These 5 Vegetables Are the Best Sources of Prebiotics, Study Finds

A recent study has identified the specific foods that have the highest concentration of prebiotics as the significance of gut health gains ground in the field of nutrition. The study clarifies the advantages of using prebiotics to keep a balanced gut microbiota.

The study, which was presented at Nutrition 2023, the American Society for Nutrition's annual meeting, used available literature to assess the prebiotic content of thousands of different food kinds, highlighting those with the highest probiotic content.

These foods are not only healthy for gut flora but also high in fiber, a vitamin that many Americans' diets lack.

In a statement, Cassandra Boyd, a master's student at San José State University who conducted the research alongside Assistant Professor John Gieng, PhD, said that other studies have suggested that eating foods high in prebiotics is healthy.

"Increasing fiber intake while eating in a way that supports microbiome wellness may be more feasible and approachable than you think."

Prebiotics vs probiotics

Understanding how prebiotics and probiotics differ is essential to comprehending their function in maintaining gut health. Probiotics contain living organisms, whereas prebiotics provide food for the microbiome. Both have distinct yet beneficial effects on intestinal health.

Prior research has connected increased prebiotic consumption to better blood glucose control, increased mineral absorption (including calcium), and indicators of better immunological and digestive health. Although the International Scientific Association for Probiotics and Prebiotics recommends a daily intake of 5 grams of prebiotics, the current dietary recommendations do not include this information.

In order to perform the study, the researchers used the Food and Nutrient Database for Dietary Studies, a popular tool for nutrition and health research, to examine the prebiotic content of 8,690 items. They discovered that prebiotics were present in around 37% of the foods in the database. Dandelion greens, Jerusalem artichokes, garlic, leeks, and onions were among the top prebiotic-rich foods, with prebiotic concentrations ranging from 100 to 240 mg/g.

Asparagus, cowpeas, onion rings, creamed onions, onion rings, Kellogg's All-Bran cereal, and onion rings all had between 50 and 60 mg/g of prebiotics.

"According to Boyd's early literature study findings, foods like onions and other comparable foods have a higher overall prebiotic content since they include a variety of prebiotics in different forms"

Various varieties of onions and related foods are used as both key ingredients and seasoning in a wide range of recipes. Since Americans frequently eat these things, it would be possible for people to boost their intake of prebiotics by focusing on these meals.

Boyd estimated that a person would need to eat roughly half of a small (4-ounce) onion to receive 5 grams of prebiotics based on the team's findings.

Notably, foods containing wheat appeared lower on the list, whereas animal goods like dairy, eggs, and meats had little to no prebiotic content.

The study's authors hope it will serve as a starting point for evaluating prebiotics' effects on health and establishing new dietary recommendations. But they emphasized the need for more study to comprehend how cooking impacts prebiotic levels and to more accurately evaluate foods with diverse ingredients.

For improved intestinal health, use plant proteins

The results of this study could pave the way for more individualized and successful dietary recommendations—and the significance of consuming plant-based foods—to support general wellbeing and a healthy gut flora as gut health continues to gain prominence in the field of nutrition.

Another investigation, which was reported in the academic journal Proceedings of the National Academy of Sciences, discovered that a particular carbohydrate associated with plant proteins serves as a prebiotic food source for the bacteria in our intestines.

The study found that a species of gut microorganisms uses plant N-glycans, a form of complex carbohydrate present in plant foods, as nutrients, despite the fact that fruit and vegetables are the finest source of nutrients for a healthy gut microbiome (the collection of microbes that naturally reside inside humans).

According to the study's primary author, Lucy Crouch, "the gut microbiome is an incredibly important feature for human health, and this finding will enable us to better understand the microbiome." We may think about how future diets can be devised that encourage a healthy gut and, as a result, improve our general health by discovering the specific enzymes that these microorganisms utilize to digest their food.