In one trial,2 researchers found that the time free from episodes of asthma/rhinitis was longer and the cumulative number of asthma and rhinitis episodes was lower in the probiotics group. In another trial,3 researchers found improvement in the pulmonary function, a significant increase in peak expiratory flow rate, and decreases in the clinical symptom scores for asthma and AR in the patients treated with probiotics compared with the control group. The beneficial effects of probiotics treatment in patients with both asthma and AR (but not asthma alone) can be explained by the fact that probiotics treatment has consistently been shown in clinical trials to be beneficial in patients with AR. In a systematic review by our group,4 we also found that probiotics intake improved the quality-of-life score (standardized mean difference, −1.17; 95% CI, −1.47 to −0.86; P < .00001) and decreased the number of episodes per year in patients with AR. This has important clinical as well as therapeutic implications if we consider the concept of united airways disease or allergic rhinobronchitis.5 Increasing evidence shows a close link between the upper and lower airways and suggests rhinitis may have an important impact on asthma. The result of any common inflammatory process can explain some of the complex interactions among rhinitis, sinusitis, bronchial hyperresponsiveness/asthma, and viral infections. Moreover, evidence that treatment of rhinitis benefits patients with asthma has recently provided further support for the hypothesis.