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. 2023 Feb 7;24(4):3277. doi: 10.3390/ijms24043277

Table 1.

Most-relevant published clinical trials from the last 15 years reporting effects on UTI treatment after supplementation with food-derived polyphenols.

Trial Type Subjects No. of Subjects Age
(Years)		 Treatment(s) Duration of Treatment Main Outcomes Ref.
Procyanidins
R, DB, PC Elderly Woman 153 78.1 ± 8.3 (Cranberry group)
79.0 ± 9.4 (Placebo group)

  • 300 mL per day of a commercially available standard cranberry beverage (containing 27% cranberry juice)

  • 300 mL per day of a specially prepared synthetic placebo drink

 6 months 42% of the pathologic bacteriuria (p < 0.01) compared to the control group and 27% odds of remaining bacteriuric-pyuric (p < 0.01) compared to the control group [44]
R, DB, PC Premenopausal women 150 32 ± 9.8 (Cranberry group)
30.0 ± 11.8 (Lactobacillus group)
29.0 ± 10.5 (Control group)

  • 100 mL of lactobacillus drink (containing 4 × 1010 cfu of Lactobacillus GG/100 mL) five days a week for one year (Lactobacillus group)

  • 50 mL of cranberry–lingonberry juice (containing 7.5 g cranberry concentrate and 1.7 lingonberry concentrate in 50 mL of water)

 6 months −20% of recurrence (p < 0.05) compared to the control group [45]
R, DB, PC Women 300 Over 50

  • 125 mL placebo juice once daily, before sleeping. Group P

  • 125 mL cranberry juice (containing > 40 mg proanthocyanidin per 125 mL) once daily, before sleeping. Group A

 24 weeks 29.1% of patients showed UTI relapse in group A
49.2% of patients showed UTI relapse in group P, (log-rank test; p = 0.0425)		 [46]
R, DB, PC Subjects undergoing elective gynecologic surgery 160 >18 years old

  • 2 cps of cranberry juice (equivalent to two 8-ounce servings of cranberry juice) twice per day

  • 2 cps of placebo g 2 times per day

 6 weeks after surgery Lower UTI occurrence in the cranberry treatment group compared to the placebo group (15/80 patients (19%) versus 30/80 (38%) [47]
R, DB, PC Woman
with
recurrent UTIs		 182 55.3 ± 13.3 year (active group)
55.1 ± 10.9 year (placebo group)

  • Placebo

  • 500mg of cranberry powder

 6 months Cranberry group, the UTIs were significantly fewer (10.8% vs. 25.8%, p = 0.04)
Cranberry group experienced a longer time to first UTI than the placebo group (p = 0.04)		 [48]
R, DB, PC Children with normal urinary anatomy or grade I or II VUR 263 1–16 years old

  • Placebo juice

  • 5 mL/kg body weight cranberry juice

 6 months −6 days on antimicrobials per patient-year; 95% CI, −7 to −5; p < 0.001) [52]
R, DB Premenopausal women
with recurrent UTIs		 221 18 years or older

  • 480 mg trimethoprim-sulfamethoxazole (TMP-SMX) once daily

  • cranberry caps 500 mg twice daily

 12 months 78.2% vs. 71.1% patients with at least 1 symptomatic UTI, cranberry vs. TMP-SMX group [53]
R, DB Women with two or more antibiotic-treated UTIs in the previous 12 months 137 ≥45 years

  • 100 mg trimethoprim

  • cranberry extract 500 mg

 6 months Time to first recurrence of UTI was not significantly different (log-rank test: Δ = 2.7, χ2 (2.7, 1) p = 0.100)
84.5 days median time to UTI recurrence (cranberry group), 91 days for trimethoprim group (U = 166, p = 0.479).		 [55]
Catechins
R, SB,
PC 		Premenopausal nonpregnant women with acute uncomplicated cystitis 70 18–50 years

  • Placebo powder + 480 mg tablets of co-trimoxazole twice daily for three days (placebo group)

  • Green tea catchins (four 500 mg caps/die) + 480 mg tablets of co-trimoxazole twice daily for three days (green tea group)

 3 days Green tea group exhibited significant improvement in urinalysis data (abnormal urine color, pyuria, and bacteriuria) among with Placebo group, except for hematuria
After 4 weeks, 2.86% of patients in the green tea group, and after 6 weeks, 15.38% of patients in the placebo group had the symptoms of recurrent cystitis		 [72]
Quercetin
CT Subjects with
documented interstitial cystitis		 22 53.1 years

  • 1 caps of Cysta-Q complex (containing 500 mg of quercetin) twice daily

 4 weeks From 11.3 +/− 0.6 to 5.1 +/− 0.7 (p = 0.000001) improved the mean problem index
From 11.9 +/− 0.9 to 4.5 +/− 0.5 (p = 0.000001) mitigated the mean symptom index
From 8.2 +/− 0.4 to 3.5 +/− 0.4 (p = 0.000001) the mean global assessment score ameliorated		 [102]
MC, CT, PS Postmenopausal women
with recurrent UTIs during the last year		 145

  • Group 1: 56.4 ± 3.2

  • Group 2: 56.6 ± 2.9

  • Group 3: 57.0 ± 4.1

  • Group 1: Vaginal estrogens (0.005% estriol vaginal gel, daily for three weeks and then twice weekly up to 12 weeks; repeat treatment every three month)

  • Group 2: HA, CS, curcumin and quercetin per os ((2 capsules daily for 15 days a month for 3 months, then one capsule daily for 15 days a month for the next 9 months)

  • Group 3: HA, CS, curcumin and quercetin associated with vaginal estrogens

 12 months After 6 months, in group 3 was reduced the recurrent UTIs episodes compared to those receiving single treatments (group 1 and group 2) [103]
Tannins
CT, PS Nephropathic patients affected by recurrent UTIs 26 >18 years old

  • Oral supplementation (containing 4.57 mg of hydrolyzable tannins, 0.94 mg of anthocyanosides, 0.51 mg of proanthocyanidins, 0.18 mg of quercetin derivatives)

  • Untreated subjects (control group)

 6 weeks In supplemented group a
significant reduction in urine leukocyte content was observed.
Urinary bacterial flora decreased significant untreated weeks of treatment vs. untreated subjects		 [105]

Abbreviations: R: randomized, CT: clinical trial, PS: pilot-study, MC: multicentric, PC: placebo-controlled, DB: double-blind, SB: single-blind.