Inhibition of bacterial adherence to bladder cells has been assumed to account for the beneficial action ascribed to cranberry juice and cranberry juice cocktail in the prevention of urinary tract infections (A. E. Sobota, J. Urol. 131:1013-1016, 1984). We have examined the effect of the cocktail and juice on the adherence of Escherichia coli expressing surface lectins of defined sugar specificity to yeasts, tissue culture cells, erythrocytes, and mouse peritoneal macrophages. Cranberry juice cocktail inhibited the adherence of urinary isolates expressing type 1 fimbriae (mannose specific) and P fimbriae [specific for alpha-D-Gal(1----4)-beta-D-Gal] but had no effect on a diarrheal isolate expressing a CFA/I adhesin. The cocktail also inhibited yeast agglutination by purified type 1 fimbriae. The inhibitory activity for type 1 fimbriated E. coli was dialyzable and could be ascribed to the fructose present in the cocktail; this sugar was about 1/10 as active as methyl alpha-D-mannoside in inhibiting the adherence of type 1 fimbriated bacteria. The inhibitory activity for the P fimbriated bacteria was nondialyzable and was detected only after preincubation of the bacteria with the cocktail. Cranberry juice, orange juice, and pineapple juice also inhibited adherence of type 1 fimbriated E. coli, most likely because of their fructose content. However, the two latter juices did not inhibit the P fimbriated bacteria. We conclude that cranberry juice contains at least two inhibitors of lectin-mediated adherence of uropathogens to eucaryotic cells. Further studies are required to establish whether these inhibitors play a role in vivo.

INTRODUCTION: Cystitis is a bacterial infection of the lower urinary tract which causes pain when passing urine, and causes urgency, haematuria, and suprapubic pain not associated with passing urine. Recurrent cystitis is usually defined as three episodes of urinary tract infection in the previous 12 months, or two episodes in the previous 6 months. METHODS AND

OUTCOMES: We conducted a systematic review and aimed to answer the following clinical question: Which interventions prevent further recurrence of cystitis in women experiencing at least two infections per year? We searched: Medline, Embase, The Cochrane Library, and other important databases up to April 2007 (BMJ Clinical Evidence reviews are updated periodically, please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA).

RESULTS: We found 14 systematic reviews, RCTs, or observational studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions.

CONCLUSIONS: In this systematic review we present information relating to the effectiveness and safety of the following interventions: continuous antibiotic prophylaxis (trimethoprim, co-trimoxazole, nitrofurantoin, cefaclor, or a quinolone or cephalexin); continuous prophylaxis with methenamine hippurate; cranberry juice and cranberry products; oestrogen (topical) in postmenopausal women; passing urine after intercourse; postcoital antibiotic prophylaxis; single-dose self-administered antibiotic.

Lower urinary tract symptoms (LUTS) are a common condition in older men. The objective of the present study was to evaluate the efficacy and tolerability of cranberry (Vaccinium macrocarpon) powder in men at risk of prostate disease with LUTS, elevated prostate-specific antigen (PSA), negative prostate biopsy and clinically confirmed chronic non-bacterial prostatitis. Forty-two participants received either 1500 mg of the dried powdered cranberries per d for 6 months (cranberry group; n 21) or no cranberry treatment (control group; n 21). Physical examination, International Prostate Symptom Score, quality of life (QoL), five-item version of the International Index of Erectile Function (IIEF-5), basic clinical chemistry parameters, haematology, Se, testosterone, PSA (free and total), C-reactive protein (CRP), antioxidant status, transrectal ultrasound prostate volume, urinary flow rate, ultrasound-estimated post-void residual urine volume at baseline, and at 3 and 6 months, and urine ex vivo anti-adherence activity were determined in all subjects. In contrast to the control group, patients in the cranberry group had statistically significant improvement in International Prostate Symptom Score, QoL, urination parameters including voiding parameters (rate of urine flow, average flow, total volume and post-void residual urine volume), and lower total PSA level on day 180 of the study. There was no influence on blood testosterone or serum CRP levels. There was no statistically significant improvement in the control group. The results of the present trial are the first firm evidence that cranberries may ameliorate LUTS, independent of benign prostatic hyperplasia or C-reactive protein level.

OBJECTIVE: To evaluate the influence of plum-, cranberry- and blackcurrant juice on urinary stone risk factors.

