Effect of oral cranberry extract (standardized proanthocyanidin-A) in patients with recurrent UTI by pathogenic E. coli: a randomized placebo-controlled clinical research study

Int Urol Nephrol. 2016 Sep;48(9):1379-86. doi: 10.1007/s11255-016-1342-8. Epub 2016 Jun 17.

Abstract

Purpose: To evaluate the effect of cranberry extract (PAC-A ~ proanthocyanidin-A) on the in vitro bacterial properties of uropathogenic (E. coli) and its efficacy/tolerability in patients with subclinical or uncomplicated recurrent UTI (r-UTI).

Materials and methods: After obtaining clearance from the ethics committee and administering a written informed consent, 72 patients with r-UTI were enrolled as per protocol (November 2011 to March 2013) in this prospective study, to randomly receive (PAC-A: group I, 36) or (placebo: group II, 36), for 12 weeks. Any change/reduction in the incidence of r-UTI at 12 weeks was construed to be the primary endpoint of this study.

Results: After 12 weeks, bacterial adhesion scoring decreased (0.28)/(2.14) in group I/II (p < 0.001); 32/36 (88.8 %) and 2/36 (5.5 %) in groups I and II, respectively, turned MRHA negative (p < 0.001); biofilm (p < 0.01) and bacterial growth (p < 0.001) decreased in group I; microscopic pyuria score was 0.36/2.0 in group I/II (p < 0.001); r-UTI decreased to 33.33 versus 88.89 % in group I/II (p < 0.001); mean subjective dysuria score was 0.19 versus 1.47 in group I/II (p < 0.001), while mean urine pH was 5.88 versus 6.30 in group I/II (p < 0.001). No in vitro antibacterial activity of cranberry could be demonstrated, and no adverse events were noted.

Conclusions: The overall efficacy and tolerability of standardized cranberry extract containing (PAC-A) as a food supplement were superior to placebo in terms of reduced bacterial adhesion; bacterial MRHA negativity; urine pH reduction; and in preventing r-UTI (dysuria, bacteriuria and pyuria). Larger randomized controlled trials are needed to elucidate the precise role, exact dose and optimal duration of PAC-A therapy in patients at risk of r-UTI.

Keywords: Cranberry; Escherichia coli; Lactobacillus; Non-antibiotic strategies; Proanthocyanidin-A; Urinary tract infection; Vaccinium macrocarpon.

Publication types

  • Randomized Controlled Trial

MeSH terms

  • Administration, Oral
  • Adolescent
  • Adult
  • Aged
  • Bacterial Adhesion / drug effects
  • Biofilms / drug effects
  • Dietary Supplements
  • Dysuria / microbiology
  • Escherichia coli / drug effects
  • Escherichia coli Infections / complications
  • Escherichia coli Infections / prevention & control*
  • Hemagglutination Tests
  • Humans
  • Hydrogen-Ion Concentration
  • Middle Aged
  • Phytotherapy*
  • Plant Extracts / pharmacology
  • Plant Extracts / therapeutic use*
  • Prospective Studies
  • Pyuria / microbiology
  • Recurrence
  • Secondary Prevention
  • Urinary Tract Infections / microbiology
  • Urinary Tract Infections / prevention & control*
  • Urine / chemistry
  • Vaccinium macrocarpon / chemistry*
  • Young Adult

Substances

  • Cranpac
  • Plant Extracts