 The cause of CD could be different according to age at onset of CD symptoms. Indeed we know that some very young patients at CD diagnosis have particular genetic variants as abnormalities of the IL10R that are regarded as quite monogenic disease. In the other way, the microbiota also undergoes substantial changes at the extremes of life, in infants and older people and the ramifications of which are very few being explored. The comparison of microbiota by principal component analysis and genetic profile of patients with CD beginning at the extremes of life could help us to better known physiopathology of CD according to age and provide arguments that CD beginning at the extremes of life could be different diseases. 