Postbiotics

By Darren Wright

The next gut health superstar? Learn what postbiotics are and how they can keep you healthy all year round.

Many of us are still trying to wrap our heads around gut health concepts like the microbiome, probiotics and prebiotics. Now, a recently published article on the CBC website has proclaimed postbiotics as the hottest new supplement for the gut. What are postbiotics and what do they do for our health?

First, let’s look at some of the better-known areas of gut health.

What is the microbiome?

When discussing gut health, everything revolves around the mysterious world inside our bodies known as the microbiome. The microbiome is the community of microorganisms that live in and on our body, primarily in our gut. These microorganisms include bacteria, fungi and viruses that can number over 100 trillion within each of us.

Emerging science has linked the condition of our microbiome to the overall well-being of our mind and body. There is a strong connection between the health of our gut and our brain, affecting every system in the body. A microbiome rich in healthy bacteria can improve our mood and the performance of our immune system.

The foods we eat impact our microbiome as the bacteria within our gut digest those same foods. Foods that contain probiotics and prebiotics can improve the composition of our microbiome, leading to better health outcomes. 

Most of us know probiotics…

Probiotics are living microorganisms that populate the microbiome, providing health benefits to their human host. They are often referred to as “good” bacteria. Conversely, pathogens or “bad” bacteria can promote disease. Increased research in recent years has affirmed that brain, digestive and immune health are all linked to whether the population of the microbiome is tilted towards beneficial or bad bacteria. Eating probiotic-rich foods, such as yogurt and kefir, or supplementing with probiotic capsules or powders containing strains such as lactobacillus and bifidobacterium can help increase the ratio of probiotics versus pathogens.

Some of us know prebiotics…

To grow and proliferate, the living microorganisms in the gut require nourishment or fuel. The microbiome feeds on prebiotics. When the microbiome consumes prebiotics, beneficial metabolites are produced that benefit our body and mind. These metabolites supply energy for our gut lining and nutrients such as vitamins, amino acids, proteins and peptides.

By adding prebiotics to the diet, humans can encourage the growth and proliferation of beneficial bacteria in the microbiome, in turn improving the health of the gut. Prebiotics are found in foods such as fibrous leafy greens, fruits (apples) and vegetables (onions, garlic). They can also be supplemented as powders in the form of fibres like inulin, fructooligosaccharides (FOS) and acacia. 

But what are…postbiotics???

Postbiotics are not living microorganisms like probiotics. In fact, they are not alive at all. Postbiotics are inactivated microorganisms that can provide numerous health benefits by supporting the microbiome. 

In the past, postbiotics have been referred to as “zombie probiotics.” Only since 2021 has there been an official definition of just what a “postbiotic” is. The International Scientific Association for Probiotics and Prebiotics (ISAPP) declared that postbiotics are a “preparation of inanimate microorganisms and/or their components that confers a health benefit on the host.”¹

Postbiotics are not new, despite only being recently defined. In the 1980’s, researchers discovered that heat-inactivated L. acidophilus bacteria had a beneficial effect on human digestive health.² Years later, evidence emerged that the metabolites released from heat-inactivated bacteria delivered immune modulating benefits to humans by helping the microbiome defend against pathogens.³ Postbiotics are now being researched for their potential for anti-inflammatory, weight management, antioxidant and immune supporting properties.

Official Definition of Postbiotics as defined by the ISAPP:1

“Postbiotics are a preparation of inanimate microorganisms and/or their components that confers a health
benefit on the host.”

Fermented foods are becoming widely consumed by health seekers in Canada. Drinks like kombucha and kefir, foods like yogurt, natto and tempeh all contain metabolites like those found in postbiotics and tout health benefits. Are all fermented foods considered to be postbiotics? The answer is no. While fermented foods may contain some postbiotics, a true postbiotic must meet the officially accepted criteria, which means it is from a clearly defined source and provides proven benefits to the host. 

How do you take postbiotics?

Postbiotics are now available as supplements, our favourite postbiotics are made by Certified Naturals. They usually come in the form of tablets or capsules. The source of the postbiotics can be either heat-inactivated bacteria or yeast. In either case, the postbiotics have been fermented outside the body in a consistent, controlled environment and are ready to deliver beneficial metabolites directly to your gut without relying on your own microbiome to produce them. These metabolites can include vitamins, minerals, amino acids, polyphenols, beta glucan and polysaccharides. You can think of postbiotics as a fermented “multivitamin” for the gut.

