When the cartoon program "Scooby-Doo, Where Are You!" premiered in 1969, hardly anyone in the U.S. had heard of the ancient Chinese brew kombucha, a fermented drink that's made from tea, sugar, and a glob of yeast and bacteria called a SCOBY (symbiotic cultures of bacteria and yeasts).

But more recently, kombucha has become one of the top-selling fermented drinks, with supermarkets selling about $180 million worth in 2015.

The supposed benefits of kombucha include lowering blood pressure and bad cholesterol, knocking out bacteria, promoting heart health, fighting cancer, and easing gastric problems.

But does it really deliver?

Research shows that it's hard to know what you are getting when you buy it or make it at home. That’s because kombucha’s "powers" change depending on the tea leaf, sugar content, fermentation time, and the composition of the SCOBY that's used.

However, researchers do say it may provide the same benefits as drinking tea and eating fermented foods — including improved digestion and a healthier gut biome.

As for other claims, extensive reviews of available kombucha studies show that "benefits" were found in lab animals, not in humans.

Also, Blue Cross Blue Shield cautions: "[Kombucha] naturally contains minor amounts of alcohol, so it's best to avoid drinking kombucha if you're pregnant or breastfeeding."

The Cleveland Clinic explains that while the Centers for Disease Control and Prevention recommends limiting intake to 12 ounces a day, most commercially sold bottles contain much more.

Bottom line: Maybe consider enjoying a cup of tea and some yogurt instead.