What Are Synbiotics? Benefits, Dosage, Side Effects, Supplement - Dr. Axe

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What Are Synbiotics Supplements? Top 6 Synbiotics Benefits


Synbiotics - Dr. Axe

By now, you’ve probably heard about prebiotics and probiotics. But what about synbiotics? Although few are familiar with synbiotics, this powerful supplement packs in the power of both prebiotics and probiotics to deliver a megadose of health benefits. Not only can it boost digestion and aid in the treatment of several common conditions, but it may also help keep your heart healthy, promote weight loss, relieve inflammation and more.

So where can you find synbiotics, what should you look for and what benefits does a synbiotic provide in the body? Here’s what you need to know.

What Are Synbiotics?

So what are synbiotics? The term “synbiotics” refers to any supplement that contains a blend of both prebiotics and probiotics. Synbiotics can help support gut health by increasing the amount of beneficial bacteria in the digestive tract while also providing these bacterial cells with the fuel they need to function and thrive.

Synbiotics can be found in supplement form, which often combine nutritious plant-based prebiotic fibers with specific health-promoting strains of probiotics. However, you can also pair prebiotic and probiotic foods to make your own synbiotics, which can confer a wide array of benefits for health. In fact, studies show that synbiotics may help support digestion, improve heart health, enhance immunity, increase weight loss and decrease inflammation.

Probiotics, Prebiotics, Postbiotics and Synbiotics

By this point, you may be wondering: What are probiotics, prebiotics and synbiotics? And furthermore, what is a postbiotic and how can it impact your health?


Prebiotics are substances found in fiber that are broken down by the beneficial bacteria in the gut and used as a source of fuel to optimize the health of the gut microbiome. Probiotics, on the other hand, are a type of live microorganism found in the digestive tract that can confer an extensive set of health benefits to the host, ranging from improved digestion to increased weight loss and beyond. Synbiotics supplements combine both of these beneficial compounds, allowing them to work together in the gut to improve health. Postbiotics, meanwhile, are considered the byproduct of bacterial fermentation in the intestines.

While this may seem fairly confusing, it’s pretty straightforward once you break down the scientific jargon. The main difference between prebiotics vs. probiotics is that prebiotics provide energy for the probiotics, or beneficial bacteria in your gut, which ultimately produce postbiotics. Synbiotics combine prebiotics and postbiotics, which is why filling your diet with synbiotics can deliver the benefits of both to support better health.

Benefits of Synbiotics

  1. Support Digestive Health
  2. Enhance Immune Function
  3. Improve Mental Health
  4. Boost Weight Loss
  5. Promote Heart Health
  6. Decrease Inflammation

1. Support Digestive Health

Synbiotics pack a double punch when it comes to gut health by supplying a steady stream of both prebiotics and probiotics to the body. Probiotics are a form of beneficial bacteria that help promote proper digestion. In fact, probiotics have been shown to improve several aspects of digestive health and may aid in the treatment of diarrhea as well as conditions like ulcerative colitis and irritable bowel syndrome (IBS).

Prebiotics can also help enhance digestive health by providing fuel for the beneficial bacteria in your gut. This leads to the production of short-chain fatty acids like butyric acid. Butyric acid has been shown to support regularity and decrease symptoms of both IBS and inflammatory bowel disease (IBD).

2. Enhance Immune Function

Research suggests that digestive health and immune function are closely linked. Some studies even show that about 70 percent to 80 percent of the body’s immune cells are housed right in the digestive tract. Synbiotics can help enhance immune function by increasing the amount of good bacteria in the gut while simultaneously decreasing inflammation.

Several studies have found that supplementing with probiotics can improve immunity. According to one study out of Finland, consuming milk with probiotics decreased the incidence and severity of respiratory infections by about 17 percent among children. Probiotics have also been shown to help reduce the risk of urinary tract infections by nearly 50 percent in women.

3. Improve Mental Health

Adding synbiotics to your diet may improve cognitive function and protect mental health by delivering a hearty dose of both probiotics and prebiotics in each serving. According to one massive review published in the Journal of Neurogastroenterology and Motility, certain types of bacteria, such as Lactobacillus and Bifidobacterium, have been shown to enhance memory and improve symptoms of anxiety, depression, autism spectrum disorder and obsessive-compulsive disorder.

Another study conducted in Iran found that taking probiotics for eight weeks was able to significantly decrease symptoms of depression compared to a control group. Probiotics have also been shown to help improve other aspects of mental health by decreasing symptoms of stress and anxiety.

4. Boost Weight Loss

One of the most impressive benefits of synbiotics is their ability to boost weight loss and crank up fat-burning. Probiotics, for example, may help block fat absorption to cut calorie consumption. In fact, one study published in the British Journal of Nutrition found that supplementing with Lactobacillus gasseri led to a 8.5 percent reduction in belly fat after just 12 weeks.

Meanwhile, prebiotics are found primarily in high-fiber foods, which have been linked to a lower body weight and decreased body fat. Prebiotic foods have also been shown to support satiety in animal studies, which can help promote feelings of fullness to increase weight loss.

5. Promote Heart Health

Heart disease is a huge problem around the globe. In fact, it’s estimated that nearly 44 percent of the United States population will have some form of heart disease by the year 2030. Synbiotics can help keep your heart healthy and strong by reducing several heart disease risk factors.

