Exposition orale et devenir dans l'intestin des nanoparticules alimentaires : exemple de l'argent et du dioxyde de titane

Facing the growing use of nano-manufactured products in many consumer goods, including those from the agro-food sector, the consequences of chronic exposure in humans set public health issues. The oral route of exposure remains largely unknown although a nano-sized fraction of particles is found in food additives/supplements or incorporated into packaging in contact with food. Once ingested, nanoparticles may transit within the gastro-intestinal tract, be chemically and morphologically transformed, and impact the luminal environment before crossing the epithelial barrier and distributing to the systemic compartment. This review focuses on nano-silver and nano-titanium dioxide. Despite their specificities and differences, a close relationship exists between physico-chemical reactivity and bioavailability/biopersistence within the gut. Few data are to date reported on the interactions between nano-silver/nano-titanium dioxide, microbiota and mucus, which are key players in intestinal homeostasis and host health, with a putative impact on nanoparticle distribution to the systemic compartment.