Conclusions The current evidence is not sufficiently strong to verify a preventive role of probiotics in AR , but probiotics may improve the overall quality of life and nasal symptom scores .
Background Allergic rhinitis ( AR ) is a disease of respiratory allergy , and probiotics can provide a potential strategy for its management .
The purpose of this study was to carry out a systematic review to investigate the role of probiotics in the prevention and treatment of AR .
Improvements in Seasonal Allergic Disease with Lactobacillus plantarum No. 14
We conducted two r and omized , placebo-controlled , double-blind studies of Lactobacillus plantarum No. 14 ( LP14 ) in female students with seasonal allergic diseases . We also examined the mitogenic activity and cytokine inducibility of LP14 using Peyer ’s patch cells and mesenteric lymph node cells of swine . For subjects who took 8.7 × 108 of LP14  , a significant improvement in ocular symptom-medication score was observed . In the placebo group , the T helper type 1 (Th1)/T helper type 2 ( Th2 ) ratio tended to decrease after a 6-week intake period , while in the LP14 group , the percentage of Th1 cells significantly increased . Post-intake eosinophil counts significantly increased in comparison to those at intake cessation in the placebo group , but it appeared to be suppressed in the LP14 group . There were no changes in fecal microflora .  LP14  strongly induced the gene expression of Th1-type cytokines . This study indicates the clinical effects of LP14 on seasonal allergic diseases
Conclusions The current evidence is not sufficiently strong to verify a preventive role of probiotics in AR , but probiotics may improve the overall quality of life and nasal symptom scores .
Background Allergic rhinitis ( AR ) is a disease of respiratory allergy , and probiotics can provide a potential strategy for its management .
The purpose of this study was to carry out a systematic review to investigate the role of probiotics in the prevention and treatment of AR .