A double-blind, randomized, parallel, placebo-controlled study to evaluate the efficacy and safety of a probiotic containing Lactobacillus paracasei (eN-Lac®) for the treatment of children with perennial allergic rhinitis (year-round nose irritation caused by allergy)

INTERVENTION: Subjects who meet all eligible requirements for entry into the study will be randomized into one of the four treatment groups in 1:1:1:1 ratio as shown below: 1. One capsule of Lactobacillus paracasei (eN‐Lac®) 2 X10(8) CFU per capsule, once daily 2. One capsule of Lactobacillus paracasei (eN‐Lac®) 2 X10(9) CFU per capsule, once daily 3. One capsule of Lactobacillus paracasei (eN‐Lac®) 1 X10(10) CFU per capsule, once daily 4. One matching placebo capsules, once daily The treatment period is 12 weeks. CONDITION: Perennial allergic rhinitis (PAR) ; Ear, Nose and Throat PRIMARY OUTCOME: Dose response of LPmeasured using net change in mean NTSS (Nasal Total Symptom Score) at the 12th week treatment visit (compared to baseline). NTSS is recorded daily by the patients using a DRC (Daily Record Card). INCLUSION CRITERIA: 1. Subjects with age of 5‐16 years old (inclusive) 2. Subjects with a history of PAR for at least 1 year 3. Subjects with either one of the following test results (test results within 12 months before study are acceptable) 3.1. Positive skin‐prick test reaction (wheal ?3mm larger than the diluents control) 3.2. Positive reaction determined by the CAP or MAST(Multiple allergosorbent test) system 4. Subjects with mean NTSS of no less than 5 throughout the screening period (4 to 10 days); at least 4 days should be recorded during the screening period; and the NTSS of the day before day‐0 (first dosing day) visit is no less than 5 5. Subjects’ parents or their legally acceptable representatives have signed the written informed consent form SECONDARY OUTCOME: ; 1. Net change of the 2nd, 4th, and 8th week evaluations compared to the baseline on NTSS; 2. Net change of the 2nd, 4th, 8th and 12th week evaluations compared to the baseline on each individual symptom score rated in the NTSS items; 3. Net change of the 2nd, 4th, 8th and 12th week evaluations compared to the baseline on NTSS by investigator’s evaluation at site; 4. Net change of the 2nd, 4th, 8th and 12th week evaluations compared to the baseline on each individual symptom score rated by NTSS by investigator’s evaluation at site; 5. Global assessment by the investigator as categorized into 4 levels of complete relief, partial relief, no relief, worse.; 6. Net change of the serum interferon‐? (IFN‐?) concentration during the treatment period (IFN‐? at Visit 6 – IFN?at baseline); 7. Net change of the serum total IgE (Immunoglobulin E) concentration during the treatment period (IgE at baseline‐IgE at Visit6); ; Safety endpoints:; 1. Vital signs change: The vital signs including blood pressure, pulse rate, respiratory rate and body temperature will be assessed for changes compared to baseline; 2. Adverse event incidence: Adverse event will be recorded for each of the visits starting from the baseline visit; 3. Physical examination changes: physical examinations will be performed for the 4th and 12th week visit. Changes in physical examination results for these two during‐treatment visit will be considered as one of the safety observations.; 4. Blood laboratory test result changes: The blood laboratory tests including the following items will be tested periodically: WBC (White blood cell) with differential counts, RBC (Red Blood Cell), hemoglobin, hematocrit, platelet , MCV (Mean Corpuscular Column), MCH (Mean Corpuscular Hemoglobin), MCHC (Mean Corpuscular Hemoglobin Concentration), AST (Aspartate aminotransferase), ALT (Alanine aminotransferase), albumin, total protein, total bilirubin, Alkaline phosphatase, LDH (Lactate dehydrogenase), creatinine, BUN(Blood Urea Nitrogen), uric acid, glucose, Potassium, Calcium, Phosphorus, Sodium, Chloride, Magnesium, and Iron.; 5. Urine laboratory test results changes (Qualitative changes): The urine laboratory tests including the following items will be tested at the 4th and 12th week visit: WBC, RBC, pH, protein, glucose, and ketone body.;