Probiotic treatment halves recurrent UTI risk.
Concern about increasing resistance to commonly used antimicrobials such as trimethoprim-sulfamethoxazole and fluoroquinolones has led to a search for alternative means to prevent urinary tract infections (UTIs). Recent studies have focused on hydrogen peroxide-producing strains of lactobacilli.
These lactobacilli comprise the dominant vaginal flora, competing with and regulating other urogenital microbes, including the harmful Escherichia coli. Women with recurrent UTIs typically have depletion of vaginal lactobacilli at the time of their E. coli infections (J. Infect Dis. 1998;178:446-50).
For their research, Dr. Ann E. Stapleton of the University of Washington in Seattle, and her colleagues, recruited 100 women with current cystitis and histories of recurrent UTI to be randomized to Lactin-V (Osel Inc., Mountain View, Calif.), a product containing Lactobacillus crispatus, or placebo (Clin. Infect. Dis. 2011;52:1212-7). The women (median age 21, median number of UTIs before study 4.5) applied Lactin-V or placebo daily for 5 days, then once weekly for 10 weeks. They were seen in scheduled follow-up visits at 1 week (visit 3) and 10 weeks (visit 4) after beginning Lactin-V or placebo and for symptomatic UTIs. Investigators collected urine samples for culture and vaginal swabs to assess the level of colonization of L. crispatus. Of the 50 women randomized in each group, 48 were entered into analysis.
Recurrent culture-confirmed UTI occurred in 7 of 48 women (15%) receiving Lactin-V vs. 13 of 48 women (27%) receiving placebo (relative risk, 0.5; 95% confidence interval, 0.2-1.2).
The researchers said mat the quantitative molecular method used to assess vaginal flora following UTI afforded them a more precise picture of changes in the balance of vaginal microbiota than seen in previous trials. High-level vaginal colonization with L. crispatus throughout follow-up was associated with a significant reduction in recurrent UTI only for women using the suppositories, they added. This finding was "striking," they said.
Dr. Stapleton and her colleageus hypothesized that the use of Lactin-V "confers a significant advantage over repopulation of the vaginal microbiota with endogenous L. crispatus," and that the L. crispatus isolate used in the intervention offered "unique properties for protection" over the natural recolonization process.
The researchers did not compare Lactin-V to prophylactic antibiotics, but they noted that a meta-analysis of 10 randomized controlled trials evaluating continuous antimicrobial prophylaxis (Clin. Evid. [online] 2008 Jul 17;2008. pii:0801) found rates of recurrent UTI reduced to 12% (24 of 195 participants) compared with 65% (116 of 177 participants) among placebo recipients, "with a [relative risk] of rUTI that is very comparable to our findings (RR, 0.21; 95% CI, 0.13-0.33)."
RELATED ARTICLE: VITALS
Major Finding: Recurrent culture-confirmed UTI occurred in 7 of 48 women (15%) receiving Lactin-V, compared with 13 of 48 (27%) receiving placebo.
Data Source: A randomized, placebo-controlled trial involving 100 women in a university clinic setting who used vaginal suppositories containing Lactobacillus crispatus.
Disclosures: The study was funded by the National Institute of Diabetes and Digestive and Kidney Diseases, and the Office of Research in Women's Health, National Institutes of Health; Dr. Stapleton and her coauthors said they had no relevant financial disclosures.
BY JENNIE SMITH
FROM CLINICAL, INFECTIOUS DISEASES
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|Title Annotation:||INFECTIOUS DISEASES|
|Publication:||Internal Medicine News|
|Date:||May 1, 2011|
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