Fiber is the talk of the town! Everyone is always talking about how important fiber is in your diet and how you should be eating more of it. So, you began to look for ways to include this magical ingredient in your diet... only to discover that there are two types of fiber: soluble and insoluble. 

Things just got more confusing. So, you turned to the internet and landed here. Sound about right? Well, welcome to OLIPOP. Let's get started breaking down the details on all things soluble vs insoluble fiber so you can get on with your day (and feel healthier along the way!). 

What is Fiber? 

Dietary fiber, sometimes referred to as roughage or bulk, comprises the components of plant foods your body can neither digest nor absorb. Unlike other food elements, like fats or proteins, that your body breaks down and absorbs, your body cannot digest fiber. Instead, it passes through your stomach and colon relatively intact. [1] But just because your body can't digest it doesn't mean it's useless! 

Soluble vs Insoluble Fiber 

There are two types of dietary fiber: soluble and insoluble. Your body needs both to maintain proper digestive health. Here is the difference between the two: 

• Soluble fiber: Dissolves in water. The result is a gel-like substance that slows down the digestive process and makes you feel full. 
• Insoluble fiber: Does not dissolve in water. Instead, it passes through your small intestine into the large intestine, where it draws water into your stool for aided bowel regulation. Essentially, this fiber acts as bulk to keep your digestive system running smoothly. [2] 

Alright, that's a (very) brief overview of the differences between soluble and insoluble fiber. Let's dig a little deeper. 

Soluble Fiber 

If you've ever seen or eaten chia seeds and noticed the gel that forms around them, then congratulations: you've seen soluble fiber in action. Soluble fiber is the type of fiber we use in OLIPOP. 

This soluble fiber may also work as a prebiotic and comes from ingredients including chicory root, cassava root, Jerusalem artichoke, guar gum, and acacia fiber. This invisible fiber is in every can of OLIPOP because it supports your digestive health.* But just because you can't see them doesn't mean these plant fibers aren't working hard for your health with every single sip. 

What is Soluble Fiber? 

Soluble fiber is part of your dietary fiber intake, and it plays a major role in supporting your digestive health. When soluble fiber enters your stomach, it begins to collect water, dissolve, and turn into a gel. And this gel helps slow down your digestion. 

As a “get-it-done” and “get-it-done-fast” society, this may sound like a bad thing, but we promise you it’s not. Here’s the thing: when your digestion slows down, your body can better absorb the vitamins and nutrients from your food. It also helps you feel fuller. 

Soluble fiber also works as a prebiotic, aka the key to the balance of your gut's microbiome. When prebiotics make their way to your large intestine, your gut microbes ferment and transform them into supportive compounds like short-chain fatty acids (SCFAs). [3] [4] 

Benefits of Soluble Fiber 

Beyond aiding digestion, there's a wealth of information and research surrounding the many ways soluble fiber benefits your health. For example, prebiotic fiber (aka a type of soluble fiber) is critical and works as food for the beneficial bacteria living in your gut. 

Looking for your bottle of probiotics or think we made a spelling mistake writing 'pre' not 'pro’? Well, we’re impressed by your diligent reading comprehension! But we actually meant prebiotics. Probiotics and prebiotics are different and play different roles in your health and digestion. Essentially, probiotics are live microorganisms (often called “good” bacteria) that can support your body. Prebiotics, on the other hand, are specific substrates, such as certain dietary fibers, that are used as fuel by those beneficial bacteria living in your gut, ultimately leading to a health benefit. 

Prebiotics refer to a diverse category that includes carbohydrates, resistant starches, pectins, and other beneficial ingredients that your army of good bacteria (probiotics) loves to eat. By feeding them a variety of prebiotic sources, you’re offering them the food sources they enjoy, ultimately helping them produce compounds that deliver a health benefit to you. 