DESIGN: Investigations were carried out in 12 healthy male subjects aged 18-38 y. All subjects received a standardized diet formulated according to the dietary recommendations of the German Society of Nutrition. The subjects provided 24 h urine collections in a control, three loading phases. In each loading phase a neutral mineral water was substituted for 330 ml of the particular juice.

RESULTS: Cranberry juice decreased the urinary pH, whereas the excretion of oxalic acid and the relative supersaturation for uric acid were increased. Blackcurrant juice increased the urinary pH and the excretion of citric acid. The excretion of oxalic acid was increased too. All changes were statistically significant. The plum juice had no significant effect on the urinary composition.

CONCLUSION: It is concluded that blackcurrant juice could support the treatment and metaphylaxis of uric acid stone disease because of its alkalizing effect. Since cranberry juice acidifies urine it could be useful in the treatment of brushite and struvite stones as well as urinary tract infection.

Clinical, epidemiological and mechanistic studies support the role of cranberry (Vaccinium macrocarpon Ait.) in maintaining urinary tract health. Cranberry proanthocyanidins contain A-type linkages and have been associated with preventing adhesion of P-fimbriated uropathogenic Escherichia coli to uroepithelial cells. It is not known if the presence of the A-type linkage is a prerequisite for anti-adhesion activity. Other commercial sources of proanthocyanidins with all B-type linkages have not previously been screened for this activity. The goals of this study were to compare the in vitro anti-adhesion activity of A-linked proanthocyanidins from cranberry juice cocktail with the anti-adhesion activities of B-linked proanthocyanidins from commercial grape and apple juices, green tea and dark chocolate, and determine if anti-adhesion activity is detectable in human urine following consumption of single servings of each commercial food product. Structural heterogeneity and presence of the A-type linkage in cranberry proanthocyanidins was confirmed utilizing MALDI-TOF/MS and DI/ESI MS, as was the presence of all B-type linkages in the proanthocyanidins from the other commercial products. The isolated A-type proanthocyanidins from cranberry juice cocktail elicited in vitro anti-adhesion activity at 60 microg/ml, the B-type proanthocyanidins from grape exhibited minor activity at 1200 microg/ml, while other B-type proanthocyanidins were not active. Anti-adhesion activity in human urine was detected following cranberry juice cocktail consumption, but not after consumption of the non-cranberry food products. Results suggest that presence of the A-type linkage in cranberry proanthocyanidins may enhance both in vitro and urinary bacterial anti-adhesion activities and aid in maintaining urinary tract health.

No abstract - Introduction: It is well “known” by the general lay public that cranberry juice is helpful in treating and preventing urinary tract infections (UTIs). However, the evidence for this assumption has never been critically reviewed in urologic reports or elsewhere. The evidence for the two proposed mechanisms of action of cranberry juice, urinary acidification and inhibition of bacterial adherence, are critically analyzed.

OBJECTIVE: This study compares the effects of daily cranberry juice to those of Lactobacillus in children with recurrent urinary tract infections (UTIs).

MATERIAL AND METHODS: Eighty-four girls aged between 3 and 14 years were randomized to cranberry, Lactobacillus or control in three treatment arms: G1, cranberry juice 50 ml daily (n=28); G2, 100 ml of Lactobacillus GG drink on 5 days a month (n=27); and G3, controls (n=29). The study lasted for 6 months.

RESULTS: Only four subjects withdrew: 1/28 (3.5%) from G1, 1/27 (3.7%) from G2 and 2/29 (6.8%) from G3, because of poor compliance to the established protocol. There were 34 episodes of UTIs in this cohort: 5/27 (18.5%) in G1, 11/26 (42.3%) in G2 and 18/27 (48.1%) in the G3, with at least one episode of infection (p0.05).

CONCLUSION: These data suggest that daily consumption of concentrated cranberry juice can significantly prevent the recurrence of symptomatic UTIs in children.

PURPOSE: Cranberry proanthocyanidins have been identified as possible inhibitors of Escherichia coli adherence to uroepithelial cells. However, little is known about the dose range of this effect. Furthermore, it has not been studied directly in the urogenital system. To address these issues we tested the effect of a cranberry powder and proanthocyanidin extract on adherence of a P-fimbriated uropathogenic E. coli isolate to 2 new urogenital model systems, namely primary cultured bladder epithelial cells and vaginal epithelial cells.

