Lower urinary tract infections (UTIs) affect up to 50% of adult women^1,2. An uncomplicated urinary tract infection (UTI) is one that occurs in a healthy host in the absence of structural or functional abnormalities of the urinary tract. Recurrent urinary tract infection (rUTI) refers to ≥2 infections in six months or ≥3 infections in one year.³

Recurrent UTIs (rUTIs) occur due to bacterial reinfection or bacterial persistence. Persistence involves the same bacteria not being eradicated in the urine 2 weeks after sensitivity-adjusted treatment. A reinfection is a recurrence with a different organism, the same organism in more than 2 weeks, or a sterile intervening culture.

Clinical diagnosis of each UTI episode is supported by symptoms of dysuria, frequency, urgency, hematuria, back pain, self-diagnosis of UTI, nocturia, costovertebral tenderness and the absence of vaginal discharge or irritation. Commonly, the clinical diagnosis of UTI is aided by laboratory investigations, which include, urine routine microscopic examinations and culture and sensitivity test. Recently, few serum and urine biomarkers have been identified in rUTI with good correlation to treatment. The biomarkers identified in the serum include, granulocyte colony stimulating factor (GCSF), Macrophage colony stimulating factor (MCSF), interleukin-5 (IL-5) and urinary nerve growth factor (NGF)⁴. Albeit long term prophylaxis with antibiotics forms the mainstay in reducing the frequency of rUTIs in women, increased health costs, adverse effects, drug resistance and alteration of the normal flora in the intestines are few of the issues encountered with it. At present, there is no well-established recommendation for a ‘standard’ prophylactic antibiotic management to prevent the occurrence of rUTIs⁵_­.

Probiotics are defined as “a preparation of, or a product containing viable, defined micro-organisms in sufficient numbers, which alter the microflora (by implantation or colonisation) in a compartment of the host and by that exert beneficial health effects in this host”⁶. There are a number of species and strains of probiotics available that are used in many formulations administered via several different routes. Probiotic organisms (e.g. lactobacillus) are thought to establish a barrier against infectious pathogens ascending the urinary tract, colonising, and subsequently causing infection⁷.

Although many clinical trials have been carried out to assess the individual effect of probiotics in patients of rUTIs with varied effects, there is a paucity of data on the combined effect of probiotics along with antibiotics on prevention of UTI especially in Indian scenario. We therefore plan to carry out a clinical trial assessing the effect of add-on probiotics in adult women with rUTI.

Study Hypothesis

The hypothesis of the proposed study is that the group taking add-on probiotic will have a lower recurrence rate than those taking placebo based on the literature. The investigators aim to identify to what degree that difference is and whether or not it is an acceptable difference given the greater degree of an antibiotic resistance.

The aim of the proposed study is to assess the efficacy and safety of the add-on probiotic in preventing recurrent urinary tract infection in adult women.