Effects of probiotics on the recurrence of bacterial vaginosis: a review

Bacterial vaginosis (BV) is a common cause of genital discomfort in women in reproductive ages, which causes many complications. Bacterial vaginosis is usually treated by metronidazole and clindamycin. However, this protocol does not prevent its recurrence, which is a main complaint of the patients. The number of lactobacilli in the vagina of women with BV is significantly lower than that in healthy women. Hence, efforts have been made to normalize vaginal flora by oral or vaginal administration of lactobacilli. The objective of the present study was to review clinical evidences available regarding the efficacy of probiotics in the prevention and treatment of BV.

Published randomized controlled trials were searched in PubMed, Science Direct, and the Cochrane Database between 1990 and 2011. Search terms included bacterial vaginosis, urinary tract infection, lactobacillus, and probiotics.

Orally consumed probiotics are believed to ascend to the vaginal tract after they are excreted from the rectum; vaginal administration allows for direct replacement of the probiotics for unhealthy vaginal microbiota and occupation of specific adhesion sites at the epithelial surface of the urinary tract, which consequently results in maintenance of a low pH and production of antimicrobial substances like acids and hydrogen peroxide. Receiving Lactobacillus acidophilus, Lactobacillus rhamnosus GR-1, and Lactobacillus fermentum RC-14 at a dose of at least 10 CFU/day for 2 months has been shown to present the patients with better results.

Although the results of different studies are controversial, most studies have been in favor of the probiotics in the prevention or treatment of BV, and no adverse effects have been reported. Therefore, it may be helpful to recommend daily consumption of probiotic products to improve public health among women.