Gels are a representative state for polysaccharides in both natural and artificial systems. The nature of the inter-chain associations within the junction zones is important and models for such interactions between like polysaccharides are based on X-ray diffraction studies of oriented gels. Here we describe the extension of such studies to a binary gel (xanthan-carob) in order to characterize for the first time intermolecular binding between different polysaccharides. Xanthan-carob binding has been proposed to explain gelation of the mixtures and as a model for host-pathogen recognition and adhesion of Xanthomonas bacteria within plant vascular systems. Our data suggest that the established model1–7 is incorrect and point to an alternative association mechanism.