SIRT1 and metabolic syndrome: These findings, taken together with the data showing that expressions of irisin, FGF21, bile acid synthetic genes, TGR5, and SIRT1 are upregulated in SAT and BAT (Figs 2B–2G, 2L, 3A and 3B), suggest that the protective effect of L. plantarum treatment against HFD-induced dyslipidemia is associated with enhanced irisin-, FGF21-, and bile acid-mediated WAT browning and BAT thermogenesis.