Your Gut’s Clean-Up Crew: Soluble and Insoluble Fiber

 

Fiber does a lot more than just “keep things moving.” Inside your gut, two types of fiber—soluble and insoluble—show up every day with different jobs, working as a clean-up crew to support everything from digestion and heart health to cognitive function and metabolic balance.

Soluble fiber works like a sponge, absorbing water and forming a gel-like substance that helps trap cholesterol, slow carbohydrate digestion, and nourish beneficial gut bacteria. 

Insoluble fiber takes the role of the broom, adding bulk to your stool and sweeping waste through the colon to keep your digestive system regular and efficient. 

When these two types of fiber show up together on your plate, they support a wide range of systems that keep you feeling your best. 

Let’s take a closer look at what each member of this gut clean-up crew brings to the table—starting with soluble fiber and the many ways it quietly supports your health behind the scenes. Then, we’ll explore the essential work of insoluble fiber and why it’s just as important to your daily routine. 

 

Soluble Fiber: The Sponge That Soaks It All Up

Soluble fiber supports metabolic, cardiovascular, and gut health through its unique ability to form a gel-like substance during digestion. Think of it as your gut’s sponge—soaking up water, thickening as it moves through the digestive tract. 

Soluble fiber forms a gel-like substance in the gut and coats the inside lining of the intestine.  This slows the rate at which sugar is absorbed into the bloodstream.  This process attenuates the extreme blood sugar spike that typically occurs when we consume carbohydrates without fiber.  Soluble fiber also soaks up water, causing it to swell.  This contributes to delayed gastric emptying, which makes us feel full faster and stay full longer. 

That same sponge-like gel binds to substances like cholesterol and bile acids, helping remove them from the body through waste. Over time, this can contribute to healthy cholesterol levels and overall cardiovascular function. 

Meanwhile, in the lower digestive tract, soluble fiber serves as a fuel source for beneficial gut bacteria. As they ferment this fiber, they produce short-chain fatty acids—compounds that help maintain the integrity of the gut lining, signal satiety, support immune health, and reduce inflammation throughout the body. 

Insoluble Fiber: The Broom That Keeps Things Moving

Insoluble fiber acts like a broom in your digestive tract—adding bulk and sweeping waste through the colon to keep things moving efficiently. Unlike soluble fiber, it does not dissolve in water or form a gel. Instead, it remains largely intact as it passes through your system, supporting regular bowel movements and preventing constipation.

By helping material move through the intestines more efficiently, insoluble fiber supports digestive comfort and reduces the risk of irregularity and buildup that can lead to discomfort. For many people, insoluble fiber is what keeps everything on schedule and functioning smoothly. 

While it’s best known for promoting regularity, insoluble fiber has additional benefits that deserve more attention. It supports long-term colon health and contributes to microbial diversity in the gut by encouraging movement and reducing stagnation. A consistent intake of insoluble fiber supports the body’s natural elimination process—no harsh cleanses required. 

The Perfect Team: How Soluble and Insoluble Fiber Work Together

Soluble and insoluble fiber have very different tasks, but their combined impact is what makes a fiber-rich diet so powerful. Soluble fiber slows things down—supporting steady blood sugar, feeding the gut microbiome, and helping the body eliminate excess cholesterol. Insoluble fiber speeds things up—promoting regularity, reducing stagnation, and keeping waste moving through the digestive tract.

This natural balance between sponge and broom is what supports a truly healthy digestive rhythm. The gel-forming properties of soluble fiber help soften stool, while the bulk from insoluble fiber gives it structure and encourages movement. Together, they help keep your gut resilient, responsive, and in sync with the rest of your body.

Their synergy extends beyond digestion. A diet rich in both types of fiber supports metabolic stability, gut barrier function, microbial diversity, and overall elimination. 

Both types of fiber are essential—together, they help your body stay balanced, efficient, and supported from the inside out. 

Now that we’ve covered what each member of the clean-up crew does—let’s look at where to find them. These everyday grocery items are some of the best sources of soluble and insoluble fiber—and a great place to start if you’re building a fiber-rich plate. 

Top 20 Foods High in Both Soluble and Insoluble Fiber

Ranked by total fiber per standard serving

Split Peas (cooked)

Approximately 8 grams of fiber per ½ cup cooked.

An excellent source of both fiber types, especially rich in fermentable soluble fiber.

