“What’s the difference between prebiotics vs probiotics?”
…This is a frequently asked question that comes up a lot in my functional nutrition practice!
Needless to say, prebiotics and probiotics are hot commodities in my field of gut health (for good reason). But unfortunately there’s also a lot of misunderstanding and exploitation when it comes to what they do and how they work.
While they may SOUND the same, prebiotics and probiotics are actually two totally different “things” which work together in tandem and synergy to keep your gut healthy.
In this article I’ll distill down the key similarities and differences between prebiotics vs probiotics – and then I’ll explain why & how you might want to incorporate them in combination to support a healthy gut.
Disclaimer: This article was written for educational purposes only. This is not meant to replace medical or nutritional advice from your treatment team.
- Make sure to consult a doctor and a functional dietitian / holistic nutritionist who specializes in gut health if you’re navigating digestive health issues such as irritable bowel syndrome (IBS), inflammatory bowel disease (IBD), small intestinal bacterial overgrowth (SIBO), leaky gut, and/or dysbiosis.
Table of Contents
What are prebiotics?
In essence, prebiotics are a type of naturally-occuring “functional foods” which serve the purpose of feeding and supporting the growth of healthy microbes (“probiotics”) in your gut. (More on probiotics next!)
From a food science lens, prebiotics are indigestible or poorly digested carbohydrates/fibers and/or certain antioxidants (“polyphenols”), which are naturally occurring in and derived from most plant-based foods as well as honey.
Prebiotics in foods and herbs
What most people don’t realize is they can easily get a natural abundance of prebiotics just through eating a balanced and diverse diet, and even via certain types of herbs and spices.
(Feel free to download my Prebiotic Foods & Herbs List PDF, and you can also read more about the different types of prebiotic foods and herbs here!)
Prebiotic supplements
Sometimes, people with dysbiosis (aka an imbalanced ecosystem of gut microbes, with not enough probiotics and a subsequent overgrowth of “bad” microbes), need more aggressive, therapeutic doses of prebiotics to help re-populate their “good” probiotic microbes.
That being said, being in our unprecedented time of more chronic illness, combined with access to cutting-edge research, and also some marketing manipulation, prebiotics are now also available and in high-demand via an entire spectrum of different types of fancy supplements.
- This can be for better or worse, depending on the product, and depending on your individual needs!
What are probiotics?
Probiotics are certain types of microbes (bacteria and/or fungus/yeast) which have a beneficial effect on our health and wellbeing.
- While research is only now hitting the tip of the iceberg, it’s safe to say these microscopic allies have been proven to help support everything from healthy digestion to immunity, detoxification, mental health, cognitive function, skin, hormones, cardiovascular health, metabolism, lung function, and more. (1, 2, 3, 4, 5, 6, 7, 8, 9)
Probiotic strains (common types)
While research has already uncovered thousands of different strains of beneficial probiotic bacteria and fungus, the top 5 of the most common types of probiotic strains found in probiotic functional foods and supplements (and ideally in a healthy gut) include (10):
- Lactobacillus spp.
- Acidophilus spp.
- Bifidobacteria spp.
- Bacillus spp.
- Saccharomyces boulardii
However, it’s important to keep in mind: the above list is not even the tip of the iceberg when it comes to all the different of types of probiotics living in the gut and the human body!
Probiotics in the body
In the human body, most probiotics live in the gut (mostly in the colon), but they can also be found in pretty much all mucous membranes of the body (including not limited to the skin, eyes, ears, mouth, lungs, and genitalia), where these healthy microbes serve as our first line of defense against invaders.
Probiotics in food
Probiotics are also naturally-occurring in certain types of lacto-fermented foods such as yogurt, kefir, kombucha, raw sauerkraut, unpasteurized, vinegar-free kimchi, raw, lacto-fermented, vinegar-free pickles, and other types of raw, lacto-fermented veggies made without vinegar.
Our ancestors used to consume probiotic foods more often and in larger quantities, before they had access to refrigerators, which may or may not be one reason why chronic gut issues and autoimmune disorders were anecdotally not as prevalent in history as they are nowadays…
Probiotic food “imposters” (beware!)
