What Are Prebiotics, Probiotics, and Postbiotics? Understanding the Difference

• Prebiotics are substances that beneficial microorganisms can selectively use and that provide a health benefit. They support the microbes already living in your gut.

• Probiotics are live microorganisms that provide a health benefit when consumed in adequate amounts. The specific microorganism or strain matters.

• Postbiotics are preparations of inanimate microorganisms and/or their components that provide a health benefit. They are not simply “dead probiotics.”

• The three are different, not interchangeable. Some gut-health formulas combine them to provide different forms of microbiome support.

Your gut contains a large community of microorganisms, so you’ll often see prebiotic, probiotic, and postbiotic used together on supplement labels. The terms sound similar, but they describe different things. 

Prebiotics provide substrates that certain microorganisms can use, probiotics are specific live microorganisms, and postbiotics are non-living microbial preparations or components with a demonstrated health benefit. 

Knowing that distinction makes gut-health labels much easier to interpret and helps you avoid assuming that every product using the word “biotic” works in the same way.

The Three “Biotics” at a Glance

Prebiotics, probiotics, and postbiotics all relate to the gut microbiome, but they work in fundamentally different ways. The easiest way to tell them apart is to look at what they are and what they contribute:

“Biotic” does not automatically mean the same thing. A fiber is not necessarily a prebiotic, a microorganism is not automatically a probiotic, and a postbiotic is more specific than simply a microorganism that has been killed. The distinction comes down to what the ingredient is and whether it meets the scientific definition for that category.

What Is a Prebiotic?

A prebiotic is a substrate that is selectively used by microorganisms in your body and provides a health benefit. Many prebiotics are carbohydrates or types of dietary fiber, but prebiotic and fiber are not interchangeable terms.

For something to qualify as a prebiotic, it isn't enough for it to simply reach the gut or be used by bacteria. There needs to be evidence that particular microorganisms can selectively use it and that this use contributes to a health benefit.

Prebiotics are also not microorganisms themselves. They provide a substance that certain microorganisms can use.

Examples include certain oligosaccharides, such as fructooligosaccharides (FOS) and galactooligosaccharides (GOS). Arabinogalactan, a type of plant-derived polysaccharide, is the prebiotic included in Tribiotic+.

What Is a Probiotic?

A probiotic is a live microorganism that provides a health benefit when consumed in adequate amounts.

That definition is more specific than simply calling something a “good bacteria.” A microorganism has to meet the criteria for a probiotic, and the benefits associated with one probiotic cannot automatically be applied to every other microorganism.

The specific strain matters, too. Different strains can have different properties and evidence behind them, so a label that simply says “probiotics” doesn't tell you the whole story.

Tribiotic+ contains several probiotic strains in its NeuroBiome Blend, including Lacticaseibacillus rhamnosus R0011, Lactobacillus helveticus R0052, Bifidobacterium longum R0175, and Lactobacillus reuteri PBS072. 

What Is a Postbiotic?

A postbiotic is a preparation of inanimate microorganisms and/or their components that provides a health benefit.

This is where the terminology gets particularly confusing. You may see postbiotics described simply as “dead probiotics,” but that's not an accurate definition.

A postbiotic is deliberately prepared from microorganisms that are no longer alive, or from their components, and the resulting preparation must meet specific scientific criteria to be called a postbiotic. So:

• Probiotic: live microorganisms

• Postbiotic: an inanimate microbial preparation and/or its components

They're therefore different categories, even though postbiotics can originate from microorganisms used in probiotic research. Tribiotic+ includes Bifidobacterium longum CECT-7347 as its postbiotic component. 

Why Are They Sometimes Used Together?

Prebiotics, probiotics, and postbiotics approach microbiome support from different directions:

• Prebiotic → provides a substrate that certain microorganisms can selectively use.

• Probiotic → provides specific live microorganisms.

• Postbiotic → provides a preparation of inanimate microorganisms and/or their components.

Because their roles are different, a supplement can combine them rather than relying on a single category. The idea is not that one type replaces another, but that each can contribute a different form of microbiome support. 

Research has investigated these categories both individually and in combination, although the evidence for any particular combination depends on the ingredients, strains, doses, and health outcome under study.

Tribiotic+ by Bioligent follows this three-part approach by combining arabinogalactan as its prebiotic, multiple probiotic strains in its NeuroBiome Blend, and heat-activated Bifidobacterium longum CECT-7347 as its postbiotic component.

That doesn't mean everyone needs all three, or that a three-part formula is automatically better. The value of a combination depends on what each ingredient is, what evidence supports it, and what type of support you're actually looking for.

So, Which One Is Better?

There isn't one “better” option because prebiotics, probiotics, and postbiotics aren't competing versions of the same thing. They work differently and can serve different purposes within a gut-health formula.

Prebiotics provide a substrate that certain microorganisms can use, probiotics provide specific live microorganisms, and postbiotics provide inanimate microorganisms or their components. What matters when choosing between them or a formula that combines them is the quality of the ingredients, the evidence behind the specific strains or components, and what you're actually looking to support.

Tribiotic+ takes the combined approach, bringing a prebiotic, probiotic strains, and a postbiotic together in one formula for comprehensive microbiome support.

Want to see whether Tribiotic+ fits your goals? Explore Tribiotic+ and learn how its three-part approach supports your gut and gut-brain health.

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