Background: Glycan structures, which are bound to the surface of proteins and lipids, are involved in numerous physiological and pathological processes including cell-cell interaction, antibody receptor binding, cellular infection by viruses and many other. Codified in the glycan structure, each nutrient contains a specifc glycosignature depending on the dietary source. Moreover, dietary glycans might influence human health due to potential incooperation of foreign glycans in the human glycome. Thus, we aimed to determine the glycan composition of different food sources and of samples collected along the gastrointestinal tract for a better understanding of the fate of dietary glycans. Method: The N-glycome of different food products and oro-gastrointestinal samples was characterized by MALDI mass spectrometry in positive mode after purification and derivatization with methylamine. After labelling with DMBA, total and specific sialic acid content was quantified by HPLC-RP-FL. Results: We observed substantial variations in N-glycome and monosaccharide composition depending on the source of the food: vegetable, fungal, meat, milk (human vs animal milk), and cheese (fermented milk). Starting from the mouth throught the stomach and the intestine, different degree of gylcan hydrolysis was observed, with mainly the sialic acid residues being cleaved from the glycan structure. Conclusion: Our results clearly confirm the species-specific glycan pattern reflected by a distinct N- glycome and sialic acid amount and composition in different food, but also in gastrointestinal samples. As the dietary glycan composition influences human health, immuno-nutritional effects should be taken into consideration.