However, the lawsuit, filed Wednesday, alleges the low-sugar, "gut-healthy" sodas contain such small amounts of prebiotic fiber (just 2 grams per serving) that the average consumer wouldn't experience any health benefits from drinking them.

"A consumer would need to drink more than four Poppi sodas in a day to realize any potential health benefits from its prebiotic fiber," the suit, which seeks $5,000,000 in financial damages, says. "However, even if a consumer were to do this, Poppi's high sugar content would offset most, if not all, of these purported gut health benefits."

The complaint goes on to say that an inulin-based diet could cause "inflammation and even liver damage" with doses as low as 10 grams per day and demands a jury trial to determine whether Poppi has broken the law with its advertisements.

Poppi's sodas, which have gone viral in the years since their 2018 appearance on "Shark Tank," sell for $2.49 a can through the manufacturer's website.

The colorful cans of apple cider vinegar-infused sodas have become so popular that the suit noted Forbes reporting from March that the brand sits at a 19% market share — more than 1.5x that of Coke products — and is the 11th-fastest growing beverage brand, beating out companies like Gatorade and Liquid Death.

Representatives for Poppi did not immediately respond to a request for comment from Business Insider.