Disclosed are genetically-engineered gram-negative bacterial cells for the production of an oligosaccharide of interest, wherein the bacterial cell possesses a saccharide transporter and/or a porin being expressed from a recombinant gene or a deregulated endogenous gene, thereby facilitating the translocation of the oligosaccharide of interest from the cell's cytoplasm into the cell's environment. Also disclosed are methods for producing an oligosaccharide of interest which used said genetically-engineered gram-negative bacterial cells.