Crazy, I was wondering about this,
I did a bit of research on quinine in tonic water, and promptly obtained a weeks supply.
Guess what? After I drank the first glass, my guts began to heave, the second glass gave me "abundant" gas, but all that was absent the 2nd day.
So I did, in fact, postulate, that the quinine had nuked the viruses in my gut, the gas produced from their demise and digestion.
Well, well well. If you don't drink at least 2 tall glasses of tonic a day, you may well regret it……