Whether you get your good bacteria fix with a dose of supplements in the morning or a heaping bowl of yogurt, chances are you've heard of probiotics — the friendly little organisms that live in fermented foods. But did you know that probiotics actually need food of their own?
That's where prebiotics, a type of fiber, comes into play. While most fiber-filled fruits and vegetables are solid sources of prebiotics, these nine foods are the real MVPs of gut health.
Think of your gut as a garden of microflora and prebiotics as the fertilizer.
What Are Prebiotics?
You may be familiar with probiotic foods and their gut health benefits but prebiotics are just as important. While probiotic foods (like yogurt or sauerkraut) supply your body with live, friendly gut bacteria, prebiotic foods actually feed your gut bacteria, according to the Mayo Clinic. Think of your gut as a garden of microflora and prebiotics as the fertilizer.
Our bodies are actually incapable of digesting prebiotics — so, when they're eaten, the bacteria in your gut ferments them along your GI tract, according to the University of Massachusetts Medical School Center for Applied Nutrition. This helps the good gut bacteria grow, which can promote healthy digestion and combat inflammation.
"Prebiotics help feed probiotics so they can flourish creating a stronger microbiome," says Lisa Moskovitz, RD. "A healthy microbiome can not only improve the digestion and absorption of nutrients, but it can also boost the immune system and even your mood."
When probiotics and prebiotics are taken together, that's called "synbiotics," as both work synergistically, according to the International Food Information Council Foundation.
As with probiotics, you can take prebiotics in supplement form but there are several high-fiber foods out there that are natural sources of prebiotics. In order to boost your gut health, prebiotics should make a regular appearance in your daily diet, recommends Moskovitz. "The more prebiotics in your diet, the more nutrients you will be getting, including vitamins, minerals and antioxidants."
Although they're commonly prized for their potassium content, bananas are a great food for your gut bacteria, too, according to the Academy of Nutrition and Dietetics.
Bananas contain fructooligosaccharides (FOS), which are fructose molecules that the body can't breakdown itself but are metabolized by your gut bacteria, according to Food Intolerance Diagnostics. FOS, classified as dietary fiber, not only promotes the growth of intestinal microorganisms but can also help promote healthy digestion in the body.
Try adding bananas to yogurt to get a dose of prebiotics and probiotics in one healthy breakfast.
Read more: Top 10 Health Benefits of Bananas
2. Jerusalem Artichokes
You probably won't confuse this root with the standard artichoke (Google it; they couldn't look more different). Jerusalem artichokes, aka sunchokes, are a type of root veggie that's beige in color and very different from the large green vegetable you're used to seeing at supermarkets.
Jerusalem artichokes get a lot of attention for having a high concentration of inulin, a prebiotic fiber that's a type of FOS, according to an August 2014 study published in the Journal of the Science of Food and Agriculture. Inulin is a non-digestible carbohydrate, also known as a fructan, according to an August 2016 study published in Carbohydrate Polymers. Inulin not only promotes healthy gut bacteria but can also help enhance your body's absorption of minerals and help stimulate the immune system.
3. Chicory Root
Think you've never eaten it? It's likely that you have — at least in some form. Chicory root, high in inulin, is a widely used ingredient in food products, added to provide texture and cut down on the amount of fat or sugar. While you probably haven't eaten chicory root on its own, it's often added to processed foods, like nutrition bars or cookies, to boost their fiber content.
Inulin can help promote healthy digestion and is even well-tolerated by people with sensitive stomachs who regularly suffer from gastrointestinal distress, according to an August 2017 study published in the Journal of Clinical Gastroenterology. You can purchase chicory root fiber on Amazon.com and add it to basically everything.
4. Alliums: Leeks, Garlic and Onions
Leeks, like garlic and onions, are a member of the allium vegetable family that's rich in FOS. Although leeks may not be on your weekly shopping list, it's easy to start including them in your diet, says Beth R. Sobel, RD.
