Probiotics/Lactobacillus as a Prophylactic Aid in Recurrent Bacterial Cystitis in Women. A Randomized, Prospective, Double-Blinded, Placebo Controlled, Multi-Center Study.

Chronic recurrent bacterial cystitis is a condition that is disabling to a great extent and which influences quality of life and freedom of movement. The episodes can be painful, and lead to extensive use of antibiotics, which in itself promotes development of bacterial strains increasingly resistant to antibiotics, but do not prevent relapses. Almost all cystitis' in women are ascending infections from bacteria in the vagina, following colonization from the rectum. There have, however, been reported indications that there may be bacteria colonies within the urothelium that might give rise to relapses of the infections, rather than pure reinfection from ascending pathogens.

Probiotics are cultures of viable microorganisms, which show a positive effect on the general condition of the host when administered. Among the lactic acid bacteria (LAB), lactobacilli are the most commonly used for probiotics, and they have an excellent safety record. In terms of UTI, weekly or twice weekly intravaginal instillation of Lactobacillus strains GR-1 and B-54 have led to reduced recurrences. This concept has been supported by a 2006 pilot study showing that intravaginal administration of Lactobacillus crispatus GAI 98322 every two days for one year, had the potential to reduce the UTI recurrences. Another approach has been taken whereby lactobacilli are administered orally with a view of simulating how the pathogens reach the vagina. The studies have shown that L. rhamnosus GR-1 and L. reuteri (formerly fermentum) RC-14 can reach the vagina after daily oral ingestion, and they can lower the bacterial and yeast pathogen numbers.

The aim of the study is to try to normalize the vaginal bacteriological milieu so that the more pathogenic subpopulation of bacteria strains are displaced and are less likely to cause UTI.