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 .
Bacillus clausii effects in children with allergic rhinitis
Allergic rhinitis is characterized by T-helper (Th)2 polarization as elevated levels of Th2-derived cytokines , including interleukin (IL)-4 , IL-5 and IL-13 , have been evidence d at nasal level in allergic rhinitics ( 1 ) . Th2 cytokines play a pathogenic role as they induce IgE synthesis and eosinophil infiltration . Th2 polarization in allergic subjects may occur as consequence of reduced pressure of microbial agents in the gut : the so-called Hygiene Hypothesis ( 2 ) . Probiotics may stimulate immune system at all mucosal surfaces and exert a primary prevention of atopic diseases and reduce allergic symptoms and inflammatory parameters ( 3 ) . We previously found out that Bacillus clausii was capable of modulating cytokine pattern at nasal level in allergic children with recurrent respiratory infections ( 4 ) . Particularly , B. clausii restored physiological Th1 polarization and induced T-regulatory cell response , as documented by increased levels of IL-10 and tumor growth factor (TGF)b after treatment ( 4 ) . Therefore , we conducted a pilot study to investigate the potential effects exerted by B. clausii on nasal symptoms , eosinophils , and symptomatic use of antihistamines in children with allergic rhinitis . Twenty allergic children , 13 males and seven females , with an average age of 13.4 years ( range 12–15 ) were consecutively evaluated . A detailed clinical history and a complete physical examination , including allergy evaluation , were carried out for each patient . The diagnosis of allergic rhinitis due to pollen sensitization was made according to vali date d criteria ( 5 ) . The study was blinded both to the investigator who performed the nasal eosinophil assessment and the investigator who carried out statistical analysis . Symptomatic use of levocetirizine ( 5 mg tablets ) was prescribed for all children . Ten of them were r and omly treated with oral B. clausii ( EnterogerAL LERGY 2 0 0 5 : 6 0 : 7 0 2 – 7 1 0 • COPYRIGHT a 2005 BLACKWELL MUNKSGAARD • ALL R IGHTS RESERVED • CONTRIBUT IONS TO THIS SECT ION WILL NOT UNDERGO PEER REV IEW , BUT WILL BE REV IEWED BY THE ASSOCIATE ED ITORS
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 .