Comment by bhaney
> From what I can tell, a strain of the bacteria was found in the wild that created less acid and seemed to lead to less carries
I think you're confused about which changes to the bacteria were natural and which were engineered. A strain in the wild was discovered that produced a weak antibiotic that it had also developed a resistance to, but it still had the original metabolic pathway that produced lactic acid. Researches took that strain and genetically modified it to produce ethanol instead of lactic acid, and then relied on the natural antibiotic-related mutations to get this strain to replace common S. Mutans in the oral microbiomes of test subjects.
The useful non-acidic property of the strain is entirely artificially introduced. The natural mutation in the wild just allowed for outcompeting and replacing bacteria that lack it. There would be no benefit from personally experimenting with the natural non-engineered strains.
If that strain produces ethanol and can colonize the guts, then it has the potential to cause the auto-brewery syndrome. That a good reason to be careful!