Updated project metadata. Bacteroidetes are abundant members of the human microbiota, and species occupying the distal gut are capable of utilising a myriad of diet- and host-derived glycans. Transport of glycans across the outer membrane (OM) of these bacteria is mediated by SusCD protein complexes. Additionally, cell surface-exposed lipoproteins, namely surface glycan binding proteins and glycoside hydrolases, play critical roles in the capture and processing of large glycan chains into transport-competent substrates. Here we show that, for the levan and dextran utilisation systems of Bacteroides thetaiotaomicron, the additional OM components assemble on the core SusCD transporter, forming stable glycan utilising machines which we term ‘utilisomes’. Single particle electron cryogenic electron microscopy (cryo-EM) structures in the absence and presence of substrate reveal concerted conformational changes that rationalise the role of each component for efficient nutrient capture, as well as providing a direct demonstration of the pedal bin mechanism of substrate capture in the intact utilisome.