People of every age experience digestive issues from time to time, but as we get older, annoyances like constipation, diarrhea and gas can become increasingly common. Aspects of our physical health change naturally with age, but poor diet, reduced digestive enzymes and unbalanced gastrointestinal flora can wreak havoc on both our digestive and immune systems.

There are countless products on the market right now to help improve gut health and immune function, but do any of these actually work? Which options are best for a senior’s unique issues? I contacted Woodson Merrell, MD, ScD (hc), to get some answers on how to maintain gut health as we age.

Dr. Merrell is a pioneer in the field of Integrative Medicine, which focuses on all factors that influence a patient’s health and utilizes therapies and interventions from many different scientific and medical disciplines. His practice in New York City utilizes tools like nutrition, acupuncture, herbal medicine, and mind-body stress reduction techniques in conjunction with conventional internal medicine and diagnostics to help his patients regain and maintain optimum health.

Dr. Merrell addresses my questions about aging and digestive health in his own words below.

Why Is the Aging Digestive System so Problematic?

“With age often comes reduced amounts of gastric, pancreatic and other digestive system secretions,” Dr. Merrell says. “This, coupled with additional insults like poor dentition, inadequate diet and an unhealthy microbiome can set the stage for weak digestion and reduced nutrient absorption. This can lead to a weaker immune system and leakage of unwanted molecules into the circulatory system [aka leaky gut], all of which can ultimately cause adverse outcomes for every other system of the body that is served by the digestive system.”

What Are Some Signs That Things May Be Starting to Go Awry?

“Occasional gas, bloating, abdominal discomfort, poor elimination, temporary fatty stool, fatigue, headache and numerous other local and systemic outcomes may be indicators of gut health decline.”

What Do Digestive Enzymes Do?

“Generally speaking, enzymes are catalysts that speed up biological reactions. Digestively speaking, they lower the amount of energy that is required to transform the foods we ingest into molecules that are small enough to pass through the intestines and into circulation. These can be our own endogenously produced enzymes or supplemental enzymes taken with meals.

"Examples of the most common enzymes are amylases that digest carbohydrates, lipases that digest fats, and proteases that digest proteins. Without these enzymes, we’d be unable to break the bonds that hold our food together and unlock the nutrients and energy within. While our bodies do produce enzymes, it is clear that pancreatic enzyme production can decrease with age and ill health. Fortunately, wise diet and lifestyle choices can play a role in the way we age and may be of great help in supporting digestive and overall wellbeing.”

Do I Need to Take Supplemental Enzymes?

“There are a few instances when enzyme supplementation is clearly beneficial. For example, individuals with pancreatic insufficiency require supplements because they are unable to produce enzymes and digest food properly. In other instances, specific enzymes can help us consume the foods we enjoy and minimize digestive distress after the fact. People who suffer from lactose intolerance because they do not produce enough of the enzyme lactase to digest the specific kind of sugar found in dairy. Lactase supplements (most commonly known by the brand name Lactaid) help minimize this sensitivity.

“Those who stick to primarily plant-based, high-fiber diets can experience frequent gas and bloating. A little bit of this is normal, but it can be irritating and embarrassing. Another enzyme supplement (known by the brand name Beano) contains alpha-galactosidase, which specializes in breaking down sugars in notoriously gassy foods (like legumes and cruciferous vegetables) and minimizes discomfort that results from the digestion of these foods. These powerful proteins can help many, but deciding whether to try them depends on your health, unique dietary habits, lifestyle factors and digestive issues.”

What Kind Should I Buy?

“Since we are all totally unique individuals with often fluctuating dietary choices, there really is no one ‘right’ or best enzyme formula everyone. When seeking an enzyme supplement, it may be wise to take an initial look at the types of foods you typically consume and find a formula designed for a diet similar to yours. You may also want to obtain another formula designed for foods you do not eat frequently because they cause you problems. If you eat very small meals or are very sensitive to new supplement inclusions, then a gentler potency product may be a good fit.

"For example, if you have no gall bladder or experience difficulty properly digesting and absorbing fats, but understand the nutritional value of essential fatty acids like fish oils, then a high lipase formula may be appropriate. If you eat a vegan or vegetarian diet that is rich in legumes, grains and vegetables, or simply wish to enjoy some cuisine rich in these fibrous, often gas-forming foods, then a formula that includes more amylase and cellulase enzymes for breaking down larger starches may be best.

“If you’ve tried a high-potency full-spectrum formula (one that includes proteases for proteins, lipases for lipids or fats, amylases for carbohydrates, and cellulases for fiber) but are still experiencing digestive difficulty, then wheat, dairy or some other dietary intolerance may be the culprit. You might wish to use a formula designed to address common food intolerances instead. These formulas include enzymes like DPP-4 (for gluten and dairy casein), alpha-Galactosidase (for starches in beans), lactase (for lactose in dairy), and xylanase (for fiber). You can use them in addition to the more basic enzymes mentioned above.

