Digestion is a function of gut health, which affects the gastrointestinal tract, including the mouth, throat, stomach, intestines, digestive and absorptive capacity, and the microbiome.
Experiencing Digestive Issues
It is normal to experience digestive issues from time to time, such as an upset stomach, gas, heartburn, constipation or diarrhea.
However, if these symptoms occur regularly they can be hugely disruptive to daily life.
If you’re experiencing digestive issues frequently then it is important to visit a healthcare professional, who can conduct further testing and provide a diagnosis.
Ways to Improve Your Digestion
If you don’t have a digestive condition but want to improve digestion, there are several diet and lifestyle changes that can have a positive impact.
These aim to boost gut health, which not only influences digestion but also provides other health benefits, such as supporting the immune system.
Eating prebiotic-rich foods can be helpful, such as
- and whole grains
Healthy gut bacteria, called probiotics, feed on non-digestible carbohydrates called prebiotics, which encourages them to multiply in the gut.
Research has shown that prebiotics can help probiotics become more resilient to certain environmental conditions, such as pH and temperature changes (1).
Chewing food thoroughly is important because this is where digestion begins. Studies have demonstrated that poor chewing decreases nutrient absorption (2). Your teeth break down food into smaller pieces so that the enzymes in your digestive tract can break it down more easily.
Chewing thoroughly means that the stomach has to do less work to turn the solid food into the liquid mixture that enters the small intestine.
Chewing also produces salvia, such starts to break down the carbohydrates and fats in the meal. In the stomach, salvia acts as a fluid, mixing with the solid food to allow it to pass smoothly through the intestines.
Avoiding taking unnecessary antibiotics is also helpful because these harm the healthy gut bacteria, with damage lasting as long as 6 months after use (4).
The Centers for Disease Control and Prevention have estimated that 30% of the antibiotics prescribed in the United States are unnecessary (5). It is therefore not a bad idea to explore alternatives with your healthcare provider before deciding to use antibiotics.
Quitting smoking is important for the gut, as well as for lung and heart health. A review found that smoking changes intestinal flora by increasing potentially harmful microorganisms and decreasing beneficial ones (6).
In addition to worsening digestive symptoms, this can also increase the risk of conditions such as inflammatory bowel disease.
Physical activity can also improve digestion. This is because exercise helps food travel through the digestive system.
One study found that moderate exercise, such as cycling and jogging, was able to increase gut transit time by almost 30% (7).
Other research demonstrated that 30 minutes of walking per day was able to significantly reduce symptoms of constipation (8).
Also, relaxing around mealtimes is important to support digestive health. A study found that people who were anxious when they ate experienced more indigestion and bloating than those who were more relaxed (9).
In addition to making diet and lifestyle changes to improve digestion, there are several supplements that can be helpful.
These supplements can help to reduce negative digestive symptoms and promote positive gut health.
Although there are many supplements claiming to boost digestive health, not all have been demonstrated to be effective in scientific literature.
For example, digestive enzymes are commonly advocated as being beneficial but the majority of studies indicate that they do very little to improve digestion.
7 Most Helpful Supplements for Digestion and Gut Health
Here are the best evidence-based supplements for digestive health:
Psyllium refers to the fibers from the plant Plantago ovata. It is water-soluble and gel-forming and can increase fecal moisture and weight.
How does psyllium boost digestive health?
Clinically, it is used as a bulk laxative and provides a more gentle alternative to caffeine or senna. The bulk occurs as a result of water and gas absorption in the small intestines and colon, which give chyme (digested food) more size and softness.
A study found that 8.8-15g of psyllium husk taken daily for one week was associated with an increase in fecal weight and moisture attributed to the gel-forming element of the psyllium husk (10).
Psyllium is poorly fermented, which means that bulk can be retained in the colon, rather than being metabolized by bacteria. It is one of the few fiber sources that does not seem to cause flatulence.
A study using intrarectal catheters measured less ‘flatus boluses’ following the acute ingestion of 30 g of psyllium (11).
Psyllium also seems to be effective for reducing digestive symptoms when taken long term.
One open-label study found that supplementation of 10 g of psyllium seeds twice daily for a year in those in remission from ulcerative colitis had improved remission rates compared to those taking 500 mg mesalamine three times per day (12).
Also, psyllium can improve transit time. A study found that taking psyllium husk daily for two weeks was associated with an increase in transit time and markers of fecal weight compared to a control (13).
How do I take psyllium?
Depending on the severity of digestive symptoms, as little as 5 g of psyllium taken with meals alongside at least 200 ml of water, can be effective.
It is recommended to start with 5 g at each meal and then increase or decrease the amount, depending on the results.