"Leeks can be roasted in the oven, grilled, sautéed or braised in a simple broth. One of my favorite combinations is simply roasting leeks, fennel and sweet potatoes in the oven with some olive oil, salt and pepper." Beth recommends cutting the stalks lengthwise and washing them thoroughly under running water to remove any dirt or debris. "The most edible portion of the leek is from the bottom of the stalk up to where it turns green." Leeks are also a flavorful addition to blended soups, especially the traditional potato-leek soup.
If you're unwilling to try some of the more unusual foods that are recommended for their prebiotic content, it's good to know that at least a couple of commonly eaten items are known for the same: Garlic and onions.
"A simple way to include some prebiotic foods in your diet is to enjoy sautéed garlic and onions with your favorite veggies," says Robin Foroutan, RDN, a dietitian-nutritionist specializing in integrative medicine and digestive health. "Homemade salsa with plenty of garlic and onion is also a prebiotic powerhouse."
5. Whole Grains
Whole grains such as whole oats, whole wheat and barley are great sources of non-veggie-derived prebiotics, according to the International Food Information Council Foundation.
These common grains are known to reduce the risk of heart disease and metabolic diseases like obesity and diabetes, in part due to the high concentration of prebiotic beta-glucan compounds present in oats, Foroutan says. Beta-glucans are also found in other cereal grains, especially barley, as well as yeast, mushrooms and seaweed.
Not only can whole grains provide digestive benefits but they also contain nutrients like magnesium and iron and supply antioxidants that you can't find in fruit and vegetables, according to the Whole Grains Council.
Read more: 13 Powerful Grains and Seeds
You might not think of honey as containing "indigestible fiber," but it contains about 25 different oligosaccharides, according to the University of Arizona College of Agriculture and Life Sciences. Oligosaccharides have been shown to promote the growth of probiotic strains bifidobacteria and lactobacilli, according to an April 2013 study published in Nutrients.
7. Dandelion Greens
"One of my favorite food sources of prebiotics are dandelion greens, a delicious bittersweet green that grows alongside the dandelion flower," says Sobel. "They are also a great plant-based source of vitamin A, calcium, vitamin K and iron."
The raw leaf is a delicious addition to salads, Sobel says. But since they are somewhat bitter, many people enjoy combining them with other milder, sweeter greens. A sweet citrus-based dressing can help to soften the greens slightly and cut some of their bitter flavor.
Given the high fiber content (about 4 grams per cooked cup, according to the USDA), you may not be shocked to learn that asparagus is another source of natural prebiotics, according to the Academy of Nutrition and Dietetics.
Like the Jerusalem artichoke, asparagus is high in inulin and FOS, both of which can help promote the growth of healthy gut bacteria, according to a 2016 study published in Acta Scientiarum Polonorum Technologia Alimentaria. Asparagus is also rich in antioxidants, like vitamins C and E.
Read more: 5 Probiotic-Rich Recipes Your Gut Will Love
- Mayo Clinic: "What Are Probiotics and Prebiotics"
- Academy of Nutrition and Dietetics: "Prebiotics and Probiotics: Creating a Healthier You"
- Food Intolerance Diagnostics: "Fructo-oligosaccharide Intolerance"
- Journal of the Science of Food and Agriculture:Prebiotic Potential of Jerusalem artichoke (Helianthus tuberosus L.) in Wistar rats: Effects of Levels of Supplementation on Hindgut Fermentation, Intestinal Morphology, Blood Metabolites and Immune Response"
- Carbohydrate Polymers: "Inulin: Properties, Health Benefits and Food Applications"
- International Food Information Council Foundation: "Functional Foods Fact Sheet: Probiotics and Prebiotics"
- Journal of Clinical Gastroenterology: "Effect of Chicory-derived Inulin on Abdominal Sensations and Bowel Motor Function"
- Whole Grains Council: "Whole Grains 101"
- University of Arizona College of Agriculture and Life Sciences: "Is Honey the Same As Sugar"
- USDA: "Asparagus, Cooked"
- Acta Scientiarum Polonorum Technologia Alimentaria: "Antiradical Capacity and Polyphenol Composition of Asparagus Spears Varieties Cultivated Under Different Sunlight Conditions."
- Nutrients: "Fiber and Prebiotics: Mechanisms and Health Benefits"