You wrote, "Is it possible that acetaldehyde and ethanol behave differently from lactic acid? Maybe." I'll note that they behave differently in one way: acetaldehyde has a very low boiling point, 68.36°F. That's why you can smell it so strongly on an alcoholic's breath! There's an argument that low levels of acetaldehyde produced in the mouth will evaporate into the breath quickly and constantly, while lactic acid sticks around. However, the speed at which it will evaporate is an empirical question, and I'm not confident in saying there will be no harm in people with ALDH deficiency.
There's also the question of how the biofilm will retain it, and what areas of the gums and throat will be coated in such biofilms.
If anyone is otherwise interested in the Lumina "displace harmful bacteria with less-harmful ones" approach but concerned about this alcohol metabolism issue, I have an alternative for you to investigate. Oral probiotics such as "ProBiora" have been on the market for some time, and they take the approach of introducing bacteria that compete with S. mutans while not being implicated in caries themselves. These solutions are probably less powerful than Lumina advertises itself to be, and are not permanent, which removes a bit of the "cool factor" but in my mind does not make them less valuable.
Interesting.
You wrote, "Is it possible that acetaldehyde and ethanol behave differently from lactic acid? Maybe."
I'll note that they behave differently in one way: acetaldehyde has a very low boiling point, 68.36°F. That's why you can smell it so strongly on an alcoholic's breath! There's an argument that low levels of acetaldehyde produced in the mouth will evaporate into the breath quickly and constantly, while lactic acid sticks around. However, the speed at which it will evaporate is an empirical question, and I'm not confident in saying there will be no harm in people with ALDH deficiency.
There's also the question of how the biofilm will retain it, and what areas of the gums and throat will be coated in such biofilms.
If anyone is otherwise interested in the Lumina "displace harmful bacteria with less-harmful ones" approach but concerned about this alcohol metabolism issue, I have an alternative for you to investigate. Oral probiotics such as "ProBiora" have been on the market for some time, and they take the approach of introducing bacteria that compete with S. mutans while not being implicated in caries themselves. These solutions are probably less powerful than Lumina advertises itself to be, and are not permanent, which removes a bit of the "cool factor" but in my mind does not make them less valuable.