Identification of Predictive Blood Biomarkers of Recurrent Urinary Tract Infections

Inclusion Criteria: * Female aged 18 to 28 years; * Subject accepting to be serologically tested for HIV and HCV; * Subject considered healthy by the physician on the basis of medical history and clinical examination; * Subject with a body mass index between 18.5 and 30 kg/m2; * Subject understands and speaks French and is able to give written consent; * Subject affiliated to Social Security or a similar regime; * Having reported a single cystitis since the age of 14 (Group 1), or 3 or more cystitis over a 12-month period since the age of 14 (Group 2). Exclusion Criteria: * Subject protected by law under guardianship or curatorship, or unable to participate in a clinical study under Article L. 1121-16 of the French Public Health Code; * Subject who has participated in a clinical research study in the last 3 months in which he/she was exposed to a pharmaceutical product or medical device; * Subject who has stayed in a tropical or subtropical country in the last 3 months; * Pregnant or breastfeeding subject for women of childbearing age; * Subject with special diet for medical reasons and prescribed by a doctor or dietician (e.g. a low-calorie diet or a diet intended to lower cholesterol levels); * Subject who regularly consumes large quantities of alcohol, i. e. more than 50 g of pure alcohol per day (e. g. more than 4 glasses of 150 ml wine, more than 4 pints of 250 ml beer, or more than 4 glasses of 40 ml containing strong alcohol); * Subject who has used an illegal recreational drug in the past 3 months; * Subject who has taken an immunosuppressive or immunomodulatory drug (excluding intranasally or topically administered corticosteroids) in the past 2 weeks, or for more than 14 consecutive days in the past 6 months; * Subject who has been vaccinated within the last 3 months; * Subject who received a blood transfusion or immunoglobulins in the last 3 months; * Subject stating that he has not been fasting for at least 10 hours; * Subject reporting HIV or HCV status; * Subject who had an infectious episode or was treated with antibiotics during the 4 weeks prior to the visit; * Subject with a positive urinary pregnancy test; * Subject with a severe and/or chronic and/or recurrent pathology, in particular: * A chronic inflammatory and/or autoimmune or allergic disease and in particular a chronic inflammatory disease of the intestine (Crohn's disease, ulcerative colitis), epidermis (psoriasis, atopic dermatitis), joints (rheumatoid arthritis), nervous system (multiple sclerosis), type I diabetes; * High blood pressure or type II diabetes; * A neurodegenerative disease. * Subject who has been diagnosed with cancer and has not been in remission for more than 5 years.