GtfW of Lactobacillus reuteri strain DSM 20016 is a member of the glycoside hydrolase 70 family. The enzyme is a 4,6-α-glucanotransferase converting pure malto-oligosaccharide substrates into oligosaccharides and linear α-glucan product mixtures. Using maltose as starting material, a diversity of glucose-based oligosaccharides are formed. The compounds are separated with HPAEC-PAD, and analysed with MALDI-TOF-MS and 1D 1H NMR spectroscopy. The identified glucose-based products have a degree of polymerization between Dp 3-6, containing α(1→4)-, and α(1→6) glycosidic linkages.