Digestion is the mechanical and enzymatic process of breaking down food into its small building blocks for absorption into the bloodstream. Foods contain three macronutrients that require digestion before they can be absorbed: fats, carbohydrates, and proteins. Through digestive processes, fats are digested into fatty acids, carbohydrates into monosaccharides, and proteins into amino acids before absorption. (1)
Naturally made digestive enzymes by the gastrointestinal tract and its accessory organs are a vital part of the digestive system that ensures foods are broken down and fully absorbed. Without them, maldigestion, malabsorption, and nutrient deficiencies can occur. In certain health conditions, digestive enzyme insufficiency may occur, and replacement enzymes may be necessary to prevent unwanted sequelae. Keep reading to learn about digestive enzymes, what happens during an enzyme insufficient state, and how functional medicine can help.
What Are Digestive Enzymes?
Digestive enzymes are proteins made in various locations within the digestive system that catalyze enzymatic reactions to break down and digest macronutrients into their small building blocks for absorption. Vitamins, minerals, and water are also products of digestion that are absorbed into the bloodstream. (1, 2)
Types of Digestive Enzymes
Thousands of digestive enzymes contribute to digestive processes. Enzymes are classified by the macronutrient they break down and are categorized into three main subtypes. (3)
Amylases: are responsible for the digestion of carbohydrates, sugars, and starches.
Proteases: (or peptidases) break down proteins.
Lipases: digest fat.
The action of digestive enzymes is promoted by other digestive secretions, like hydrochloric acid (stomach acid), produced by the stomach, and bile, produced by the liver, stored in the gallbladder and secreted into the small intestine. (1)
Where Are Digestive Enzymes Produced?
Digestive enzymes are also produced in the mouth, stomach, and small intestine. Chemical digestion begins in the mouth when salivary and lingual glands produce amylases to begin starch digestion. (1)
Stomach acid begins to denature proteins, and if produced in sufficient amounts to create an acidic enough stomach environment, the stomach will produce pepsin, which initiates the digestion of proteins. (1)
Along with pancreatic digestive enzymes, the small intestinal surface, called the brush border, is rich in maltase, sucrase, lactase, and peptidases (collectively referred to as brush border enzymes), which complete the digestion of carbohydrates and proteins before absorption. (1, 4)
What Causes Low Digestive Enzyme Production?
Digestive enzyme deficiency or insufficiency is a lower-than-normal production and secretion of digestive enzymes.
Gastrointestinal and genetic conditions can contribute to various forms of enzyme deficiencies. Congenital sucrase-isomaltase deficiency is a genetic disorder characterized by insufficient sucrase to digest certain sugars (5). Lactose intolerance, characterized by lactase deficiency, can be hereditary or acquired, caused by acute gastrointestinal infections, small intestinal bacterial overgrowth (SIBO), celiac disease, and Crohn's disease. Cystic fibrosis, autoimmune diseases (e.g., Sjogren's syndrome), and pancreatitis can also all contribute to the development of exocrine pancreatic insufficiency (EPI), which occurs when the pancreas doesn't produce enough digestive enzymes.
Lifestyle and environmental factors also can impact digestive efficiency. Excessive alcohol consumption, smoking, and stress can diminish digestive enzyme production. (3)
Symptoms of Low Digestive Enzymes
- Abdominal bloating and distension
- Constipation and/or diarrhea
- Abdominal pain and cramping
- Heartburn and reflux
- Flatulence and gas
Chronic digestive enzyme insufficiency can lead to malnutrition, presenting as (6):
- Unintentional weight loss
- Dry skin and lesions
- Poor immune function: frequent infection and delayed wound healing
- Muscle wasting
- Bleeding gums and nosebleeds
- Night blindness
- Changes to and loss of the menstrual cycle
- Growth delays
- Changes in mood: anxiety, depression, irritability
- Anemia and vitamin deficiencies
Functional Medicine Labs to Test for Root Cause of Low Digestive Enzymes
Functional medicine labs are invaluable in holistically evaluating the causes of digestive symptoms and repercussions of enzyme deficiencies. Functional medicine labs can use blood, stool, and salivary samples to diagnose digestive enzyme insufficiency, underlying causes of digestive dysfunction, and developing complications of poor digestion. These lab results help functional medicine practitioners implement personalized root-cause treatment plans for their patients.
CBC & CMP
Obtaining a complete blood count (CBC) and comprehensive metabolic panel (CMP) is a practical and cost-effective screening for the cause and effects of low digestive enzymes. Together, these two tests can indicate the presence of infection, nutrient deficiencies, anemias, and liver/gallbladder dysfunction contributing to and resulting from poor digestive function.
Fecal elastase measures exocrine pancreatic function, and a level less than 200 μg/mL is considered diagnostic for EPI. A comprehensive stool test includes pancreatic elastase and other fecal markers of maldigestion, which, if elevated, are signs of digestive enzyme insufficiency. Additionally, stool tests measure intestinal inflammatory markers that can indicate underlying causes of enzyme insufficiency, such as SIBO, celiac disease, and inflammatory bowel disease.
