Prebiotics, Probiotics, Synbiotics, and Postbiotics: What are the Differences?


You may be familiar with probiotics by now, but what about Prebiotics? Synbiotics? Postbiotics? Even though they all sound fairly similar, they are quite different. And each of them has its own purpose when it comes to gut health. Today, we're going to be discussing each of these in detail so that by the end, you'll be able to confidently identify each type and know which one or several is going to be beneficial for you and your gut and optimal health.


In this topic, we're going to be covering a brief overview of each of these, just to get a feel for the differences. And then we're going to tackle each one in depth so that you can have a thorough understanding of what they are and what they do. Lastly, we'll cover my best tips for how to pick the right supplement for you.


Hello everyone! My name is Katie Krejci and I'm a gut health functional medicine dietitian at Oswald Digestive Clinic, where we help people improve and eliminate bothersome gut issues like gas, bloat, diarrhea, constipation, and more. You can schedule an Initial appointment or you can just start by

downloading our FREE GUIDE: 5 Ways to Improve Gut Health.


What are Probiotics, Prebiotics, Synbiotics, and Postbiotics?

  • Probiotics are a group of live bacteria or yeast organisms that greatly benefit our gut health and immune function. We obtain these from fermented foods or supplements.


  • Prebiotics, they're not bacteria at all. Prebiotics are mostly non-digestible food fibers that provide a food source for the live bacteria in our gut prebiotics simulate the growth and or activity of probiotics.


  • Synbiotics refer to a combination of both probiotics and prebiotics. Since prebiotics is a great fuel source for the live bacteria in probiotics, it only makes sense to combine them together.


  • Postbiotics are what's left over after the probiotic bacteria finishes fermenting the prebiotics. While it sounds like just waste products, these leftovers actually have functional bioactive compounds.

That wasn't too complicated, right? Now that we have a general understanding of what these four items are let's break them down further.


Probiotics

The word "probiotics" come from the Greek word, meaning "for life". And that's because they're living organisms that benefit their hosts, which in this case is our bodies. By boosting gut and immune function, they do this by competing with pathogenic microorganisms or bad bugs, as I like to call them, and essentially crowd them out.

So, think of your gut as a garden where the beneficial microorganisms are the veggies that you want to grow and the bad bugs are the weeds. If the weeds start to take over, you're in trouble.

Some strains of probiotics help clean out these weeds by producing substances like lactic acid, hydroperoxides, and defensins that can kill off these pathogens. Other strains work a little bit more passively by competing with pathogens for nutrients or making the gut environment less inhabitable by increasing mucus production or decreasing the PH. Probiotics even function by healing and improving the function of our intestinal lining. Lastly, probiotics can help modulate our immune system and help with synthesizing neurotransmitters like GABA and serotonin, which can help with stress and anxiety. As I hinted at earlier, not all probiotic strains are created equal though. Each kind of probiotic has a slightly different profile and action in our bodies. So, while we often talk about probiotics as a whole, their effects shouldn't be generalized.


Probiotic supplements can contain a single strain or a blend of multiple strains. Each strain provides slightly different results. Some strains are effective for diarrhea where others can help with high cholesterol and others yet are best used for eczema. This just goes to show how diverse and amazing these live provides bacteria are. And to be honest, there's still so much research being done on probiotics. And while we're learning a lot along the way it's still very much in its infancy. So, there's still a lot we don't know, but we're learning more and more every day. This topic is growing and evolving, but what I'm going to be sharing with you today is the most up-to-date information that we have at the moment. If you're not sure which strain or combination of strains is right for you, definitely listen to the end for a great discussion on how to pick one, or get in touch with us at Oswald Digestive Clinic and we'd love to customize a nutrition plan for you.

We've made it to prebiotics and prebiotics are an interesting category because we eat them. However, they aren't for us. They are for our gut bacteria.


Did you know that we have as many bacteria as we have cells in our body? That's a lot of bacteria and they are hungry.

Prebiotics

Prebiotics provide an excellent food source for our gut bacteria and as a result, we can experience a lot of benefits. Research has shown the following positive effects on our human physiology from prebiotics. So higher levels of probiotics in our gut, like the helpful lactobacillus, enhance absorption of minerals from the food that we're eating, increased production of short-chain fatty acids, and overall healing from intestinal permeability or leaky gut.


Another thing that can happen is reduced gut inflammation and overall inflammatory markers like C-reactive protein. We can experience a reduction in colon pH with a reduced risk of bacterial microbial or viral infection, including C diff, improved cholesterol, and triglyceride glucose levels. Also, just improved motility in our GI tract. By bulking that stool, we can also experience improved vagus nerve function, which is that nerve that connects our brain with our digestive system.


And lastly, improved hydration and bone health. An ideal prebiotic is one that is able to resist breakdown from stomach acid, bile salts, or pancreatic enzymes, and enter the lower section of our gastrointestinal tract unscathed and freely available to feed our gut bacteria.



What are some food examples of prebiotics?


We have insoluble fibers. So, things like the skins from the apples, bran, and root vegetables. Resistant starch, so underripe bananas, rice, potatoes, or oats. Then there are the polyphenols and phytochemicals. Those are the actual color pigments in our food artichokes, asparagus, garlic, Jerusalem artichokes, onion, plantains, and sea vegetables. Those are just a few. Lastly, we have processed oligosaccharides that you can find in foods in supplements. So, if you ever see the words inulin or GOS, FOS those are prebiotics as well.


