What is Prebiotic Fiber? Are Dietary & Soluble Fiber the Same?

Many people know fiber is essential, but not all fibers are alike. Soluble fiber, insoluble fiber, and prebiotic dietary fiber play different roles in digestion and overall wellness. This article will break down the differences to help readers understand where prebiotic dietary fiber might fit in their wellness routine. Let’s start with a simple question: what are prebiotics?^†

What Is Prebiotic Fiber?

What is prebiotic fiber? What is it that makes prebiotic dietary fiber so special? Prebiotic fiber is a type of dietary fiber that the body cannot digest. Instead, it serves as food for the beneficial microorganisms in the gut, supporting digestive health. You might find this fiber in prebiotic foods like bananas, artichokes, onions, garlic, leeks, and whole grains in your diet.^†

What are the benefits of prebiotics? By providing your body with a source of prebiotic dietary fiber, you promote the growth of beneficial gut microorganisms. Our gut microbiome comprises innumerable strains of bacteria, and supporting the beneficial strains can help you promote a balanced gut and digestive system. ^†

Nature Made^® offers several Prebiotic Dietary Fiber Supplements to help support your gut, including our Prebiotic Fiber Drink Mix, which can be mixed into your favorite non-carbonated beverage.^†

What Is Dietary Fiber?

So, if that’s what prebiotic dietary fiber is, what’s good old regular dietary fiber? Is all dietary fiber the same thing? Why do we need it, and is it all important? Let's tackle this one at a time. Dietary fiber is all types of fiber we find in plant-based foods that our bodies cannot fully break down.

While all fiber found in food is dietary fiber, not all dietary fiber is the same; several different physical and chemical properties define different types of dietary fiber. These qualities are soluble, insoluble, viscous, and fermentable. Fibers from various food sources can fall into one or more of these categories.

We'll break down exactly what each category means later in this blog. What's important to know is that the overall function of dietary fiber in the body is to help support healthy digestion. This can happen in a few ways: prebiotic fiber helps by feeding beneficial bacteria in the gut, but not all dietary fiber has prebiotic properties. To get a bit deeper into it, we'll explain the different types of dietary fiber. ^†

What Is Soluble Fiber?

When researching fiber for your diet or supplements, you might come across the term "soluble fiber." What exactly does that mean? Soluble fiber is the category of fiber that dissolves in water. That means when you get soluble fiber in your diet, it takes on a gel-like consistency when it combines with water in your gut.

What does soluble fiber do in your gut? Are most prebiotics soluble fiber? All prebiotics are soluble fiber; however, not all soluble fiber is prebiotic.^[1] Non-prebiotic soluble fiber still has a function in the gut: it helps slow digestion and can contribute to a feeling of fullness. ^†

Where might you find soluble fiber in food sources? Soluble fiber is found in oats, beans, apples, and citrus fruits. Nature Made^® offers Kids First^® Fiber Gummies to provide a convenient kid-sized serving of Prebiotic Fiber in two daily gummies to help support kids digestive health.^†

What Is Insoluble Fiber?

Here's the flip side of soluble fiber: insoluble fiber. Now, it's obvious what that means in a literal sense: fiber that doesn't dissolve in water. But what does that practically mean in your gut? Insoluble fiber doesn't dissolve in water and passes through your digestive system largely intact.

Insoluble fiber is not prebiotic, it doesn't feed gut bacteria. It serves a more physical role in the body, adding bulk to stool and supporting occasional digestive regularity. You find insoluble fiber in whole grains, nuts, seeds, and vegetables like carrots and celery. ^†

What is Viscous Fiber?

Viscous fiber is a type of soluble fiber that thickens when mixed with fluid, creating a thicker, more viscous gel.^[2] You can find viscous fiber in oats and barley.^[3]

What is Fermentable Fiber?

