohydrates in the small intestine (i.e. proteases to break down proteins into amino acids; amylase to cleave complex carbohydrate molecules into manageable sugars; and lipase to facilitate the breakdown of lipids).

Plant-sourced enzymes like bromelain (from pineapple) and papain (from papaya) provide proteolytic enzymes, which break down proteins, and are included in many digestive formulas. These can be very useful to take every day with food or even as the occasional “aftermeal” enzyme to encourage the completion of the digestive process. They have additional use as systemic enzymes in promoting healthy inflammation resolution and are suitable for vegetarians and vegans. Gluten specific proteases can be included in specialist formulations to assist in the degradation of gluten proteins.

Microbial-sourced enzymes from fungi (including yeasts) and bacterial sources can be used by vegetarians and vegans and have good gastric resilience. Microbial enzymes can include amylase, glucoamylase, proteases, lipase and multiple types of saccharidases including lactase (to digest lactose), alphagalactosidase (for digesting beans, legumes and cruciferous vegetables) and cellulase (to digest cellulose), along with hemicellulase, xylanase and pectinase, which are all very important enzymes for digesting plant components. Phytase is another supplementary digestive enzyme that can be taken in a broad-spectrum formulation to support the digestion of phytic acid, a component of plant material that binds minerals reducing their bioavailability.

Supplementing with microbial types of digestive enzymes can be particularly useful when switching to a more plant-based diet by helping digestion of tougher plant components like cellulose and increasing nutrient bioavailability. They are also complementary to those enzymes produced by the pancreas so are not considered to “override” the natural digestive enzyme action.


Lipases Lipase – found in humans, plants and certain microbes Essential for digestion of fats (e.g. triglycerides and phospholipids) in conjunction with the emulsification effects of bile salts (lecithin) that are released from the gallbladder. Lipase from pancreatic juices and bile from the gallbladder mix in the bile duct and are secreted into the duodenum. Lipase deficiency can lead to steatorrhea and many fat handling problems in the body.
Proteases Gluten proteases – found in certain microbes Digest highly resistant proline-rich peptides in gliadin fraction of gluten and casein that can lead to activation of the immune system in the gut resulting in autoimmune damage to intestinal tissue as seen in conditions like coeliac disease. In addition, gluten and casein-derived proline-rich peptides may exert opioid-like activity in the central nervous system causing sedation (i.e. post-meal drowsiness) and food addictions. Think of feeling sleepy after a carbohydrate heavy meal or even feeling addicted to bread! Further along this neurological scale gluten and casein are believed to trigger neurological symptoms encountered in children with autism spectrum disorders. Gluten is most prevalent in wheat and processed bread products. Casein makes up 80-90% of cow’s milk proteins versus 0.2% goat’s milk.
Alkali proteases –found in certain microbes Digest proteins within pH 4.0-11. Optimal activity is around pH6, which is found in the small intestines.
Acid proteases – found in certain microbes Digest proteins within pH 2.0-6.0, which is the range found in the stomach and small intestines. Optimal activity is around pH4.5.
  Bromelain – found in pineapples When taken with food bromelain contains protease enzymes to help digest proteins to small peptides and individual amino acids.
Carbohydrases Amylase – found in humans and certain microbes Starch and glycogen specific enzymes that break down polysaccharides into disaccharides. Also works in conjunction with gluten-specific proteases to break down the carbohydrate portion of gliadin found in gluten that, along with the proline peptides, causes autoimmune damage and symptoms found in conditions like coeliac disease and gluten intolerance. It is important to supplement with both amylase and gluten-digesting proteases for full benefits.
  Amyloglucosidase – found in plants and certain microbes Breaks down amylase disaccharides into monosaccharides. Think of starch as a tree; amylase works on digesting starch units (i.e. saccharides) from the end of branches inwards until it comes to a fork where it stops as the links are different. Glucoamylase breaks down these “fork” links so starch digestion is complete. Amylase and amyloglucosidase should always be taken together.
  Lactase – found in babies, plants and certain microbes Digests the milk sugar lactose into galactose and glucose. Lactase is naturally produced in the digestive tract of infants (unless they have congenital lactase deficiency). However, the LCT lactase producing gene activity decreases into adulthood so that many adults are unable to effectively digest lactose. For many, this results in symptoms of lactose intolerance.
  Alpha galactosidase – found in certain microbes. Hydrolyses raffinose, stachyose and verbascose in legumes, whole grains and some vegetables into simple sugars glucose, galactose and fructose. Known to reduce gas production when eating fermentable carbohydrates.
  Invertase (type of sucrase) – found in humans, plants and certain microbes. Breaks down sucrose and maltose into fructose and glucose.
Fibrolytic Enzymes Phytase – found in plants and certain microbes Digests phytic acid from nuts, seeds, grains and cereals such as bran and wheat into myo-inositol and phosphates. Phytic acid is considered an “anti-nutrient” as it binds essential minerals, such as zinc, resulting in decreased bioavailability, i.e. reduced absorption in the gut.
  Cellulase – found in plants and certain microbes Breaks down cellulose, a plant fibre found in fruit and vegetables. Chitin, a structural component of Candida albicans yeast cell walls, has virtually identical structure to cellulose. Cellulase may therefore help reduce Candida infection.


