Lactobacillus taken after a course of antibiotics for a nongynecologic infection does not prevent vaginal yeast infections, reported Marie Pirotta, M.B., and her colleagues at the University of Melbourne (Australia).
The benefits of probiotics such as lactobacillus have long been promoted for overall health and for vaginal problems specifically. A previous study conducted by Dr. Pirotta and her associates found that 40% of 751 women with a history of vulvovaginitis had eaten yogurt or administered lactobacillus orally or vaginally to prevent vulvovaginitis after they had taken antibiotics.
In their subsequent 14-day double-blind study, 235 women were randomized to one of four treatment groups: oral plus vaginal lactobacillus, oral lactobacillus plus vaginal placebo, oral placebo plus vaginal lactobacillus, and oral and vaginal placebo (BMJ 2004;329:548).
Overall, 55 women developed postantibiotic vulvovaginitis, ranging from 17% to 29% of the women in each of the four groups. Compared with placebo, the odds ratio for developing vulvovaginitis was 1.06 with oral lactobacillus and 1.38 with vaginal lactobacillus.
“Our results should prompt health professionals to inform women that lactobacillus is unlikely to prevent postantibiotic vulvovaginitis and that they should consider using proven antifungal treatment if symptoms develop,” the investigators said.