What Are Prebiotics?

Marisa Moore

Chances are, you've heard about probiotics. You know, those good gut bacteria that may provide a boost to gut health and offer a variety of other health benefits. Probiotics are also present in yogurt and other fermented foods like kimchi and kombucha, as well as supplements.

But what are prebiotics? They're essentially compounds that feed the friendly bacteria in the gut. They are largely fermentable carbohydrates -- meaning us humans cannot digest them. Prebiotics help nourish gut bacteria so they can better thrive.

To remember the difference between probiotics and prebiotics, take this advice from Hannah D. Holscher, assistant professor of nutrition at the University of Illinois: "When I think about prebiotics, I remember the 'e' for the energy they provide for gut bacteria. And for probiotics, I think of the 'o' for organism in the gut microbiome."

Health Benefits of Prebiotics

Getting enough prebiotics may mean boosting your health in a variety of ways since the compounds seem to help reduce chronic inflammation in the body. "Prebiotics have been shown to help tamp down and reduce systemic inflammation, which is an underlying mechanism linked to heart disease," Holscher says.

Plus, consuming prebiotics regularly and consistently may help fight off harmful bacteria in the gut and boost immunity. They may also have a positive impact on blood cholesterol and triglycerides, and on mental health. Certain prebiotic fibers may also help with satiety and therefore help with weight management.

[See: 11 Foods and Beverages That May Promote Calm.]

Where to Find Prebiotics

Here's the really good news: There's a good chance you are already getting some prebiotics in your diet. Prebiotics are naturally found in foods like bananas, onions, garlic, asparagus, dandelion greens and sunchokes (or Jerusalem artichokes). But most Americans get their prebiotics from grains like wheat in the form of pasta or bread, for example. Getting prebiotics from foods may mean maintaining a more diverse diet overall, which may further boost health.

Another popular prebiotic source is supplemental fibers. Inulin from chicory root is one of the most common forms. It's often added to high-fiber bars, cereals and a variety of other foods to enhance the flavor.

Prebiotic fiber powder supplements are readily available at health food stores and online. You can add them to smoothies, a bowl of oats or your morning coffee to easily boost your daily intake. If you go the supplement route, do the research, Holscher recommends. Choose a high-quality supplement from a company that follows good manufacturing practices and does independent lab testing on its products to help maintain quality and purity.

[See: Pharmacist Recommended Vitamins and Supplements.]

Recommended Dose of Prebiotics

Research shows there may be a health benefit from as little as 3 grams of some prebiotics per day. For reference, that's just under a half-cup of cooked onions. But instead of zeroing in on a certain number, you might aim to get a variety of different sources throughout the day.

If you've ever experienced gas and bloating after eating a high-fiber granola bar, yogurt or another food with added inulin or chicory root, you probably ate too much fiber too quickly. Start with small amounts and increase until your body is used to it.

[See: Health Issues That Are Sometimes Mistaken for Gluten Sensitivity.]

If you feel overwhelmed with the idea of adding one more thing to your day, Holscher recommends simply focusing on "eating the rainbow for gut health." Eating lots of different fruits and vegetables, nuts, legumes and whole grains will help you get fiber and different phytonutrients, which can deliver health and nutrition benefits for gut health and beyond. Focus on meeting your fruit and vegetable needs for the day and those prebiotics will follow.