Non-glycosylated stimulating factor of granulocyte colonies (G-CSF) which is obtained by recombinant technology.The naturally occurring product is found in breast milk. A very high molecular weight explains the insignificant or no excretion into milk that has been observed both with Lenograstim and Filgrastim. Its low oral bioavailability hampers absorption into infant plasma from the breast milk ingested, as for their proteic nature it is degraded in the gastrointestinal tract, not being absorbed. Filgrastim is not absorbed by the infant's gut even during the neonatal period or prematurity. The granulocyte colony-stimulating factor has been used in premature newborns, both on prevention and treatment of neonatal sepsis and/or necrotizing enterocolitis without adverse effects being observed among treated infants. The bovine G-CSF is found in the usual diet of meat eaters.