Hi there . . . I have heard about gardenella from friends and myth for years but recently experienced it myself and it was very embarrassing so I know the feeling! From what I understand it's a bacteria that is normally found in your anus but when it gets into your vagina and other factors like stress or illness combine to change your vaginal ph and reduce the amount of good bacteria there, the gardenella multiplies quickly. It can give off a fishy odor that gets quite strong.
I tried to treat myself with yogurt, acidophilus suppositories and tea tree oil suppositories but in the end ended up at the doctor's office for a prescription for flagil. Take all pills! The flagil got rid of it but I still eat lots of yogurt to keep the good acidophilus bacteria abundant.

I hope this helps!