Prebiotics may not be as widely recognized as probiotics, but they’re quickly becoming a common term in conversations about diet and nutrition. In simple terms, prebiotic fibers are plant-based compounds that move through the digestive system without being broken down like other nutrients. Along the way, they serve as nourishment for the community of microbes living in the gut.*

While probiotics are live microorganisms, prebiotics are the “fuel” that supports them. Both play distinct but complementary roles in the broader landscape of microbial balance.

Prebiotics in Food

Prebiotic fibers are naturally present in many everyday foods. They are found in a wide range of fruits, vegetables, grains, and legumes. Common examples include:

• Garlic, onions, and leeks – often used as cooking bases around the world.
• Bananas – especially when slightly green.
• Chicory root and Jerusalem artichokes – among the richest sources.
• Whole grains and legumes – staples of traditional diets.

These foods contain fibers such as inulin, fructooligosaccharides (FOS), and galactooligosaccharides (GOS).

Prebiotics are not destroyed by heat, so they can withstand normal cooking. This makes them versatile ingredients that appear in both raw and prepared meals across cultures.

Prebiotics in Supplements

In addition to being part of whole foods, prebiotic fibers are also available in supplement form. They can be found as powders, capsules, chewables, or even added to beverages.

These supplements are often derived from natural plant sources such as chicory root or acacia gum. Because prebiotics are non-digestible fibers, they do not rely on living organisms or colony-forming units (CFUs) like probiotics do. Instead, they are measured by weight, often in grams or milligrams per serving.

Supplemental prebiotics are sometimes combined with probiotics in “synbiotic” products, which aim to provide both the microbes and the fiber that can support them.

Understanding Types of Prebiotic Fibers

Not all fibers are considered prebiotics. Prebiotics are specific types of carbohydrates that selectively interact with beneficial microorganisms in the gut environment. Some of the most studied prebiotic fibers include:

• Inulin – commonly extracted from chicory root.
• FOS (Fructooligosaccharides) – naturally found in many fruits and vegetables.
• GOS (Galactooligosaccharides) – often present in legumes.

While all prebiotics are fibers, not all fibers qualify as prebiotics. Insoluble fibers, for example, play a different role by adding bulk and supporting digestion in other ways.

Product Variety and Use

Prebiotic fibers can be incorporated into foods, beverages, and nutritional blends. For example, they may be added to protein powders, fiber-enriched snacks, or functional drinks. 

Products may contain a single source of prebiotic fiber or a combination of several types. Just as with probiotics, not all products are the same, and the choice depends on personal dietary preferences and lifestyle.

A Growing Area of Interest

From ancient diets based on roots and legumes to today’s growing interest in functional foods, prebiotic fiber has always been a natural part of human nutrition. Its resurgence reflects a broader cultural movement toward plant-based eating and a renewed appreciation of the unseen role fibers play in our diet.

As research continues to explore how fibers interact with the body and microbial communities, prebiotics remain an exciting area of scientific and consumer focus.

As always, talk to your doctor before taking any prebiotic fiber supplements. Get professional advice if you think you might need any supplement or are already taking one to ensure you’re not exceeding the amounts you may need.