Prebiotics vs. Probiotics: Differences Explained

Medically Reviewed By Grant Tinsley, PhD
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Our bodies have billions of bacteria that help us stay healthy. Both prebiotics and probiotics help increase the healthy bacteria in your body. Yet, prebiotics and probiotics differ in how they do this. Probiotics are live organisms in foods or supplements containing microbes or microorganisms that can positively affect the gut.

Some people may refer to these microorganisms as “good” or “friendly” bacteria. By contrast, prebiotics are components of foods that can encourage the growth of healthy bacteria.

This article explains the difference between prebiotics and probiotics and their benefits. It also discusses side effects and safety as well as foods and dietary supplements that contain prebiotics and probiotics.

The difference between prebiotics and probiotics

Someone spoons honey into a bowl of yogurt.
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Prebiotics are nondigestible components in food that support the growth and activity of probiotics, which are living microorganisms. Prebiotics are found in fiber-rich plant foods, such as fruits, vegetables, whole grains, and nuts.

Probiotics then multiply in the gut and help restore an optimal balance in the gut’s bacterial population.

They have health benefits, such as improving digestion, when you consume them in food or dietary supplements.

Benefits of probiotics

Probiotics help your body maintain healthy microorganisms. Common probiotics include the following bacteria:

  • Lactobacillus
  • Bifidobacterium
  • Saccharomyces
  • Streptococcus
  • Enterococcus
  • Escherichia
  • Bacillus

Microorganisms live naturally in our bodies, and many of them can be found in probiotic products, such as dietary supplements. These may offer various health benefits, and different products may have diverse benefits.

Improved digestion

Probiotics help protect your digestive tract from harmful microorganisms. They improve your digestion and gut function by restoring the balance of bacteria in your large intestine.

Healthy immune system

Probiotics may influence the body’s immune response, helping support the health of your immune system.

Learn more about probiotics and their health benefits here.

Benefits of prebiotics

Prebiotics may also provide certain health benefits.

Weight management

Prebiotics, found in fiber-rich foods, can cause a feeling of fullness. This may help with controlling your weight.

Protection from infection and disease

Prebiotics help protect against gut infections and may protect against some types of cancer. They can be good for gut health in healthy people and those with particular health conditions. They may positively affect people with osteoporosis, diabetes, and colorectal cancer.

Improved immune function

Prebiotics can increase the absorption of certain minerals such as calcium and magnesium and improve immune function by decreasing harmful bacteria in the body.

Can you take prebiotics and probiotics together?

Prebiotics help support the growth and activity of probiotics. Synbiotics are products that combine probiotics and prebiotics. The use of them together is sometimes called microbiome therapy.

While prebiotics and probiotics need to be taken together to reap the full health benefits, they should be a regular part of your diet. Always talk with your healthcare professional before taking prebiotic or probiotic supplements.

Food sources of prebiotics and probiotics

Not all foods and dietary supplements labeled as probiotics have proven health benefits. This depends on the types and amounts of microorganisms they contain. They also may not have the same benefits for all people.


Probiotics are present in various fermented foods. These include:

  • yogurt
  • kefir
  • aged cheeses
  • pickled fruits or vegetables
  • kimchi
  • kombucha
  • miso
  • tempeh (fermented soybeans)
  • sourdough bread
  • sauerkraut
  • beer

Prebiotics feed the probiotic microbes and are in various fiber-rich, plant-based foods. The International Scientific Association for Prebiotics and Probiotics recommends consuming at least 5 grams of prebiotics daily for improved gut health.

In some people, prebiotics may cause gas and bloating. They may also cause abdominal pain or diarrhea if taken in large doses. An increase in gastroesophageal reflux (GERD) could be the result of large daily doses.


Foods that are rich in prebiotics include:

  • bananas
  • leeks
  • onions
  • peas
  • garlic
  • asparagus
  • artichokes
  • berries
  • kiwifruit
  • soybeans
  • honey
  • wholegrain foods
  • breast milk

Prebiotic and probiotic supplements

Probiotics are also in dietary supplements and some beauty products. Dietary supplements labeled as probiotics contain a wide variety of microorganisms and amounts. Any health benefits of the product depend on the specific microorganisms, not the number it contains.

The Food and Drug Administration (FDA) regulates probiotics as a dietary supplement, food ingredient, or drug. If sold as a dietary supplement, probiotics do not require FDA approval before a manufacturer can market them. Products marketed as a drug have to meet stricter requirements for FDA approval as safe and effective.

Be sure to check with your doctor before adding any dietary supplement to your diet, especially if you have a health issue. If you have a serious underlying health condition, your doctor can help monitor any changes while you are taking probiotics.

Side effects and safety of prebiotics and probiotics

Though plenty of research has been done on prebiotics and probiotics, there is still much to learn about their side effects, safety, and benefits for certain health conditions.

According to the National Center for Complementary and Integrative Health, there are certain precautions to take when considering the use of probiotics:

  • The risk of harmful effects from probiotics is greater in people with severe illnesses or compromised immune systems.
  • Possible harmful effects of probiotics include infections, production of harmful substances by the probiotic microorganisms, and transfer of antibiotic resistance genes to other microorganisms in the digestive tract.
  • Some probiotic products have been reported to contain microorganisms other than those listed on the label. In some instances, these contaminants may pose serious health risks.

Frequently asked questions

Below are some frequently asked questions about probiotics and prebiotics.

Do I need prebiotics or probiotics?

Prebiotics and probiotics are part of a regular, healthy diet. Whether you need to supplement your diet with one or both depends on your overall health. Be sure to talk with your doctor before adding any supplement to your diet.

Which is better, prebiotics or probiotics? Do you need both?

Prebiotics and probiotics can offer health benefits and should be part of your regular diet. Depending on your overall health, you may not need to add supplements to your diet. Talk with your doctor about what is right for you.

Who should take prebiotics?

Prebiotics may provide health benefits for people generally healthy and those with certain health conditions. Talk with your doctor or a dietitian about whether prebiotics may benefit you.


Prebiotics and probiotics help increase the healthy bacteria in your body. While probiotics are live microorganisms that provide health benefits, such as improved digestion, prebiotics provide the nutrients that help probiotics thrive.

Though researchers are still studying the benefits of prebiotics and probiotics, they may help support the health of your immune system and protect against infection and diseases, such as certain types of cancer.

Prebiotics are found in fiber-rich, plant-based foods, while probiotics are in foods and dietary supplements. If you are considering a probiotic dietary supplement, check with your doctor to be sure it’s right for you.

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Medical Reviewer: Grant Tinsley, PhD
Last Review Date: 2022 Aug 2
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