What Is The Difference Between A Probiotic and a Prebiotic??

Humans are walking talking rainforests! The ecosystem in our body is complex and fascinating! We are amazing creatures!

Our guts are like a rainforest!

Did you know that we have 10 times MORE bacteria cells then human cells? Now guess where most of these bacteria cells reside??

If you guessed your gut, then you guessed right!

There are beneficial AND opportunistic bacteria living together in our guts.

These residence make up our gut microbiome. A balanced microbiome is key to a healthy functioning gut.

How do these bacteria thrive and what do they need to grow?

Do they need probiotics or prebiotics? What is the difference between a probiotic and prebiotic?

Allow me to clarify the differences between the two and how both a prebiotic and a probiotic are very important for the maintenance of a healthy gut microbiome.


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Opportunistic Bacteria

Our intestines have a plethora of bacteria. There really is no such thing as good or bad microbes because each type is important for proper gut function and in performing useful tasks for your body.

Photo by Andrzej Pobiedziński from FreeImages

However, opportunistic bacteria is the kind of bacteria that, if left to take over, will do whatever it can to survive which usually leads to gut issues. These types of microbes may produce toxins that are detrimental to your overall well-being.

Some examples of the toxins that these pathogens produce are lipopolysaccharide, B.fragilis toxin, methane and hydrogen sulfide. Production of these metabolites may lead to systemic inflammation, bloating, flatulence, abdominal discomfort, constipation, and gastrointestinal distress. These buggers will weaken the intestinal wall, and they will overthrow the beneficial bacteria.

In a balanced gut, there are opportunistic bacteria, but in the right amount, as even this type of bacteria is important for proper gut function and in turn, immune function.

Beneficial Bacteria

Photo courtesy of the Public Health Image Library.

As stated above, there really is no such thing as good or bad microbes, however some bacteria produce metabolites that are beneficial to your gut and overall well-being. These bacteria are considered beneficial.

Beneficial bacteria get their energy by metabolizing (breaking down) undigested carbohydrates and gut secretions. The bi-product of metabolizing carbohydrates is short chain fatty acids (SCFA), such as: acetate, propionate and butyrate.

These short chain fatty acids and other metabolites are beneficial for our gut lining and gut function.

For example, butyrate is a primary energy source for the cells in our gut lining. This short chain fatty acid helps to strengthen our gut lining, which helps to keep the gut barrier strong. A strong gut barrier is what helps to prevent a leaky gut.

Other metabolites that are beneficial to healthy gut function are: Vitamin K, Biotin (B7), Folate (B9) and neurotransmitters like GABA.

In short, a proper amount of beneficial bacteria help to keep opportunistic pathogens (bacteria) at bay.


Now you have the basic information on what good (beneficial) and bad (opportunistic) bacteria are, let’s talk about probiotics.

What is a Probiotic?

Probiotics are live microorganisms that are used to help add to the beneficial bacteria in your body. Many of the microorganisms in probiotic products are similar to the ones that live in our bodies.

The most common way to consume a probiotic is to supplement with a pill or powder probiotic.


Some common strains of bacteria found in most probiotics come from the group of bacteria called: lactobacillus and bifidobacterium. There may also be yeasts like saccharomyces boulardii found in some probiotic products as well.

Probiotics can also be found in fermented foods like sauerkraut, kimchi, kefir and even yogurt. Eating fermented foods daily is an easy, cost effective way to keeping up the beneficial bacteria in your gut.

Why is eating fermented foods more cost effective? Well a really good probiotic can be quite pricey, but fermenting your own food is cheaper…..and tastier! If you don’t have the time or desire to make your own fermented foods, there are plenty of grocery and health food stores that carry fermented food products.

Superstore, Sobeys, Save On Foods, and Nutters all carry some forms of fermented foods. Costco even carries sauerkraut. There are also many local health food stores in your area that carry all sorts of fabulous fermented foods. Light Cellar, is a local store near me that makes and sells their own fermented foods. If you decide to buy fermented foods from your local grocery stores remember to buy these foods from the refrigerated section. The pickles that you can find down one of the grocery aisles, (you know the ones that are near the ketchup); those have preservatives in them to make them shelf stable so that they don’t have to be refrigerated.

All the good bacteria will have been destroyed in these products. These products will not add to the good bacteria in your gut. They taste good, but have no added probiotic benefits.

The real fermented products will be found in the refrigerated sections of the health food aisle in your local grocery store.


If probiotics are just more beneficial bacteria, then what are prebiotics?

What is a Prebiotic?

Prebiotics are what feed and help beneficial bacteria to multiply and strengthen.

Preboitics are non digestible food ingredients that help to grow or increase activity of beneficial microorganisms ( like bacteria and fungi ) in your intestines! A great example of a prebiotic is fiber!! Fiber is found in most vegetables. Some examples of a great prebiotic vegetable are:

  • Asparagus
  • Dandelion Greens
  • Garlic
  • Apples
  • Onions
  • Leeks
Photo Courtesy of Christine Siracusa

The fibre from these vegetables (and many more), then feed your intestinal microbiota. The bacteria feeds on these prebiotics, which are then broken down into SCFAs (Short Chain Fatty Acids). Some examples of short chain fatty acids are lactic acid and butyrate.

