Antibiotics prevent UTIs better than probiotics

Antibiotics are still better than probiotics at preventing urinary tract infections, but at least "good bacteria" don't add to a person's antibiotic resistance, a new study concludes.

Recurring UTIs are common among some women and low-dose antibiotics are sometimes used to prevent them. The worry is that overuse of the drugs also reduces their effectiveness by making disease-causing bacteria like E. coli resistant.

"This is an increasing worldwide problem, resulting into less and less treatment options for (severe) bacterial infections in all countries of the world," Dr. Suzanne Geerlings, from the Academic Medical Center at the University of Amsterdam in The Netherlands and one of the new study's authors, wrote in an email to Reuters Health.

Geerlings and her colleagues recruited 252 women between January 2005 and September 2007 for a trial to compare the use of antibiotics and probiotics to prevent UTIs.

The participants, who lived in communities surrounding the medical center, were all postmenopausal - a time when vulnerability to UTIs increases because of hormonal changes, according to the researchers.

All the participants reported having had at least three UTIs in the year before the trial began, and the average number was seven.

Lactobacilli vs Antibiotics to Prevent Urinary Tract Infections A Randomized, Double-blind, Noninferiority Trial in Postmenopausal Women

Results The mean number of symptomatic UTIs in the year preceding randomization was 7.0 in the trimethoprim-sulfamethoxazole group and 6.8 in the lactobacilli group. In the intention-to-treat analysis, after 12 months of prophylaxis, these numbers were 2.9 and 3.3, respectively. The between-treatment difference of 0.4 UTIs per year (95% CI, −0.4 to 1.5) was outside our noninferiority margin. At least 1 symptomatic UTI occurred in 69.3% and 79.1% of the trimethoprim-sulfamethoxazole and lactobacilli participants, respectively; median times to the first UTI were 6 and 3 months, respectively. After 1 month of trimethoprim-sulfamethoxazole prophylaxis, resistance to trimethoprim-sulfamethoxazole, trimethoprim, and amoxicillin had increased from approximately 20% to 40% to approximately 80% to 95% in E coli from the feces and urine of asymptomatic women and among E coli causing a UTI. During the 3 months after trimethoprim-sulfamethoxazole discontinuation, resistance levels gradually decreased. Resistance did not increase during lactobacilli prophylaxis.

Conclusions In postmenopausal women with recurrent UTIs, L rhamnosus GR-1 and L reuteri RC-14 do not meet the noninferiority criteria in the prevention of UTIs when compared with trimethoprim-sulfamethoxazole. However, unlike trimethoprim-sulfamethoxazole, lactobacilli do not increase antibiotic resistance.Mariëlle A. J. Beerepoot, MD; Gerben ter Riet, MD, PhD; Sita Nys, PhD; Willem M. van der Wal, PhD; Corianne A. J. M. de Borgie, MD, PhD; Theo M. de Reijke, MD, PhD; Jan M. Prins, MD, PhD; Jeanne Koeijers, MD; Annelies Verbon, MD, PhD; Ellen Stobberingh, PhD; Suzanne E. Geerlings, MD, PhD