A clinical reading on “World Allergy Organization-McMaster University Guidelines for Allergic Disease Prevention (GLAD-P): Probiotics”

Abstract

To the Editor Since the immunomodulatory properties of probiotics have been described, the effect of probiotic supplementation has been investigated in several trials and it has been also proposed as a preventive intervention for the development of allergic diseases. Recently two important evidence-based recommendations about the use of probiotics in the prevention of allergy were published [1, 2] with conflicting conclusions, in particular the most recent guideline [1] seems to be partially in contradiction with the previous statements about prevention of eczema. For these reasons, we tried to analyze the evidences leading to these recommendations [1] to highlight the aspects that can be more directly related or correlated with clinical practice. This clinical reading was addressed to offer some reflections about the methods used to formulate such recommendations, and the possibility to adopt in the clinical practice the proposed conclusions. We tried to retraces the path proposed by the Authors to analyse three important questions about the efficacy of probiotics in preventing allergic diseases if administrated to pregnant women (first question), to breastfeeding mothers (second question) and in healthy infants (third question). These questions have been investigated by using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach [3], to perform a systematic review of randomized controlled trials and formulate recommendations. In summary, the GRADE method aims to define a rigorous and explicit method for the production of clinical recommendations. According to this method, the knowledge of advantages and disadvantages, benefits and risks of an intervention is necessary to make decisions in the health field. The GRADE approach also provides a three-phases decisional framework: a) formulation of a clinical question, with the choice and the formal evaluation of its related outcomes, and systematic evaluation of the scientific literature and the quality of the evidence; b) evaluation of the benefits and risks associated to the intervention, taking also in consideration its feasibility, the necessary resources and the patients’ preferences; c) formal definition of the strength of the recommendation. From a methodological point of view, it should be noted that the recommendations are directed to patients, clinicians and other health care professionals with different objectives, as clearly explained in the guidelines introduction. Each recommendation can have different levels of strength: strong recommendation indicates that patients would like to receive the intervention and that clinicians should actuate it. Conditional or weak recommendation indicates that the majority of patients would like to receive the intervention, but many other not, as well as they hope that clinicians would recognize that different choices may be appropriate for different patients, by taking advantage of decision-making tools to help patients to make consistent choices. In the results section of the guidelines we can read that “Currently available evidence does not indicate that probiotic supplementation reduces the risk of developing * Correspondence: giampaolo.ricci@unibo.it Pediatric Unit, Department of Medical and Surgical Sciences, University of Bologna, S. Orsola-Malpighi Hospital, Pad 16, via Massarenti 11, 40138 Bologna, Italy Full list of author information is available at the end of the article