CONTEXT: The prevention of urinary tract infection recurrence (UTI) in children has been a challenge yet to be solved. Current practice in children with recurrent UTI (RUTI) suggests that antibiotic prophylaxis may prevent further episodes of UTI and future complications. 

OBJECTIVE: To conduct a systematic review and meta-analysis of randomized controlled trials comparing prophylaxis options for the prevention of UTI and kidney scarring in children with a history of RUTI. 

DATA SOURCES: We conducted a systematic literature search through major electronic databases (PubMed/Medline, Scopus and Cochrane Library) up to November 26th, 2023. Mean difference and SD were used for continuous outcomes and odds ratio for dichotomous outcomes. 

STUDY SELECTION: Our meta-analysis included 3335 participants from 23 studies. 

DATA EXTRACTION: The primary outcome was the effect of the different prophylaxis options on the incidence of symptomatic UTI in children with RUTI during prophylactic treatment. 

RESULTS: Cranberry products and nitrofurantoin lead to lower odds of symptomatic UTI episodes during prophylaxis compared with the control group and control, trimethoprim-sulfamethoxazole, or trimethoprim groups accordingly. Nitrofurantoin may be the best option for UTI incidence reduction compared with all available documented interventions. 

LIMITATIONS: No prophylaxis option has been shown to reduce kidney scarring. 

CONCLUSIONS: Nitrofurantoin and cranberry products may decrease the incidence of symptomatic UTI episodes in pediatric patients with a history of RUTI. Future randomized control trials studying nonantibiotic prophylaxis options focusing on children with UTI recurrence and the risk for kidney scarring are needed to draw further conclusions. Copyright © 2024 by the American Academy of Pediatrics.

Introduction: Escherichia coli is the most common uropathogen in humans, dogs and cats. Dietary consumption of cranberry (Vaccinium macrocarpon) is known to be associated with a reduction in uropathogenic E. coli (UPEC) adhesion to human and canine urinary epithelial cell lines, but this has not been shown in cats. 

Material and Methods: Six neutered domestic cats, one male and five females, were randomly fed three diets successively, one containing 0.1% cranberry powder, one containing 0.3% cranberry powder, and one being the control without cranberry. Naturally emitted urine was collected on the last two days of each period of two weeks and used for bacterial growth. Adherence to Crandell-Rees feline kidney (CRFK) uroepithelial cells of the feline UPEC C571 strain (positive for the papC gene marker for P-fimbriae and the fimA marker for type 1 pili and negative for the gene of the alpha haemolysin cytotoxin hlyA, and additionally non-haemolytic in vitro on blood agar) was quantified after growth in urine samples. 

Results: Significant reductions in bacterial adherence to CRFK cells were observed for 60% of cats receiving 0.1% cranberry powder supplementation and for all cats receiving 0.3% cranberry powder supplementation, compared to the same animals consuming the control diet. 

Conclusion: Dietary supplementation with cranberry may provide some degree of protection to cats against adhesion of UPEC to feline uroepithelial cells.

Introduction: Escherichia coli is the most common pathogen isolated from the urine of dogs with urinary tract infections (UTIs). While there are many studies in humans investigating the potential for the prevention of UTIs by dietary consumption of cranberry, few analogous studies have been carried out in dogs. 

Material and Methods: Eight dogs, four male and four female, were successively fed two diets, first a control without cranberry, and then the second diet containing cranberry extracts. Naturally excreted urine was collected on the tenth day after the start of each diet for 24 h and used for bacterial growth. MadinDarby canine kidney cell adherence by the uropathogenic E. coli G1473 strain expressing type 1 pili and positive for P pili and haemolysin gene markers was quantified after growth in urine samples. 

Results: Significant reductions in bacterial adherence to MDCK cells (from -16.5 to -73.4%, P < 0.05) were observed in the four females but not in the males after consumption of the cranberry extracts compared to the same animals consuming the control diet. 

Conclusion: Dietary supplementation with cranberry may provide some degree of protection to female dogs against adhesion of uropathogenic E. coli to urinary epithelial cells.

OBJECTIVE: This study was designed to determine the effect of cranberry extract used in patients with single urinary tract infections. 

METHODS: Patients with simple-type urinary tract infections were divided into two groups. Treatment with fosfomycin or cranberry tablet was started. On days 1, 3, and 7 of the treatment, whether there was a decrease in the complaints was evaluated with a Likert-type scale. The recovery status of urinary tract infections and the well-being of patients were compared via antibiotic and cranberry groups. 

