Safety and Efficacy of Lactococcus Lactis Probiotic Bacteria for the Treatment of Chronic Rhinosinusitis

Despite advances in medical treatments and surgery for chronic rhinosinusitis (CRS), there remains a large number of patients who continue to suffer from chronic sinusitis despite standard therapies. This research project has the goal of evaluating the safety and effectiveness of a potentially novel therapy for patients with CRS refractory to medical and surgical therapies, consisting of the introduction of a live probiotic bacteria (L lactis W136) directly into the nasal and sinus cavities via irrigation. In total, 24 patients suffering from refractory CRS will be recruited from ongoing clinical activities by the research team of Martin Desrosiers at the CHUM hospital. Study duration is six weeks, and will be performed in three phases, with six visits planned in total. 1. Two-week observation period where only saline irrigation is administered. 2. Treatment period of 14 days (D0 to D14) during which L lactis W136 will be administered twice-daily. 3. Post treatment observation period of two weeks (D14 to D28) during which the patient will cease probiotic but will continue to irrigate his nose with only saline. Assessment will use symptom questionnaires, quality of life questionnaires and endoscopic examination of the sinus cavities. Sinus culture will be performed at each visit to assess development of unusual infections. Exploratory assessments of gene expression and microbiome profiling will be performed to explore underlying mechanisms.