For better gut health, you'll need to eat both probiotics and prebiotics. But the good news is, you probably already are.
Oats breakfast coconut milk porridge with apple, banana, blueberry and honey on a light background, top view. Vegetarian healthy food
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By now, you've likely heard about probiotics, the beneficial bacteria living in the gut and regulating everything from digestion to immunity. You can get probiotics from fermented foods like yogurt, sauerkraut, pickles, kefir and kombucha. But once we've populated our gut with these healthy bugs, how do we ensure they survive and prosper? Enter prebiotics.

What Are Prebiotics?

Prebiotics are the foods that probiotics like to eat. More specifically, they are the dietary fibers that certain foods contain that promote the growth of beneficial gut bacteria. There are two main types of fiber, insoluble, which passes through the gut unchanged, and soluble, which is broken down during digestion. Prebiotic fibers are the soluble fibers, the most common of which is inulin. There's also resistant starch, which is not technically a fiber but acts as a prebiotic, providing food for probiotic bacteria.

Why Are Prebiotics Important?

If you eat foods that contain prebiotic fiber, the population of healthy bacteria living in your gut will grow and flourish, which means smoother digestion, stronger immunity, and balanced hormones, among other benefits. What's more, when probiotic bacteria digest these fibers, they produce byproducts called short-chain fatty acids, nutrients that have been shown to improve metabolism. If your diet is lacking in prebiotic foods, the healthy bacteria in your gut will slowly die off and/or be replaced by potentially harmful bacteria. These bad bacteria, which feed on unhealthy foods like sugar, can cause gastrointestinal issues, blood sugar swings, metabolic slowdowns, and more.

What Foods Contain Prebiotics?

Prebiotic fibers are found primarily in plants, including roots, greens, and whole grains. Top sources include Jerusalem artichokes (or sunchokes), onions, garlic, underripe bananas, asparagus, barley, oats, apples and flaxseeds. Unlike vitamins and minerals that can be broken down or lost when exposed to heat, cooking does not affect the fiber content of foods, so these prebiotic foods can be enjoyed in any recipe and still deliver the benefits.

Some of these prebiotic-rich foods, like onions, garlic, oats and apples, are likely already staples in your kitchen, but the others are also a cinch to cook with. Try this recipe for simple Roasted Jerusalem Artichokes, whip up a one-pan meal with a Chicken, Asparagus and Mushroom Skillet or a warm and cozy Beef, Barley and Vegetable Soup, or bake up some moist and sweet Banana Date Flaxseed Bread.

In addition to food sources, you can also get prebiotic fibers (primarily inulin) in supplement or powder form. Inulin powder ($24/2.2-pound bag; is inexpensive and flavorless and can be mixed with water, blended into smoothies, or even dissolved in coffee, tea or hot chocolate.

How Often Should I Be Eating Prebiotics?

The short answer: Every day. The average American consumes about 15 grams of fiber daily, much of which is prebiotic fiber, but the daily recommendation for fiber intake is at least 25 grams. Fortunately, it's easy to incorporate prebiotics into every meal of the day. You can stir a sliced banana and some flaxseeds into oatmeal at breakfast, have a salad with onions and barley for lunch, snack on an apple in the afternoon, and roast some Jerusalem artichokes or asparagus with garlic to enjoy with dinner.

For days when your menu seems light on these fibers, a supplement can come in handy, with just one teaspoon of inulin powder typically delivering about three grams of prebiotic fiber. But if this seems like a lot, don't panic. Adding just one daily serving of these foods to your diet will be something your good gut bugs will surely thank you for.

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