Oral intake of silica nanoparticles exacerbates intestinal inflammation.

Nanoparticles, i.e., particles with a diameter of ≤100 nm regardless of their composing material, are added to various foods as moisturizers, coloring agents, and preservatives. Silicon dioxide (SiO, silica) nanoparticles in particular are widely used as food additives. However, the influence of SiO nanoparticle oral consumption on intestinal homeostasis remains unclear. The daily intake of 10-nm-sized SiO nanoparticles exacerbates dextran sulfate sodium (DSS)-induced colitis, whereas the daily intake of 30-nm-sized SiO nanoparticles has no influence on intestinal inflammation. The exacerbation of colitis induced by consuming 10-nm-sized SiO nanoparticles was abolished in mice deficient in apoptosis-associated speck-like protein containing a CARD (ASC). Our study indicates that the oral intake of small SiO nanoparticles poses a risk for worsening intestinal inflammation through activation of the ASC inflammasome.