Butyrate is a Short Chain Fatty Acid that helps to strengthen the intestinal epithelial lining…..aka the gut lining. What does this mean? This means that the more prebiotic fibre you eat, the stronger and healthier the beneficial bacteria become. This then leads to more production of Short Chain Fatty Acids like Butyrate. More butyrate means a stronger gut lining, which means your body can break down and absorb nutrients from food better!

Start thinking about the amount of plant based foods you are eating. Perhaps adding a few more servings of vegetables to your meal plan would be a good idea for you… and your guts!

Synbiotic – What is this?

We’ve talked about probiotics and prebiotics, but what are synbiotics??

Synbiotics are food ingredients or dietary supplements combining probiotics and prebiotics. This combination is supposed to improve the viability of the probiotic.

There is growing evidence showing that synbiotics play a role in influencing the microbiome of the intestines by helping to alleviate various health issues related to the gut.

Understanding the effects of synbiotics has increased, however there is still so much left to learn and researchers are discovering new info every day.

Take Care of Your Inner Rainforest

Photo courtesy of Kunal Shinde

There is ongoing research on the health benefits of prebiotics, probiotics and synbiotics with regard to gut health and overall health.

What are your thoughts? Have you found probiotics to be beneficial to your health? Do you take a synbiotic? If you do, have you noticed a difference in your overall health?

Or are you giving fermented foods a try? If so, have you noticed any changes in your gut health?

Leave a comment below as I’d love to hear about your experiences!

Our bodies are so unique and what works for one person won’t work exactly the same way for another person.

Keep feeding your bodies whole, unprocessed foods.

Add in a good quality probiotic or even synbiotic, especially during cold and flu season and now the season of covid-19.

Drink plenty of water, get plenty of sleep and keep that immune system strong!


Anna aka The Gut Nerd

PS: Some links in this post are affiliate links.  I will receive a monetary payment if purchases are made from these links.  I have used products similar to the products I promote, or I have used the actual product I am promoting.  My goal with promoting these products is to help you obtain and maintain a healthy gut.  

12 thoughts on “What Is The Difference Between A Probiotic and a Prebiotic??”

  1. I’ve been taking probiotics for years but I’ve never heard of prebiotics. It’s great to learn that certain foods help the bacteria in my gut and the probiotics I’m taking work better and more efficiently. I’ll have to include these in my diet, I enjoy most of the vegetables in the list so it won’t be hard. I was hoping for more options and other ways to get prebiotics but this was very informative. 

    • A wide variety of fruits and vegetables will help you to get a lot of prebiotics for your body.  There are links in my article that will guide you towards suggested prebiotic supplements that you can take. But honestly, the easiest way to get these prebiotics is to eat a wide variety of whole unprocessed fruits and veggies! Thanks for your comment!

  2. Taking care of our inner rain forest is a must. And I must thank you for dealing with all these terms in a way that any of us could understand. When we understand something we care about it. And that’s the point in this whole article. I acknowledge we play an important role regard to gut health. And having this sort of knowledge has a direct impact on our overall health.

    • Thanks Henry, I’m glad you found this article easy to understand and enjoyable to read!  Do you take a probiotic or eat fermented foods?


  3. Thanks for a great article explaining the difference between prebiotics and probiotics. I knew about probiotics and I have taken them previously. I didn’t know as much about prebiotics. I think I need to look at them a little more closely and see how they can benefit my health. How long is it until a difference is seen?

    • A prebiotic is a simple as eating more veggies!  Fiber is a prebiotic.  You really don’t need a supplement for it. However, Acacia Powder is a great supplement to try as you can mix it in with food, baking, sauces smoothies and even coffee and tea.  Like with all things natural, feeling a difference in how your body is working, takes time. It’s not overnight. When it comes to gut health, it’s a two steps forward, one step back kinda journey.  There is no magic number as to when you will see or feel a difference.  It’s all about long term. I hope that makes sense.  There’s a link in my blog post that will direct you to acacia fiber, if you are wanting to give it a try!

  4. I was surprised that you did not mention foods rich in resistant starch as prebiotic. These include underripe bananas, beans and unprocessed intact while grains. See http://Www.ResistantStarchResearch.com for the evidence. Resistant starch makes more butyrate than any other fiber tested. It has been shown to improve insulin sensitivity overnight, increase satiety, reduce inflammatory biomarkers and inflammation, and reduce leaks thru a leaky gut.

    • You are right! I totally missed that one! And I literally was just reading about resistant starch in the book The Microbiome Solution!
      Thank you for bringing that very important one up.

  5. My boyfreind been taking probiotics everytime we were traveling in South Asia and I occasionally did too. Luckily I am really a vegetable lover and I think I got plenty of nutrients, the only problem is I don’t drink enough of water although I carry around my water bottle all the time. Thats really interesting I didn’t have clue there are prebiotics. I have learned something new thanks for sharing.

  6. Hi Anna,
    Thank u for the heads up on my personal rainforest. Jokes apart, the knowledge of Prebiotics, probiotics and Synbiotics is wonderful, and I am quite surprised at myself that I never tried to find out this earlier.
    I will surely include some Probiotics in my diet.
    Aparna Bansal


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