World Allergy Organization-McMaster University Guidelines for Allergic Disease Prevention (GLAD-P): Probiotics

Alessandro Fiocchi, Pediatric Hospital Bambino Gesù
Ruby Pawankar, Nippon Medical School
Carlos Cuello-Garcia, McMaster University Health Sciences Centre
Kangmo Ahn, Sungkyunkwan University School of Medicine
Suleiman Al-Hammadi, United Arab Emirates University
Arnav Agarwal, McMaster University Health Sciences Centre
Kirsten Beyer, Charité Klinik für Pädiatrie
Wesley Burks, University of North Carolina
Giorgio Canonica, University of Genoa
Motohiro Ebisawa, Sagamihara National Hospital
Shreyas Gandhi, University of Toronto
Rose Kamenwa, Aga Khan University
Bee Wah Lee, National University of Singapore
Haiqi Li, Chongqing Medical University
Susan Prescott, University of Western Australia
John Riva, McMaster University
Lanny Rosenwasser, University of Missouri
Hugh Sampson, Mount Sinai School of Medicine
Michael Spigler, Food Allergy Research & Education
Luigi Terracciano, University of Milan
Andrea Vereda-Ortiz, ospital Infantil Universitario Niño Jesus
Susan Waserman, McMaster University
Juan Yepes-Nuñez, McMaster University Health Sciences Centre
Jan Brożek, McMaster University
Holger Schünemann, McMaster University


Background: Prevalence of allergic diseases in infants, whose parents and siblings do not have allergy, is approximately 10% and reaches 20–30% in those with an allergic first-degree relative. Intestinal microbiota may modulate immunologic and inflammatory systemic responses and, thus, influence development of sensitization and allergy. Probiotics have been reported to modulate immune responses and their supplementation has been proposed as a preventive intervention.

Objective: The World Allergy Organization (WAO) convened a guideline panel to develop evidence-based recommendations about the use of probiotics in the prevention of allergy.

Methods: We identified the most relevant clinical questions and performed a systematic review of randomized controlled trials of probiotics for the prevention of allergy. We followed the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach to develop recommendations. We searched for and reviewed the evidence about health effects, patient values and preferences, and resource use (up to November 2014). We followed the GRADE evidence-to-decision framework to develop recommendations.

Results: Currently available evidence does not indicate that probiotic supplementation reduces the risk of developing allergy in children. However, considering all critical outcomes in this context, the WAO guideline panel determined that there is a likely net benefit from using probiotics resulting primarily from prevention of eczema. The WAO guideline panel suggests: a) using probiotics in pregnant women at high risk for having an allergic child; b) using probiotics in women who breastfeed infants at high risk of developing allergy; and c) using probiotics in infants at high risk of developing allergy. All recommendations are conditional and supported by very low quality evidence.

Conclusions: WAO recommendations about probiotic supplementation for prevention of allergy are intended to support parents, clinicians and other health care professionals in their decisions whether to use probiotics in pregnancy and during breastfeeding, and whether to give them to infants.