Okay, so what happens if I (french) kiss a person that is taking this bacteria producing continuously mutacin-1140 and ethanol ? Could it take over my mouth, and I would ended up mutacin tolerant, and accelerating my cirrhosis ?
In theory yes, in practice no. Application is unlikely to be succesful without an extremely thorough cleaning of your mouth (think post-dentist). In the absence of dental-visit quality cleaning, the recommendation is to brush your teeth multiple times, using fresh brush heads, which results in an acceptable, but still not 100% success rate.
Infants being kissed by their mothers might get it though, as they lack an already existing micro-biome in their mouths against which the new bacteria would need to compete.
Additionally, if you were in a relationship with someone and were consistently kissing that person over time, it might eventually establish a foothold. But a single kiss, no matter how wet and sloppy, is almost certainly not enough.
