The 8 Best Prebiotic Foods for Better Gut Health, According to Dietitians

Probiotics—aka the live microorganisms found in cultured dairy products and other fermented foods—are likely something you've heard of. Whether it's the yogurt you eat for breakfast, kefir smoothie you have for a snack or kimchi rice bowl for dinner, probiotics are readily available in many popular foods.

Pictured Recipe: Bean & Barley Soup

But, what about prebiotics? What are prebiotics, and why are they getting so much attention in the nutrition world? In this article, we'll cover those questions as well as the eight best prebiotic foods to add to your diet for better gut health.

What Are Prebiotics?

The lesser known "biotic" of the microbiome, prebiotics are gaining popularity thanks to the role they play in supporting gut health, as well as their potential to benefit urinary, oral and skin health. Prebiotics are food for the microbes that reside in your gastrointestinal tract and help keep them healthy and thriving. The term "prebiotics" was originally introduced by two scientists, Glenn Gibson and Marcel Roberfroid, in 1995 in The Journal of Nutrition. However, in 2008, the International Scientific Association for Probiotics and Prebiotics expanded upon and redefined the term prebiotics. In a 2010 article in Food Science & Technology Bulletin Functional Foods, prebiotics was defined to include "a selectively fermented ingredient that results in specific changes in the composition and/or activity of the gastrointestinal microbiota, thus conferring benefit(s) upon host health."

According to gut health expert and registered dietitian Kate Scarlata, M.P.H., RDN, "Plant foods are the biggest source of nourishment for our intestinal-dwelling flora. You can find prebiotics in many of your favorite fruits, veggies, nuts, seeds and whole grains, too."

Read on to find out the registered dietitian-approved best prebiotic foods for better gut health.

The 8 Best Prebiotic Foods for Better Gut Health

1. Bananas

Budget-friendly and convenient, bananas are one of the most versatile sources of prebiotics. According to Roxana Ehsani, M.S., RD, CSSD, LDN, registered dietitian nutritionist and board certified sports dietitian, bananas get a bad rap as being too high in sugar; however, the sugar they contain is naturally occurring (not added) and they are loaded with nutrients. Bananas contain fiber (about 3 grams in a 6-inch banana), but they also contain a type of prebiotic fiber known as inulin, which Ehsani explains can help stimulate the growth of good gut bacteria in your gut.

A small 2011 study published in Anaerobe found that the prebiotic benefit whole bananas offer may promote the growth of microbes in the gut with regular consumption. While the results weren't statistically significant, they spurred other studies that have explored this concept further.

A more recent 2020 study published in the Journal of Food Science and Technology used powders in that had been extracted from local plants—one being the banana—to explore the prebiotic potential they had. Scientists found that the prebiotic potential of these plant extracts not only supported the growth of probiotics in vitro, but also inhibited the growth of pathogenic bacteria that can increase disease risk.

2. Barley

Barley, an underused grain in many kitchens, is highly nutritious, rich in both fiber and protein, and is versatile in the kitchen. One half-cup serving of cooked pearled barley (about 79 grams) contains 3 grams of fiber. According to Ehsani, "Barley doesn't have an overpowering taste, so you can dress it up to be savory or sweet. You can use it instead of rice, quinoa or oats in almost any recipe."

Recent review research published in a 2021 issue of the journal Foods supported past findings on the prebiotic potential of cereal grains and found that barley contains one of the highest levels of beta-glucan. Beta-glucan has shown not only prebiotic potential, but is also a promising functional food ingredient thanks to its ability to thicken, stabilize and emulsify a dish. Swapping barley into your stir-fry, soup or side dish is a promising way to reap the benefits of prebiotics.

3. Garlic

Small but mighty, garlic is one of the most commonly used prebiotic foods on the market. While one clove of garlic (about 3 grams) has only about 0.1 grams of fiber, it still is a great prebiotic source to consider thanks to its functional components.

A 2022 study published in Current Research in Food Science showed that garlic saccharides, or sugars, obtained from garlic polysaccharides in a controlled setting exhibited prebiotic effects. Scarlata echoed this research, sharing, "Garlic is rich in fructans, a well-known prebiotic fiber. Fructans promote the abundance of key health-promoting microbes such as Bifidobacterium, Lactobacillus and Faecalibacterium prausnitzii. F. prausnitzii is one of the most abundant bacteria, or probiotics, in a healthy gut microbiome. It's been shown to be low or depleted in several intestinal disorders such as inflammatory bowel disease."

