Research progress on the role of gut microbiota dysregulation in the pathogenesis of diabetic nephropathy

There are about over 100 trillion microbial cells in human gut,which affect the nutritional,metabolic,physiological and immune functions of the host.This paper reviews the differences in gut microbiota between patients with diabetic nephropathy(DN)and healthy people.These differences lead to the disorder of symbiotic relationship,which may have induced the progression of DN,as well as targeted interventions to reconstruct the symbiotic relationship.Recent studies have found that endotoxin from intestinal bacteria and a large number of toxic metabolites were produced by fermentation of gut microbiota,such as trimethylamine-N-oxide,indoxyl sulfate and p-cresol sulfate,leading to the disruption of intestinal barrier function.Endotoxin and bacterial metabolites,entering the systemic circulation,were involved in DN progression by mediating inflammatory responses,renin-angiotensin-system and vascular injury.The reduction of some beneficial bacterial metabolites in DN patients,such as short-chain fatty acids,would weak body energy metabolism and destroy glucose homeostasis.In addition,gut microbiota is essential for the conversion of bile acids,and plays an important role in the development of DN by synthesizing secondary bile acids and regulating glucose and metabolic balance through foresaid X receptor(FXR)and G protein-coupled bile acid receptor(TGR5).Animal and clinical studies have revealed that probiotics,prebiotics,fecal microbiota transplantation,and Chinese medicine intervention may have potential therapeutic effects in maintaining a metabolically balanced gut microbiota to reduce the progression of DN,end-stage renal disease and cardiovascular complications.

Mg/Al complex oxides-A new type of solid basic catalyst for epoxidation

Hydrotalcites known as anionic clays are found in nature. Hydrotalcites, hydrotalcite-like compounds, and calcined hydrotalcites (as mixed or complex oxides) as highly active, selective catalysts play an important role in many base/catalyzed reactions. Mg/Al hydrotalcite (MAH) as precursor was used to prepare Mg/Al metal complex oxides (MAO), used as epoxidation catalysts in the current research. In this paper, some primary physical and catalytic properties of MAH and MAO were investigated. The results indicated that the qualified MAH (Mg/Al mol ratio of 3) can be achieved when the suspension was crystallized under 80°C for 16h, and after being filtered, dried at 100 °C for 5h in a oven. MAO was prepared by calcining MAH for 4h in a muffle furnace, and calcination temperature was determined to be 500 °C by a differential scanning calorimeter (DSC). Crystal structure and parameters of MAH and MAO were characterized by X/ray diffraction (XRD), good crystal structure was observed and typical peaks of MAH were detected when 2θ was at 11.5 (003), 23.0 (006), 35.0 (009), and 61.0 (110), respectively. The morphology of calcined precursor, i.e. MAO, was investigated with scanning electron microscopy (SEM);the finer lamellar structure and smaller average size of 3μm was observed. Molding research was performed and confirmed by SEM, the results indicated that the surface bulge and cavity with size of several micrometers were increased, which simultaneously suggested the increasing of specific surface area. The catalytic activity of molding MAO was finally examined by using octanol as starting reagent and ethylene oxide as reactant, and narrower molecular distribution was observed comparing with the traditional catalyst-KOH.