My gf has symptoms of bv (fishy odor) ever since we've been having unprotected sex. i've noticed she now has a vaginal body scrub in the shower, we also use ph balancing lubes, she eats fruits..are there any holistic cures or preventative measures?

BV certainly is the most common cause of fishy vaginal odor, but not the only one. She should be professional examined to confirm the diagnosis and exclude other causes and contributors. Among other things, other STIs like gonorrhea and chlamydia can trigger BV, and trichomonas (itself an STI) causes the identical odor. No effective holistic management is known, including the things you mention.