Probiotics Supplementation in Premature Infants

Inclusion criteria * Gestational age between 26 weeks and 31 weeks * Birth weight between 700 to 1600 g * Eutrophic infants (weight between -2 to 2 DS, Usher curves) * Admitted to one of the participating hospital unit within the 8 days following the birth, the birth date equals the 1st day of life. * Still on parenteral feeding or infusion on the 5th day of birth Non inclusion criteria * Digestive disorders \> or equal to 1b on Bell stage * Severe intra-ventricular haemorrhage (stage 3-4) before 5th day of life. * Severe malformations or digestive malformations * No antenatal corticosteroid therapy * Severe medical or surgical disorder affecting the absorption, digesting and as a result the growth (Hirschsprung disease, lactose intolerance, cow milk protein allergy, mucoviscidosis). * Parents geographical distance preventing the hospitalization follow-up in the hospital participating unit (geographical distance planned before the infant reaches 1500 g or 32 weeks of gestational age) Exclusion criteria * Enteral/Oral feeding termination during more than 72 hours due to severe digestive disorders (\> or equal to 2a on Bell stage ) * Serious digestive surgery