Unfortunately, our food industry likes to capitalize on food and nutrition industry trends.
That being said, most mainstream, store-bought pickles, sauerkraut and kimchi products on the market are actually pasteurized (sterilized) and/or they are made with sugar/vinegar, which interfere with the lacto-fermentation.
(In other words, fermented foods which have been pasteurized and/or made with vinegar/sugar secretly don’t have any probiotics!) 🙁
This is deceiving, since the mainstream gut health narrative is that “sauerkraut and kimchi are probiotic foods.” And most people don’t realize this is not to be taken at face value as a blanket statement!
Prebiotics and probiotics: similarities
First and foremost, we know that both prebiotics and probiotics are both widely available on the market as functional foods, herbs, and gut health supplements.
But there’s also a ton of overlap in the roles and benefits of prebiotics and probiotics when it comes to their gut health benefits and outcomes for certain types of gut issues.
For example, prebiotics and probiotic foods and supplements are both linked with higher levels of special health-promoting chemicals called short-chain fatty acids (aka “post-biotics” – a conversation for another time!).
- According to research, since prebiotics FEED the “good guys” (such as Lactobacillus and Bifidobacteria), it is no surprise that consuming certain types of prebiotics administered over just a few months resulted in significant improvements in short-chain fatty acid levels and reduced pathogen levels which were measured via before-and-after stool samples.(11, 12)
- In my clinical experience via comprehensive stool analysis testing with my clients who are navigating IBS/IBD/SIBO, people who have higher levels of Lactobacillus and Bifidobacteria probiotics in their colon tend to also have healthier levels of short-chain fatty acids, and vice versa.
- When Lactobacillus and Bifidobacteria probiotic counts are lower, so are the post-biotic counts in those stool analysis test results.
Also, in my experience, most people with IBS/IBD will find that taking a prebiotic and/or probiotic supplement will make them feel better, and people with SIBO tend to notice that most prebiotics and probiotics actually make them feel worse.
Prebiotics vs probiotics: the key differences
In terms of their roles in gut health, prebiotics are the nutritional constituents from food/herbs which FEED the probiotic microbes, allowing the probiotics to grow and multiply in your gut and ferment, leading to a beneficial bi-product (“post-biotic”) called short-chain fatty acids. (13)
Their main key differences, in summary, are:
- Prebiotics are plant-based food/herbal constituents, while probiotics are live microorganisms.
- Prebiotics are often constituents of fiber, while probiotics FERMENT these fibers in the gut.
- Probiotics are naturally occurring in the human body, while prebiotics are not.
Prebiotics and probiotics in tandem: a dynamic duo
The prebiotics which get fermented by the probiotics is what leads to the production of beneficial post-biotics in your gut. So, the whole is truly greater than the sum of its parts!
- Postbiotics are actually the “thing” directly responsible for nourishing the cells of your gut lining, regulating/optimizing gut pH, keeping bad “pathogenic” microbes under control, and lots more. (13)
When we use these in combination, it’s a great way to help repopulate (aka “reinoculate”) your microbiome by supporting the growth of good stuff, while simultaneously killing off “pathogenic” bad microbes responsible for symptoms of IBS.
- “Reinoculate” is actually step #3 of 5, in the 5R protocol for gut repair! 😎
Foods or supplements – which is better?
First of all, if you ask 100 different health practitioners, you’ll probably get 100 different answers. Below are my own perspectives, based on the culmination of my research, first-hand experiences (as a former IBS sufferer), and of course clinical experience!
Prebiotic foods vs supplements
If you ask me, when it comes to PREbiotics, I believe that eating a diverse diet (i.e. embodying the holistic nutrition fundamentals) is a generally more holistic, synergistic and cost-effective way to get prebiotics than to pay for expensive supplements.
Probiotic foods and supplements
As for PRObiotics: this really depends! Each person’s individual microbiome (ecosystem of microbes in the gut) is as unique as our fingerprint, so no two people are going ot benefit from the exact same protocol.
