Metabolic syndrome (MetS) is a chronic disease associated with the disturbance of gut microbiota homeostasis. Metabolites derived from gut microbes play essential roles in MetS prevention and therapy. Here, we focused on the inhibitory effect of the extract of millet bran protein (EMBP) on a high-fat diet (HFD)-induced MetS, aiming to identify gut microbiota and their metabolites that involve in the anti-MetS activity of EMBP. The obesity, chronic inflammation, insulin resistance in MetS mouse models were abolished after EMBP treatment. The protective mechanism of EMBP against HFD-induced MetS may depend on improved gut barrier function. Using microbiome analysis, we found that EMBP supplementation improved gut microbiome dysbiosis in MetS mice, specifically upregulating Bacteroides acidifaciens. The fecal microbiota transplantation (FMT) also demonstrated this phenomenon. In addition, metabolomic analysis showed that EMBP mediates metabolic profiling reprogramming in MetS mice. Notably, a microbiota-derived metabolite, gamma-aminobutyric acid (GABA), is enriched by EMBP. In addition, exogenous GABA treatment produced a similar protective effect to EMBP by improving NRF2-dependent gut barrier function to protect HFD-induced MetS. The results suggest that EMBP suppress host MetS by remodeling of gut microbiota as an effective candidate for next-generation medicine food dual purpose dietary supplement to intervene in MetS.

The biological effect of rare earth represents the dual natures of promoting cell proliferation and apoptosis. The research on the biological effect of rare earth compound has aroused wide concerns, but it remained unknown for the transmembrane and distribution under the action of rare earth oxide nanoparticle with cell as well as its biological effects. In the present data, it was firstly observed that the nano Eu₂O₃ entered the living HeLa cell by endocytosis using Laser Scanning Confocal Microscope. The distribution of nano Eu₂O₃ was in the cytoplasm around the nucleus. Moreover, we studied the effect of nano Eu₂O₃ on living cells under the condition of in vitro culture. The result showed that within the low concentration range (<1.0 mg/mL), the nano Eu₂O₃ had no obvious effects on the apoptosis and the cell cycle, although the morphology appeared changes. When the concentration gradually rose, it had dramatic biological effects. 1.0 mg/mL nano Eu₂O₃ caused the cellular damages and led to the vacuolation on the cell surface. Meanwhile, it obviously promoted the apoptosis of Hela cells, which suggested that 1.0 mg/mL nano Eu₂O₃ induced a necrotic cell reaction with respect to the nature of cytotoxin.