Progress on probiotics as add-on therapy for allergic rhinitis

Allergic rhinitis (AR) is a frequent disease characterized by type 2 inflammation and typical symptoms. Dysregulation of the immune system, sustained by defective T regulatory cells, leads to type 2 inflammation, mainly concerning eosinophil infiltration of the nasal mucosa. In addition, dysbiosis of intestinal and upper airway microbiota is detectable in many AR patients. Therefore, probiotic supplementation may be a valuable therapeutic option for managing AR patients. Several studies investigated this issue. Interesting outcomes originated from randomized controlled trials. Even though there is no complete agreement about the use of probiotics in AR, adequate evidence suggests their potential use as an add-on strategy in managing patients with AR.