How can i prevent getting bv again? is there any supplements to help keep my bacteria balanced out?

MetroGel, boric acid: If you've had BV only once or rarely, sit tight; it may not return. If already a recurrent problem or becomes so, discuss 2 options with your doctor: metronidazole vaginal gel (Metrogel®), convenient but expensive; or boric acid vaginal capsules, a bigger hassle (the pharmacy has to prepare them specially) but not so costly. Supplements, probiotics, dairy, lactobacillus, etc aren't likely to help.