Top five foods rich in prebiotics

In a new study, scientists estimated the prebiotic content of thousands of food types by using pre-existing literature to find out which foods offer the highest prebiotic content.

According to the study, the top five foods that pack the greatest prebiotic punch are:

1. dandelion greens
2. Jerusalem artichokes
3. garlic
4. leeks
5. onion

Prebiotics, which can be thought of as food for the microbiome, are different from probiotics, which contain live microorganisms. Both can potentially benefit microbiome health, but they work in different ways.

In addition to supporting gut microbes, prebiotic rich foods contain high amounts of fibre.

“Eating prebiotic dense foods has been indicated by previous research to benefit health,” said Cassandra Boyd, a master’s student at San José State University who conducted the research with Assistant Professor John Gieng, PhD.

For the study, researchers used previously published scientific findings to analyse the prebiotic content of over 8600 foods contained in the Food and Nutrient Database for Dietary Studies, a resource many scientists use to study nutrition and health.

About 37% of the foods in the database were found to contain prebiotics. Dandelion greens, Jerusalem artichoke, garlic, leeks and onions had the greatest amounts, ranging from about 100–240 milligrams of prebiotics per gram of food (mg/g). Other prebiotic-rich foods included onion rings, creamed onions, cowpeas, asparagus and even Kellogg’s All-Bran cereal, each containing around 50–60 mg/g.

Boyd will present the findings at NUTRITION 2023, the flagship annual meeting of the American Society for Nutrition held 22–25 July in Boston.

“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,” Boyd said. “Multiple forms of onions and related foods appear in a variety of dishes as both flavouring and main ingredients.”

Based on the team’s findings, Boyd said a person would need to consume approximately half of a small onion to get 5 g of prebiotics.

Wheat-containing items rank lower on the list. Foods with little or no prebiotic content include dairy products, eggs, oils and meats.

The researchers noted that more research is needed to understand how cooking impacts prebiotic content and to better assess foods that contain multiple ingredients.

Image credit: iStock.com/matejmm