Abstract : The first months of life have to be seen as a crucial period in term of implementation of the postnatal immunity. This immunological induction will be made possible through an optimization of the interface between innate and adaptive immunities in the submucosal area. A better understanding of those complex mechanisms should allow finding the best way to introduce the dietary antigen in the early stage. Maybe, it should favour a optimal tolerance to the dietary antigen and reduce the now observed increase of immune deviances later on.