Described is a matrix to identify mother's milk missing fucosyltransferase-2 (FUT2) dependent glycans which comprise a line of a glycan binding protein such as a lectin or antibody suitable to bind 2′fucosyl-glycans and a line of a positive control to bind a mother's milk protein. For instance, this matrix is porous and allows for transport by capillary force of compounds of mother's milk such as glycoproteins. Especially, the glycan binding protein is the plant lectin from Ulex europaeus. A diagnostic kit comprising one or more of such matrices and a device suitable to receive such a matrix provided with a milk application window and a read-out window has been described as well. Finally a kit-of-parts comprising such a diagnostic kit and one or more feeding doses of 2′fucosyl-glycans has been disclosed.