<qa>  What was the main reason for the experiment?Symbiotic interaction between probiotics Living alimentary microbials supplemental, affecting positively host by improving intestinal microbial equilibrium Fuller, 1989 and human digestive tract was amply experimented and seems to be an interesting solution to orientate neonates digestive flora. Many studies showed a probant efficiency of probiotic supplementation in neonates on ECUN, despite abnormally high ECUN incidence in control group. Nevertheless, our aim is to test clinical efficiency of two new probiotics strains. Bifidobacterium Longum and Lactobacillus GG on Oral Nutrition volume at Day 14 and Day 21 and safety Adverse Events in very premature babies. 