Table 1:

Detailed inclusion and exclusion criteria

Inclusion Criteria

Exclusion Criteria

Age > 55 years English-speaking Willing to comply with study procedures (including catheterization for urine sampling) Have been prescribed vaginal estrogen and willing to use this for >6 weeks prior to sampling For recurrent UTI groups: Diagnosed with recurrent UTI in the prior 24 months (Clinical definition of recurrent UTI required >3 culture proven UTIs* within 12 mo. OR >2 culture proven UTIs within 6mo at the time of diagnosis) Not using UTI prevention supplements (such as methenamine, D-mannose, cranberry, probiotics) OR willing to discontinue for 6 weeks prior to sampling For prophylactic antibiotics group: Have been prescribed daily antibiotic^ prophylaxis medication and will have used this for >6 weeks prior to sampling

Instrumentation of urinary tract (e.g. cystoscopy) in prior month Neurogenic bladder or any other need for chronic intermittent catheterization History of prior pelvic radiation Active malignancy Breast cancer within previous 5 years or taking any anti-estrogen medication (e.g. aromatase-inhibitors or selective estrogen receptor modulators) History of neurologic condition that may affect urinary function (e.g. stroke, multiple sclerosis, spinal cord injury, Parkinson’s disease) Known renal insufficiency with creatinine > 1.3 Pregnant or breastfeeding Immunocompromised, immunosuppression, or chronic steroid use Intravaginal pessary use Using only post-coital antibiotic prophylaxis (excluded from all groups)

^*Culture proven UTI requires urinary symptoms (e.g. dysuria, suprapubic pain, increased urinary frequency, hematuria) and a urine culture showing ≥ 10⁴ colony forming units (CFU) of a dominant organism. Though in some instances, there can be multiple organisms with ≥ 10⁴ colony forming units, mixed flora cultures are not considered positive.

^{^}Antibiotic was selected based on clinical indications; acceptable antibiotics included trimethoprim, nitrofurantoin, or cephalexin.