Synthetic biology as a field is in its infancy. It’s coming along fast and the possibilities are absurdly endless, but it’s hard to overstate how complex of a problem this really is.
The idea that it’ll magically outcompete the rest of your extremely diverse, hyper complex, and largely beneficial mouth biome alone with just one treatment and no maintenance immediately shows it as a scam. We aren’t there yet.
You’re on the right track. It’s long been established that non human animals cannot consent to sex because of the power difference between them, even if the non human animals could communicate well.