The risk of urinary tract infection in vegetarians and non-vegetarians: a prospective study

Plant-based diets, animal agriculture, and the connection with urological and planetary health

PURPOSE OF REVIEW

We summarize the latest evidence regarding the impact of plant-based diets on urological and planetary health to facilitate patient counseling and research regarding dietary intervention.

RECENT FINDINGS

Studies have highlighted the association of plant-based diets with a lower risk of multiple urological conditions including prostate cancer, erectile dysfunction, benign prostatic hyperplasia, and nephrolithiasis, as well as benefits for planetary health.

SUMMARY

Plant-based diets are associated with numerous benefits that co-promote urological and planetary health.

Effects of dietary intervention on diabetic nephropathy: an umbrella review of systematic reviews and meta-analyses of randomized controlled trials

Objective

To evaluate the quality of evidence, potential biases, and validity of all available studies on dietary intervention and diabetic nephropathy (DN).

Methods

We conducted an umbrella review of existing meta-analyses of randomized controlled trials (RCTs) that focused on the effects of dietary intervention on DN incidence. The literature was searched via PubMed, Embase, Web of Science, and the Cochrane Database of Systematic Reviews. According to the Grading of Recommendations, Assessment, Development and Evaluation (GRADE), evidence of each outcome was evaluated and graded as "high", "moderate", "low" or "very low" quality to draw conclusions. Additionally, we classified evidence of outcomes into 4 categories.

Results

We identified 36 meta-analyses of RCTs and 55 clinical outcomes of DN from 395 unique articles. Moderate-quality evidence suggested that probiotic supplementation could significantly improve blood urea nitrogen (BUN), total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) levels in DN patients. Low-quality evidence indicated that probiotic supplementation significantly improved the serum creatinine concentration, urinary albumin-creatinine ratio (UACR), fasting blood glucose (FBG), HbA1c and high-density lipoprotein cholesterol (HDL-C) in DN patients. In addition, low-quality evidence suggested that a salt restriction diet could significantly improve the creatinine clearance rate (CrCl) in patients with DN. Low-quality evidence suggested that vitamin D supplementation could significantly improve the UACR in patients with DN. In addition, low-quality evidence has indicated that soy isoflavone supplementation could significantly improve BUN, FBG, total cholesterol (TC), triglyceride (TG) and LDL-C levels in patients with DN. Furthermore, low-quality evidence suggested that coenzyme Q10 supplementation could significantly improve HbA1c, TC and HDL-C in patients with DN, and dietary polyphenols also significantly improved HbA1c in patients with DN. Finally, low-quality evidence suggested that supplementation with antioxidant vitamins could significantly improve the serum creatinine concentration, systolic blood pressure, and HbA1c level in patients with DN. Given the small sample size, all significantly associated outcomes were evaluated as class IV evidence.

Conclusion

Moderate to low amounts of evidence suggest that supplementation with probiotics, vitamin D, soy isoflavones, coenzyme Q10, dietary polyphenols, antioxidant vitamins, or salt-restricted diets may significantly improve clinical outcomes in patients with DN.

Systematic Review Registration

https://www.crd.york.ac.uk/PROSPERO/, identifier CRD42024512670.

Cranberry Supplements for Urinary Tract Infection Prophylaxis in Pregnant Women: A Systematic Review of Clinical Trials and Observational Studies on Efficacy, Acceptability, Outcomes Measurement Methods, and Studies' Feasibility

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 outcomes 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.

The Plant-based Prescription: How Dietary Change Can Improve Both Urological and Planetary Health

In this editorial, we discuss the relationship between meat consumption and many major urological conditions (eg, prostate cancer, kidney stones, urinary tract infections) and how dietary choices could simultaneously benefit genitourinary health and the environment, which in turn will have downstream impacts on public health.

Intestinal Microbiota Correction in the Treatment and Prevention of Urinary Tract Infection

Intestinal microbiota is a topical subject of modern research. The maintenance of a healthy intestinal micro biota is an important component of homeostasis, and violations of its composition and functions, called dysbiosis, are associated with a number of diseases, including urinary tract infections. Antimicrobial therapy leads to significant changes in the intestinal microbiota and causes the possibility of urinary tract infection recurrence. In this regard, it is important to study methods of microbiota correction in order to restore its structural and functional integrity.

Escherichia coli Isolated from Vegans, Vegetarians and Omnivores: Antibiotic Resistance, Virulence Factors, Pathogenicity Islands and Phylogenetic Classification

Pathogenic strains of Escherichia coli have acquired virulence factors, which confer an increased ability to cause a broad spectrum of enteric diseases and extraintestinal infections. The aim of this study was to analyze the antimicrobial resistance profile of and the presence of virulence-associated genes (VAGs) in E. coli fecal isolates from omnivores, vegetarians and vegans. A control group of 60 isolates from omnivores, as well as a study group with 41 isolates from vegetarians and 17 from vegans, were analyzed. Isolates from both groups showed a high rate of resistance to ampicillin, amoxicillin-clavulanic acid and nalidixic acid, and some of them were positive for the ESBL test (12% of isolates from vegetarians/vegans and 5% of isolates from omnivores). The most predominant VAGs detected in isolates from omnivores were fimH (70%), iutA (32%), fyuA (32%) and traT (32%), while among isolates from vegetarians or vegans, the most predominant were traT (62%), kpsMT k1 (28%) and iutA (22%). Most isolates from omnivores (55%) were positive for PAI I536, while most of those from vegetarians/vegans (59%) were positive for PAI IV536. Phylogenetic group A, composed of commensal non-pathogenic isolates that survive in the intestinal tract, was the most prevalent in both control and study groups. Some VAGs were found in only one of the groups, such as the pathogenicity island PAI III536, found in 12% of the isolates from omnivores, while the kpsMT III gene (15%) was detected only among isolates from vegetarians/vegans. Interestingly, this gene codes for a polysaccharide capsule found mainly in E. coli isolates causing intestinal infections, including EPEC, ETEC and EHEC. Finally, our results show that there were no advantages in vegetarian or vegan diets compared to the omnivorous diet, as in both groups we detected isolates harboring VAGs and displaying resistance to antibiotics, especially those most commonly used to treat urinary tract infections.

