This trial involved 100 women with recurrent urinary tract infections (UTIs), who were seen at the University of Washington and an average age of 21. Lactobacillus crispatus or placebo was inserted vaginally for 5 days and then once weekly for 10 weeks, starting 7-10 days after they had received standard antibiotic therapy for their UTI. The lactobacillus crispatus suppositories contained 10 billion CFUs/mL.
The levels of L. crispatus colonization were evaluated with a vaginal swab and their UTI status was followed at 1 and 10 weeks. Women in both groups had depletion of Lactobacillus colonization. At week 10, at least one UTI had occurred in 15% of the L. crispatus individuals versus 27% in the placebo individuals. A high level of L. crispatus colonization was achieved in 93% of the crispatus subjects versus 68% of the placebo subjects. The risk for a recurrent UTI was lower in the women who received L. crispatus versus placebo, in those with high colonization.
Commentary: UTIs are very common in women and more than half of women in the U.S. will experience at least one in their life. Ten to twenty percent of all women have a UTI at least once a year. The use of antibiotics for UTIs potentially adds to the problem, in that drug resistance occurs, and the antibiotic itself depletes the vaginal and bladder lactobacillus species that serve to prevent UTIs. Normal vaginal flora is dominated by hydrogen peroxide producing lactobacilli that competitively inhibit the infection causing bacteria of the urethra and bladder, particularly Escherichia coli. The question these researchers asked was, can a hydrogen peroxide producing vaginal probiotic prevent recurrent UTIs. The answer is, yes they can- and in this case, Lactobacillus crispatus was the test subject.
Reference
Stapleton A, et al. Randomized, placebo-controlled phase 2 trial of a Lactobacillus crispatus probiotic given intravaginally for prevention of recurrent urinary tract infection. Clin Infect Dis 2011; May 15; 52:1212