Doses up to 30 g seem to be well tolerated, as long as enough water is consumed at the same time.
Yacon refers to the plant Smallanthus sonchifolius, which is a tuber vegetable similar to a potato that is commonly found in South America. It has a sweet taste so the syrup is often used as an alternative sweetener.
The syrup contains a large number of fructooligosaccharides (FOS), which are prebiotic fibers that are partially absorbed.
How does yacon boost digestive health?
Yacon is beneficial for both intestinal mobility and fecal moisture.
A placebo-controlled, double-blind study found that 20 g of yacon syrup taken daily for two weeks was able to reduce transit time to 64% of baseline levels, as well as increasing stool frequency and moisture (14).
Also, there was no bloating observed during the study, demonstrating that it was well tolerated.
How do I take yacon?
To obtain the benefits for digestive health, it is recommended to consume 20 g of yacon per day, in syrup form, around one hour before a meal.
Lactobacillus reuteri is a species of probiotic bacteria. It can be found in the human intestinal tract although this is often not in high amounts.
It was initially used to treat necrotizing colitis, a gastrointestinal disease associated with infection and inflammation that is dangerous for babies and children, especially those born prematurely.
Interest in the bacteria grew after research demonstrated that the immune system could be influenced by changing aspects of the digestive system.
Although there has been a lot of interest in full-spectrum probiotic supplements (those with many different strains of healthy bacteria), research of the effectiveness of these for digestive health has been mixed.
There are some studies that have shown them to be beneficial, some that have found no difference and others that have even demonstrated that digestive symptoms get worse when taking them. It seems to be highly dependent on the particular gut bacteria profile of the individual.
From a scientific perspective, it is also difficult to know which aspects of a multi-strain bacteria are improving or worsening symptoms when it is taken as a single supplement.
For these reasons, recent research has tended to focus on particular strains of probiotics, such as Lactobacillus reuteri.
How does Lactobacillus reuteri boost digestive health?
Lactobacillus reuteri is effective in reducing symptoms of constipation.
A prospective, multicenter, double-masked, placebo-controlled randomized clinical trial found that L reuteri DSM 17938 taken daily for 90 days significantly increased bowel evacuations and therefore reducing constipation as well as improving other gastrointestinal symptoms, compared to placebo (15).
It can also decrease symptoms of diarrhea.
A randomized, double-blind, placebo-controlled pilot study found that taking L. reuteri 1×10 colony-forming units twice daily for four weeks was able to significantly reduce the frequency of diarrhea from 50% in placebo to 7.7% (16).
How do I take lactobacillus reuteri?
Particular strains of lactobacillus reuteri are more suitable for supplementation than others. Two that are known to be most appropriate are Lactobacillus reuteri ATCC 55730, DSM 17938, and ATCC 6475, which can all survive oral supplementation even without an enteric capsule.
The most effective dose is typically between one billion to one hundred billion colony-forming units taken over a day.
This can be taken in either a single dose or split doses, as both seem to be equally effective. Some studies have even shown that every other day may sufficient to provide benefits for digestion.
Lactobacillus reuteri can be taken with or without food but should not be taken alongside a hot drink as this will destroy the bacteria.
Glutamine is one of the 20 naturally occurring amino acids in dietary protein. It is considered to be a conditionally essential amino acid, which means that it is normally produced in sufficient amounts in the body but in specific cases, additional supplementation is needed to meet requirements.
It is effective in improving both intestinal and immune health because the cells in these systems use glutamine as a preferred fuel source to glucose.
How does glutamine boost digestive health?
Glutamine has been shown to improve intestinal permeability.
A study found that glutamine preserves the gut barrier function and prevents the permeability of toxins and pathogens from the gut lumen into mucosal tissue and circulation (17).
It can also be effective in reducing the digestive symptoms of Crohn’s disease.
A randomized controlled trial found that taking 0.5g/kg ideal body weight daily for two months was able to significantly improve both intestinal permeability and morphology (18).
How do I take glutamine?
To obtain the benefits of glutamine for gut health, it is recommended to start by taking 5 g per day.
There are risks to taking extremely high doses, such as excessive ammonia in serum. However, this is only of concern at doses of 0.75 g/kg bodyweight.
Glutamine can be taken either with or without meals and in one single dose or multiple doses.
Senna alexandrina is a plant that contains sennosides, which have a laxative effect. It is a plant native to Sudan that grows to a height of between two and three feet.
It has a long history of use in ayurvedic medicine and is known as swarnapatri in Sanskrit.
How does senna alexandrina boost digestive health?
Senna alexandrina can increase intestinal motility and reduce constipation.
Research has found it to be effective in over 90% of cases, compared to placebo while causing minimal cramping (19).
