an iNtravaginal probiotic may reduce recurrence

Recurrent urinary tract infections are a problem for 2 to 3 percent of women and a source of great discomfort and expense. Some help may be on the way, according to the results of a new study, which suggest that use of a probiotic can reduce recurrence rates.

The National Institute of Diabetes and Digestive and Kidney Diseases reports that 20 percent of women can expect to experience a urinary tract infection at some time during their lives. Women who experience three infections are likely to have more, and 80 percent of such women get a recurrence within 18 months of their last infection.

The risk of urinary tract infection has been associated with a lack of bacteria called lactobacilli in the vagina. Therefore, restoring these bacteria in the vaginal environment may help prevent recurrence of urinary tract infections.

To test this idea, researchers from four different medical facilities conducted a double-blind, placebo-controlled trial that enrolled 100 young women who had a history of recurrent urinary tract infections. The women randomly were assigned to take either an intravaginal suppository probiotic called LACTIN-V that contained Lactobacillus crispatus (50 women) or a placebo (50 women) once daily for five days, then once a week for 10 weeks.

The study participants were followed up at one week and 10 weeks after the start of the study, at which time urine samples and vaginal swabs were collected. Forty-eight women in each group completed the study.

Within the study period, urinary tract infection recurred in 7 of 48 women (15%) in the probiotic treatment group compared with 13 of 48 women (27%) in the placebo group.

Urinary tract infections are typically treated with antibacterial drugs, and the drug chosen depends on the patient’s history and the results of urine tests to identify the bacteria causing the infection. The drugs most often prescribed include trimethoprim, trimethoprim/sulfamethoxazole, amoxicillin, nitrofurantoin, and ampicillin. Another group of drugs called quinolones also may be prescribed and include ciprofloxacin, norfloxacin, ofloxacin, and trovafloxin.

The results of this new study suggest probiotic treatment may reduce the risk of recurrent urinary tract infection in women who tend to get repeat infections. Study author Ann Stapleton, MD, of the University of Washington in Seattle noted that this probiotic needs to be tested in larger trials “to determine if use of vaginal Lactobacillus could replace long-term antimicrobial preventive treatments.”