Gut dysbiosis and paediatric Crohn's disease

The main objective of this manuscript is to discuss our present knowledge of the relationships between dysbiosis and paediatric Crohn's disease (CD). The therapeutic role of the methods currently used to re-establish normal gut microbiota composition is also analysed.PubMed was used to search for all of the studies published from January 2008 to June 2018 using the key words: "Crohn's disease" and "gut dysbiosis" or "microbiota" or "microbioma" or "probiotic" and "children" or "paediatric". More than 100 articles were found, but only those published in English or providing evidence-based data were included in the evaluation.Gut microbiota are primary actors in CD's pathogenesis. The new techniques developed in metagenomics allow us to reveal new details of microbiota composition in healthy subjects and CD patients, and to elucidate the link between microbiota and numerous pathologies, such as obesity, allergies and type 1 diabetes mellitus.Discoveries on the role of gut microbiota could potentially disclose new therapeutic options for CD treatment and improve the existing therapies. Further studies are needed to facilitate the diagnosis and tailor the therapy of a pathology that is an increasing burden on public health.