“…The secretor gene encodes for α1,2 fucosyltransferase (FUT2), whereas the Lewis blood type is determined by the Lewis gene, which encodes for α1,3/1,4 fucosyltransferase (FUT3) (De Vries, Knegtel, Holmes, & Macher, ). Due to variations in the maternal fucosyltransferases the quantity and type of carbohydrates are differently expressed in pyloric or duodenal mucus and intestinal secretions (Mattos, ). Although HMOs and HMGPs fucosylation has been extensively studied (Doherty, Lodge, Dharmage, Dai, & Lowe, ), HMOs and HMGPs sialylation is not well understood yet (Grabarics, Csernák, Balogh, & Béni, ; Yan et al., ).…”