Kombucha (also tea mushroom, Manchurian mushroom, formal name: Medusomyces gisevii) is a variety of fermented, lightly effervescent sweetened black or green tea drinks that are commonly intended as functional beverages for their supposed health benefits. Kombucha is produced by fermenting tea using a “symbiotic ‘colony’ of bacteria and yeast” (SCOBY). Actual contributing microbial populations in SCOBY cultures vary, but the yeast component generally includes Saccharomyces and other species, and the bacterial component almost always includes Gluconacetobacter xylinus to oxidize yeast-produced alcohols to acetic and other acids
Although it has been claimed to have numerous health benefits, there is no good evidence that drinking kombucha has such effects. In contrast, there are several documented cases of serious adverse effects, including fatalities, related to kombucha drinking, possibly arising from contamination during home preparation