Colloidal transport in the intestinal mucus
Résumé
The last boundary between ingested food and the gastrointestinal (GI) tract mucosa is the mucus barrier. This highly complex viscoelastic medium has evolved to provide a robust barrier that can trap and immobilise potentially hazardous particulates such as bacteria but still allow the passage of nutrients to the epithelial surfaces (1,2). These conflicting properties are particularly important in the small intestine where the mucus layer is thinnest and the majority of nutrients absorption takes place. However, the rules governing this selective barrier function, particularly in relation to transport of particulates, remain unknown. Recent studies show that surface properties of microparticles can largely impact on colloidal transport in the intestinal mucus (3).
The physico-chemical characteristics of the absorption of nutrients depend on the structure of post-digestion food particles which, in turn, is determined by the original food structure and the kinetics and pattern of its enzymatic breakdown in the GI tract. Detailed characterisation of both, the colloidal aspects of digestion and the transport of post-digestion food particles in the intestinal mucus is required for rational design of foods with controlled behaviour in the GI tract, improving their nutritional quality and maintaining human health, thus overcoming diet-related health problems. Here, we summarise our recent studies on the effect the structure of intestinal mucus on the rate of colloidal transport in the mucus.