RESULTS: After the treatment, the leukocyte levels of the cranberry users were at the same level as those of the other group, and the rate of well-being and the portion of patients that reported to be very well on days 3 and 7 in the cranberry group was significantly higher compared with the fosfomycin group (p<0.05). 

CONCLUSION: Considering the results of this study, it was determined that the patient's complaints decreased from day 3 and their well-being increased with the use of cranberry only. Specifically, on day 7, the well-being of the cranberry group was higher than that of the fosfomycin group. For this reason, cranberry is a favorable alternative to antibiotics in uncomplicated and simple urinary tract infections.

PURPOSE: The aim of this narrative literature review was to summarize evidence regarding bacteriuria and urinary tract infections (UTIs) in patients living with a urinary diversion and the use of cranberry products for the prevention of these infections. 

METHODS: We searched for articles in the English language and available in full text to address the role of cranberry products in the management of UTIs in those with urinary diversions. We searched the electronic databases of MEDLINE, PubMed, and the Cochrane Central Register of Controlled Trials between January 2003 and December 2023. Thirty-two elements were read in full and 9 elements that evaluated UTIs and/or the role of cranberries in preventing UTIs are included in this narrative review. 

RESULTS: Research indicates no significant difference in UTI rates, microbiology, or antibiotic sensitivity and resistance patterns between the different types of urinary diversions (orthoptic diversions, ileal conduit diversions, and continent cutaneous diversions). Similar to persons with an intact urinary tract, Escherichia coli (a prevalent coliform bacteria) was the most prevalent pathogen resulting in symptomatic UTIs. In addition, we found that E. coli strains persisted in urinary diversions involving reconstructed intestinal segments for prolonged periods of time despite antibiotic treatment. We found sparse evidence suggesting that cranberry products are effective for the prevention of UTIs after ileal conduit urinary diversion. 

CONCLUSIONS: There are inconsistencies in the definition of bacteriuria in the literature making it difficult to compare findings among the studies. Clinical guidance discussing the optimal method for obtaining a urine specimen from a urinary diversion and its management is limited. Research studies on the use of cranberry products to treat UTIs in persons living with a urinary diversion are urgently needed.

Cranberry supplements are commonly used to prevent urinary tract infections (UTIs). However, their usefulness is uncertain in pregnant women. We aimed to comprehensively summarize the current knowledge on cranberry supplements' efficacy and acceptability during pregnancy in addition to the outcome's measurement methods and studies' feasibility. To achieve it, we searched PubMed, PMC, and Europe PMC databases plus screened citations followed by critical appraisal of included eligible English written primary studies that (1) focused on pregnant women supplemented with any cranberry supplements; (2) provided data on cranberry supplements' efficacy, acceptability, outcomes measurement methods, and studies' feasibility; (3) included human subjects; and (4) published worldwide. Two randomized clinical trials (RCTs) and one nested cohort study, including 1156 pregnant women in total, contributed to our analysis. A tendency toward UTI reduction was demonstrated, although the results' validity was impacted by significant juice-induced gastrointestinal intolerance (23%; 44 of 188 subjects). Changing the form of supplementation from cranberry juice to capsules reduced the issue, causing side effects in one of 49 subjects (2%). Nevertheless, both RCTs still experienced significant recruitment and retention problems, which were at 33% and 59% on average, respectively. Newly acquired safety data on 919 more subjects suggests no increased risks of all malformations, vaginal bleeding, and neonatal complications. Investigating cranberry capsules' efficacy as a non-antibacterial option for UTI prevention in pregnant women has become a feasible and important direction with the current advancement in understanding cranberry supplements' actions, recommended doses plus regimens, and their safety in the population. We reviewed the challenges and discovered knowledge gaps and the implementation strategies for future studies.

BACKGROUND: Cranberries contain proanthocyanidins (PACs), which inhibit the adherence of p-fimbriated Escherichia coli to the urothelial cells lining the bladder. Cranberry products have been used widely for several decades to prevent urinary tract infections (UTIs). This is the fifth update of a review first published in 1998 and updated in 2003, 2004, 2008, and 2012.OBJECTIVES: To assess the effectiveness of cranberry products in preventing UTIs in susceptible populations.

SEARCH METHODS: We searched the Cochrane Kidney and Transplant Specialised Register up to 13 March 2023 through contact with the Information Specialist using search terms relevant to this review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Registry Platform (ICTRP) Search Portal and ClinicalTrials.gov.

