Pr. Harry Sokol, Saint-Antoine Hospital, Ap-HP, France

The pathogenesis of inflammatory bowel disease (IBD) is related to an activation of the gastrointestinal immune system towards the gut microbiota in genetically susceptible hosts and under the influence of environmental factors. The microbial community of the human gastrointestinal tract is fundamental to health and is influenced by environmental and genetic factors. The loss of the delicate balance of this complex ecosystem, called dysbiosis, is implicated in many diseases, including IBD. IBD patients show an altered composition of the gut microbiota, with notably a decrease in the abundance of anti-inflammatory bacteria such as Faecalibacterium prausnitzii. Besides changes in composition, many microbiota functions are altered in IBD. These data are now converted into new biomarkers and treatments.