A Growing Interest in Microbiome-Supporting Ingredients

At Natural Products Expo West, Justin Green, PhD, director of scientific affairs at EpiCor, discussed the growing interest in postbiotics and how they differ from more familiar microbiome ingredients such as probiotics.

Green explained that probiotics are live microorganisms—typically bacteria or yeast—that have been well characterized and shown to provide health benefits when consumed in sufficient amounts. Importantly, not all bacteria qualify as probiotics; specific strains must be scientifically demonstrated to support health. Historically, the prevailing assumption in microbiome science was that these microbes needed to be alive to exert beneficial effects, largely because the human gut is home to a complex ecosystem of living microorganisms that help digest food and produce metabolites beneficial to the host.

Postbiotics, by contrast, consist of inactivated or non-living microbes. Although they originate from the same types of microorganisms used in probiotics, they are rendered inactive through processes such as heat treatment or pasteurization. For many years, researchers believed this inactivation would eliminate potential benefits, since the organisms could no longer colonize the gut.

However, Green noted that scientific observations began to challenge this assumption. In some studies designed to compare live probiotics with heat-killed controls, researchers occasionally observed that the non-living microbes still produced measurable health effects—and in some cases even greater benefits than their live counterparts. These findings suggested that microbial components or metabolites themselves may interact with the body in meaningful ways.

According to Green, postbiotics may exert their effects through interactions with the gut lining and immune system rather than by establishing colonies in the gastrointestinal tract. Microbial cell components and metabolites can signal physiological responses, helping the body regulate immune activity or maintain microbial balance.

Using EpiCor’s yeast-derived postbiotic ingredient, Green explained that certain postbiotic signals may help place the immune system in a heightened state of readiness while moderating inflammatory responses. As microbiome research continues to evolve, postbiotics are emerging as an additional category within the broader microbiome-focused nutrition market.

A transcript of his conversation can be found below.

Nicholas Saraceno: We are here at the 45^th annual Expo West here in Anaheim, CA. I'm Nico Saraceno, senior editor of Nutritional Outlook, and I’m joined today by Dr. Justin Green. He's the director of scientific affairs with Epicor. First of all, Dr. Green, thank you so much for taking the time.

Justin Green: It’s my pleasure.

Saraceno: I know there's a lot going on. Very busy here at day one of Expo West. Very busy. Very big. Since I've been here, it's grown exponentially. Let’s start with the microbiome. The interest has expanded over the years. How do postbiotics differ from the earlier categories?

Green: It's good that you call them microbiome products, because that's the one thing that links them all. Now two that are the simplest are probiotics, as far as what they are, are probiotics and postbiotics. So probiotics are microbes. What I mean by that is single cell organisms, so your bacteria or your yeast, sometimes even algae, but usually as bacteria are yeast, single cell, that's all that matters, that are well characterized. They have specific strains, specific species, and they are are known to be good for your health. Just because you've eaten a lot of bacteria doesn't mean you've eaten a probiotic. It has to be shown that particular strain has been shown for your health.

Now what happened was that was thought to be the main mode of action is that it had to be alive. That's the key part, had to be alive. Talking about postbiotics, that's going to be the one difference. Postbiotics are killed, they're dead. The definition says inanimate, because it sounds nicer than killed or dead. Yeah, and it's the same thing.

It's killed way before you would do anything else, pasteurization, so a high heat and killing all of it. So that's the difference. You have microbes. In both cases, probiotics is alive, and with postbiotics, it is dead. Now, back when probiotics were being studied, it was assumed that it had to be alive for its mode of action. And the reason for that was that is the microbiome. And people started appreciating the microbiome. You've got this whole ecosystem of live microbes in our gut. It used to be, people didn't even know about microbes, right? Once they started learning about microbes, they found that, oh, they're living in us, but it was assumed they were just taking advantage of us. They're right there where they need to be, where our food is coming. We can't do anything about it. They're so small, they're just there.

Finally, people realize, no we could get rid of these guys, if we wanted to, we have a very strong immune system. We can get rid of these guys. We're letting them be there. And we're letting them be there for a reason. They're digesting food for us, giving us these great metabolites that are there right where we need it, right in the large intestine, and some in the small intestine as well.

The assumption was, probiotics are good for you. They're live microbes. Some of them are the same species as the microbes that are our gut. They must need to get there and colonize, set up shop. That's only going to do that if it’s alive. And that does two things. It's right where it needs to be. A lot of the things that these microbes make are good for us, but if we just ate them, we would digest them before it got to our large intestine.

The other thing is that there's only so much real estate in our gut, and if you colonize a part of your gut with something that's good, that means there's less space for anything that's bad. So it's also kind of out competing anything that might not be good for us with our gut. They would do science, and every once in a while, they would have as a negative control that kills probiotics.

And yes, often only the live probiotic would give a health benefit, and every once in a while, the dead probiotic would also give a health benefit. Also, sometimes the dead probiotic would give more of a health benefit than the live probiotic. So thinking had to change a little bit. Yes, probably one reason some probiotics are good for you is that it has to be alive and colonize the gut. But there are other ways that we interact with microbes, and they don't have to be alive.

Essentially, they're interacting the parts of them and the things that they make; thousands of different things can interact with our gut lining, interact with our microbiome. They don't have to be alive. There just has to be an interaction. And there are responses that are coded into us to have that can give good help.

I like to think of our body as a computer, as constantly looking at the surroundings and making the proper response. And that's true, our gut lining is the scanner of that computer, and what postbiotics do is give a ton of information to that scanner, and there's all sorts of responses that our body will have to that stimulation. In the case of EpiCor, which is a postbiotic we're talking about now, one of those signals is, put your immune system on alert, but keep inflammation down.