Foods that pack the greatest prebiotic punch to keep your gut healthy are dandelion greens, Jerusalem artichokes, garlic, leeks, and onions, suggests a new study.
The study comes amidst growing evidence that consuming prebiotics -- certain types of fibre often found in plants that stimulate beneficial bacteria in your gut -- can help to maintain a healthy gut microbiome.
Studies have linked higher prebiotic intake with improved blood glucose regulation, better absorption of minerals like calcium, and markers of improved digestive and immune function.
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.
"Eating prebiotic dense foods has been indicated by previous research to benefit health," said Cassandra Boyd, student at San Jose State University in the US.
"Eating in a way to promote microbiome wellness while eating more fibre may be more attainable and accessible than you think," she added.
Although 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 organisation that established the currently held definition of prebiotics -- recommends an intake of 5 grams per day.
For the study, researchers used previously published scientific findings to analyse the prebiotic content of 8,690 foods.
About 37 per cent 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 Kellogg's all-bran cereal, each containing around 50-60 mg/g.
"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. "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 grams 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 study was presented at the ongoing NUTRITION 2023, the annual meeting of the American Society for Nutrition held from July 22-25 in Boston.