It starts out looking like a pancake, but it’s actually a complex colony of yeast and bacteria. And when it’s fed with organic black tea and sugar, “it transforms the resulting liquid into a refreshingly sweet and sour, lightly sparkling beverage with a fruity fragrance,” wrote Dr. Thomas L. Stone, in the American Nutrition Association’s Nutrition Digest. This beverage is known as kombucha, and because the process of creating it involves fermentation (similar to making vinegar), it can offer a delicious boost to the good bacteria in your gut.