Sources of Soluble Fiber 

Looking to increase your intake of soluble fiber? Thankfully, you don't have to force down chalky fiber drinks or spend your days in a vegetable garden. Today, you can get soluble fiber in a ton of different foods and drinks (hint: OLIPOP 😉). If you're looking for ways to add more soluble fiber to your diet, here's what you have to look for: 

• Inulin: Part of the fructan group, inulin is most commonly found in chicory root, Jerusalem artichoke, asparagus, bananas, garlic, leeks, and onions. We use inulin in our 9g Fiber Line, so they're packed with soluble fiber. 
• Resistant dextrins: This soluble fiber has prebiotic properties and is derived from starch (including cassava/tapioca starch). [5] They’re called “resistant” because they resist digestion in the small intestine, making their way intact to the large intestine. [6] We use resistant dextrins from cassava root in both our 6g and 9g Fiber Line. 
• Guar fiber: This soluble fiber comes from the seeds of the guar plant, a drought-resistant legume primarily grown in South Asia. We use guar fiber as part of our 6g Fiber Line.  
• Acacia fiber: Also known as gum arabic, this soluble fiber comes from the hardened sap of acacia trees, primarily Acacia senegal and Acacia seyal. We use acacia fiber as part of our 6g Fiber Line.  
• Pectins: Derived from the cell walls of fruits and vegetables. They help to thicken and are most commonly found on the ingredients list of jellies and jams. 
• Psyllium: Absorbs water in the intestines to help add bulk to your stool. This polysaccharide comes from Plantago ovata seeds and is often added as a powder to food or drink. 
• Fructooligosaccharides (FOS): Short fructose chains with prebiotic properties that are sometimes used as a low-calorie sweetener. You can find FOS in fruits, vegetables, and grains such as chicory, asparagus, onions, wheat, and tomatoes. 
• Beta-glucans: These complex carbohydrates are a type of soluble fiber naturally found in oats, barley, yeast, fungi, algae, and more.  

Insoluble Fiber 

Now that we've discussed soluble fiber, it's time to address insoluble fiber. Refresher: insoluble fiber is the kind that does not dissolve in water. Like soluble fiber, insoluble fiber is good for your health but plays a different role. 

What is Insoluble Fiber? 

Warning: a little bit of potty talk is coming your way! If insoluble fiber had a resume, it would spend a long time talking about... how it softens your stool and makes it easier to pass through your colon. While soluble fiber can also help with this, insoluble fiber is especially known for this benefit. As insoluble fiber passes through your small intestines, it draws water into the large intestine, which helps keep your stool soft. 

Benefits of Insoluble Fiber 

Insoluble fiber has many benefits, especially when it comes to "regulation." Unlike soluble fiber, insoluble fiber speeds up your digestion. It's the ying to soluble fiber's yang. By speeding up your digestion, insoluble fiber helps waste continue moving through your bowels, preventing occasional constipation. [7] 

Insoluble fiber also increases fecal bulk. Insoluble fiber helps fecal material move through your digestive system and increase stool bulk. This is essential for maintaining digestive regularity, and particularly helpful for those who struggle with occasional constipation. 

Sources of Insoluble Fiber 

Whole grains, whole wheat, seeds, nuts, and root vegetables, like the following, are common types of insoluble fiber-rich foods: 

• Wheat bran 
• Corn bran 
• Oats 
• Popcorn 
• Nuts and seeds 
• Potatoes 
• Carrots 
• Beets 
• Brown rice 
• Flaxseed 
• Green beans 

The average diet usually contains a little more insoluble fiber than soluble. But overall, the average American's fiber intake is significantly lower than the recommended daily allowance. 

Back when we were hunter-gatherers, humans consumed 150 grams of fiber a day, but today, we aren’t even close to this number! Healthy men and women under age 50 require 25 to 38 grams of fiber daily. However, over 90% of Americans don’t consume that recommended amount. [8] This massive deficiency is what nutritionists refer to as the “fiber gap.”  

Why OLIPOP Uses Soluble Fiber 

Soluble fiber, the invisible fiber, is hiding in every can of OLIPOP, supporting your digestive health.* Just because you can’t see them doesn’t mean these plant fibers aren't working hard for you with every sip. 

We added soluble fiber because it’s hardly noticeable in your drink. And with it, we're helping close the fiber gap. Modern, fast diets have reduced the amount of important fiber in our diets. That 'fiber gap' causes a whole host of health problems, especially in the gut microbiome. 

