Whether you have yeast infection or bacterial vaginosis, both are actually related to the bacteria population residing in the vaginal area. Below is the abstract from the journal paper titled "Vaginal microbiota and the use of probiotics", published in Interdiscip Perspect Infect Dis. 2008;2008:256490, authored by Cribby S, Taylor M, and Reid G.

"The human vagina is inhabited by a range of microbes from a pool of over 50 species. Lactobacilli are the most common, particularly in healthy women. The microbiota can change composition rapidly, for reasons that are not fully clear. This can lead to infection or to a state in which organisms with pathogenic potential coexist with other commensals. The most common urogenital infection in premenopausal women is bacterial vaginosis (BV), a condition characterized by a depletion of lactobacilli population and the presence of Gram-negative anaerobes, or in some cases Gram-positive cocci, and aerobic pathogens.

Treatment of BV traditionally involves the antibiotics metronidazole or clindamycin, however, the recurrence rate remains high, and this treatment is not designed to restore the lactobacilli. In vitro studies have shown that Lactobacillus strains can disrupt BV and yeast biofilms and inhibit the growth of urogenital pathogens. The use of probiotics to populate the vagina and prevent or treat infection has been considered for some time, but only quite recently have data emerged to show efficacy, including supplementation of antimicrobial treatment to improve cure rates and prevent recurrences."

Probiotics for treating imbalanced vaginal microflora are available in capsules, such as Fem-Dophilus capsules.