The literature provides low-to-moderate evidence that probiotics are effective in preventing UTIs in women (see Table 1). Abdulwahab, Abdulazim, Nada, and Radi (2013) examined the effect of vaginal Lactobacillus from 100 healthy women on the growth of uropathogenic E. coli isolates from 100 women with recurrent UTIs. They found that the majority of Lactobacilli in healthy women without UTIs were L. acidophilus, L. fermentum, and L. delburekii. In addition, they found that all vaginal Lactobacilli strains (from asymptomatic women) could inhibit the growth of E. coli on the agar plate. The weakness of this study, however, is that it was done in a laboratory. The women with recurrent UTIs did not actually receive Lactobacillus (although it was their E. coli strains that received them).
Two studies went one step further by examining human prophylaxis with Lactobacilli, either orally or vaginally, as means to prevent recurrent UTIs. Beerepoot et al. (2012) compared the effects of oral L. rhamnosus and L. reuteri (109 CFU twice daily) with trimethoprim-sulfamethoxazole (TMP-SMX, 480 mg daily) on preventing recurrent UTIs in 252 postmenopausal women. In their randomized control trial, they found that after 12 months of prophylaxis, the mean number of symptomatic UTIs decreased form 7.0 (from the previous year) to 2.9 in the TMP-SMX group and from 6.8 to 3.3 in the Lactobacilli group. Although TMP-SMX decreased the number of symptomatic UTIs more than the Lactobacilli, both methods of prophylaxis groups were effective in significantly reducing the number of recurrent UTIs in women. At least one UTI with bothersome symptoms occurred in 69.3% and 79.1% of the individuals taking TMP-SMX and Lactobacilli; median time to the first recurrent UTI were six and three months. Although Lactobacilli was not found noninferior to TMP-SMX with regard to decreasing mean number of symptomatic UTIs, proportion of individuals with UTIs or time to the first UTI, the authors did find some benefits of Lactobacilli over TMP-SMX for prophylactic use.
Antibiotic resistance from E. coli (causing UTI and in urine and feces of asymptomatic women) to sulfamethoxazole, trimethoprim and amoxicillin increased after one month from 20% to 40% to 80% to 95% in the TMP-SMX group. After 12 months of TMP-SMX prophylaxis, 100% of urinary E. coli was found resistant to trimethoprim and sulfam eth oxazole. No antibiotic resistance occurred in the Lactobacilli group. In addition, Lactobacilli may be more effective in preventing complicated UTIs. The authors found that women with complicated UTIs experienced an average of 4.4 recurrent infections in the TMPSMX group and 3.4 in the Lactobacilli group. No differences in adverse events were found between intervention groups; no long-term effects of antibiotics on health were measured in this research (Beerepoot et al., 2012).
Stapleton et al. (2011) considered the effect of an intravaginal probiotic, L. crispatus, for prevention of recurrent UTIs in 100 premenopausal women. In their randomized, placebo-controlled phase 2 trial, they found that L. crispatus was associated with reduced symptomatic UTIs. Fifteen percent of women taking L. crispatus and 27% of women taking placebo experienced recurrent UTIs. Vaginal colonization with L. crispatus was high for most women receiving the probiotic intervention. After 10 weeks, high-level vaginal L. crispatus colonization was 93% compared to 68% in individuals receiving placebo. Women taking the probiotic who achieved a high level vaginal L. crispatus colonization had significantly lower recurring UTIs; in contrast, women in the placebo group who were able to achieve high-level vaginal colonization of L. crispatus, did not experience a reduction in UTIs. Fifty-six percent of individuals receiving the probiotic intervention experienced adverse effects compared to 50% in the placebo group. Incidence of bacterial vaginosis or candida was low in both groups, and there was no significant difference in pyuria in either group.
Each of the three studies above examined different species of Lactobacilli. Abdulwahab et al. (2013) investigated the effects of L. acidophilus, L. fermentum, and L. delburekii. Beerepoot et al. (2012) studied L. rhamnosus and L. reuteri and Stapleton et al. (2011) investigated L. crispatus. The experimental design also differed significantly between the three studies. Therefore, it is difficult to compare the above studies. However, all three studies provide evidence that even with different strains of Lactobacilli and different routes of receiving the probiotic, Lactobacilli can reduce recurrent UTIs in women.
Urol Nurs. 2015;35(1):18-21. © 2015 Society of Urologic Nurses and Associates