Fructan intake from foods like garlic, bananas and artichokes, Scarlata shares, is associated with improving the intestinal barrier (a protective gut layer that keeps intestinal contents in the gut versus permeating into the bloodstream), improved laxation and better cholesterol and blood sugar regulation.

If the thought of peeling garlic makes your head spin, consider purchasing peeled garlic or minced garlic in a jar to keep handy in your refrigerator.

4. Jerusalem Artichoke

Although Jerusalem artichokes aren't the most popular vegetable, Ehsani notes, they do pack in the fiber. One cup of Jerusalem artichoke (about 150 grams) contains 2.4 grams of fiber. Plus, Jerusalem artichokes, like bananas, contain inulin fiber as well, which acts as a prebiotic. Ehsani shares, "Inulin can help grow beneficial gut bacteria in the microbiome. It also assists in having easier-to-pass bowel movements, meaning less straining or pushing is required."

A 2018 study published in Current Developments in Nutrition explored the function of the eight main prebiotic sources commonly found in the literature and while only time will tell if it remains in the top three, inulin continues to demonstrate one of the most widespread researched prebiotic benefits thanks to its fermentation in the gut.

5. Kiwifruit

Vibrant and beautiful, kiwifruit is a great addition to help increase your prebiotic intake. Scarlata shares, "Kiwifruit is rich in polyphenols, plant chemicals that have been shown to have prebiotic activity, in turn boosting the health-promoting gut flora." While much research on kiwifruit is a bit older (here circa 2012 and the publication is no longer in circulation), it still provides a benchmark to add more kiwifruit to your daily routine. One kiwifruit (about 75 grams) contains 2.3 grams of filling fiber and can easily be incorporated into a sweet treat with dark chocolate or a summer salsa with mango and tomato.

As an added bonus, Scarlata notes, green kiwifruit can help keep you regular!

6. Legumes

From chickpeas and black beans to edamame, lentils and more, the legume family remains a top source of prebiotics. Foods from this category contain a type of prebiotic known as galacto-oligosaccharides. If you experience flatulence after consumption of these foods, you're not alone.

Scarlata shares, "The well-known intestinal gas effects post bean consumption is simply a reminder that our gut flora are fermenting the prebiotic fiber in the beans, providing key health benefits along the way, such as increasing health-promoting bacteria, such as Bifidobacteria. Bifidobacterium promotes immune function, produces B vitamins, protects us from invading pathogens, and produces butyrate, a short-chain fatty acid that has anti-inflammatory properties and is fuel for the colon."

While the fiber content will vary slightly depending on your legume of choice, one half-cup serving of cooked lentils (about 100 grams) provides 8 grams of filling fiber.

7. Oats

Oats, like barley, are a delicious and versatile prebiotic source, rich in beta-glucan, shown to enhance the growth of health-promoting microbes. One half-cup of old fashioned oats (dry, about 40 grams) contains 4 grams of fiber. Plus, Scarlata shares, as an added bonus, eating oats can help manage both cholesterol levels and blood sugars.

Whether you're in the mood for sweet or savory, you can serve oats with fruit and nuts for your morning meal or add your favorite spices and top with an egg for dinner. Scarlata encourages you to get creative in your kitchen and sub in oat flour in your favorite recipe or try uncooked oats in overnight oats or energy balls.

8. Potatoes

Potatoes get a bad rap for having more carbs than many other types of vegetables, Ehsani shares, but they are a highly nutritious food. One cooked white potato (about 156 grams) contains approximately 2.4 grams of fiber found in both the flesh and skin.

A 2023 study published in Nutrients explored the use of a branded strain of resistant potato starch on the human microbiome of 75 participants. Scientists found that daily consumption for 4 weeks of the 3.5-gram dose of the commercial prebiotic strain of resistant potato starch not only stimulated growth of beneficial health-promoting bacteria, but also reduced diarrhea and constipation in the treatment group.

Whether you are a purple, sweet or white potato fan, Ehsani says, "You reap the benefits of getting some fiber which helps support a healthy, balanced and moving gut."

The Bottom Line

As nutrition research continues to evolve, it's important to focus on variety and to be intentional about including not only probiotics in your regular eating pattern, but prebiotics as well. Focusing on a plant-forward diet is a great way to ensure you are getting a well-rounded intake of prebiotics in your diet. When in doubt, consider adding a colorful fruit and veggie, whole grain and serving of beans or lentils to your plate to increase your prebiotic intake.

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