You'll probably start to notice changes from age 10 upwards, but there's no right or wrong time to start. Some people go through puberty later than others. This is normal. If you have no signs of puberty by the age of 16, see a doctor for a check-up.
The probiotic strain Lactobacillus is used to treat BV and other bacterial genitourinary infections. It works by restoring a healthy microflora balance to the urogenital tract and preventing the spread of pathogenic bacteria. There are a number of different probiotic products available to address BV symptoms.
In addition to the Flagyl or Vancomycin, my personal experience with C-Diff is that adding a good probiotic supplement to your diet, preferably one that includes Saccharomyces boulardii which is believed to help prevent Clostridium Difficile, can help the good bacteria to repopulate the gut.