Recurrent Urinary tract infection (UTI) continues to be a major health problem in women and is now complicated by increasing cases of antibiotic resistance. In females, urinary pathogens almost always infect the host by ascending from the rectum or vagina to the urethra and bladder (Lane MC et al, Infect Immun 2005; 73: 7644-7656). Likewise, the probiotic bacteria that predominate in the vagina of healthy women, spread to the rectum and perineum and form a barrier to prevent entry by uropathogens (Reid G & Bruce AW, World J Urol 2006; 24: 28-32). Inverse association has been reported between H2O2 producing lactobacilli and vaginal E. coli colonization in women with recurrent UTIs (Gupta K et al, J Infect Dis 1998; 178: 446-450). In a similar manner, Lactobacilli colonizing the intestine via oral route emerge at the rectum and transfer passively to the vagina and bladder.

In two pilot studies, the safety and potential of oral and vaginal probiotics for prevention of recurrent UTI was confirmed (Czaja CA et al, Infect Dis Obst Gynecol 2007: 1-8; Anukam KC et al, Adv Urol 2009: 1-5). In a Phase II trial using vaginal probiotic, high colonization with vaginal lactobacilli was associated with a reduction in recurrence of UTI (Stapleton AE et al, Clin Infect Dis 2011; 52:1212-1217). Considering the possible role, that probiotics may modulate the urinary microflora, this randomized double blind placebo controlled study is designed to determine the effect of administering oral or/and vaginal probiotic on the microflora in females with history of recurrent UTI. Another objective is to evaluate the reduction in incidence of a/symptomatic UTI compared to placebo.

Bacterial vaginosis (BV) is a condition characterized with complex multi-species microbiota dominated with Gardnerella vaginalis and other bacterial pathogens replacing probiotic lactobacilli. BV is also a risk factor for recurrent UTI. In a study by Onderdonk AB, VSL#3 suppressed the growth of a common vaginal pathogen Gardnerella vaginalis in continuous culture simulating the vaginal environment (J Clin Gastroenterol 2006; 40:256-259). VSL#3 strains were found to colonize in the intestine thereby increasing fecal concentration of Streptococcus thermophilus, bifidobacteria and lactobacilli (Venturi et al, Aliment Pharmacol Ther 1999; 13: 1103-1108). The probiotic strains in VSL#3 were detected in human feces after oral bacteriotherapy (Brigidi et al, Int J Food Microbiol 2003; 81: 203-209). Considering this, we hypothesize that VSL#3 given orally may prevent ascension of pathogens from rectum to urinary bladder.

Florisia has been proven effective in curing bacterial vaginosis in a few clinical trials. In an Indian study, Florisia cured BV in 80% of women and significantly reduced vaginal pro-inflammatory cytokines IL-1β and IL-6 (Hemalatha et al, Eur J Clin Microbiol Infect Dis, Epub 10 Jul 2012). In another study, Florisia cured BV in all the enrolled women. Two weeks after completion of therapy, the treatment was successful in 61% of women and vaginal malodor was significantly reduced (Mastromarino et al, Clin Microbiol Infect 2009; 15: 67-74).

After reviewing the available literature, the study drugs I intend to use in this trial project are VSL#3 oral capsule and Florisia vaginal tablet. Both the products are available in India and will be procured directly either from the market or the manufacturer for the study purposes. VSL#3 is a mixture of 8 different strains of freeze-dried lactic acid bacteria and bifidobacteria; each capsule containing not less than 112.5 billion colony forming units (CFU). Two capsules of VSL#3 will be given once daily for 4 months. Florisia is a vaginal tablet containing at least 1 billion CFU of lyophilized L. brevis CD2, L. salivarius subsp. salicinius, and L. plantarum. One tablet will be inserted in vagina for 8 days every month for 4 months.