“Some high quality formulas even provide teams or blends of enzymes within the same category, like multiple proteases, multiple amylases and multiple lipases. Single, un-blended enzymes can generally only perform in an acidic, neutral or alkaline setting. Blending allows the teams to perform digestive functions for you in all settings throughout the GI tract.

“Other formulas contain enzymes along with adenosine triphosphate (ATP), which is the body’s energy currency. ATP is very important for facilitating digestive processes like enzyme production, gastric acid secretion, peristalsis, transportation of nutrients across intestinal linings and more. We all make ATP, but production tends to decline with age. ATP is in raw foods, but, like enzymes, it is destroyed through cooking and processing mechanisms, so supplemental ATP may also go far in assisting gut function. Still other formulas contain both blended digestive enzymes and probiotics along with ATP). These combination formulas can be a convenient, cost-effective way to give yourself more complete digestive support.”

How Are Enzymes Different from Probiotics?

“Both enzymes and probiotics are essential for healthy, efficient digestion and overall digestive wellness, but there are significant differences between the two. Probiotics are living organisms, while enzymes are non-living proteins composed of amino acids. Probiotic supplements can enter the gastrointestinal tract and take up residence there, cohabitating with the body’s own cells. Enzyme supplements also enter the GI tract, but cannot function as a permanent resident. This explains why the body needs a regular supply of enzymes each and every time a meal or snack is ingested. Probiotics are similar to the good bacteria found in the human digestive tract and are associated with numerous health benefits, such as supporting our immune system.

“Probiotics make limited amounts of certain enzymes, such as proteases and amylases, which can support digestion. However, the amounts of enzymes that probiotics make may pale in comparison to the amounts of enzymes that the pancreas releases or that enter the digestive tract through supplementation. Probiotics also play a role in helping the cells of the small intestine to absorb and uptake nutrients that the enzymes break free from the foods. They are very important to the production of many other beneficial molecules such as neurotransmitters and help to create a healthy immune system—70 percent of which is located in the gut. As you can easily see, both probiotics and enzymes are critical for good gut health."

What Do Probiotics Do?

“According to the World Health Organization, probiotics are classified as ‘live microorganisms which, when administered in adequate amounts, confer a health benefit on the host.’

“There are many different families and species of beneficial bacteria that fit this description. Just like different types of plants within one family can vary greatly, and different members within your own family each have their own unique features, each different probiotic has its own traits. There are so many variances between species that listing all the benefits or mechanisms of action for each one would be too massive an undertaking for a single article such as this.

"One of the most well-known species right now, Lactobacillus acidophilus DDS-1, produces cellulase, lactase and protease which can assist with digestion of fiber, milk sugar (lactose), and protein respectively. Some probiotics serve to nourish intestinal cells and encourage their growth and health which can have a beneficial effect on healthy nutrient absorption. Overall they improve digestion, make for a healthier gut lining, and help keep the immune system strong.”

What Kind of Probiotics Should I Buy?

“If your digestive supplement formula is a two-in-one and contains both enzymes and probiotics, then there is likely no need to take two separate products. If your enzyme formula contains no probiotics and you eat very few fermented, cultured and raw foods (such as kefir, yogurt, kimchi, sauerkraut and kombucha) that are naturally high in probiotics, you may wish to take a probiotic supplement.

“Considering that we are all biochemically unique individuals, once again, there is no one-size-fits-all formula. That being said, it is important to select products that guarantee potency until their expiration date, not just at the time of manufacture. Look for products that contain species that are well-researched and either known to withstand the harsh stomach acids and bile secretions of the gall bladder, or come in encapsulated pills to ensure the bacteria make it to your colon. The Lactobacillus family, in general, is the mainstay of probiotic formulas (DDS-1, GG, and rhamnosus are some subspecies of these). Bifidophilus and Bacillus species can also be added. Try to look for a formulation with at least one billion CFU (colony forming units) per serving."

Has Food Changed Over the Last 50 Years, or Is the Problem Just Aging Bodies?

“Unfortunately, foods have indeed changed over the past decades. In fact, nutrient levels in crops today are markedly lower than they were 50 years ago. There’s not only less of what should be in foods, but more of what shouldn’t be (pesticides, herbicides, preservatives, etc.). Cooking, processing, and preserving foods can further diminish nutrients and destroy the enzymes, probiotics and ATP that naturally occur in fresh, raw foods. All of these beneficial components are either significantly low or non-existent in cooked, processed foods.

“Of course, nutrient-dense choices are critical, but even the best of selections and intentions do not guarantee optimal nutrient, enzyme, probiotic, and ATP intake. As mentioned previously, the aging process may only add to the minimized digestibility of foods, reduced nutrient uptake and weak nutrient status. Fortunately, enzyme and probiotic supplementation may play a key role in working with the body’s own natural processes to fortify digestive and overall wellbeing.”


Thank you, Dr. Merrell, for educating us on the roles that enzymes and beneficial bacteria play in digestion and overall health. If you are considering trying enzyme and/or probiotic supplements, speak with your primary care physician, a dietician or a gastroenterologist to see if these treatments might be a good fit for you.