Fig. 8.

Re-establishment of germ free (GF) mice with the faecal microbiota of Au@P-NPs-treated animals summarizes the effects of Au@P-NPs on body weight increase and energy expenditure. GF animals were inoculated either with the faecal slurry of HFD-fed animals (HFD recipients) or Au@P-NPs-treated animals (Au@P-NPs recipients) and reserved in metabolic cages with a less-fat containing diet during the early days of PC. Animals were shortly shifted into GF cages and kept under aseptic conditions. (a) body weight increase; (b) energy intake; (c) energy expenditure (the connection among metabolic rate and body weight was stabilized by using body mass^0.75). (d and e) Taxonomic gut microbial profile of HFD and Au@P-NPs recipients at phylum and the LTL obtained at indicated days PC. (f) LEfSe calculation of taxa at the LTL likely better discriminates the GM of HFD and Au@P-NPs recipients at days PC. (g) F/B ratio in HFD and Au@P-NPs recipients. (g–n) The abundance of specific bacteria was measured by qPCR analysis and the number of copies of each taxon was stabilized by 3 ​× ​10⁹ copies of total bacteria. Two-way frequent measurements ANOVA with BPHT applied to assess the significant differences between time points. ∗P ​< ​0.05, ∗∗P ​< ​0.01 and ∗∗∗P ​< ​0.001.