Article image

Top five prebiotic-rich foods that will boost your gut health

Prebiotics are a form of dietary fiber that fuel the beneficial bacteria residing in your gut, enhancing their health, growth and activity. These bacterial helpers, in turn, play a crucial role in digestion, immunity, and even mood regulation. 

The fascinating world of the gut microbiome has gained a lot of attention in recent years. More and more studies have confirmed its significance in overall health. This new study is shedding light on how we can actively boost our gut health through dietary changes. In particular, the incorporation of prebiotics.

Researchers led by Cassandra Boyd, a master’s student at San José State University, and Professor John Gieng analyzed thousands of foods to identify those with the highest prebiotic content.

Top five foods for prebiotic gut health

The analysis revealed that the top five foods rich in prebiotics are dandelion greens, Jerusalem artichokes, garlic, leeks, and onions. Interestingly, these foods also boast a high fiber content – a nutrient often lacking in typical American diets.

“Eating prebiotic dense foods has been indicated by previous research to benefit health,” said Boyd. She further emphasized that a dietary approach promoting microbiome wellness while simultaneously increasing fiber intake “may be more attainable and accessible than you think.”

These insights will be presented by Boyd at NUTRITION 2023, the annual flagship event of the American Society for Nutrition, held in Boston from July 22-25.

Health benefits of prebiotic foods

The implications of increased prebiotic intake are substantial. Previous studies have connected it with improved blood glucose regulation, enhanced absorption of minerals like calcium, and indicators of improved digestive and immune function. 

Most dietary guidelines do not currently specify a recommended daily allowance for prebiotics. The International Scientific Association for Probiotics and Prebiotics – a non-profit scientific organization that established the current definition of prebiotics – recommends an intake of five grams per day.

During the study, Boyd and her team used existing scientific literature to analyze the prebiotic content of 8,690 foods found in the Food and Nutrient Database for Dietary Studies. This database is a widely-used resource in nutrition and health research. 

Remarkably, researchers found that about 37 percent of the foods in the database contain prebiotics. The top five foods ranged from about 100-240 milligrams of prebiotics per gram of food.

Additional insights

“The findings from our preliminary literature review suggest that onions and related foods contain multiple forms of prebiotics, leading to a larger total prebiotic content,” said Boyd. Foods like onion rings, creamed onions, cowpeas, asparagus, and even Kellogg’s All-Bran cereal were also found to be rich in prebiotics.

If you’re wondering how much onion you’d need to eat to reach the recommended 5 grams of prebiotics, Boyd suggests about half of a small 4-ounce onion would suffice. Conversely, foods like dairy products, eggs, oils, and meats demonstrated little or no prebiotic content.

The team’s research helps us understand which foods could benefit our gut microbiome. It also provides a foundation for other scientists to delve deeper into the health impacts of prebiotics. This could lead to future dietary guidelines that incorporate prebiotic recommendations. 

However, Boyd and her team acknowledged the need for more research. In particular, scientists need to investigate how cooking influences prebiotic content and how to evaluate foods with multiple ingredients.

It’s important to note that while these findings were evaluated and selected by a committee of experts for presentation at NUTRITION 2023. They have not undergone the same peer review process required for publication in a scientific journal. 

Prebiotics vs. probiotics 

Probiotics and prebiotics are both important for gut health, but they serve different roles and come from different sources.

Prebiotics are types of dietary fiber that act as food for the good bacteria in your gut. Essentially, they feed the probiotics. Your body can’t digest them, but gut bacteria can. This process of digestion by gut bacteria leads to multiple benefits. These include a healthier gut environment, better digestion, lower levels of inflammation, and potentially other health benefits.

A variety of foods, especially fruits, vegetables, and whole grains, contain prebiotics. These contain complex carbohydrates such as fiber and resistant starch.

Probiotics, on the other hand, are live beneficial bacteria. These are the microorganisms that are being “fed” by the prebiotics. They help keep your gut healthy by outcompeting harmful bacteria and fungi, producing substances that lower inflammation, aiding in the digestion of foods, and carrying out other beneficial tasks.