However, there are some general “rules of thumb” which I tend to stick to and keep in mind, in my clinical practice:
- If you have relatively healthy, normal digestive patterns (aka, mostly “3’s” and “4’s” on the Bristol Stool Chart), incorporating probiotic foods into your diet on a regular basis is a great idea, and you most likely don’t need to be flooding your body with specific expensive probiotic strains in capsule form. (Save your $!)
- If you’re suffering from a chronic gut issue such as IBS/IBD, you may actually benefit from incorporating probiotic foods AND supplements into your regimen, in therapeutic doses, to address underlying dysbiosis. (Increasing good bacteria helps to crowd out the “bad” guys!)
- If you’re confused/overwhelmed, and you’d like a custom plan tailored to YOUR body, I encourage you to consult a functional dietitian and get a comprehensive stool analysis test such as a GI MAP or something similar!
- If you suspect you may have an intolerance to high-tyramine foods or a histamine intolerance and/or you are taking a MAOI-inhibitor (14), fermented probiotic foods will not be a good fit since they are naturally very high in both tyramine and histamine.
- In any of these cases, you should consult your doctor and dietitian about the possibility of probiotic supplements.
- If you have small intestinal bacterial overgrowth (SIBO) or suspect this, you’re more likely to have an adverse reaction to probiotic supplements, since they may amplify fermentation of the bacteria in your intestines.(I see this happen a lot in my clinic!) Keep this in mind, if you find that probiotic foods/supplements seem to make you feel worse.
- If this is the case, you may need to test and address your SIBO (alongside working with a qualified gastrointestinal doctor and holistic/functional dietitian who is trained in SIBO) before considering prebiotics or probiotics in your regimen.
Can / should you take prebiotics and probiotics together?
Yes and yes- assuming you’ve determined (with help from your treatment team) that prebiotics and probiotics are a good fit for you. 😉
For real though, consuming prebiotics and probiotics together (whether as foods or supplements or both) within 15-30 minutes of each other is anecdotally helpful.
Having them as food/with food is even better – since they will get carried down to the colon more effectively.
More resources
If you enjoyed this article and found it helpful, you may also want to check out the following:
- Ultimate Prebiotic Foods & Herbs List PDF (Free Download)
- Probiotic AND Prebiotic Foods List PDF (Free, Downloadable, and Printable) – With Product Links & Recipes
- Top 4 Prebiotic Drinks to Try (2023)
- What’s the Best Sauerkraut for Probiotics and Gut Health?
- 11 Evidence-Based Raw Sauerkraut Health Benefits, According to a Gut Health Dietitian
- Should You & Can You Take Prebiotics and Probiotics Together?
- Sauerkraut with Probiotics (Recipe)
- Iron Supplements and Probiotics: What You Need to Know
- GI Mapping: An Integrative, Cutting-Edge Component of Gut Health Treatment
- Honey for IBS: Benefits & Contraindications
The bottom line & next steps
Prebiotic and probiotic foods and supplements are a growing trend in the gut health industry. While we’re being taught that we “should” be buying and taking fancy, expensive cutting-edge supplements, that is not always the case!
For most healthy adults, eating a balanced and diverse diet with a variety of fruits, veggies, and other plant-based foods and herbs, combined with your favorite probiotic-rich functional foods (with not too much added sugar or artificial sweeteners) on a regular basis is sufficient to support a healthy gut.
For others navigating a gut health condition like IBS/IBD, you’ll likely need more therapeutic doses of probiotic foods and/or supplements, to help rebalance and optimize your gut microbiome.
(A comprehensive stool analysis test is a great way to get a detailed snapshot profile of what’s going on in your gut microbiome, so your treatment team can tailor your recommendations accordingly!)
If you find you’re getting adverse reactions to most prebiotic/probiotic foods/supplements, you should consider consulting a doctor and a functional dietitian, so you can be tested and treated for small intestinal bacterial overgrowth (SIBO).
Wanna learn more about how to optimize your gut health with foods, herbs, supplements, mindset shifts, and holistic lifestyle practices? If so, feel free to join us in my free private Facebook group: Whole-istic Living for Better Gut Health!
XO – Jenna