What’s the Difference: Prebiotics, Probiotics and Postbiotics

First came probiotics, then prebiotics, and now the newest member of the "biotics" family is postbiotics. What are they, and why are they good for you? Here's what you need to know.

Photo: Hiroshi Watanabe / GettyImages

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Biotics” are very trendy in this day and age. With the focus on immunity as people seek to improve their health through dietary means, gut-friendly foods and supplements are receiving more widespread attention to help individuals achieve these goals. The big question that remains though is: What are the differences between all these “biotics” and do you really need to supplement? Let’s dive into this a bit further.

What Are Prebiotics, Probiotics, and Postbioics?

Prebiotics and probiotics have been widely talked about for some time. However, they have different mechanisms in how they benefit immune health. For instance, prebiotics are often referred to as the “food” for probiotics. They are considered non-digestible carbohydrates and fiber that are fermented by the microbes (or probiotics) found within the gastrointestinal system (or gut.)

Probiotics are live microorganisms that offer a benefit to the host (or person) they dwell in. While there are naturally occurring probiotics that live in the gut already, there are many foods (and supplements) that can be included in the diet to increase the benefits that both pre- and probiotics offer to your total health.

While there are many studies on the mechanisms of action and benefits of prebiotics and probiotics in human health, the term postbiotics is relatively newer with very limited research. What is known about postbiotics is that they are not live microorganisms, but rather the substances produced by the metabolic activity of the probiotics present in the gut.

According to nutrition expert Jessie Wong, MAcc, RDN, LD, “When probiotics ferment prebiotics, it produces by-products that are coined the term postbiotics. Postbiotics can include many different products including metabolites, short-chain fatty acids (SCFAs), microbial cell fractions, functional proteins, and others. While there are definitions for pro- and prebiotics, there’s not yet a recognized definition for postbiotics.”

Sheri Berger, RDN, CDCES, agrees with Wong’s input, noting that while limited in research, some studies have shown postbiotics may help maintain a healthy immune system, support gut integrity, lower inflammation, and possibly help prevent type 2 diabetes.

Can Diet Meet Your “Pre-, Pro-, and Post-biotic” Needs?

Simply put: yes! Nutrition experts widely agree there’s truth to the statement “eat the rainbow” when it comes to your gut health and the family of pre-, pro- and postbiotics.

Kelsey Lorencz, RD Plant-Based Registered Dietitian, Wong, and Berger all recommend eating a wide variety of plant-based foods to fill your body with a wonderful balance of pre-, pro- and postbiotics. And, truthfully, many foods contain all three of these gut health powerhouses so you can certainly do so without taking a supplement in many cases.

To ensure you’re building your plate with all three in mind here is a quick refresher on foods to focus on to get all three.

Prebiotic rich foods:

Probiotic-rich foods:

  • Fermented Foods (yogurt, kefir, sauerkraut, kimchee)
  • Other Fermented Cheeses and Cultured Products

Since postbiotics are formed from the metabolism of probiotics, eating prebiotics and probiotics will also mean you are eating foods that help generate postbiotics in your body as well.

When Should You Supplement?

Like everything in nutrition, there is no black and white answer to this question. However, Wong shares that people can get all the pre-, pro-, and post- biotics from diet so there is no need to supplement if a person is eating a wide range of plant-based food, a good amount of dietary fiber and some fermented food. She recommends people consume 30g of fiber per day from real food (not powdered or supplements) and 30 different types of plants a week for optimal gut health.

With that said, Lorencz and Wong both agree that sometimes supplements may be warranted when dealing with specific health conditions. For instance, research has demonstrated that not all probiotics are created equally. While some strains are beneficial for adults struggling with irritable bowel syndrome (IBS), others are specifically tailored to help with diabetes management, infant health, etc.

With this in mind, before popping a pre-, pro-, or post- biotic pill, speak with a trained healthcare provider in the microbiome to ensure the strain you are taking is recommended for the condition you are experiencing. Wong points out that while taking probiotics may have productive function, it may also contribute to future diseases depending on the strain and the individual’s microbiome.

Bottom Line

Fill your plate with a variety of plant-based and fermented foods to reap the benefits of all three biotics to further support your immune health. Consider adding these veggie-rich dishes to your meal plan this week:

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