Fermented foods like yogurt, sauerkraut, kimchi, kombucha, pickles, and some cheeses contain probiotics. You can also take them as supplements, but if possible, it’s generally best to obtain them from food sources.

In a nutshell, probiotics are beneficial bacteria, and prebiotics are food for those bacteria. Both are essential for maintaining a healthy gut microbiome, and they often work best when taken together.

“Synbiotic” therapy refers to the practice of using prebiotics and probiotics together to enhance their beneficial effects.

More about prebiotics

Prebiotics are a class of dietary fiber that nourish beneficial gut bacteria, supporting their growth and multiplication. Found in various food items, these fibers play a vital role in promoting overall health and well-being.

First identified in the mid-1990s, prebiotics gained recognition for their unique ability to selectively stimulate the growth and activity of beneficial gut bacteria. These compounds reach the colon undigested, where they serve as food for specific bacteria, chiefly Bifidobacteria and Lactobacilli.

Their interaction with gut microbiota contributes to various health benefits including enhanced digestive health, improved immune response, and potentially reduced risk for certain diseases.

Sources of Prebiotics

Prebiotics naturally occur in a range of foods. Foods high in prebiotics include chicory root, Jerusalem artichoke, garlic, onions, leeks, asparagus, bananas, barley, oats, apples, wheat bran, and flaxseeds. People can also consume prebiotics through fortified foods and dietary supplements.

Types of Prebiotics

Different types of dietary fibers act as prebiotics. Key types include:

Fructooligosaccharides (FOS)

FOS, naturally occurring in foods like asparagus, garlic, and onion, helps stimulate the growth of Bifidobacteria in the gut.

Galactooligosaccharides (GOS)

GOS, found in legumes, lentils, and human milk, also enhances Bifidobacteria growth while potentially reducing harmful bacteria.

Inulin prebiotics

This prebiotic, present in chicory root and Jerusalem artichoke, supports Bifidobacteria and can increase stool frequency in people with constipation.

Xylooligosaccharides (XOS)

XOS, extracted from bamboo shoots and corn cobs, has shown potential to improve gut health and bowel function.

Resistant starch

Found in green bananas, oats, and cooked and cooled potatoes, resistant starch passes through the small intestine and ferments in the large intestine, providing fuel for beneficial bacteria.

Health benefits of prebiotics

Digestive health

Prebiotics enhance the growth and activity of beneficial gut bacteria, thereby supporting digestive health. They can aid in alleviating constipation, promoting regular bowel movements, and maintaining overall gut health.

Immune function and prebiotics

Prebiotics may enhance the body’s immune response. They help balance the composition of gut microbiota, which interacts with the immune system, potentially strengthening immune defense.

Bone health

Some studies suggest that prebiotics may improve mineral absorption, which can contribute to bone health.

Weight management with prebiotic foods

Prebiotics could play a role in weight management by promoting feelings of fullness, reducing appetite, and potentially influencing body fat storage.

Heart health and prebiotic foods

By influencing the production of short-chain fatty acids and potentially reducing cholesterol levels, prebiotics may contribute to heart health.

Prebiotic foods and mental health

Emerging research indicates a connection between gut health and brain function, suggesting that prebiotics may have potential benefits for mental health.

Safety and side effects of prebiotic foods and supplements

Prebiotics are generally safe for consumption. However, overconsumption may lead to side effects like bloating, gas, stomach cramps, and diarrhea, especially in individuals with sensitive digestive systems. It’s advisable to gradually increase prebiotic intake to allow the gut to adapt.

In summary, prebiotics form a crucial part of our diet, fostering beneficial gut bacteria and potentially improving various aspects of health. Incorporating a variety of prebiotic-rich foods into the diet can aid in maintaining a healthy and diverse gut microbiome.


Check us out on EarthSnap, a free app brought to you by Eric Ralls and

News coming your way
The biggest news about our planet delivered to you each day