Therapeutic role of probiotics in asthma and allergic rhinitis

摘要

We read with great interest the article by Chen et al. The authors have conducted a randomized clinical trial and found that, probiotic supplementation benefited school children suffering from allergic airway diseases (asthma and allergic rhinitis-AR) and this was associated with improvement in the immunological parameters. There are few points that need comment. Therapeutic role of probiotics in allergic airway diseases have been tested in few clinical trials. Though treatment with probiotics benefits subjects with either AR or both AR and asthma, no published trial to date has found beneficial effects of probiotics in subjects with asthma only. Giovannini et al. in a randomized clinical trial (pre-school children with mild to moderate persistent asthma and/or mild to severe persistent AR, receiving for 12 months either Lactobacillus casei or placebo) found that, the time free from episodes of asthma/rhinitis was longer, the cumulative number of asthma and rhinitis episodes was lower in the probiotic group. Neither any children with asthma benefited from probiotic use nor there were any significant changes in immunological parameters. Wheeler et al. in a crossover double-blinded design (two 1-month crossover phases), studied the effect of live active yogurt with or without Lactobacillus acidophilus in 15 adult patients with moderate asthma. Though there was increase in the interferon gamma and decreased eosinophilia; the authors were unable to detect changes in clinical parameters (mean daily peak flows or changes in spirometric values and quality of life scores) in asthma patients. In a systematic review, we found that, probiotic intake improved the quality of life score [standardized mean difference (SMD) -1.17 (95% CI -1.47 to -0.86; P < 0.00001)], and decreased the number of episodes per year in subjects with AR. There is increasing evidence for a close link between the upper and the lower airways and rhinitis having an important impact on asthma ("united airways" hypothesis). The result of any common inflammatory process can explain some of the complex interactions among rhinitis, sinusitis, bronchial hyperresponsiveness/asthma, and viral infections. Moreover, medical treatment of rhinitis benefiting subjects with asthma has recently provided further support for the hypothesis. So, though the authors in present study have found probiotics to be beneficial in treatment of subjects having concomitant asthma and AR, it is still unclear, whether probiotics have any role in treatment of subjects with asthma only. We hope that future trials will try to address this issue by separately studying the effects of probiotics in three groups of subjects (e.g., those with asthma, AR, asthma and AR).