Probiotics in allergic riniti: myth or reality? A systematic review and meta-analisys

Objectives: A review of the scientific evidence for the use of probiotics in allergic rhinitis (AR). Data Sources: The studies reviewed had been collected from the PubMed and Cochrane Trial Register databases. According to EBM criteria, the included studies were randomized, double-blind and placebo controlled (RCTs). The research covered the period from 2000 to 2011. According to the inclusion criteria, 23 articles were found. Results: Seventeen studies evaluated the clinical parameters of AR: the severity of symptoms improved in 14 RCTs while neither improvement nor worsening was recorded in 3 RCTs from a clinical point of view. Twenty studies evaluated the laboratory parameters of AR. The immunological parameters were influenced in different way by the use of probiotics. The fluctuations of the gut microbiota, that normally occur during the pollen season in allergic patients, were inhibited by the use of these agents. The meta-analysis was performed for IgE levels outcomes, in 4 trials, and for the number of bifidobacteria in the fecal microbiota outcomes, in 3 trials, using probiotics-treated groups and control groups. Conclusion: Systematic review would seem to suggest the validity of probiotics in the treatment of allergic rhinitis. The results of the meta-analysis, currently, do not show sufficient evidence.