The main objective is to assess the nutritional benefit of probiotics supplementation on premature infants growth. As secondary objectives, different parameters related to probiotics tolerance will be measured.

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