Have you Heard of Postbiotics?

Many of my clients come to me asking questions about terms they’ve heard about, and how they can affect their gut health. Most have heard about probiotics, some about prebiotics, but postbiotics? If you’re like so many others, this can all get a little confusing.

Let’s start with the one most familiar, probiotics. These are often known as the “good bacteria”, and are found in supplements as well as foods. To learn more about probiotics, see my post here. The term probiotics is getting thrown around pretty loosely, and many think that all fermented foods are probiotics. But actually, this isn’t the case. By definition, probiotics are “live microorganisms that, when administered in adequate amounts, confer a health benefit on the host.” The important part of that definition is having studies that show a health benefit on the host (that’s us!). While kombucha, kimchee, and sauerkraut are fermented foods, they do not have actual studies showing they contain microbes that improve gut-health in humans. So technically, they are not probiotics! In fact kefir, and some yogurts, are the only fermented foods so far, that truly contain probiotics. Now that doesn’t mean you shouldn’t eat fermented foods, they taste great and can help with digestion, but we can’t yet say whether or not they actually do anything beneficial for our gut health.

If probiotics are beneficial microbes, what are prebiotics? Prebiotics are the foods we eat, that feed our healthy gut microbes. Like probiotics, in order to be a prebiotic, we have to have studies that show a health benefit. Prebiotics include certain fibers that can be found in foods such as garlic, onions, bananas, wheat, oats, apples, beans, nuts, and inulin (chicory root). Prebiotics also include foods that contain polyphenols which are in foods such as berries, kiwi, soy, coffee, cocoa, tea, red wine, and olive oil. While some people who are sensitive to FODMAPs can’t tolerate some prebiotic foods, their benefit to gut health is the reason it’s always important to make sure you learn if you can eat even small amounts of some of these foods, and not over-restrict your diet.

Now, what are postbiotics? This is a new term that is being used in certain circles, but doesn’t yet have a true scientific definition. Postbiotics are the bioactive compounds produced by microbes during a fermentation process. They include microbial cells, their cell constituents, and the metabolites produced by the microbes. Some of these metabolites are vitamins, and short chain fatty acids (SCFA). These SCFA are produced by our microbes when we eat prebiotic foods. SCFA are fuel for the cells in the colon, and can decrease inflammation, improve gut barrier function, and immune health. They have also been linked to regulating obesity, blood sugar, appetite, and cardiovascular effects. What’s really interesting about postbiotics, is unlike probiotics which are living microbes, some postbiotics are actual parts of the microbial cell, and have been shown to be even more beneficial when they’re dead! These are sometimes called paraprobiotics or ghost- probiotics. Since the microbes in our gut are living in communities, sometimes what one type of organism produces can be food for another type of organism, which in turn produces substances that provide health benefits to us.

Does this all sound complicated? It certainly can be, and we’re still learning so much about how important our microbes are in keeping us healthy. So, what’s the best way to get pro, pre, and postbiotics?

1. Enjoy fermented foods, but get your probiotics from foods like kefir and yogurt.
2. Eat the greatest variety of plant foods possible, to provide the prebiotics that feed the good microbes in your gut.
3. If you think any probiotic or prebiotic foods may be causing you uncomfortable GI symptoms, let me help you. Together we can find out which foods, and how much of them you can tolerate. This way you can eat as many of these delicious foods as possible, while providing your gut with needed postbiotics.

Here’s to your health!

Resources:

https://pubmed.ncbi.nlm.nih.gov/31387262/

https://www.nature.com/articles/nrgastro.2017.75

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6801921/