What Is FOS? 

Understanding Fructooligosaccharides and Their Role in Gummies

If you've ever read the ingredient list on a fiber, probiotic, or wellness supplement, you may have noticed an ingredient called FOS. 

Short for fructooligosaccharides, FOS is a type of carbohydrate naturally found in certain plants. It's commonly used in foods and dietary supplements because it can provide both mild sweetness and prebiotic fiber. 

But what exactly is FOS, and why is it used in products like gummies?

What Is FOS? 

FOS, or fructooligosaccharides, is a type of prebiotic fiber. It belongs to a group of carbohydrates made up of short chains of fructose molecules. While the name may sound complicated, FOS occurs naturally in a variety of plant foods and has been part of the human diet for centuries. 

Unlike some carbohydrates, FOS is not fully digested in the upper digestive tract. Instead, it continues on to the large intestine, where it can serve as a food source for beneficial bacteria that are part of the gut microbiome. This is why FOS is often classified as a prebiotic.

What Is a Prebiotic? 

Prebiotics are substances that help nourish beneficial bacteria in the gut. 

You may already be familiar with probiotics, which are live microorganisms found in certain foods and supplements. Prebiotics and probiotics are related, but they serve different functions. 

A simple way to think about it is: 

• Probiotics are beneficial microorganisms. 
• Prebiotics help provide nourishment for those microorganisms. 

Because of this relationship, prebiotics are commonly included in products focused on digestive and gut health.

Where Does FOS Come From? 

FOS occurs naturally in a variety of plant foods, including: 

• Chicory root 
• Garlic 
• Onions 
• Asparagus 
• Bananas 
• Jerusalem artichokes 

Because it is naturally present in many foods, FOS has long been part of the human diet. Today, plant-derived FOS, often sourced from chicory root, is often used in foods and dietary supplements as a source of prebiotic fiber, but that’s not the only benefit it can provide a gummy formula. 

Why Is FOS Used in Gummies? 

One of the things that makes FOS unique is that it can serve more than one purpose within a formula. 

FOS has a naturally sweet taste, making it a useful alternative to traditional sweeteners in gummy supplements. When used as the primary sweetening ingredient, it can help create sugar-free products while still delivering a pleasant taste experience. 

Depending on the formulation, FOS may also contribute prebiotic fiber. This combination of sweetness and functionality makes it a versatile ingredient in a wide range of gummy supplements, from fiber and probiotic products to gummies formulated for entirely different wellness goals. 

The Bottom Line 

FOS, or fructooligosaccharides, is a naturally occurring prebiotic fiber found in a variety of plants. 

Because it can provide both mild sweetness and prebiotic fiber, FOS is commonly used in foods and dietary supplements, including gummies. Its ability to serve multiple functions within a formula makes it a versatile ingredient for products focused not only on digestive and gut health, but on limiting added sugar, as well. 

Whether you encounter FOS in a fiber gummy, a prebiotic supplement, or another wellness product, it's an ingredient that helps bring together both function and flavor.