SELECTION CRITERIA: All randomised controlled trials (RCTs) or quasi-RCTs of cranberry products compared with placebo, no specific treatment or other intervention (antibiotics, probiotics) for the prevention of UTIs were included.

DATA COLLECTION AND ANALYSIS: At least two authors independently assessed and extracted data. Information was collected on methods, participants, interventions and outcomes (incidence of symptomatic UTIs, positive culture results, side effects, adherence to therapy). Risk ratios (RR) with 95% confidence intervals (CI) were calculated where appropriate. Study quality was assessed using the Cochrane risk of bias assessment tool. Confidence in the evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.

MAIN RESULTS: For this update, 26 new studies were added, bringing the total number of included studies to 50 (8857 randomised participants). The risk of bias for sequence generation and allocation concealment was low for 29 and 28 studies, respectively. Thirty-six studies were at low risk of performance bias, and 23 studies were at low risk of detection bias. Twenty-seven, 41, and 17 studies were at low risk of attrition bias, reporting bias and other bias, respectively. Forty-five studies compared cranberry products with placebo, water or no specific treatment in six different groups of participants. Twenty-six of these 45 studies could be meta-analysed for the outcome of symptomatic, culture-verified UTIs. In moderate certainty evidence, cranberry products reduced the risk of UTIs (6211 participants: RR 0.70, 95% CI 0.58 to 0.84; I = 69%). When studies were divided into groups according to the treatment indication, cranberry products probably reduced the risk of symptomatic, culture-verified UTIs in women with recurrent UTIs (8 studies, 1555 participants: RR 0.74, 95% CI 0.55 to 0.99; I = 54%), in children (5 studies, 504 participants: RR 0.46, 95% CI 0.32 to 0.68; I = 21%) and in people with a susceptibility to UTIs due to an intervention (6 studies, 1434 participants: RR 0.47, 95% CI 0.37 to 0.61; I = 0%). However, there may be little or no benefit in elderly institutionalised men and women (3 studies, 1489 participants: RR 0.93, 95% CI 0.67 to 1.30; I = 9%; moderate certainty evidence), pregnant women (3 studies, 765 participants: RR 1.06, 95% CI 0.75 to 1.50; I = 3%; moderate certainty evidence), or adults with neuromuscular bladder dysfunction with incomplete bladder emptying (3 studies, 464 participants: RR 0.97, 95% CI 0.78 to 1.19; I = 0%; low certainty evidence). Other comparisons were cranberry products with probiotics (three studies) or antibiotics (six studies), cranberry tablets with cranberry liquid (one study), and different doses of PACs (two studies). Compared to antibiotics, cranberry products may make little or no difference to the risk of symptomatic, culture-verified UTIs (2 studies, 385 participants: RR 1.03, 95% CI 0.80 to 1.33; I = 0%) or the risk of clinical symptoms without culture (2 studies, 336 participants: RR 1.30, 95% CI 0.79 to 2.14; I = 68%). Compared to probiotics, cranberry products may reduce the risk of symptomatic, culture-verified UTIs (3 studies, 215 participants: RR 0.39, 95% CI 0.27 to 0.56; I = 0%). It is unclear whether efficacy differs between cranberry juice and tablets or between different doses of PACs, as the certainty of the evidence was very low. The number of participants with gastrointestinal side effects probably does not differ between those taking cranberry products and those receiving a placebo or no specific treatment (10 studies, 2166 participants: RR 1.33, 95% CI 1.00 to 1.77; I = 0%; moderate certainty evidence). There was no clear relationship between compliance with therapy and the risk for repeat UTIs. No difference in the risk for UTIs could be demonstrated between low, moderate and high doses of PACs.

AUTHORS' CONCLUSIONS: This update adds a further 26 studies, taking the total number of studies to 50 with 8857 participants. These data support the use of cranberry products to reduce the risk of symptomatic, culture-verified UTIs in women with recurrent UTIs, in children, and in people susceptible to UTIs following interventions. The evidence currently available does not support its use in the elderly, patients with bladder emptying problems, or pregnant women.

Background: Cranberries (particularly in the form of cranberry juice) have been used widely for several decades for the prevention and treatment of urinary tract infections (UTIs). The aim of this review is to assess the effectiveness of cranberries in treating such infections.

Objectives: To assess the effectiveness of cranberries for the treatment of UTIs.

Search methods: We searched the Cochrane Kidney and Transplant Register of Studies up to 1 August 2023 through contact with the Information Specialist using search terms relevant to this review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Registry Portal (ICTRP) Search Portal and ClinicalTrials.gov.

