Mucus and microbiota as emerging players in gut nanotoxicology: The example of dietary silver and titanium dioxide nanoparticles

AbstractGiven the growing use of nanotechnology in many common consumer products, including foods, evaluation of the consequences of chronic exposure to nanoparticles in humans has become a major public health issue. The oral route of exposure has been poorly explored, despite the presence of a fraction of nano-sized particles in certain food additives/supplements and the incorporation of such particles into packaging in contact with foods. After their ingestion, these nanoparticles pass through the digestive tract, where they may undergo physicochemical transformations, with consequences for the luminal environment, before crossing the epithelial barrier to reach the systemic compartment. In this review, we consider two examples, nano-silver and nano-titanium dioxide. Despite the specific features of these particles and the differences between them, both display a close relationship between physicochemical reactivity and bioavailability/biopersistence in the gastrointestinal tract. Few studies have focus...