Probiotics, prebiotics, now postbiotics? What is known and not about the latest research on the intestine

Probiotics have been all the rage in recent years, as more and more food companies have advertised active bacteria in their products and consumers have become more aware of the role of bacteria in keeping their gut healthy.

Also in the “biotic” family are prebiotics, the things that probiotics eat, like foods rich in fiber.

Postbiotic is a less familiar term, but according to some microbiologists it is a broad area of ​​interest.

“Understanding what the microbiota is and how it changes in disease was a big deal five years ago,” said Lisa Osborne, assistant professor in the Department of Microbiology and Immunology at the University of British Columbia.

“Then we realized that maybe it’s not necessarily who’s there but what they’re doing, the postbiotics that are being produced and how that affects the host’s post-response response. It’s still a relatively new field.”

Postbiotics are the wastes left over after your body has digested probiotics and prebiotics. Some postbiotics are the product of fermentation and some postbiotics are the structural parts of the cells themselves.

They can be found in fermented foods, but your gut can also produce them, said Jennifer Stearns, a microbiologist and assistant professor in the department of medicine at McMaster University, to CBC’s host Dr. Brian Goldman. The dose.

Although an official definition of postbiotic has only been decided upon by experts in the last year, researchers have been well aware of postbiotics in the human gut for several years.

Kombucha is a fermented product which according to experts may contain prebiotics, probiotics and postbiotics. (Credit: iStock / Getty Images)

“People are trying to figure out how to improve their gut health in order to improve their overall health. And postbiotics are just part of that conversation,” Stearns.

Yet even though the term is already popping up on commercial supplements, there are still many unknowns when it comes to postbiotics and potential health benefits, Stearns said.

Which ones are they?

Last year, a group of experts from around the world specializing in nutrition, microbiology, food science and other research areas have reached a consensus on the definition of postbiotics.

The panel organized by the International Scientific Association of Probiotics and Prebiotics (ISAPP) agreed that a postbiotic is a “preparation of inanimate microorganisms and / or their components that confers a health benefit to the host”.

Most people will receive postbiotics from fermented foods such as kefir or kimchi.

“When you eat fermented foods, then you’re getting it all. You’re getting the prebiotic, the probiotic and the postbiotic. It’s the super mix,” Stearns added.

Postbiotics can also come in the form of an oral supplement that can be purchased online. But most Canadians won’t have easy access to them on store shelves, some experts say, and warn against buying them in oral supplement form.

“It’s still so new that it’s not something I would recommend, although you might find it at a health food store,” Osborne said.

Health Canada has not approved any natural health products with postbiotics as a “recommended use or purpose,” a spokesperson said.

Postbiotics are also becoming increasingly popular in the skin care industry, which focuses primarily on the skin microbiome.

Identified as a top trend by WGSNa global source for trend forecasting, the next evolution of beauty inspiration from Korea and Japan will put fermented ingredients in the spotlight.

Are there any proven health benefits of postbiotics?

The gut microbiota (also known as microorganisms) and its relationship to general health is an important area of ​​research.

Researchers are trying to gain a better understanding of the gut-brain connection and what a “healthy” gut microbiome looks like.

Often dubbed the “second brain,” the enteric nervous system (ENS) found within the digestive system has been shown to have effects on our mood and brain health.

“Friendly” lactobacillus bacteria seen through a scanning electron microscope. (The Associated Press)

A clinical study recently published in the peer-reviewed Journal of the American Medical Association, for example, found that a highly pure urolithin A supplement – a postbiotic gut microbiome – can improve muscle endurance in older adults.

Another possible postbiotic, butyrate, a short-chain fatty acid, was shown in some cases to reduce inflammation, said Andrea Azcarate-Peril, a microbiologist and associate professor at the University of North Carolina in the Chapel Hill Department of Medicine and Nutrition.

A 2009 published study in the peer-reviewed journal Diabetes also found that butyrate dietary supplementation can “prevent and treat diet-induced insulin resistance” and obesity in mice that ate a high-fat diet.

But Stearns cautions that the oral supplement hasn’t been extensively tested in humans for weight loss.

Although ISAPP does not technically recognize butyrate as a postbiotic, some of the researchers who spoke with CBC did.

Postbiotics could also prevent common infectious diseases such as upper respiratory tract infections and acute gastroenteritis, but more clinical studies are still needed. according to one of the experts involved in creating the definition of postbiotics.

What do we not know about postbiotics?

Azcarate-Peril said more needs to be done to better understand how postbiotics can help reduce inflammation and other health problems, or if they can’t help at all.

“There is enough knowledge to be more specific” in the research questions asked, he said.

Stearns said one of the reasons postbiotics are an interesting research area is because they are “emerging as a safer alternative” to probiotics.

Probiotics are live organisms and there may be a small risk of infection if given to those who are immunocompromised, he said. Since postbiotics are dead bacteria, there is the potential that they may be safer for some, adding more research to understand their potential is needed.

It is also not yet known how effective an oral postbiotic can be for someone’s health and for specific health conditions, Stearns said.

He said that for now, eating fermented foods is an easier way to achieve “the desirable effect of probiotic and postbiotic organisms.”

Produced and written by Stephanie Dubois

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