# Efficacy of Escherichia coli Nissle 1917 for the Prevention of Recurrent Urinary Tract Infections in Women: A Preliminary Controlled Prospective Study

## TL;DR

This study found that Escherichia coli Nissle 1917 may help reduce recurrent urinary tract infections in premenopausal women.

## Contribution

The study demonstrates EcN's potential as a non-antibiotic preventive strategy for recurrent UTIs in premenopausal women.

## Key findings

- 55% of EcN-treated patients remained UTI-free compared to 35% in the control group.
- EcN prophylaxis was associated with fewer patients experiencing multiple UTI recurrences.

## Abstract

Background/Objectives: More than 50% of adult women experience at least one urinary tract infection (UTI) during their lifetime, and approximately 25% develop recurrent UTIs (rUTIs), defined as ≥2 episodes within six months. Management of rUTI is challenging and often requires long-term, multimodal preventive strategies. Escherichia coli Nissle 1917 (EcN) is a non-pathogenic probiotic strain with demonstrated antagonistic activity against pathogenic enterobacteria. This study evaluated the efficacy and safety of EcN in preventing symptomatic recurrences in premenopausal women with rUTI. Methods: In this prospective observational study, 40 premenopausal women with rUTI were enrolled. Twenty patients received EcN prophylaxis (twice daily for four weeks, followed by once daily for eight weeks), while 20 patients received no prophylaxis and served as controls. Patients were followed for six months (three months of treatment and three months post-treatment). The primary outcome was the frequency of symptomatic rUTI episodes during follow-up. Results: Forty patients were analyzed (20 EcN; 20 controls). During the six-month observation period, 55% (11/20) of patients in the EcN group remained UTI-free compared with 35% (7/20) in the control group. Two patients (10%) in the EcN group experienced a single recurrence versus three (15%) in the control group. Recurrent episodes (≥2 UTIs) occurred in 35% (7/20) of EcN-treated patients compared with 50% (10/20) of controls. Overall, EcN prophylaxis was associated with a lower proportion of patients experiencing multiple recurrences. Conclusions: Prophylaxis with E. coli Nissle 1917 was associated with a reduced rate of recurrent UTIs compared with no prophylaxis in premenopausal women, supporting its potential role as a non-antibiotic preventive strategy in rUTI management.