Silver nanoparticle effects on the murine cecal microbiome after 28 days of oral gavage

This study was part of the NIEHS Consortium for Nanotechnology Health Implications Research (NCNHIR). We evaluated murine cecal microbial communities after 28 days of oral gavage with silver nanoparticles (AgNP) of differing coatings (citrate, polyvinylpyrrolidone) and differing size (20 nm, 110 nm), in comparison to silver acetate, water, or cefoperazone (antibiotic). There were no changes in community structure or diversity parameters for mice receiving AgNP or silver acetate in comparison to water, in contrast to significant changes in mice receiving an antibiotic. This study demonstrated that oral administration of AgNP at doses up to 2000x the EPA oral reference dose is unlikely to affect the gut microbiome.