A physiologically relevant approach to characterize the microbial response to colloidal particles in food matrices within a simulated gastrointestinal tract

► Using conventional methods to study nanoparticle effects may give misleading results. ► Changes in the properties of colloids perturb homeostasis of microbial communities. ► The size and surface charge of colloids are different after simulated digestion. ► Planktonic bacterial cultures are less affected to colloids than bacterial biofilms.