The value of the fermented foods and vegetables: pre-, pro- and postbiotics

You have most likely heard about probiotics and prebiotics, but have you heard about postbiotics? Postbiotics are non-viable (dead) microorganisms or parts of them, as well as their metabolites (the products they produce).

While postbiotics haven't received as much attention as probiotics and prebiotics in the past, some authors argue that they might be just as important. After all, microorganisms do not always need to be alive to interact with the body. Some vaccines are non-viable pathogens and still stimulate the immune system to create protective antibodies. The metabolites are a significant part of why these microorganisms are beneficial for us in the first place.

I have often heard people say, "there is no value in a fermented product anymore if the probiotics have been killed off," referring to pasteurized fermented products. I would like to argue that this is not necessarily true! If you have the chance to consume safe non-pasteurized fermented products, that would, of course, be even more beneficial. But even in pasteurized products, some postbiotics will remain and provide additional value to the consumer. So as long as these are fermented products with a good composition, they will have extra value either way, and you should definitely include them in your diet.

What are prebiotics, probiotics and postbiotics?

I Prebiotics

Prebiotics are compounds that probiotics can utilize or "feed on" to provide health benefits for the consumer. This includes some soluble and insoluble fibers in food. Recently, polyphenols are also considered potential prebiotics.

Both can be found in vegetables, fruits, and whole grain products. You'll also find some prebiotics in milk products.
Examples of prebiotics are inulin, fructooligosaccharides (FOS), and galactooligosaccharides (GOS).

Just like us, microorganisms have different preferred foods. By consuming prebiotics that are preferred by beneficial bacteria, you're giving them a better chance of thriving, which they compensate for by creating beneficial compounds for your body and fighting against harmful microorganisms.

II Probiotics

Probiotics are live microorganisms that can survive through the gastrointestinal tract and reach the intestines to provide a health benefit when consumed in large enough quantities.

These are mostly found in fermented vegetables, fruits, and fermented milk products (kimchi, sauerkraut, yogurt, kefir, etc.).
Examples of these are Lactobacillus spp. and Bifidobacterium spp.

If you've looked at the physiology section of this blog, you might recognize something about the image in the middle. The probiotic strains we try to consume are the same as some of the most common beneficial microorganisms inhabiting the gut. That is why they are recommended to restore the balance in the microbiota after antibiotic treatment and other cases when it may be disrupted.