• Posted July 28, 2026

Prebiotic Soda Health Claims Questioned In New Nutrition Study

Prebiotic soda is one of the latest health crazes, promising better gut health while helping slake thirst.

But a new study suggests these drinks aren’t delivering on their promises to customers.

On average, prebiotic sodas contain as much sugar as fiber, and their average fiber levels might not be high enough to support a healthy gut, researchers reported at the annual meeting of the American Society for Nutrition.

“I would encourage consumers not to be swayed by marketing claims and to carefully review the Nutrition Facts label,” said lead researcher Carlos Soto-Díaz, a doctoral student at the University of North Carolina at Chapel Hill

“While certain types of prebiotic fibers have been shown to support gut health, the extent to which the amounts found in these beverages provide meaningful benefits is still unclear,” Soto-Díaz said in a news release. “Any potential benefits should be considered alongside the product’s overall nutritional profile, including calories, sugars and non-nutritive sweeteners.”

Prebiotics are dietary fibers that your body can’t digest. Instead, they serve as food for your microbiome, the trillions of good bacteria that help maintain your overall health.

Nutrition experts and influencers have been highlighting the importance to gut health of prebiotics alongside probiotics, which contain the good bacteria that support a healthy microbiome.

Prebiotic sodas have been flying off the shelves in the United States, with estimated sales of $777 million in 2025, researchers said in background notes.

For the new study, researchers analyzed the ingredients of 108 prebiotic sodas launched in the U.S. between 2021 and 2025.

On average, prebiotic sodas contained about 35 calories, 5 grams of sugar and 5 grams of fiber for every 12-ounce can.

This places prebiotic sodas lower than regular sodas and fruit drinks when it comes to calories and sugar content, but higher than diet sodas or flavored sparkling waters, researchers said.

“Many products include nutrition and functional claims that may overstate their nutritional quality. For example, some labels claim ‘no added sugar,’ yet the product may still contain around 10 grams of total sugars from sources like juice,” Soto-Díaz said.

“This raises concerns that such claims may create a ‘health halo,’ leading consumers to believe the product is healthier than its overall nutritional profile suggests,” he said.

Prebiotic sodas do contain more fiber than other beverages, ranging from 2 grams to 9 grams per can, researchers said.

But consumers shouldn’t assume that a can of prebiotic soda contains a meaningful amount of fiber, and should not rely on these sodas as a primary source of dietary fiber, researchers warned.

Other types of foods heavy in prebiotics, according to Harvard Medical School, include:

• Garlic

• Onions

• Bananas

• Jerusalem artichokes

• Soybeans

• Asparagus

• Whole-grain products like cereals and breads

Soto-Díaz presented these findings Saturday at the nutrition society’s annual meeting, which took place in National Harbor, Maryland.

Findings presented at medical meetings should be considered preliminary until published in a peer-reviewed journal.

More information

Harvard Medical School has more on prebiotics.

SOURCE: American Society for Nutrition, news release, July 25, 2026