Selection criteria: All randomised controlled trials (RCTs) or quasi-RCTs of cranberry juice or cranberry products for the treatment of UTIs. Studies of men, women or children were to be included.Data collection and analysisTitles and abstracts of studies that were potentially relevant to the review were screened and studies that were clearly ineligible were discarded. Further information was sought from the authors where papers contained insufficient information to make a decision about eligibility.Main resultsNo studies were found that fulfilled all of our inclusion criteria. Seven studies were excluded because they were the wrong study design, mixed interventions or did not report any relevant outcomes. One study is ongoing; however, its current status is unknown.

Authors' conclusions: After a thorough search, no RCTs which assessed the effectiveness of cranberry juice for the treatment of UTIs were found. Therefore, at the present time, there is no good quality evidence to suggest that it is effective for the treatment of UTIs. Well-designed parallel-group, double-blind studies comparing cranberry juice and other cranberry products versus placebo to assess the effectiveness of cranberry juice in treating UTIs are needed. Outcomes should include a reduction in symptoms, sterilisation of the urine, side effects and adherence to therapy. The dosage (amount and concentration) and duration of therapy should also be assessed. Consumers and clinicians will welcome the evidence from these studies.

PLAIN LANGUAGE SUMMARY: Still waiting for evidence about whether cranberries are useful for treating urinary tract infectionsCranberries contain a substance that can prevent bacteria from sticking to the walls of the bladder. This may help reduce bladder and other urinary tract infections (UTIs). Cranberries (usually as cranberry juice) have been used to try and treat UTIs, particularly in high-risk groups such as older people. Cranberries have few adverse effects. This review found no studies reporting the effects of cranberry juice or other cranberry products on the treatment of UTIs.

BACKGROUND AND OBJECTIVE: With over 50% of women suffering from at least one episode of urinary tract infection (UTI) each year and an increasing prevalence of antimicrobial resistance, efforts need to be made to clearly identify the evidence supporting potential non-drug interventions. This study aims to compare the effects of cranberry juice, cranberry tablets, and increased liquids for the management of UTIs.

METHODS: PubMed, Embase, and Cochrane CENTRAL were searched for randomised controlled trials. The primary outcome was the number of UTIs, and the secondary outcomes were UTI symptoms and antimicrobial consumption. A risk of bias assessment was performed using the Cochrane risk of bias tool, and the certainty of evidence was assessed using Grading of Recommendations Assessment, Development and Evaluation.

KEY FINDINGS AND LIMITATIONS: A total of 20 trials (3091 participants) were included, with 18 studies highlighting a 54% lower rate of UTIs with cranberry juice consumption than no treatment and a 27% lower rate than placebo liquid. Cranberry juice also resulted in a 49% lower rate of antibiotic use than placebo liquid and a 59% lower rate than no treatment, based on a network meta-analysis of six studies. The use of cranberry compounds also reduced the prevalence of symptoms associated with UTIs.

CONCLUSIONS AND CLINICAL IMPLICATIONS: With moderate to low certainty, the evidence supports the use of cranberry juice for the prevention of UTIs. While increased liquids reduce the rate of UTIs compared with no treatment, cranberry in liquid form provides even better clinical outcomes in terms of reduction in UTIs and antibiotic use and should be considered for the management of UTIs.

PATIENT SUMMARY: With the increasing prevalence of antimicrobial-resistant UTIs, alternate non-drug treatment options for its management are required. Available evidence supports the use of cranberry compounds and increases in fluid intake for managing UTIs.

The mechanism by which cranberry-lingonberry juice (CLJ) prevents urinary tract infections (UTI) in children remains unknown. We hypothesized that it alters the composition of the gut or urinary microbiome. Altogether, 113 children with UTIs were randomly allocated to drink either CLJ or a placebo juice for 6 months. We collected urinary samples at 3 months and fecal samples at 3, 6 and 12 months and used next-generation sequencing of the bacterial 16S gene. The children who consumed CLJ had a lower abundance of Proteobacteria (p = 0.03) and a higher abundance of Firmicutes phylum (p = 0.04) in their urinary microbiome at 3 months than did those in the placebo group. The abundance of Escherichia coli in the urinary microbiome was 6% in the CLJ group and 13% in the placebo group (p = 0.42). In the gut microbiome the abundance of Actinobacteria at 3 and 12 months was higher in the children receiving CLJ. The diversity of the urinary and gut microbiome did not differ between the groups. The children drinking CLJ had a different urinary and gut microbiome from those receiving a placebo juice. A healthy urinary microbiome may be important in preventing UTIs in children.