Fiber + GLP-1: Supporting Natural Pathways and Today’s Therapies

What You’ll Learn in This Post

In this post, you’ll discover how fermentable prebiotic fiber connects to GLP-1—your body’s natural fullness and blood sugar–balancing hormone. You’ll learn:

• What early science revealed about fiber’s role in stimulating GLP-1

• The difference between fermentable and non-fermentable fibers—and why it matters for metabolic health

• How short-chain fatty acids (SCFAs) produced by gut bacteria signal GLP-1 release

• Why prebiotic fiber is both a natural activator of GLP-1 and a helpful companion for people using GLP-1 therapies

• Every day sources of fermentable fiber that support gut health, blood sugar balance, and long-term wellness 

Fiber + GLP-1: Supporting Natural Pathways and Today’s Therapies

Conversations about GLP-1 hormones and medications continue to grow. From weight management to blood sugar balance, people are interested in how this hormone works—and how lifestyle choices can support it. In our recent FAQ guide, we walked through the basics of GLP-1, what it does in your body, and how prebiotic fiber can help. 

Today, we’re taking the next step by looking at what the science has demonstrated over the years and what it means for you right now.

Fiber’s Connection to GLP-1

Long before GLP-1 medications came into the spotlight, researchers were studying how diet affects our natural GLP-1 production. As far back as the 1990s, studies showed that fermentable fibers could trigger greater GLP-1 release after eating. In one early trial, dogs fed fermentable fibers like beet pulp and gum arabic had higher GLP-1 levels, steadier blood sugar, and healthier insulin responses compared to dogs fed low-fermentable fibers.

Why does this matter? Because the mechanism is the same in humans. When fermentable fiber reaches your large intestine, your gut bacteria ferment it into short-chain fatty acids (SCFAs). These SCFAs signal specialized intestinal cells—called L-cells—to release GLP-1. The hormone then slows digestion, helps regulate insulin, and tells your brain that you’re satisfied.

The science is clear: fermentable prebiotic fibers are one of the body’s natural activators of GLP-1. 

The Fiber Difference: Fermentable vs. Non-Fermentable

When most people hear the word “fiber,” they think of it as one big category. But not all fibers act the same way in the body. Some fibers, like cellulose, are non-fermentable—they pass through the digestive system largely unchanged, adding bulk but not doing much else.

Fermentable fibers are different. These fibers can be broken down by your gut bacteria. When fermented, they create beneficial byproducts that influence gut health, hormone release, and even blood sugar balance. This is the type of fiber that stimulates GLP-1, making it especially important for metabolic health.

just better.® prebiotic fiber falls into this category. It is a fermentable, soluble fiber that does way more than help you stay regular—it actively supports the body’s signaling systems for appetite, fullness, and blood sugar regulation. 

Can all types of fiber stimulate GLP-1?

No. Only fermentable fibers—like those found in beans, oats, and just better.® prebiotic fiber—are broken down by gut bacteria into short-chain fatty acids (SCFAs). These SCFAs directly signal your gut cells to release GLP-1. Non-fermentable fibers, like cellulose, are still healthy for digestion but do not trigger this hormone pathway. 

Building on Early Evidence

More recent human research has built on these early findings. Clinical trials show that higher intakes of soluble, fermentable fiber are linked to: 

• Improved post-meal blood sugar balance

• Increased satiety and reduced cravings

• Better weight management outcomes

This makes sense when we remember that GLP-1 plays a central role in all three. When your body releases GLP-1 naturally, you feel fuller, experience steadier energy, and avoid the spikes and crashes that often lead to overeating.  

How Short-Chain Fatty Acids (SCFAs) Enter the Picture

So how exactly does fermentable fiber lead to GLP-1 release? The answer lies in short-chain fatty acids (SCFAs)—compounds like acetate, propionate, and butyrate that are produced when gut bacteria ferment fiber.

These SCFAs act as chemical messengers. They interact with receptors on specialized intestinal cells, called L-cells, prompting the release of GLP-1. From there, GLP-1 gets to work: moderating how quickly food leaves the stomach, supporting insulin release, and signaling satiety to the brain.

This chain reaction—fiber → SCFAs → GLP-1—shows why fermentable prebiotic fiber is more than “just fiber.” It’s an active partner in your body’s natural ability to manage hunger, cravings, and blood sugar.

Fiber as a Companion to GLP-1 Therapies

For individuals already using GLP-1 medications, dietary fiber remains an important component. Many individuals experience digestive side effects when starting or adjusting to these therapies—things like constipation, nausea, or discomfort. Adding the right kind of prebiotic fiber can help ease these challenges. 

That’s where just better.® prebiotic fiber stands out. It is a fermentable fiber that dissolves completely, without grit, bloating, or gas. It supports regularity and nourishes the gut microbiome, creating a healthier environment while your body adapts to therapy. 

Many healthcare providers specializing in obesity medicine recommend pairing soluble prebiotic fiber with GLP-1 medications for this exact reason. 

In other words, prebiotic fiber can support the natural GLP-1 pathways and make GLP-1 therapies easier to adapt to with fewer side effects. 

Why It Matters for Everyday Health

Even if you’re not using GLP-1 medications, the connection between fermentable fiber and GLP-1 is powerful. It reinforces the idea that your body already has incredible systems for managing hunger, cravings, and blood sugar balance—you just need to feed them the right way.

By choosing a diet rich in soluble, fermentable fiber from foods like beans, fruits, vegetables, and whole grains—and by supplementing when your diet falls short—you give your gut the tools to activate GLP-1 naturally. This not only supports metabolic health but also improves digestion, heart health, and long-term wellness. 

Everyday Sources of Fermentable Fiber

If you’d like to support your body’s GLP-1 pathways through food, here are a few everyday sources of fermentable fiber you can add to meals and snacks:

• Beans and lentils – versatile in soups, salads, or dips

• Oats and barley – great for breakfast or baking

• Apples, bananas, and berries – simple fruit options with soluble fiber

• Onions, garlic, and asparagus – flavorful vegetables with natural prebiotic effects

Adding just better.® prebiotic fiber alongside these foods can help you close the fiber gap, especially on busy days when meals don’t always include enough fiber-rich ingredients.

Bringing It Together

We now know that fiber is more than just “roughage.” The right kinds of fiber communicate directly with your gut to produce hormones that guide metabolism. They help steady blood sugar, regulate appetite, and support sustainable health goals.

Whether you’re looking for ways to naturally encourage your body’s GLP-1 production or you’re seeking comfort and support while taking GLP-1 medications, prebiotic fiber is a proven ally.

At just better.®, we’re here to keep you fiber-rich and science-strong—helping you feel steady, supported, and ready for wherever you are on your health journey.