Rat experiments show that adding a small amount of alcohol to their drinking water makes them live longer. The reason is thought to be the alcohol helps kill off undesirable gut bacteria, which produce LPS endotoxins. Rats on antibiotics also live longer for the same reason.
I don't think gingivitis is caused by bacteria per se. Cavities and gingivitis manifest as a consequence of lousy overall health and problems such as mineral deficiencies, not a lack of listerine. The phrase "look a gift horse in the mouth" exists because lousy teeth indicate a bunch of other health problems. It's not about horse oral hygiene.
I don't think gingivitis is caused by bacteria per se. Cavities and gingivitis manifest as a consequence of lousy overall health and problems such as mineral deficiencies, not a lack of listerine. The phrase "look a gift horse in the mouth" exists because lousy teeth indicate a bunch of other health problems. It's not about horse oral hygiene.