The Effects of Cranberry Juice on Bacterial Adhesion

Hypothesis: Metabolites in cranberry juice, have anti-adhesive properties for uropathogenic bacteria but they do not disturb the normal vaginal flora.

Study design and assays:

A crossover study design using 12 healthy women will be conducted for 50 days. The anti-adhesive properties of the urine will be determined using uropathogens and changes in the vaginal microflora will be evaluated.

Participants:

The subjects will be healthy premenopausal women aged 19-45, who have no history of chronic urinary tract infection or have had a urinary tract infection in the past 12 months, and are currently not taking antibiotics or any supplements to prevent UTI, including cranberry juice. The subjects must not have urinary tract abnormalities, requiring catheterization for micturition, be pregnant, or diabetic or have allergies to berry juices. Each test phase is 1 week (7 days) and the following protocol will be followed:

Subjects 1-3 Test phase I: water; washout phase Test phase II: cranberries; washout phase Test phase III: cranberry juice- 1/day; washout phase Test phase IV: cranberry juice- 2/day

4-6 Test phase I: cranberry juice- 2/day; washout phase Test phase II: water; washout phase Test phase III: cranberries; washout phase Test phase IV: cranberry juice- 1/day

7-9 Test phase I: cranberry juice- 1/day; washout phase Test phase II: cranberry juice- 2/day; washout phase Test phase III: water; washout phase Test phase IV: cranberries

10-12 Test phase I: cranberries; washout phase Test phase II: cranberry juice- 1/day; washout phase Test phase III: cranberry juice- 2/day; washout phase Test phase IV: water

During the washout period, the subjects will return to their normal diet with no added beverage or food, although again no cranberry juice can be consumed. The beverages/food to be taken for the 7 day phases comprise:

• Water - Control group
• Cranberry juice 1/day
• Cranberry juice 2/day
• Cranberries (dried)

Regime and sampling:

A mid stream urine sample will be collected to evaluate the anti-adhesive effects of the various treatments.

Mid stream urine will also be collected to evaluate anti-adhesive properties of the urine, and determine if changes occur following washout.

A 24 h urine will be collected after 3-4 days of each phase for urinalysis.

Vaginal swabs will be collected to determine the effect, if any, of the foods on the composition of the vaginal microflora.

Inclusion criteria

• Age 19-45 years
• Healthy pre-menopausal female volunteers with no history of urinary tract infections over the past 12 months.

Exclusion criteria

• Experienced a urinary tract infection in the past 12 months
• Receiving antibiotic therapy or supplements to prevent urinary tract infections
• Pregnant, postmenopausal or outside of the age range (19-45 years old)
• Anatomical abnormality of the urinary tract, such as following surgery
• Using a catheter to manage micturition
• Diabetic
• Allergic to berry juices