As soon as your stomach is better (probably better not before), you might also try Sauerkraut juice or even sour bread drink, it is supposed to strengthen your immune system. I drink both whenever I've caught the flue. There are no double-blind clinical studies about it but some MDs are convinced it is effective for many diseases. I guess the original Kanne bread drink is not available in the US but Sauerkraut juice might be.

https://en.wikipedia.org/wiki/Bread_Drink
http://realfoodforager.com/6-reasons-to-drink-fermented-cabbage-juice/