Investigate the effect of dietary supplements/probiotic ASTARTE™ ( L. crispatus, L. rhamnosus, L. jensenii, L. gasseri) on the microbiome composition in the intestine and vagina and thereby a reduction of risk factors for the development of rUTI during 6 months of intervention in women aged 18-40 years. This is measured by the incidence of symptomatic UTI.

Urinary tract infection (UTI) is one of the most common infections, contributing to increased antibiotic consumption and high costs. Women are often developing UTI due to the anatomically short distance from the rectum opening to the urethra. There is a risk of serious complications associated with pregnancy, where there is an increased risk of developing pelvic inflammatory disease and premature birth. This will in some cases lead to increased risk of maternal and neonatal morbidity and mortality; especially in infection with Streptococcus agalactiae. Recurrent UTI (rUTI) with urease producing microorganisms such as Proteus and Klebsiella will cause an increased risk of developing stones in the urinary tract.

Scientific studies suggest that probiotics can be effective dietary supplements reducing the risk factors for the development of infections in the intestine and vagina. Probiotics are non-pathogenic microorganisms capable of affecting gastrointestinal microbiota with a change in microbiota composition, thus increasing the production of beneficial substances when ingested in appropriate quantities. The consumption of probiotics is not considered to be associated with adverse reactions to humans because they are usually found naturally in e.g. gastrointestinal and vaginal microbiota.

A prospective study over 2-years which is conducted as a randomized placebo-controlled double-blind study. In this study the investigators will investigate the effect of probiotics ASTARTE™ ( Lactobacillus crispatus, Lactobacillus rhamnosus, Lactobacillus jensenii, Lactobacillus gasseri) on the composition of bacteria in urine, faces and vagina, and a possible reduction of risk factors for development of rUTI in women (18 to 40 years). The investigators will map the microbiota in the faeces and vagina and examine if there are a relationship between colonization of the urinary tract with pathogens and the composition of the intestinal and vaginal microbiota.

Inclusion Criteria:

• Women 18-40 years of age
• Recurrent UTI (2 times UTI within 6 months or > 3 times UTI infection within one year).
• The subjects should be informed about the trial protocol.
• The subject must be able to follow the protocol, have provided voluntary consent and have signed the declaration of consent.

Exclusion Criteria:

• Pregnancy or planning pregnancy
• Breastfeeding
• Participation in another trial with probiotic the last 30 days.
• Hypersensitivity to any ingredient in the study product
• Patients primarily admitted for a disorder other than UTI
• Antibiotic treatment for any other condition than UTI at time of recruitment the last 30 days

Women 18-40 years of age, Recurrent UTI (2 times UTI within 6 months or > 3 times UTI infection within one year).