Wait, what's the microbiome? The microbiome is the collection of microorganisms that live in, on, and around our bodies. Our microbiome is most concentrated in our digestive system and may play a role in everything from mood and mental function to immunity, skin health, metabolism, and, of course, digestive health. However, researchers continue to study the relationship between the gut microbiome and overall health.  

OLIPOP is a science-backed functional soda designed to bring fiber back into the American diet. We've assembled a global team of leading human gut microbiome research pioneers with diverse expertise spanning digestive health, prebiotic structures, model gut systems, and gut microbiome-supportive nutritional strategies. We work with them to translate cutting-edge research and findings into OLIPOP's product development. 

Every can of OLIPOP is made with OLISMART. This is a blend of several unique botanicals and prebiotics (the primo food source for beneficial bacteria). While eating a balanced diet rich in whole foods like fruits, vegetables, legumes, and whole grains is ideal for getting adequate fiber, we’re happy to help you take your first step. 

Soluble vs Insoluble Fiber: The Takeaway 

Soluble vs. Insoluble? Don’t compare! Your body needs both. You need soluble fiber to slow digestion, help your body absorb nutrients, and feed the good bacteria in your gut, so it functions properly. 

On the other hand, you need insoluble fiber to make your trips to the bathroom consistent, on schedule, and, well, more enjoyable. Incorporating OLIPOP into your diet is an easy and delicious way to give your body some fantastic, intentional ingredients that support your digestive health.* Plus, we're adding some of the fiber you need to lead a healthier, more balanced life. 

*OLIPOP 12 fl oz serving with 6 or 9g of dietary fiber. 

Sources 

1. Slavin, J. (2013). Fiber and Prebiotics: Mechanisms and health benefits. Nutrients, 5(4), 1417–1435. https://pmc.ncbi.nlm.nih.gov/articles/PMC3705355
2. James M. Lattimer and Mark D. Haub, “Effects of Dietary Fiber and Its Components on Metabolic Health,” Nutrients 2, no. 12 (December 15, 2010): 1266–89, https://doi.org/10.3390/nu2121266. 
3. Blaak, E., Canfora, E., Theis, S., Frost, G., Groen, A., Mithieux, G., Nauta, A., Scott, K., Stahl, B., Van Harsselaar, J., Van Tol, R., Vaughan, E., & Verbeke, K. (2020). Short chain fatty acids in human gut and metabolic health. Beneficial Microbes, 11(5), 411–455. https://doi.org/10.3920/bm2020.0057
4. “Probiotics, Prebiotics and the Gut Microbiota,” ILSI, n.d., https://ilsi.org/publication/probiotics-prebiotics-and-the-gut-microbiota/.
5. The science behind digestive resistant dextrin: fermentation, solubility, and digestive impact. (2025, May 7). Satoria NutriSentials. https://satorianutrisentials.com/article/the-science-behind-digestive-resistant-dextrin/
6. Prebiotic Type Spotlight: Resistant Dextrin. (2024, November). Global Prebiotic Association. https://prebioticassociation.org/prebiotic-type-spotlight-resistant-dextrin/
7. “Harvard Health,” Harvard Health, June 1, 2011, https://www.health.harvard.edu/womens-health/ask-the-doctor-what-are-the-differences-between-soluble-and-insoluble-fiber.
8. 2025 Dietary Guidelines Advisory Committee. 2024. Scientific Report of the 2025 Dietary Guidelines Advisory Committee: Advisory Report to the Secretary of Health and Human Services and Secretary of Agriculture. U.S. Department of Health and Human Services. https://doi.org/10.52570/DGAC2025

Meet our Expert This article is reviewed by Courtney McCormick, MPH, RDN, LDN, who is a paid member of the OLIPOP team. Courtney is a registered dietitian nutritionist and public health professional with nearly two decades of experience supporting nutrition initiatives across a variety of settings, including schools, community, and the consumer goods industry. Courtney is passionate about turning evidence-based nutrition into practical, everyday solutions. Here at OLIPOP, Courtney is Manager of Clinical Research and Scientific Content, helping to lead our clinical research program as we continue our commitment to science.