title: Synbiotics for Prevention and Treatment of Atopic Dermatitis: A Meta-analysis of Randomized Clinical Trials.
abstract: OBJECTIVE
  Atopic dermatitis (AD) is a highly prevalent condition that may be associated with an altered gastrointestinal microbiota that promotes an immune environment more susceptible to allergic disease. Synbiotics, a mixture of prebiotics and probiotics, have been used for the prevention and treatment of AD.
  
  
  OBJECTIVE
  To investigate the efficacy of synbiotics for primary prevention and treatment of AD.
  
  
  METHODS
  PubMed/MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials, and the CAB Abstracts Archive searchable database were searched from the inception of all databases to October 15, 2015, with no language restrictions.
  
  
  METHODS
  We included all published randomized clinical trials of synbiotics for prevention and/or treatment of AD. To be included, a publication needed to clearly define the intervention as oral administration of synbiotics (combination of probiotics and prebiotics) and must have included an assessment of AD disease severity, such as the Severity Scoring of Atopic Dermatitis (SCORAD) index, or the incidence of AD as an outcome measure. Only 8 of 257 initially identified studies (3%) met selection criteria.
  
  
  METHODS
  Data extraction was independently done by multiple observers and cross-checked to avoid errors. The quality of the selected studies was critically examined following the Cochrane guidelines. Data were pooled using a random-effects model.
  
  
  METHODS
  The primary outcomes were the SCORAD index (treatment studies) and the relative risk of AD (prevention studies). The hypothesis was formulated before data collection.
  
  
  RESULTS
  A total of 257 abstracts were screened to identify 6 treatment studies (369 children enrolled; aged 0 months to 14 years) and 2 prevention studies (1320 children enrolled; up to age 6 months in one study and term neonates aged <3 days in the other). From the 6 treatment studies included for random-effects meta-analysis, the overall pooled change in SCORAD index in those treated with synbiotics at 8 weeks of treatment was -6.56 (95% CI, -11.43 to -1.68; P = .008). Heterogeneity was significant (I(2) = 77.1%; P = .001). Subgroup analysis showed that the beneficial effect was significant only when using mixed strains of bacteria (weighted mean difference, -7.32; 95% CI, -13.98 to -0.66; P = .03) and when used in children aged 1 year or older (weighted mean difference, -7.37; 95% CI, -14.66 to -0.07; P = .048). From the 2 prevention studies included, the pooled relative risk ratio of AD in those treated with synbiotics compared with placebo was 0.44 (95% CI, 0.11 to 1.83; P = .26).
  
  
  CONCLUSIONS
  This meta-analysis shows evidence that supports the use of synbiotics for the treatment of AD, particularly synbiotics with mixed strains of bacteria and for children aged 1 year or older. Further studies are needed to evaluate the effectiveness of synbiotics for primary prevention of AD.
authors.affiliation: Department of Pediatrics, Taipei City Hospital Renai Branch and National Yang-Ming University, Taipei, Taiwan.
authors.forename: Yung-Sen
authors.initials: YS
authors.lastname: Chang
authors.affiliation: Massachusetts General Hospital for Children, Boston3Channing Division of Network Science, Brigham and Women's Hospital, Boston, Massachusetts.
authors.forename: Michelle K
authors.initials: MK
authors.lastname: Trivedi
authors.affiliation: Kanawha-Charleston Health Department, Charleston, West Virginia.
authors.forename: Ayan
authors.initials: A
authors.lastname: Jha
authors.affiliation: Department of Epidemiology, Harvard T. H. Chan School of Public Health, Boston, Massachusetts.
authors.forename: Yen-Feng
authors.initials: YF
authors.lastname: Lin
authors.affiliation: Department of Epidemiology, Harvard T. H. Chan School of Public Health, Boston, Massachusetts.
authors.forename: Liezeel
authors.initials: L
authors.lastname: Dimaano
authors.affiliation: Department of Dermatology, National Institute of Pediatrics, Mexico City, Mexico.
authors.forename: Maria T
authors.initials: MT
authors.lastname: García-Romero
mesh_terms: D003876:Dermatitis, Atopic / Q000175:diagnosis / Q000517:prevention & control / Q000628:therapy*; D006801:Humans; D015233:Models, Statistical; D016032:Randomized Controlled Trials as Topic; D012720:Severity of Illness Index; D058616:Synbiotics