Repeated Dose (28 Day) Administration of Silver Nanoparticles of Varied Size and Coating Does Not Significantly Alter the Indigenous Murine Gut Microbiome
In this clinical study, published in the journal Nanotoxicology in June 2016, researchers demonstrated that oral administration of silver nanoparticles capped with PVP or Citrate had negligible effect on gut bacteria in the murine (mouse) model – the implication being that silver nanoparticles delivered orally either through unintentional contact with consumer products, or through dietary supplementation, or as a substitute for antibiotics in animal feed would not harm beneficial digestive microbes.
The researchers wrote, “We evaluated murine gut microbial communities using culture-independent sequencing of 16S rRNA gene fragments following 28 days of repeated oral dosing of well-characterized AgNPs of two different sizes (20 and 110?nm) and coatings (PVP and Citrate). Irrespective of size or coating, oral administration of AgNPs at 10?mg/kg body weight/day did not alter the membership, structure or diversity of the murine gut microbiome. Thus, in contrast to effects of broad-spectrum antibiotics, repeat dosing of AgNP, at doses equivalent to 2000 times the oral reference dose and 100-400 times the effective in vitro anti-microbial concentration, does not affect the indigenous murine gut microbiome.”
