Method for the production of fucosylated oligosaccharides using a genetically modified prokaryotic host cell, the method comprising the steps of: - providing a prokaryotic host cell, which has been genetically modified, such, that at least (i) the activity of a fructose-6-phosphate-converting enzyme, which in the unmodified host cell has a regular level, is lowered or abolished, wherein said fructose-6-phosphate converting enzyme is selected from the group consisting of phosphofructokinase, glucose-6-phosphate isomerase, fructose-6-phosphate aldolase, a transketolase, or a transaldolase, and/or by increasing the activity of a fructose-1,6-bisphosphate phosphatase; (ii) at least one gene encoding an enzyme necessary for the de novo synthesis of GDP-fucose is overexpressed in the host cell, wherein the at least one gene encoding an enzyme necessary for the de novo synthesis of GDP-fucose is a gene encoding a ManA enzyme catalyzing the isomerization of fructose-6-phosphate to mannose-6-phosphate, a phosphomannomutase encoding gene, a mannose-1-phosphate guanosyltransferase encoding gene, a GDP-mannose-4,6-dehydratase encoding gene, or a GDP-L-fucose synthase encoding gene; (iii) an exogenous gene, encoding an alpha-1,2-fucosyltransferase and/or alpha-1,3-fucosyltransferase, is expressed in the host cell; - cultivating and/or growing said genetically modified host cell in a cultivation medium from a carbon and/or energy source that is selected from at least one of the following: glycerol, succinate, malate, pyruvate, lactate, ethanol, citrate; and - providing lactose to the cultivation medium; thereby producing the fucosylated oligosaccharide obtainable from the medium the host cell is cultivated in. - providing a prokaryotic host cell, which has been genetically modified, such, that at least (i) the activity of a fructose-6-phosphate-converting enzyme, which in the unmodified host cell has a regular level, is lowered or abolished, wherein said fructose-6-phosphate converting enzyme is selected from the group consisting of phosphofructokinase, glucose-6-phosphate isomerase, fructose-6-phosphate aldolase, a transketolase, or a transaldolase, and/or by increasing the activity of a fructose-1,6-bisphosphate phosphatase; (ii) at least one gene encoding an enzyme necessary for the de novo synthesis of GDP-fucose is overexpressed in the host cell, wherein the at least one gene encoding an enzyme necessary for the de novo synthesis of GDP-fucose is a gene encoding a ManA enzyme catalyzing the isomerization of fructose-6-phosphate to mannose-6-phosphate, a phosphomannomutase encoding gene, a mannose-1-phosphate guanosyltransferase encoding gene, a GDP-mannose-4,6-dehydratase encoding gene, or a GDP-L-fucose synthase encoding gene; (iii) an exogenous gene, encoding an alpha-1,2-fucosyltransferase and/or alpha-1,3-fucosyltransferase, is expressed in the host cell; - cultivating and/or growing said genetically modified host cell in a cultivation medium from a carbon and/or energy source that is selected from at least one of the following: glycerol, succinate, malate, pyruvate, lactate, ethanol, citrate; and - providing lactose to the cultivation medium; <EOS>