How Potent Is Your Digestive Enzyme Supplement?

Enzyme activity (or potency) is a measure of how much enzyme is needed to accomplish a specific reaction within a specified time. The Food Chemical Codex (FCC) is the industry standard for measuring enzyme activity. Each enzyme is assigned their own FCC potency (activity) unit. This not only demonstrates the amount of activity of each enzyme in a product but also ensures the enzyme levels are standardised and allows comparison between different FCC labelled products.

Unfortunately, there is currently no regulation of enzyme activity in food supplements. This can make choosing a digestive supplement a bit of a lottery. It is for this reason that you should always choose a reputable brand that states all enzyme activity in FCC units so the activity and not just the amount (weight) of the enzyme per capsule is known.

If the product states just the weight of the enzymes (e.g. in milligrams, mg) then this tells you nothing about the actual activity. That means you might choose a digestive enzyme supplement that contains say 40mg lipase over the one that contains 20mg lipase because you would think the bigger dose of lipase would have twice the activity. However, every enzyme preparation can have different activities so you would not know the real potency of either lipase dose unless the FIP FCC unit for lipase enzymes was stated. This means if you choose a digestive enzyme supplement that states enzyme activity in FCC units you are making an informed decision and can be safe in the knowledge that the activity of each enzyme has been carefully measured and standardised.

Synergistic Supplements

Digestion is not solely down to digestive enzymes but requires synergistic actions of stomach hydrochloric acid, bile salts and a healthy lining to the GI tract to enable vital nutrients to be absorbed. Complementary digestion supporting supplements that work synergistically with a digestive enzyme formula may include:

  • Betaine and pepsin and zinc citrate to support gastric hydrochloric acid levels and protein digestion.
  • Mixed strain probiotic supplement to support the levels of health promoting gut bacteria.
  • Aloe Vera whole leaf juice – bioactive polysaccharides provide wide-reaching digestive including support promoting a healthy gut lining and supporting growth of beneficial gut bacteria and digestion of proteins.
  • Colon supporting herbs like turmeric and ginger, garlic and papaya extract.
  • Lecithin powder high in phosphatidyl choline supports digestion of fats as well as healing the lining of the digestive tract.
  • Beet concentrate with taurine and pancreatic lipases to support bile flow.
  • Bile extract (porcine source) can also support bile flow and function.

Digestion Perfection

Digestion requires energy, nutrients and several interconnected stages, including synthesis and release of digestive enzymes, to function effectively, efficiently and most importantly seamlessly so our lives are not interrupted or hampered by acute symptoms or longer-term poor health.

The first stage to digestion perfection is to address the diet, encouraging reduction/elimination of foods and drinks that cause and contribute to gut inflammation and to increase more plant-based foods. Digestive juices and colon function, not to mention numerous other areas of our body, require adequate fluid levels so1.5-2L hydrating fluids daily is recommended. Digestive supporting supplements like digestive enzymes work in tandem with these dietary changes and can be used acutely or longer-term to support digestion.

Addressing lifestyle factors to manage physical, emotional and psychological stress also plays an important role in improving digestive health. Mindful eating, such as reducing stressful situations when eating and chewing food slowly and thoroughly encourages the production and release of digestive enzymes in saliva and pancreatic juices.


[1] https://openprescribing.net/chemical/0103050P0/

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2 Comments. Leave new

  • It is great blog post. I am Always read your blog. Helpful and Informative blog. Thanks for sharing these information with us.

  • Thank you for this informative piece, this was very helpful to my understanding of EPI and digestion. I’m now aware of what I can do with other digestive enzymes to better aid my recovery and overall health. I appreciate the mentions of psychological health and low stress lifestyle, which tells further insight into cause, as I have no associated diagnoses.


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