Because prebiotics is used as food for our gut bacteria, there is going to be some fermentation going on as a result. Therefore, if you're noticing a lot of uncomfortable gas and bloating after eating these types of foods, this can be a sign that you have an imbalance in your gut microbiome. So, if this is happening to you, I'd encourage you to work with a functional medicine provider to assist you in this, and here at Oswald Digestive Clinic, this is exactly what we specialize in. So, if you'd like to work with us, you can make an initial appointment.


Synbiotics

Now we've made it to synbiotics. As we've discussed in the beginning, a synbiotic supplement is one that utilizes a combination of both live probiotics and prebiotic fiber. The word synbiotic refers to the concept of synergism, where the addition of the prebiotic helps improve the survivability and successful implantation of the live bacteria into our colon. And studies on synbiotics have shown that when taken together, they result in elevated levels of bifidobacterium and lactobacillus, which are two very prominent and beneficial strains in the human GI tract. Synbiotics also help promote higher levels of digestive enzymes like lactase and lipase, which results in improved digestion. A recent randomized controlled trial in 2021 even showed that synbiotics can decrease cardiovascular risk factors, the prevalence of metabolic syndrome, and indicators of insulin resistance. This just goes to show how big of an impact synbiotics can make, not only on our gut health but on our overall health as well. One important thing to note is that not all strains of probiotics benefit from being paired with all types of prebiotics, therefore it's important that you're eating a diverse diet and utilizing a synbiotic supplement that has research to support the specific pairing that's being used. Unfortunately, this area of research is just in its infancy, but there are more and more data coming out on this every day. And it's all super exciting. So, if you're looking for some great synbiotic supplement combinations, we definitely have some of our favorites. Definitely go check those out.


Postbiotics

So postbiotics, are a collection of by-products that are produced when the probiotics in our gut feed on and ferment prebiotics. So, the name postbiotics makes sense because we're talking about components that follow the action of probiotics. While postbiotic research is still very new and we certainly don't understand them completely, it does appear that these by-products have a beneficial action on our gut and overall health. But before we jump to the benefits of postbiotics, what are they exactly? So, some things that are included in this group are short-chain fatty acids like butyrate and propionate, bacterial lysates, enzymes cell wall fragments, and even just other metabolites like vitamins and amino acids.



What exactly do postbiotics do for our health?


1. They have immunomodulatory effects. We already know that much of our immune system stems from our gut. So, it makes sense that postbiotics, especially those short-chain fatty acids would have a benefit here. Butyrate in particular can help stimulate the production of T cells in our gut to modulate our body's immune response. So great things happening there.


2. Anti-tumor effects. This can be attributed to the anti-inflammatory effect of the postbiotics plus their interaction with one gene and suppressor genes. While there isn't a ton of research on this yet, one in vitro study saw a reduction in colorectal tumor cell invasion. So super neat and we'll be learning more about this in the future, I hope.


3. Infection prevention. A few postbiotics have been shown to have antimicrobial effects by enhancing the intestinal barrier. So that pathogenic bacteria are less able to bind and cause issues. A series of studies in children found that intake of postbiotics was associated with a decrease in diarrhea, acute gastroenteritis, pharyngitis, laryngitis, and tracheitis.


4. It can reduce cardiovascular disease risk. The short chain fatty acid propionate has been shown to have statin-like effects while covering can reduce inflammation, prevent cholesterol, and accumulation, and even reduce lipid concentrations.


Postbiotics are generally less risky because they're not living organisms like probiotics therefore postbiotics may be a better alternative for high-risk or sensitive individuals. Well, that was super fun. I hope you now have a good understanding of the differences between prebiotics, postbiotics, synbiotics, and postbiotics. But before we close this topic for the day, I want to provide some guidance on how to pick the right probiotic for you.


There are so many options on the market right now and picking not only the right strain and dose is important, but so is selecting from a quality brand that you trust. One study evaluated 13 different probiotics in the market and found that only two of them had contents that matched the label. Some of the products contained as little as 7% of the viable organisms that were listed on the label. So, what you want to look for is a brand that engages in batch testing, for every single batch for potency and purity, look to see if they have passed inspection on consumer labs. And if you're not sure which brand to use, we have some of our favorite products listed.


WANT A QUALITY PROBIOTIC? CHECK THESE OUT!


1) Synbiotic Options:

2) Probiotic Combinations:


Another thing that I want to stress is that it's important to be consistent with your probiotic or fermented foods regimen to have lasting results. A common misconception that I see is thinking that probiotics stay in your system and they actually only remain in your intestine for about one to three weeks, depending on the strain. And of course, your gut environment, therefore consistency is key when it comes to probiotics.


If this topic sparked your interest and you want to learn more about probiotics, we have a YouTube video on our channel, everything from when to take a probiotic to potential side effects when taking a probiotic, go take a look to learn more.


I hope this information about the wild world of probiotics, prebiotics, synbiotics, and postbiotics was helpful to you. And you're now feeling comfortable with the terms and how they can improve your gut and overall health.


If you'd like to explore any of this information further or obtain an individualized nutrition plan, you can schedule an initial appointment at our clinic. We also take insurance and some of our clients get full coverage, which is great. Or you can just start by downloading our free guide: 5 Ways to Improve Gut Health.









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