title: Randomized, placebo-controlled phase 2 trial of a Lactobacillus crispatus probiotic given intravaginally for prevention of recurrent urinary tract infection.
abstract: BACKGROUND
  Urinary tract infections (UTIs) are common among women and frequently recur. Depletion of vaginal lactobacilli is associated with UTI risk, which suggests that repletion may be beneficial. We conducted a double-blind placebo-controlled trial of a Lactobacillus crispatus intravaginal suppository probiotic (Lactin-V; Osel) for prevention of recurrent UTI in premenopausal women.
  
  
  METHODS
  One hundred young women with a history of recurrent UTI received antimicrobials for acute UTI and then were randomized to receive either Lactin-V or placebo daily for 5 d, then once weekly for 10 weeks. Participants were followed up at 1 week and 10 weeks after intervention and for UTIs; urine samples for culture and vaginal swabs for real-time quantitative 16S ribosomal RNA gene polymerase chain reaction for L. crispatus were collected.
  
  
  RESULTS
  Recurrent UTI occurred in 7/48 15% of women receiving Lactin-V compared with 13/48 27% of women receiving placebo (relative risk [RR], .5; 95% confidence interval, .2-1.2). High-level vaginal colonization with L. crispatus (≥10(6) 16S RNA gene copies per swab) throughout follow-up was associated with a significant reduction in recurrent UTI only for Lactin-V (RR for Lactin-V, .07; RR for placebo, 1.1; P < .01).
  
  
  CONCLUSIONS
  Lactin-V after treatment for cystitis is associated with a reduction in recurrent UTI. Larger efficacy trials of this novel preventive method for recurrent UTI are warranted. CLINICAL TRIALS REGISTRATION. NCT00305227.
authors.affiliation: Department of Medicine, University of Washington, Seattle, 98195, USA. stapl@uw.edu
authors.forename: Ann E
authors.initials: AE
authors.lastname: Stapleton
authors.forename: Melissa
authors.initials: M
authors.lastname: Au-Yeung
authors.forename: Thomas M
authors.initials: TM
authors.lastname: Hooton
authors.forename: David N
authors.initials: DN
authors.lastname: Fredricks
authors.forename: Pacita L
authors.initials: PL
authors.lastname: Roberts
authors.forename: Christopher A
authors.initials: CA
authors.lastname: Czaja
authors.forename: Yuliya
authors.initials: Y
authors.lastname: Yarova-Yarovaya
authors.forename: Tina
authors.initials: T
authors.lastname: Fiedler
authors.forename: Marsha
authors.initials: M
authors.lastname: Cox
authors.forename: Walter E
authors.initials: WE
authors.lastname: Stamm
mesh_terms: D000282:Administration, Intravaginal; D000293:Adolescent; D000328:Adult; D058491:Bacterial Load; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D007778:Lactobacillus / Q000502:physiology*; D010919:Placebos / Q000008:administration & dosage*; D016133:Polymerase Chain Reaction; D019936:Probiotics / Q000008:administration & dosage*; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012008:Recurrence; D016896:Treatment Outcome; D014552:Urinary Tract Infections / Q000517:prevention & control*; D014556:Urine / Q000382:microbiology; D014621:Vagina / Q000382:microbiology; D055815:Young Adult
chemical_list: D010919:Placebos; D012336:RNA, Ribosomal, 16S