Studies have also demonstrated that senna is superior or equal in effectiveness to all other herbal laxatives (20).
How do I take senna alexandrina?
Following clinical usage, the dose shown to provide desired effects of soft and easy-to-pass stools is 1-2 g of powdered extract taken daily or fruit, typically standardized to contain between 10 and 30 mg of active sennosides.
It is recommended to take it before bed to give the laxative effect time to work and to create a morning bowel movement.
Peppermint, also known as Mentha piperita, is a hybrid plant from watermint and spearmint. It is used for its taste and smell and is used both internally and externally.
The oil of the plant seems to be the medicinal element, which is due to its high menthol content, which is a bioactive ingredient.
How does peppermint boost digestive health?
Peppermint can reduce the symptoms of irritable bowel syndrome (IBS).
A double-blind randomized placebo-controlled trial found that peppermint oil taken three times per day for six weeks was able to reduce symptoms of abdominal pain by around 20% compared to placebo, without altering other symptoms (21). However, these benefits were no longer experienced two weeks after stopping supplementation, demonstrating the importance of taking peppermint continuously.
Peppermint can also prevent colonic spasm.
A double-blind placebo-controlled randomized trial demonstrated that 0.2 ml of peppermint oil taken four hours before a colonoscopy significantly reduced colonic tension and spasm frequency compared with placebo, due to the relaxing properties of the oil (22). This resulted in reduced pain in patients and a shorter time needed to complete the procedure.
Also, peppermint is effective in reducing flatulence.
A randomized, double-blind controlled trial reported that 0.1 ml of peppermint oil taken three times per day for two weeks was able to significantly improve pain and flatulence symptoms compared to placebo (23).
Peppermint can also improve gastric emptying.
A randomized, two-way crossover study found that a 200 ml test meal of 200 kcal with 0.64 ml of peppermint oil significantly increased the early phase of gastric emptying compared to eating the test meal alone (24).
Symptoms of diffuse esophageal spasm (DES) may also be improved through peppermint supplementation.
A pilot study found that taking 5 drops of peppermint oil in 10 ml of solution eliminated esophageal spasms and reduced pain after 10 minutes of supplementation (25).
How do I take peppermint?
To support digestive health, it is recommended to take between 450-750 mg of the oil daily in 2-3 divided doses. This is equivalent to between 0.1-0.2 ml of the oil per dosage and reflects a menthol of content around 33-55%.
Although all forms of peppermint oil seem to be equally effective, for those experiencing heartburn, it is recommended to take an enteric-coated capsule to avoid the capsule breaking too early in the digestive process to provide benefits.
Ginger, also known as Zingiber officinale, is a flowering plant whose rhizome, ginger root, has traditionally been used in traditional Chinese and Ayurvedic medicine. The plant is part of the It Zingiberaceae family and is closely related to turmeric, cardamom, and galangal.
How does ginger boost digestive health?
Ginger is beneficial for reducing symptoms of nausea.
A meta-analysis that assessed the quality of conducted investigated the quality of six randomized controlled trials found that ginger was consistently effective, compared to either placebo or vitamin B6, which is often used as a reference drug (26). This is likely due to ginger’s ability to improve gastric motility.
Ginger has also been shown to be effective in reducing lower esophageal pressure.
A randomized controlled trial found that 1 g of ginger was able to significantly reduce low esophageal pressure after consumption of a beverage without affecting resting lower esophageal sphincter pressure, which is likely the result of its anti-flatulence effects (27).
Also, there is evidence that ginger can reduce colon cancer risk.
A randomized placebo-controlled trial found that 2 g of ginger extract taken daily for 28 days significantly reduced pro-inflammatory eicosanoids in the colon compared to placebo, suggesting a protective effect against colon cancer (28).
How do I take ginger?
Doses of between 1 and 3 g tend to be most effective for reducing symptoms of nausea.
For other usages of ginger, 1 g is the standard dosage, which seems to be effective in increasing intestinal motility.
Although digestive symptoms can be uncomfortable, there are several ways to reduce their severity.
This includes making dietary and lifestyle changes, such as increasing intake of prebiotic-rich foods, chewing slowly, reducing stress levels and increasing physical activity, as well as quitting smoking and avoiding unnecessary use of antibiotics.
In addition to making these alterations, adding supplementation can also help to boost gut health and reduce unpleasant digestive symptoms.
Keep Reading: The 13 Most Helpful Supplements for High Blood Pressure
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About the Author
Emma Green has a PhD, MSc and BSc in Psychology and is a certified personal trainer. She currently works as a freelance writer, producing on content on science, health and fitness for a number of online platforms. She also coaches clients online on a one-to-one basis to help them achieve their health and fitness goals. Contact Emma.