SIBO Breath Test
Bacterial overgrowth in the small intestines causes an inflammatory response and dampens the concentration of brush border enzymes in the small intestine, leading to carbohydrate maldigestion and malabsorption. Breath tests are available to diagnose SIBO, along with sucrose and lactose malabsorption, which may occur when sucrase and lactase enzymes are deficient.
An antinuclear antibody (ANA) and a multiple autoimmune reactivity screen (Array 5) are helpful blood panels to screen for autoimmune conditions that can cause damage to gastrointestinal organs and contribute to digestive enzyme insufficiency.
Acute and chronic stress activates the sympathetic nervous system and reduces parasympathetic nervous system activity, which is necessary for proper digestion and absorption. A stress panel measures adrenal hormones, cortisol and DHEA, to identify imbalances in the biological stress axis that negatively impact digestion.
Complementary and Integrative Medicine Treatment for Low Digestive Enzymes
Treatment of digestive enzyme insufficiency often relies on correcting underlying pathologies and factors contributing to the dysfunctional state. As the underlying pathology is being addressed, complementary and integrative medicinal modalities can be incorporated into a patient's routine to reduce stress and support gut health.
A mindful relaxation practice, especially before meals, can positively influence the gut-brain axis, reducing stress and stimulating the parasympathetic nervous system, which is required for healthy digestion and absorption processes.
Best Nutrition for Patients with Low Digestive Enzymes
Nutritional modifications for patients with low digestive enzymes will depend on the type and cause of digestive enzyme insufficiency.
Patients with identified pathology may benefit from therapeutic dietary interventions specific to that disease process to reduce symptoms of maldigestion. For example, patients with SIBO often feel a relief of symptoms with a low-FODMAP diet, a strict gluten-free diet is required for the successful treatment of celiac disease, and the autoimmune protocol (AIP) diet has been shown to improve markers of autoimmune disease.
How you eat can support mechanical and chemical digestion. Eating slowly, chewing food thoroughly before swallowing, and avoiding overeating will reduce the burden on digestive organs to digest food. Patients may notice improved symptoms by eating smaller, more frequent meals throughout the day versus eating three large meals daily. (7)
Digestive enzymes can be produced by plants and microbes, so eating certain foods that naturally contain enzymes can support digestion. Papaya, pineapple, and kiwi contain papain, bromelain, and actinidin, respectively, which help digest proteins. Fermented foods contain probiotics that have been shown to support lactose digestion and improve lactose intolerance. (3)
Supplements and Herbs That Increase Digestive Enzymes
People diagnosed with digestive enzyme insufficiency often need to take prescriptive or supplemental digestive enzymes with meals to help the body digest and absorb nutrients better. Pancreatic enzyme replacement therapy (PERT) is the only FDA-regulated prescription enzyme replacement therapy for EPI.
Many digestive enzyme supplements on the market vary in form, formulations, and source. Depending on health needs and diagnosis, a supplement with single or multiple digestive enzymes may be required. Popular digestive enzyme supplements include one or many of the following ingredients: betaine hydrochloric acid, pepsin, amylases, proteases, lactase, lipase, and ox bile. (3)
Restoration of a healthy small intestinal brush border may be required for some patients. Commonly recommended anti-inflammatory and gut-healing dietary supplements include ginger, curcumin, licorice root, L-glutamine, and zinc carnosine.
Digestion is a complex series of mechanical forces and chemical reactions exerted on food by the digestive tract. Digestive enzymes, predominantly produced by the pancreas, are responsible for the chemical breakdown of large food particles into small absorbable breakdown products. Disease states and environmental lifestyle factors can interfere with the normal production and secretion of digestive enzymes, causing digestive enzyme insufficiency, malabsorption, and malnutrition. If you suspect maldigestion may be contributing to your health concerns, find a functional medicine doctor to discuss integrative medicine options for the proper diagnosis and treatment of symptoms.
Lab Tests in This Article
1. Patricia, J.J., & Dhamoon, A.S. (2020, September 18). Physiology, Digestion. National Library of Medicine; StatPearls Publishing. https://www.ncbi.nlm.nih.gov/books/NBK544242/
2. Powell Key, A. (2021, November 29). What Are Digestive Enzymes? WebMD. https://www.webmd.com/diet/what-are-digestive-enzymes
3. Kielbiski, E. (2022, February 2). What Are Digestive Enzymes and How Do They Work? Fullscript. https://fullscript.com/blog/digestive-enzymes
4. Science Learning Hub. (2011, July 13). Digestive enzymes. Science Learning Hub; Science Learning Hub. https://www.sciencelearn.org.nz/resources/1840-digestive-enzymes
5. Denhard, M. (2022). Digestive Enzymes and Digestive Enzyme Supplements. Www.hopkinsmedicine.org. https://www.hopkinsmedicine.org/health/wellness-and-prevention/digestive-enzymes-and-digestive-enzyme-supplements
6. Preston, J. (2023, February 23). Functional Medicine Treatment for Malabsorption Syndrome. Rupa Health. https://www.rupahealth.com/post/functional-medicine-treatment-for-malabsorption-syndrome
7. Cox, C. (2022, October 17). How to Eat Well With EPI. WebMD. https://www.webmd.com/digestive-disorders/epi-smart-diet