Fermentable fibers are dietary fibers that feed microorganisms in a process called fermentation. Isn't that just a prebiotic, you ask? Not necessarily, as prebiotics are fermentable fibers that specifically feed beneficial gut microbiota. It's a square-rectangle situation; all prebiotics are fermentable fiber, but not all fermentable fibers are prebiotics.[4]

Nature Made^®’s fermentable Prebiotic Fiber comes in a number of forms, including Probiotic + Prebiotic Fiber Gummies. These gummies provide a source of clinically studied Probiotic bacteria to add good bacteria to your digestive tract, alongside Prebiotic Fiber to nourish your gut bacteria.^†

Comparing Prebiotic Fiber, Soluble Fiber, and Insoluble Fiber

How to Add Prebiotic Fiber to Your Diet

Now that we know the difference between the categories of dietary fiber and what they each do, how do you include prebiotic fiber in your diet? The best way to add any nutrient to your daily routine is through nutritious food sources. Incorporating fiber-rich foods like bananas, onions, and garlic into your meals is a great, tasty way to give your gut dietary sources of prebiotic fiber. However, that's not always possible or convenient, so supplementing with a prebiotic is a great way to provide additional support.^†

Prebiotic Supplements can help you maintain a consistent daily Prebiotic Fiber intake by adding to your daily wellness routine. If you’re wondering when to take Prebiotics, it’s really up to you! The best way to take a Prebiotic Supplement is consistently every day, so the best time to take them is the easiest time for you to remember. Nature Made^®’s Prebiotic Gummies help nourish good gut bacteria with an excellent source of Prebiotic Fiber in 3 gummies, suitable for adults and providing a source of fiber for kids ages 4-18.^†

A balanced approach, pairing Prebiotic Supplements with fiber-rich foods, is a great way to provide your body with well-rounded digestive support. Nature Made^®’s Gut Health Supplements include Prebiotics and Probiotics for daily digestive system support. Can you take Prebiotics and Probiotics together? Yes, they support the gut in different ways. Consult a trusted medical professional like your primary care provider before starting or changing a supplement routine.^†

Find a Simple Way to Add Prebiotics to Your Routine

Prebiotic dietary fiber isn’t the only aspect of digestive health, but they're a great way to start thinking about how to support your gut microbiome. Eating a balanced diet, staying hydrated, and keeping a consistent sleep cycle all contribute to healthy digestion. ^†

You may also be interested in probiotics, like Nature Made^® Extra Strength Probiotics Capsules, with a clinically studied Probiotic strain to help support digestive balance. What’s the difference between Prebiotics vs. Probiotics? Probiotics are live strains of beneficial gut bacteria to support your gut health, while Prebiotic supplements provide Prebiotic Fiber to feed beneficial gut bacteria.^†

Adding a Prebiotic supplement is an easy way to add digestive support to your daily routine as part of a healthy lifestyle. Explore Nature Made^®'s Digestion & Gut Health Supplements today to find the Prebiotic or Probiotic that best suits your specific health goals.^†

† These statements have not been evaluated by the Food and Drug Administration. These products are not intended to diagnose, treat, cure, or prevent any disease.

References

1. Slavin J. Fiber and prebiotics: mechanisms and health benefits. Nutrients. 2013;5(4):1417-1435. Published 2013 Apr 22. doi:10.3390/nu5041417
2. Dikeman CL, Fahey GC. Viscosity as related to dietary fiber: a review. Crit Rev Food Sci Nutr. 2006;46(8):649-663. doi:10.1080/10408390500511862
3. Guarneiri LL, Kirkpatrick CF, Maki KC. Viscous Fiber from oats and barley. Ann Transl Med. 2024;12(1):18. doi:10.21037/atm-23-1816
4. Delcour JA, Aman P, Courtin CM, Hamaker BR, Verbeke K. Prebiotics, Fermentable Dietary Fiber, and Health Claims. Adv Nutr. 2016;7(1):1-4. Published 2016 Jan 15. doi:10.3945/an.115.010546