The present invention relates to a pharmaceutical composition comprising a (poly)peptide which comprises or consists of QEP or a QEP derivative thereof, a nucleic acid molecule encoding said (poly)peptide or a vector comprising said nucleic acid molecule, for use in the prevention or in the treatment of a disease or disorder caused by, physiologically linked to or associated with glucose and/or galactose uptake, wherein said pharmaceutical composition is to be administered under a high-sugar condition. Furthermore, the pharmaceutical composition of the invention is for use in increasing insulin sensitivity. The invention further relates to a food composition comprising said (poly)peptide. The invention further relates to a method of screening for and/or identifying a compound suitable to prevent or treat said disease or disorder under a high-sugar condition. The invention further relates to a method of screening for and/or identifying a compound which modulates ornithine decarboxylase (ODC), which is capable of inhibiting (SGLT1-mediated) glucose and/or galactose uptake into a cell expressing ODC and/or which is capable of increasing the inhibitory effect of an inhibitor of glucose and/or galactose uptake into a cell expressing ODC. The invention further relates to a method for predicting a patient's non-response or response to said (poly)peptide, to a method for stratifying a patient for prevention or treatment with said (poly)peptide and to a kit for determining whether a patient suffering from said disease or disorder is a non-responder or responder to said polypeptide. The invention further relates to a method of developing and/or designing a compound/drug suitable to prevent or treat said disease or disorder.
