title: Probiotics for prevention and treatment of respiratory tract infections in children: A systematic review and meta-analysis of randomized controlled trials.
abstract: BACKGROUND
  Respiratory tract infections (RTIs) represent one of the main health problems in children. Probiotics are viable bacteria that colonize the intestine and affect the host intestinal microbial balance. Accumulating evidence suggests that probiotic consumption may decrease the incidence of or modify RTIs. The authors systematically reviewed data from randomized controlled trials (RCTs) to investigate the effect of probiotic consumption on RTIs in children.
  
  
  METHODS
  MEDLINE/PubMed, Embase, Cochrane Library, and Web of Science were systematically searched for RCTs regarding the effect of probiotics on RTIs in children. The outcomes included number of children experienced with at least 1 RTI episode, duration of illness episodes, days of illness per subject, and school/day care absenteeism due to infection. A random-effects model was used to calculate pooled relative risks, or mean difference (MD) with the corresponding 95% confidence interval (CI).
  
  
  RESULTS
  A total of 23 trials involving 6269 children were eligible for inclusion in the systematic review. None of the trials showed a high risk of bias. The quality of the evidence of outcomes was moderate. The age range of subjects was from newborn to 18 years. The results of meta-analysis showed that probiotic consumption significantly decreased the number of subjects having at least 1 RTI episode (17 RCTs, 4513 children, relative risk 0.89, 95% CI 0.82-0.96, P = 0.004). Children supplemented with probiotics had fewer numbers of days of RTIs per person compared with children who had taken a placebo (6 RCTs, 2067 children, MD -0.16, 95% CI -0.29 to 0.02, P = 0.03), and had fewer numbers of days absent from day care/school (8 RCTs, 1499 children, MD -0.94, 95% CI -1.72 to -0.15, P = 0.02). However, there was no statistically significant difference of illness episode duration between probiotic intervention group and placebo group (9 RCTs, 2817 children, MD -0.60, 95% CI -1.49 to 0.30, P = 0.19).
  
  
  CONCLUSIONS
  Based on the available data and taking into account the safety profile of RCTs, probiotic consumption appears to be a feasible way to decrease the incidence of RTIs in children.
authors: Department of Gastroenterology, Hepatology, and Nutrition Pediatric Intensive Care Unit, Shanghai Children's Hospital, Shanghai Jiao Tong University, Shanghai, PR China Department of Pathology and Laboratory Medicine, Temple University School of Medicine, Philadelphia, PA Department of Children's Healthcare, Shanghai Children's Hospital, Shanghai Jiao Tong University, Shanghai, PR China.
authors: Yizhong
authors: Y
authors: Wang
authors: Xiaolu
authors: X
authors: Li
authors: Ting
authors: T
authors: Ge
authors: Yongmei
authors: Y
authors: Xiao
authors: Yang
authors: Y
authors: Liao
authors: Yun
authors: Y
authors: Cui
authors: Yucai
authors: Y
authors: Zhang
authors: Wenzhe
authors: W
authors: Ho
authors: Guangjun
authors: G
authors: Yu
authors: Ting
authors: T
authors: Zhang
mesh_terms: D000041:Absenteeism; D002648:Child; D006801:Humans; D019936:Probiotics / Q000627:therapeutic use*; D016032:Randomized Controlled Trials as Topic; D012141:Respiratory Tract Infections / Q000628:therapy*