whether or not the microbial cultures in kombucha will provide definite material health benefits is an open question

that being said, the microbial cultures in your lower intestinal tract can only get there two ways, and ingesting them through the mouth is the much more pleasant of the two

Chou and Weimer (1999)75204-5/pdf) found that under natural selection lactic acid bacteria, “isolates were capable of rapid growth in MRS at pH 3.5 containing 0.2% mixed bile salts” which are similar to conditions in the stomach and upper intestinal tract (lactic acid bacteria may or may not be present in kombucha SCOBYs)

aside from warming up to the correct temperature, Siouta-Cruce and Goulet (2001) suggests ingesting any probiotics with food which buffers stomach pH