Most of us who take probiotic supplements do so for their digestive benefits. Probiotics can settle our stomachs and keep us regular. However, new probiotic supplements with scientific research are often very specific in their benefits. Depending on the bacterial strains used and their dosage, probiotics can have health benefits for digestive, immune, heart or brain health. 

Similarly, postbiotics are beneficial for different conditions depending on the source and fermentation process. So, don’t just take any postbiotic. Look for one that has an approved Health Canada NPN (Natural Product Number) confirming the benefits you are seeking. This means the claims have been backed up by research. 

Postbiotics for immunity and much more

For example, one well-known postbiotic sourced from fermented Saccharomyces cerevisiae (baker’s yeast) has been studied in placebo-controlled human studies for its ability to support the immune system. It has been effective as a preventative for reducing the incidence of colds and flus and for alleviating the symptoms of colds and flus, such as coughs, sore throat and excess mucus.^4,5 This postbiotic activates the natural killer cells of our immune system within just two hours of ingestion.⁶ Additional studies show its positive effect on reducing allergy symptoms and helping to keep users regular by promoting a healthy microbiome.^7,8 Other researched postbiotics include heat-inactivated Bifidobacterium that have been investigated for weight management benefits.⁹ 

The advantage of postbiotics

Once you’ve found a postbiotic that fits your health needs, one of the main advantages of taking a postbiotic over a probiotic will be stability. Probiotics are living bacteria that must be refrigerated to survive. Probiotics also can be unstable during the digestive process, making it difficult to get them to our gut intact. Postbiotics, on the other hand, are not living and do not need refrigeration. This makes postbiotics ideal for travel and eliminates the worry of whether your probiotic still contains sufficient bacteria to benefit your health condition at the time of use.

Postbiotics are fermented and manufactured in controlled, oxygen-free conditions (i.e., outside the human body), which guarantees a certain fingerprint of post-fermentation metabolites. The generation of metabolites in the human body by probiotics are subject to many uncontrollable and individual variables, which can make for inconsistent results.

With probiotic supplements, there is a small risk that the live bacteria may be absorbed through the gastrointestinal lining and enter the bloodstream in individuals with poor barrier lining. There is no risk of this with postbiotic supplementation, which is an opportunity for those who are immunosuppressed and are not advised to take probiotics.

Since every individual has a unique microbiome, each of us will tolerate individual probiotic strains differently. Since most postbiotics interact directly with the gut lining, tolerance issues are unlikely to be as extreme as with probiotics, making them easier on the system for most people.

Postbiotics are here to stay

The postbiotic category will be an area of growth in research, consumer awareness and in usage over the years to come. Do your research and find a postbiotic suitable for you! Your microbiome will thank you!

REFERENCES

1. Salminen et al. The International Scientific Association of Probiotics and Prebiotics (ISAPP) consensus statement on the definition and scope of postbiotics. Nature Reviews Gastroenterology & Hepatology. Volume 18. September 2021. Pages 649-667.

2. Bodilis, J.Y. Controlled clinical trial of Lacteol Fort compared with a placebo and reference drug (loperamide). Annals of Pediatrics, 1983, 10, 232-235.

3. Kataria. J. et al., Probiotic microbes: do they need to be alive to be beneficial? Nutrition Reviews. 2009, 23(1), 37-46.

4. Moyad, M.A. et al., Immunogenic yeast-based fermentate for cold/flu-like symptoms in nonvaccinated individuals. J. Altern. Complementary Med 2010, 16(2), 213-8.

5. Moyad, M. A., et al., Effects of a modified yeast supplement on cold/flu symptoms. Urol Nurs 2008, 28 (1), 50-5.

6. Jensen. G. S. et al., Antioxidant bioavailability and rapid immune-modulating effects after consumption of a single acute does of a high-metabolite yeast immunogen: results of a placebo-controlled crossover pilot study. J Med Food, 2001, 14(9), 1002-10.

7. Moyad, M.A., et al. Immunogenic yeast-based fermentation product reduces allergic rhinitis-induced nasal congestion: a randomized, double-blind, placebo-controlled trial. Adv Ther 2009, 26 (8), 795-804.

8. Pinheiro, I. et al. A yeast fermentate improves gastrointestinal discomfort and constipation by modulation of the gut microbiome: results from a randomized double-blind placebo-controlled pilot trial. BMC Complement Altern Med 2017, 17 (1), 441.

9. Caimari, A. et al. Heat-killed Bifidobacterium animalis subsp. Lactis CECT 8145 increases lean mass and ameliorates metabolic syndrome in cafeteria-fed obese rats. Journal of functional foods. Volume 38, Part A November 2017, Pages 251-263.