The way that it works is that the Lactobacillus Acidophilus bacteria (the good bacteria), fights the Candida Albicans bacteria (the bad bacteria) by producing lactic acid. Since the Candida bacteria, definitely does not thrive in an acidic environment, the Acidophilus will win the battle. Unless of course you give reasons for your vagina to reduce its acidity levels once again!
It is said that the lactic acid produced by the Acidophilus bacteria acts like a natural antibiotic for your body. For the most part acidophilus is available freely in most pharmacies, and if you can't find it, just ask the staff. They should be able to point you in the right direction.
And if you don't find that the Acidophilus capsules are helping you, you might want to try switching over to the powdered form, or even as a suppository.