CLINICAL QUESTION

Do oral or vaginal probiotics reduce the likelihood of urinary tract infection (UTI) recurrence in premenopausal women?

BOTTOM LINE

Probiotics containing Lactobacillus (oral or vaginal) reduce the incidence of recurrent UTI and prolong the time between UTIs in premenopausal women with frequent UTIs. Vaginal probiotics (with or without oral probiotics) outperform oral probiotics alone. Vaginal probiotics alone provide a similar benefit to oral plus vaginal probiotics and seem to be the least invasive and least costly option. (Level of Evidence = 1b)

SYNOPSIS

The study from India identified 174 women 18 to 45 years of age who had experienced at least three uncomplicated UTIs in the past year. The mean age was 36 years, and the mean number of UTIs in the previous year was slightly more than 5. The women were randomized into one of four groups: those who received oral and vaginal placebos, an oral probiotic and a vaginal placebo, an oral placebo and a vaginal probiotic, or oral and vaginal probiotics. The oral probiotic contained 112.5 billion live, lyophilized lactic acid bacteria and bifidobacteria; the vaginal probiotic contained 1 billion units of three lactobacilli strains. The groups were balanced at the start of the study, and analysis appears to have been by intention to treat. At 4 months, a symptomatic UTI had occurred in 70% of the placebo-only group, 61% of the oral probiotic group, 41% of the vaginal probiotic group, and 32% of the group that received both probiotics. The differences between the placebo-only and active treatment groups were statistically significant for the vaginal and vaginal plus oral probiotic groups. Results at 12 months were similar, with UTI rates of 95%, 77%, 61%, and 55%, respectively. Patients were asked to rate their degree of improvement, and most in the vaginal and vaginal plus oral probiotic groups rated themselves as much improved. No adverse events were reported.