What’s the Difference Between Probiotics and Prebiotics?

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Probiotics and prebiotics sound similar, yet they each play a very different role in gut health.  Read on to learn more about the important differences between probiotics and prebiotics!

What are Probiotics?

The Food and Agricultural Organization of the United Nations and World Health Organization (FAO/WHO) defines probiotics as, “Live microorganisms which when administered in adequate amounts confer a health benefit on the host” (1).  So, probiotics are considered ‘good’ bacteria that can provide a benefit to our health when adequate amounts are consumed. 

Probiotics are identified by their specific strain, which includes the genus, the species, the subspecies (if applicable), and a strain designation.  For example, the probiotic Bifidobacterium animalis lactis DN-173 010 consists of:

GenusSpeciesSubspeciesStrain Designation
BifidobacteriumanimalislactisDN-173 010

Each specific probiotic strain has been studied and each strain provides a very specific and unique health benefit.  For example, reducing antibiotic-associated diarrhea or managing irritable bowel syndrome (IBS) symptoms such as abdominal discomfort, bloating and gas.  The Clinical Guide to Probiotic Products Available in Canada  is a helpful tool to assist clinicians and consumers in understanding which probiotics have evidence for a specific indication.

You can find probiotics in supplement form or added to certain foods like yogurts or kefirs. 

What are Prebiotics?

Prebiotics are non-digestible components of food that feed the beneficial bacteria in your gut.

Prebiotics are defined as: “A substrate that is selectively utilized by host microorganisms conferring a health benefit” (2). 

So, prebiotics act as a food source for the bacteria in your gut.  Your bacteria ferment “eat” the non-digestible components of food, thereby supporting the growth of good healthy bacteria.  The good bacteria also produce short-chain fatty acids (SCFAs) that act as a fuel source in our body and supports health.

Most prebiotics are fibres, though not all fibres are prebiotics.  In order to be considered a prebiotic, the fibre must pass through the gastrointestinal tract undigested and stimulate the growth and/or activity of certain good bacteria in the large intestine (3).

Types of prebiotic fibres

Some examples of prebiotic fibres include:

• Fructo-oligosaccharides (FOS), inulin or fructans
• Galacto-oligosaccharides (GOS)
Partially hydrolyzed guar gum (PHGG)

Where are prebiotics found?

Prebiotics are naturally found in many foods such as:

Vegetables and Fruit:

  • Asparagus
  • Garlic
  • Jerusalem artichoke
  • Leeks
  • Onion
  • Bananas
  • Apples


  • Wheat
  • Barley
  • Rye
  • Oats


  • Chicory root
  • Dandelion root

Prebiotics can also be added to some food products by manufacturers such as breads, snack bars and breakfast cereals, or prebiotics can be found in supplement form.  

Take away

So, probiotics are the ‘good’ beneficial bacteria that can provide a benefit to our health when adequate amounts are consumed, whereas prebiotics are the food source for the bacteria in your gut supporting the growth of ‘good’ bacteria.

For further information check out my other blogs:

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