Differences Between Prebiotics & Probiotics: Impacts on Health


Reviewed by Dr. Alex Keller, ND – Written by Ross Bailey, MKin

While probiotics have become well known within the world of nutrition, and people are well versed in their benefits, less is known about prebiotics. You could bet 10 billion CFUs that most people would ask the question “what is the difference between prebiotics and probiotics”? (1) Well, let’s avoid the strain of the unknown and learn more about the difference between prebiotic and probiotic functions in our bodies!

Prebiotics vs probiotics

Probiotics are now commonly known as living bacteria that inhabit our digestive system. As they spend their lives in our bodies, they can grow and act to provide numerous benefits to our health.

Probiotics live in the areas of our body that work with the food that we eat. But these bacteria also need to ‘eat’ as well! After all, as living organisms, probiotics also need to produce energy to survive. This energy comes in the form of prebiotics, which are in fact the food of probiotics! As we delve deeper into the difference between prebiotics and probiotics, it will be easy to understand how this subject can provide some food for thought.

Prebiotics in support of probiotics

The word ‘prebiotic’ is used to define certain foods that probiotics will consume within your gut. These substances are often fibrous carbohydrates that our Gastrointestinal (GI) tract cannot digest for us. (2) Prebiotics are more than just food for probiotics, however. They also confer benefits to our health by selectively altering our GI’s microfloral composition and activity. (3) This means that prebiotics can positively affect the way individual strains of the microflora in our digestive systems grow and function.

Foods with prebiotics 

While probiotics are most commonly found in fermented foods such as yogurt, kombucha, or sauerkraut, prebiotics are often found in more fibrous sources. Check out this list of foods packed with prebiotics that you can easily add to your diet. Prebiotics can be found in food such as:

  • Under-ripe bananas
  • Raw garlic
  • Raw onion
  • Raw honey
  • Raw asparagus
  • Whole grain wheat and corn
  • Acacia gum

Since prebiotics can improve the benefits that probiotics provide to us, we can more effectively benefit our health by consuming foods that are high in both prebiotics and probiotics, than just by ingesting probiotics alone! That being said, why not add in some healthy snacks containing prebiotics while you are consciously consuming probiotics?

white acacia blossom

Acacia blossom. Enjoy occasional sugar-free candies or low-fat ice creams that are made from Acacia gum with less guilt!

Prebiotics + probiotics = synbiotics

Products containing specific prebiotics and probiotics that work synergistically are often referred to as synbiotics. (3) Prebiotics can be added to probiotic supplements to improve probiotic lifespan and their ability to thrive in the small intestine. So, how does the complementary nature of prebiotic and probiotic filled nutritional sources benefit our health? Let’s explore a little further!

Health benefits of prebiotics and probiotics

To provide a short list, improvements to our health through the use of prebiotic and probiotic nutritional sources can assist to: (4)

  • Reduce diarrhea
  • Reduce severe constipation
  • Increase fat metabolism
  • Modulate mineral adsorption (sticking minerals to the surface of our intestines)
  • Modulate the immune response

Gastrointestinal tract

It’s important to note that these effects are not always directly related to prebiotics themselves, but are mainly indirectly influenced by the growth and activity of the microflora in our GI tract. Simply put, the activity of the bacteria in our microbiome is primarily responsible for the positive effects that we see when consuming probiotics, however, prebiotics support and improve this activity. Common strains of the bacteria that produce the benefits mentioned above include Lactobacillus rhamnosus GG, L. reuteri, bifidobacteria and certain strains of L. casei or the L. acidophilus-group. (4) These bacteria are now popularly found in probiotic supplements and can be supported by prebiotic intake.

Mental health and hormone balance

Recent studies have also shown that the intake of prebiotics is correlated with decreased behavioral anxiety and altered genes involved in brain pathways that control emotion. (5) They are also associated with lowered cortisol levels, which may be beneficial for controlling the stress response. (6)

Weight management

A recent systematic review and meta-analysis also suggest that probiotics and prebiotics can decrease body mass, weight, and fat mass. (7) Again, this is mainly attributed to the beneficial effects that probiotics have on the body alone, or due to the increased growth and activity of the microflora as a result of introducing prebiotics to the gut.

It is important to keep in mind, however, that ingesting prebiotics and probiotics can occasionally cause the very symptoms that they were meant to assist in reducing. (8) If this is the case, consider searching for probiotics that are marked as FOS free as these do not contain the added fibers that may be causing these symptoms.

woman stretching with her hand in the air in active clothing outdoors

The microflora in our bodies are primarily responsible for the health benefits, but prebiotics can help them to flourish.

The bottom line

In summary, the difference between prebiotics and probiotics is that prebiotics are the food of probiotics that support microfloral growth and function, whereas probiotics are the bacteria that keep your gut healthy. It can certainly be argued that the best probiotic supplements are those that are consumed in combination with a diet rich in prebiotics. It appears that prebiotics mainly exert their beneficial effects by supporting and improving probiotic growth and activity within our GI tract.

Overall, ingesting nutritional sources that contain adequate levels of both prebiotics and probiotics is a fantastic way to contribute to a healthy diet and wellness plan. Remember, keeping healthy is not only about feeling good, but is also about preventing and reducing future instances of malaise. The inclusion of prebiotic and probiotic combinations are an effective way to achieve this. Choosing the right nutritional sources and maintaining a balanced diet is a great place to start! But if all else fails, go with your gut!