Gut microbiome and plasma metabolome changes in rats after oral gavage of nanoparticles: sensitive indicators of possible adverse health effects.

"Declarations Ethics approval and consent to participateThe animal facility, in which all animal work of the study was performed, holds a certificate from the International Association for Assessment and Accreditation of Laboratory Animal Care (AAALAC). The animal studies were performed with approval of the local regulatory authorities, and study protocols complied with the respective guidelines. Consent for publicationNot applicable. Competing interestsThe authors declare that they have no competing interests. Competing interests The authors declare that they have no competing interests."

"Funding Open Access funding enabled and organized by Projekt DEAL. This work was partially supported by the Federal German Ministry of Education and Research BMBF (Grants nanoGEM and nanoGRAVUR to RL and JS) and “BASF Key Technology Capability Building Alternative Toxicological Methods” to BvR, RL, SSp and WW. The funding agencies did not participate in design of the study and collection, analysis, and interpretation of data and in writing the manuscript."

"The test substances were selected from the set of the nanoGEM study [, ] i.e. SiO2 NP (SiO2.naked NP without different surface modifications; Levasil® 200) and Ag NP (Ag50 EO NP). SiO2 was supplied by BASF SE, Ludwigshafen, Germany, Ag NP by Bayer Material Sciences, Leverkusen, Germany. The test substances were delivered as dispersions and were characterized in detail in accordance with the physico-chemical endpoints described in the guidance on information requirements for nanomaterials [] to EU regulation No. 1907/2006 on the Registration, Evaluation, Authorization and Restriction of Chemicals []. The following test substance properties were determined making use of the indicated methodologies [, , ]."