it is fermented using a symbiotic culture of bacteria and yeast — also known as scoby — which includes members of the lactic acid bacteria family, not dissimilar to how kimchi is fermented.
the issue with kombucha, as i see it, is that it overpromises.
it seems to be viewed, in some circles, as a miraculous beverage with untold health properties. but the reality of the matter is that it is more or less just tea with varying levels of certain probiotic species in it.
there are no meaningful human data available to quantify the impact of kombucha on human health, but it could have a complimentary role to play in fostering a healthy gut microbiome along side a strong dietary pattern.
probiotics and fermented foods aren’t the same
the take away is that both kombucha and kimchi are essentially fermented versions of foods we already comfortably identify with as being healthy, like tea and cabbage.
does the introduction of certain probiotics via the fermentation turn these foods into superfoods? that’s a stretch, but there may be potential there that requires further human studies to confirm.
keep in mind that although fermented foods do contain varying amounts of certain probiotic species, they aren’t the same as a probiotic supplement, which contains a specific amount of specific combinations of bacterial strains and species that are more likely to have been tested via high quality human experimental studies to make sense of their potential benefits.
certain probiotic products, for example, may be recommended for those who live with irritable bowel syndrome (ibs), but this does not mean that eating a bit of kimchi or kombucha is an equivalent treatment strategy.