Jalali MM, et al. - In this randomized crossover clinical trial, researchers evaluated the effect of add-on probiotics on symptoms and quality of life (QoL) of patients with persistent allergic rhinitis (AR). The study sample consisted of 152 subjects (30.1 ± 7.6 years). For this investigation, each subject got budesonide with probiotic supplements (BP) or budesonide with placebo for 8 weeks (B), then vice versa for a further 8 weeks. In persistent AR patients, the addition of probiotics to budesonide significantly improved QoL. However, in the general population, the clinical situation of these patients may not be very representative of AR patients.