Whole-Person, Urobiome-Centric Therapy for Uncomplicated Urinary Tract Infection

A healthy urinary tract contains a variety of microbes resulting in a diverse urobiome. Urobiome dysbiosis, defined as an imbalance in the microbial composition in the microenvironments along the urinary tract, is found in women with uncomplicated urinary tract infection (UTI). Historically, antibiotics have been used to address UTI. An alternative approach to uncomplicated UTI is warranted as the current paradigm fails to take urobiome dysbiosis into account and contributes to the communal problem of resistance. A whole-person, multi-modal approach that addresses vaginal and urinary tract dysbiosis may be more effective in reducing recurrent UTI. In this review, we discuss strategies that include reducing pathogenic bacteria while supporting commensal urogenital bacteria, encouraging diuresis, maintaining optimal pH levels, and reducing inflammation. Strategies for future research are suggested.

Inflammatory, oxidative and DNA damage status in vegetarians: is the future of human diet green?

The health benefit of a vegetarian diet is still under debate as it may result in a higher intake of some beneficial micronutrients, while others may be reduced, thus influencing various metabolic pathways and health-related biomarkers. This scoping review discusses inflammatory, oxidative and DNA damage status in vegetarians and vegans compared to omnivores. Most of the reviewed studies indicated favorable effects of a vegetarian diet on oxidative status compared to omnivores but did not clearly associate particular dietary habits to genome damage. The evidence on the effect of vegetarian diet on the inflammatory and immunological biomarkers is poor, which could at least partly be explained by methodological constraints such as small sample size, short duration of vegetarianism and inconsistent definitions of the omnivorous diet. The only inflammatory biomarker that seems to be associated with the vegetarian diet was inflammatory mediator C-reactive protein, which in several studies showed lower values in vegetarians as compared to omnivores. There were very few studies on immunological markers and the results on the difference between vegetarians and omnivores were inconclusive. Although several biomarkers involved in oxidative stress and inflammation showed a beneficial association with the vegetarian diet, further research in well-defined and sufficiently sized cohorts is needed to provide more evidence.

Prospective Evaluation of Daily and Weekly Urine pH Variations Along With Diet Intake in Postmenopausal Women With Recurrent Urinary Tract Infections

OBJECTIVES

Acidic urine pH may be protective against recurrent urinary tract infections (RUTIs). After reviewing the literature, we primarily analyzed urine pH fluctuations and secondarily compared them with diet in older women with RUTIs.

METHODS

After IRB approval, postmenopausal women with documented RUTIs were enrolled. Participants were given preformatted charts to record urinalysis reagent strips (Medimpex) findings 4 times per day and concomitant food/beverage intake (food diary). Urine cultures at baseline ensured no infection during measurement period. Nutrient content reported in food diaries was analyzed by an experienced registered dietitian and compared with parallel fluctuations in urine pH.

RESULTS

Of 26 women with median age of 72 years (55-86 years), the first 3 days of diet and urine pH recordings found that 17 (65%) of 26 exhibited urine pH variation greater than 1 unit, with an overall median of 6 (5-9). Comparing dietary analysis and urine pH changes, beta-carotene (P = 0.017) and total dietary sugar intake (P = 0.036) were associated with a decrease in urine pH, whereas monounsaturated fatty acids (MFA, 22:1, P = 0.023) and protein (P = 0.028) were associated with an increase in urine pH.

CONCLUSIONS

In this real-life, observational study, 65% of older women with RUTIs exhibited notable changes in urine pH, with decreased urine pH associated with nutrients found in orange and yellow vegetables and several major food groups. A longitudinal study is needed to determine if changing an individual's diet and/or adding supplements could decrease the urine pH, thus affecting the rate of RUTIs.

Cranberry for Bacteriuria in Individuals with Spinal Cord Injury: A Systematic Review and Meta-Analysis

Background

Urinary tract infection (UTI) is common in individuals with spinal cord injury (SCI) and neurogenic lower urinary tract dysfunction (NLUTD) and in veterans with SCI who use antibiotics improperly for asymptomatic bacteriuria. Cranberry (CB) has been suggested for UTI prevention.

Methods

We performed a systematic search up to May 2020 in the following databases: AccessMedicine, BioMed Central, CINAHL, Cochrane Library, ProQuest, and PubMed. Quality assessment was performed using a specifically designed quality score. Risk ratio was calculated with both random effect model analysis (DerSimonian-Laird method) and quality effect model analysis (Doi Thalib method).

Results

Six studies on bacteriuria and SCI were reviewed. From the four studies available for meta-analysis, two of which with individuals taking both CB and control, 477 data from 415 participants were analysed (241 CB and 236 control). No significant differences were detected with meta-analysis. However, bias, limitations, and incompleteness were observed in the reviewed studies.

Conclusion

Although further studies are needed, we suggest an accurate monitoring of diet and fluid intake, the evaluation of risk for potential food or nutraceutical interactions with drugs, and the inclusion of inflammatory markers among the outcomes in addition to UTI.