"Healthy" soda is popping, but not necessarily gut-friendly

What we're hearing: "I've had patients who came to me complaining of severe bloating, to the point they couldn't put on a seat belt in the car," says Tamara Duker Freuman, a New York-based dietitian and author.

• The apparent culprit: prebiotic sodas. Freuman had the patients stop drinking them "and the bloating went away."

Soda sales jump

By the numbers: U.S. sales of prebiotic soft drinks jumped from $33 million in January 2022, to $777 million in January 2025 — according to data NielsenIQ shared with Axios.

• Olipop, one of the category leaders, was valued at $1.85 billion in its latest funding round, per CNBC.
• And PepsiCo just acquired major prebiotic soda brand Poppi for $1.95 billion.

What to know about gut bacteria

How it works: Eating prebiotics — food for gut bacteria — can be anti-inflammatory and "increase the good guys in your gut," Freuman says.

Yes, but: "You should be aiming to get your fiber from foods: fruits, vegetables, whole grains, nuts and legumes," says Hannah Holscher, registered dietitian and associate professor of nutrition at University of Illinois in Urbana-Champaign.

• Even a few grams of inulin (also called chicory root) — the fiber typically in prebiotic sodas — can be "incredibly difficult to tolerate," especially for those with conditions like IBS, Freuman says.

Research on inulin and cancer

Bigger concerns: There's emerging, but limited, research on inulin and cancer.

• "Consuming grams of inulin regularly in supplements, beverages and inulin enriched foods may increase risk of cancer, potentially by dampening anti-tumor immunity," says Andrew Gewirtz, a biomedical science professor at Georgia State University who's studied inulin in animals.
• Gewirtz also co-authored a case report on a man who developed colon cancer after taking 4g of inulin daily.

Although inulin can feed good gut bacteria, Gewirtz says that the byproducts of it (short chain fatty acids) might also help pathogens grow.

• "Further studies are needed to help identify who might benefit from it and who should avoid it," he says.

The other side: "Like any fiber, inulin may cause temporary digestive discomfort as the body adjusts to increased fiber intake," Olipop told Axios in a statement. "That's why both nutrition experts and OLIPOP recommend starting with one can and gradually increasing over time."

• The statement emphasized that Olipop offers more fiber than other prebiotic sodas, and that inulin is Generally Recognized as Safe (GRAS) by the FDA.

Poppi prebiotic soda lawsuit

As for Poppi, it denied the claim made in a class-action lawsuit that its marketing overstated the amount of prebiotic fiber and gut health benefits the drink offers.

• But the company agreed to a settlement that includes an $8.9 million fund for payments to consumers, ahead of a hearing set for May 8, the Associated Press reported.
• Consumers should be able to file a claim for a share of the Poppi settlement through poppisettlement.com, once the site's launched, according to the settlement agreement,
• Poppi didn't immediately respond to Axios' requests for comment.

Gut check on prebiotic soda

Reality check: Less than 10% of American adults get the daily recommended amount of fiber, and many Americans regularly drink sugary soda — which has links to a host of health risks.

• Substituting a prebiotic soda in place of a higher-sugar one "could be a good, helpful swap" and "help bridge the fiber gap," Holscher says.

The bottom line: Aim for a diverse diet that includes naturally fibrous foods — but if you crave soda, don't go overboard with the prebiotic drinks.

• "The occasional can is unlikely to cause major harm," Gewirtz says. "It's regular consumption that I'm not convinced is safe."

What we're watching: Beyond prebiotics, "functional" drink brands now also market beverages with ingredients for better skin, boosted vibes and balanced blood sugar.