Lentils (cooked)
Roughly 7.8 grams of fiber per ½ cup cooked.
Affordable, filling, and versatile across cuisines.

Black Beans (cooked)
Around 7.5 grams of fiber per ½ cup cooked.
Supports steady energy and digestion with a balanced fiber profile.

Navy Beans (cooked)
About 6.5 grams of fiber per ½ cup cooked.
Dense and creamy, they’re a great base for soups and stews.

Chickpeas (cooked)
Roughly 6 grams of fiber per ½ cup cooked.
A fiber-rich foundation for salads, stews, or roasted snacks.

Pear (with skin)
Around 5.5 grams of fiber per medium pear.
High in pectin and satisfying as a snack or salad topping.

Broccoli (cooked)
Approximately 5 grams of fiber per 1 cup chopped.
Packed with both types of fiber and cruciferous compounds. 

Chia Seeds
Approximately 5 grams of fiber per tablespoon.
High in soluble fiber and forms a gel when hydrated—perfect for puddings or smoothies.

Avocado
Roughly 5 grams of fiber per ½ fruit.
Creamy, satiating, and uniquely rich in both soluble and insoluble fiber.

Apple (with skin)
Approximately 4.5 grams of fiber per medium apple.
Crisp and refreshing with fiber concentrated in the peel. 

Sweet Potato (with skin)
Around 4 grams of fiber per medium sweet potato.
Naturally sweet, complex-carb source with a balanced fiber profile.

Oats (rolled, dry)
About 4 grams of fiber per ½ cup dry (approximately 2 grams when cooked).
A staple source of beta-glucan—a type of soluble fiber—and an easy base for fiber-rich breakfasts.

Raspberries
Roughly 4 grams of fiber per ½ cup.
Seed-rich berries offer solid insoluble fiber and microbiome-friendly polyphenols.

Blackberries
Around 3.8 grams of fiber per ½ cup.
Tart, vibrant, and loaded with fiber and antioxidants.

Figs (dried)
Approximately 3.7 grams of fiber per ¼ cup.
Chewy and naturally sweet with a balanced mix of both fiber types. 

Brussels Sprouts (cooked)
Roughly 3.3 grams of fiber per 1 cup cooked.
Cruciferous and filling, with prebiotic potential and structural fiber.

Carrots (raw)
About 3.5 grams of fiber per 1 cup chopped.
A fibrous, crunchy snack or easy meal add-in.

Flaxseeds (ground)
Approximately 3 grams of fiber per tablespoon.
A concentrated source of soluble fiber and lignans.

Almonds
Roughly 3 grams of fiber per 1 oz (about 23 almonds).
Crunchy, blood-sugar-friendly, and mostly insoluble fiber.

Quinoa (cooked)
Around 2.5 grams of fiber per ½ cup cooked.
Contains both fiber types and works as a base for balanced meals. 

Where just better.® Fits In: 
A Gentle Source of Prebiotic Soluble Fiber

While all prebiotic fibers are soluble, not all soluble fibers are prebiotic. Here's the difference: 

• Soluble fiber dissolves in water and forms a gel during digestion. It helps regulate blood sugar, supports cholesterol balance, and slows digestion.
  
  
• Prebiotic fiber is a specific type of soluble fiber that feeds the beneficial bacteria in your gut—helping them thrive, multiply, and produce compounds that support immune function, reduce inflammation, and strengthen the gut lining.
  

just better.® prebiotic fiber is a single-ingredient source of soluble prebiotic fiber derived from non-GMO corn. It is completely flavorless, odorless, and dissolves fully in any food or drink without grit or texture—making it simple to support your gut microbiome, digestion, and blood sugar balance all at once.

Unlike fiber blends or supplements with multiple additives, just better.® delivers what your body needs:

✅ 100% soluble fiber
✅ Prebiotic properties
✅ No gas, bloating, or artificial ingredients

At JUST BETTER BRANDS, we believe everyone should get as much fiber as possible from whole, unprocessed foods, but when that's not possible, add just better.® prebiotic fiber to your meals, drinks, and snacks for a healthy, fiber-rich upgrade! 

Wrap-Up

Your gut’s clean-up crew is always on duty—but it can only do its job when it has the right tools. Soluble and insoluble fiber keep everything running on schedule and just better.® prebiotic fiber delivers added support for your high-fiber lifestyle. 

Keep your crew equipped. Eat fiber-rich. Live just better.® 💚