MATERIALS AND METHODS: E. coli IA2 was pre-incubated with a commercially available cranberry powder (9 mg proanthocyanidin per gm) or with increasing concentrations of proanthocyanidin extract. Adherence of E. coli IA2 to primary cultured bladder epithelial cells or vaginal epithelial cells was measured before and after exposure to these products.

RESULTS: Cranberry powder decreased mean adherence of E. coli IA2 to vaginal epithelial cells from 18.6 to 1.8 bacteria per cell (p 0.001). Mean adherence of E. coli to primary cultured bladder epithelial cells was decreased by exposure to 50 mug/ml proanthocyanidin extract from 6.9 to 1.6 bacteria per cell (p 0.001). Inhibition of adherence of E. coli by proanthocyanidin extract occurred in linear, dose dependent fashion over a proanthocyanidin concentration range of 75 to 5 mug/ml.

CONCLUSIONS: Cranberry products can inhibit E. coli adherence to biologically relevant model systems of primary cultured bladder and vaginal epithelial cells. This effect occurs in a dose dependent relationship. These findings provide further mechanistic evidence and biological plausibility for the role of cranberry products for preventing urinary tract infection.

PURPOSE: We compared the effects of daily cranberry juice cocktail to those of placebo during pregnancy on asymptomatic bacteriuria and symptomatic urinary tract infections.MATERIALS AND METHODS: A total of 188 women were randomized to cranberry or placebo in 3 treatment arms of A-cranberry 3 times daily (58), B-cranberry at breakfast then placebo at lunch and dinner (67), and C-placebo 3 times daily (63). After 27.7% (52 of 188) of the subjects were enrolled in the study the dosing regimens were changed to twice daily dosing to improve compliance.RESULTS: There were 27 urinary tract infections in 18 subjects in this cohort, with 6 in 4 group A subjects, 10 in 7 group B subjects and 11 in 7 group C subjects (p = 0.71). There was a 57% and 41% reduction in the frequency of asymptomatic bacteriuria and all urinary tract infections, respectively, in the multiple daily dosing group. However, this study was not sufficiently powered at the alpha 0.05 level (CI 0.14-1.39 and 0.22-1.60, respectively, incidence rate ratios). Of 188 subjects 73 (38.8%) withdrew, most for gastrointestinal upset.CONCLUSIONS: These data suggest there may be a protective effect of cranberry ingestion against asymptomatic bacteriuria and symptomatic urinary tract infections in pregnancy. Further studies are planned to evaluate this effect.

OBJECTIVE: To test the recommendation that to avoid the complications of long-term indwelling bladder catheterization (e.g. encrustation and blockage by crystalline Proteus mirabilis biofilms) patients should drink cranberry juice.

MATERIALS AND METHODS: Urine was collected from groups of volunteers who had drunk up to 2 x 500 mL of cranberry juice or water within an 8-h period. Laboratory models of the catheterized bladder were supplied with urine from these groups and inoculated with P. mirabilis. After incubation for 24 or 48 h, the extent of catheter encrustation was determined by chemical analysis for calcium and magnesium. Encrustation was also visualized by scanning electron microscopy.

RESULTS: The amounts of calcium and magnesium recovered from catheters incubated in urine pooled from individuals who had drunk 500 mL of cranberry juice was not significantly different from that on catheters incubated in pooled urine from control subjects who had drunk 500 mL of water. However, there was significantly less encrustation (P = 0.007) on catheters from models receiving urine from volunteers who had drunk 2 x 500 mL of water than on catheters incubated in models supplied with urine from volunteers who had drunk 2 x 500 mL of cranberry juice. The amounts of encrustation on these two groups of catheters were also significantly less than that on catheters incubated in models supplied with urine from volunteers who had not supplemented their normal fluid intake. (P 0.001). Experiments in the models using artificial urine showed that increasing the low fluid intake (720 mL/24 h) characteristic of many patients undergoing long-term catheterization by factors of three and six, significantly (P 0.01) reduced the amounts of calcium and magnesium that formed on catheters. At a simulated fluid intake of 720 mL/24 h, catheters blocked with encrustation after a mean of 42.5 h, while those supplied with urine produced from an intake of 4320 mL/24 h, drained freely for > 10 days.

CONCLUSION: In this in vitro study, drinking cranberry juice did not produce urine that was inhibitory to the development of crystalline catheter-blocking P. mirabilis biofilms. The important factor in preventing catheter encrustation is a high fluid intake.