For instance, one 2017 study showed that supplementing with synbiotics for 12 weeks improved both insulin metabolism and “good” HDL cholesterol levels in people with diabetes and coronary heart disease. HDL cholesterol travels through the bloodstream, removing fatty plaque buildup to help keep arteries clear. Not only that, but some studies also suggest that probiotics may reduce blood pressure levels to promote better heart health.

6. Decrease Inflammation

Acute inflammation is a normal part of the immune response that can help protect the body against infection and disease. Chronic inflammation, on the other hand, is thought to play a central role in health and disease. It may be involved in the development of chronic conditions like heart disease, diabetes and cancer as well.

Synbiotics can provide a concentrated dose of probiotics and prebiotics, both of which can optimize gut health to lower levels of inflammation. A study by the Department of Biochemistry and Food Chemistry at the University of Turku, for example, showed that probiotics were effective at modulating the immune response in people with a milk allergy. Similarly, another study showed that administering probiotics to people with major depressive disorder decreased levels of C-reactive protein (CRP), which is one of the primary markers of inflammation in the body.

Related: Oligosaccharides: The Prebiotics that Support the Heart & Gut


Dosage and Uses

There are a variety of synbiotics supplements on the market. Each has its own set of distinct dosage guidelines for both the prebiotic and probiotic component of the supplement. Most supplements include around 500–1,500 milligrams per day of prebiotics and 1 billion to 10 billion CFU of probiotics. For best results, you should follow the recommended dosage of your supplement carefully.

Synbiotics can be used by those looking to enhance digestion, boost immunity or simply improve overall health. Ideally, they should be paired with a well-rounded diet rich in prebiotic and probiotic foods to maximize results and strengthen the beneficial bacteria in your gut.

How to Find the Best Synbiotics

Synbiotics are available in both supplement and food form, both of which can be used to boost gut bacteria and enhance health.

Synbiotics foods can be made by combining prebiotic-rich foods with several good sources of probiotics to bring a concentrated dose of both to your diet. Prebiotic foods include green bananas, chicory root, onions, oats, acacia gum, garlic and asparagus. Meanwhile, probiotics can be found in fermented foods like tempeh, natto, sauerkraut, kimchi, kombucha and kefir.

There are plenty of options for how to make your own synbiotics by pairing these nutritious ingredients. You can cook up a tasty stir-fry with asparagus, garlic, onions and tempeh along with an assortment of other veggies. Alternatively, try making overnight oats using kefir and a few of your favorite fruits.

If you decide to opt for a synbiotic supplement instead, it’s important to look for a high-quality supplement from an established and reputable brand. When looking for the best synbiotics supplements, be sure to look for a product with a high CFU count that is made with live and active cultures and has a good amount of probiotic strain diversity. Products should also contain nutritious plant-based sources of fiber to provide plenty of prebiotics as well.


Synbiotics are a relatively new concept. The idea was first introduced alongside prebiotics in a 1995 paper by scientists Marcel Roberfroid and Glenn Gibson. In the original article, they were described as:

mixtures of probiotics and prebiotics that beneficially affect the host by improving the survival and implantation of live microbial dietary supplements in the gastrointestinal tract, by selectively stimulating the growth and/or by activating the metabolism of one or a limited number of health-promoting bacteria, thus improving host welfare.

Synbiotics are categorized as either complementary synbiotics or synergistic synbiotics. Complementary synbiotics contain both prebiotics and probiotics that are independently selected for their beneficial effects on health. Conversely, synergistic synbiotics contain prebiotics that are chosen specifically to support the effects of the selected probiotics.

Typically, the official synbiotics definition comprises any supplement that contains a combination of prebiotics and probiotics. However, the United Nations Food & Agricultural Organization has suggested that the term should be reserved for supplements that contain synergistic synbiotics instead.

Risks and Side Effects

Prebiotics are fermented in the gut and can cause adverse digestive symptoms when consumed in high amounts. Probiotics may also contribute to negative side effects, such as diarrhea or abdominal pain, especially when supplementation is first initiated. For this reason, it’s best to start with a low amount of synbiotics and increase dosage gradually to assess tolerance.

You should also be sure to increase your water intake when consuming more prebiotic foods. This is because prebiotic foods are typically high in fiber, which absorbs water in the colon. Not only can this slow down digestion, but it can also cause side effects like dehydration and constipation. Drinking more water can help prevent these adverse side effects and keep things running smoothly within the digestive tract.

Final Thoughts

  • Synbiotics contain both prebiotics and probiotics, which can help provide the benefits of both in either food or supplement form.
  • There are several notable differences between postbiotics, probiotics, prebiotics and synbiotics. Prebiotics provide fuel for the probiotics, or beneficial bacteria in the gut, which produce byproducts known as postbiotics.
  • Synbiotics may help improve digestion, optimize immune function, enhance heart health, increase weight loss, promote mental health and decrease inflammation.
  • Look for high-quality supplements from reputable retailers, and opt for those that contain a high CFU count made from live and active cultures. Supplements should also contain prebiotics from healthy plant-based sources and contain minimal added ingredients or fillers.
  • Alternatively, you can enjoy synbiotics as part of a healthy, well-rounded diet by pairing prebiotic foods with probiotic ingredients, such as kombucha, kefir, natto or tempeh.

Read Next: Best Probiotic Strains for Women & Men for Disease-Fighting Gut Health

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