Medically Reviewed by Jabeen Begum, MD on September 16, 2022

What Are Prebiotics?

Prebiotics are special plant fibers that help healthy bacteria grow in your gut. This makes your digestive system work better.

Prebiotics vs. Probiotics

Both prebiotics and probiotics are good for your gut, but they help in different ways.

Prebiotics are a source of food for your gut’s healthy bacteria. They’re carbs your body can’t digest. So they go to your lower digestive tract, where they act like food to help the healthy bacteria grow.

Probiotics are live yeasts and good bacteria that live in your body and are good for your digestive system. You can take probiotics as supplements or get them through food.

Prebiotic Foods

You’ll find prebiotics in many fruits, vegetables, and whole grains like:

  • Apples

  • Artichokes

  • Asparagus

  • Bananas

  • Barley

  • Berries

  • Chicory

  • Cocoa

  • Dandelion greens

  • Flaxseed

  • Garlic

  • Green vegetables

  • Konjac root

  • Leeks

  • Legumes (peas and beans)

  • Oats

  • Onions

  • Tomatoes

  • Soybeans

  • Wheat

  • Yacon root

Some products have added prebiotics. They may say “fortified with.” Some products that may have them include:

When you’re shopping for these products, you probably won’t see the word prebiotic on the label. Instead, look for terms like:

  • Galactooligosaccharides

  • Fructooligosaccharides

  • Oligofructose

  • Chicory fiber

  • Inulin

You can also find prebiotics in dietary supplement form. Babies can get them from their mother’s milk.

Prebiotic Benefits

In addition to feeding your good gut bacteria, prebiotics can:

  • Help you absorb calcium

  • Change the rate at which foods cause spikes in blood sugar (the glycemic index)

  • Ferment foods faster, so they spend less time in your digestive system. That helps you not get constipated.

  • Keep the cells that line your gut healthy

New studies are looking into whether prebiotics can help manage gut diseases like irritable bowel syndrome, and how they might play a role in controlling obesity.

How to Use Prebiotics Safely

Try to get prebiotics from whole foods since they also have healthy vitamins, minerals, and antioxidants. Some experts say you should get at least 5 grams of prebiotics in your diet every day. Too much can lead to gas or bloating. Start with small amounts so your gut can get used to them.

Although side effects are rare, prebiotics aren’t for everyone. If you have IBS, prebiotics can make your symptoms worse, and you could have:

You shouldn’t take prebiotics if you have small intestinal bacterial overgrowth (SIBO) or FODMAPs intolerance.

Show Sources


Mayo Clinic: “Prebiotics, Probiotics and Your Health.”

Harvard Health Publishing: “Can gut bacteria improve your health?” “Glycemic index for 60+ foods.”

International Scientific Association for Probiotics and Prebiotics: “Prebiotics.”                                

Colorado State University: “The 10 best food sources of prebiotics.”

International Food Information Council Foundation: “Gut Check: Prebiotics and the Microbiome.”

Cleveland Clinic: “Prebiotics vs. Probiotics: What’s the Difference?”

UMass Medical School: “The 10 Best Prebiotic Foods for IBD.”

International Journal of Biological Macromolecules: “Health-promoting effects of konjac glucomannan and its practical applications: A critical review.”

Nutrients: “Yacon (Smallanthus sonchifolius) as a Food Supplement: Health-Promoting Benefits of Fructooligosaccharides.”

Columbia University Irving Medical Center: “What You Need To Know About Prebiotics.”

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