Vitamin D3 plus Lactobacillus reuteri DSM 17938 as Adjuvant for Allergen Immunotherapy: A Preliminary Experience

Background Allergen immunotherapy (AIT) restores T regulatory cells function and reduces Th2 polarization. Vitamin D3 (VitD3) and Lactobacillus reuteri DSM 17938 exert immune-modulatory activities, including T regulatory cells stimulation. Thus, their use as adjunctive therapy to AIT might be useful in improving AIT effectiveness. Objective This preliminary experience aimed at investigating whether a food supplement containing VitD3 plus Lactobacillus reuteri DSM 17938 could be effective in improving the effectiveness of a single pre-co-seasonal AIT course to Parietaria in patients with seasonal allergic rhinitis. Methods Globally, 30 subjects (15 males) with a mean age of 35.63 (+ 11.12) years were evaluated. All patients were treated with a single pre-co-seasonal course of sublingual immunotherapy. The food supplement (VitD3 800 UI/die and Lactobacillus reuteri DSM 17938 208 CFU/die) was taken in 15 patients for 30 days since the AIT start. Patients’ perception of symptom severity, medication use, and AIT efficacy were assessed by visual analogue scale, comparing the previous pollen season (2013) with the present one (assessed in July 2014). Results Patients treated with food supplement perceived less symptom severity (p=0.033) and medication use (p=0.047), and better AIT efficacy (p=0.01) than patients treated with AIT alone. Conclusion This pilot study suggests that VitD3 plus Lactobacillus reuteri DSM 17938 supplementation might improve the effectiveness of a single pre-co-seasonal SLIT course in reducing symptom severity and medication use in patients with seasonal allergic rhinitis.