Prebiotics – a type of gut-friendly dietary fiber – have grown in popularity in recent years. Now, new preliminary research has revealed which five foods pack the most probiotic content.
Dandelion greens, Jerusalem artichokes, garlic, leeks, and onions are the most prebiotic-dense foods humans can eat, according to a new study presented at NUTRITION 2023, the annual meeting of the American Society for Nutrition. The new research has not been peer-reviewed or published in a scientific journal.
Not only do prebiotics help support gut health, but foods rich in prebiotics contain high amounts of fiber, an essential nutrient that most Americans don’t get enough of.
“Previous research has shown that eating dense prebiotic foods is beneficial to health,” study co-author Cassandra Boyd, a master’s student at San José State University, said in a. news release. “It may be more attainable and accessible than you think to eat in a way that promotes microbiome health while eating more fiber.”
Here’s what you need to know about these prebiotic-rich foods, how prebiotics work to support gut and overall health, and how to easily add more prebiotics to your diet.
Prebiotics and probiotics benefit the body’s microbiome – the community of organisms that live inside each of us – but in different ways. While probiotics are living microorganisms, prebiotics are specialized plant fibers that can be thought of as fuel for the probiotics.
“[Prebiotics] it is possible to influence – in a beneficial way – the composition of the human gut microbiota,” it was said Deborah Cohen, DCN, RDNassociate professor in the Department of Clinical and Preventive Nutritional Sciences at Rutgers University School of Health Professions.
Some studies, for example, have linked higher prebiotic intake to better blood sugar management and absorption of essential minerals, and evidence of improved digestion and immune function.
However, more research is needed to fully understand how prebiotics can benefit the body.
“The exact health benefits and mechanisms of action of prebiotics remain the subject of ongoing research,” Scott Keatley, RD, co-owner Keatley’s Medical Nutrition Therapy, said Health. “More high-quality, human-based studies are needed to better understand these topics.”
For the new study, Boyd, along with co-author John Gieng, PhD, assistant professor of nutritional sciences at San José State University, used previous findings to analyze the prebiotic content of 8,690 foods in the Food and Nutrition Database for Nutritional Studies.
Of those foods, 37% contained prebiotics, with dandelion greens, Jerusalem artichokes, garlic, leeks, and onions containing the highest amounts (100-240 milligrams of prebiotics per gram of food).
Other foods found to have reasonable amounts of prebiotics included onion rings, cream onions, cow’s milk, asparagus, and Kellogg’s All-Bran cereal.
Onions were a surprise standout, according to the researchers. “Many types of onions and related foods appear in a variety of dishes as flavorings and as main ingredients,” Boyd said in a statement to Health. “Americans tend to eat these foods so it would be a feasible goal for people to increase their prebiotic consumption.”
Foods with fewer prebiotics included products containing wheat, as well as dairy products, eggs, oils and meat.
Although more research is needed on how prebiotics can benefit overall health, prebiotic-dense foods are still a good source of fiber, so they are an important part of a healthy, balanced diet.
Currently, the International Scientific Association for Probiotics and Prebiotics only has a recommended daily intake for prebiotics: 5 grams per day. According to Boyd, eating half a small onion — about 4 ounces — meets that recommendation.
The researchers behind this new study said they hope their findings will aid future research into the benefits of prebiotics, and perhaps even guide future nutritional guidelines.
“Researchers could do more to understand the best amounts and types of prebiotics for different groups of people, such as those with certain health conditions, the elderly and children,” Keatley said.
“More studies are also needed on the interactions between prebiotics and other dietary ingredients,” he said, “[as well as] the health benefits of different types of prebiotics, and the potential risks and benefits of prebiotic supplements.”
So far, experts recommend what you can do to get more fiber in your diet.
“Try to get 25 to 35 grams of fiber per day in your diet – the average intake of Americans is about 15 grams,” said Keatley. “Move up your whole lot slowly and you may be surprised at how much better you feel, look and function your GI tract.”