Tang (2020) Phlorizin ameliorates obesity-associated endotoxemia and insulin resistance in high-fat diet-fed mice by targeting the gut microbiota and intestinal barrier integrity,

The aim of this study was to investigate the effects of Lactobacillus fermentum Suo (LF-Suo) on activated carbon-induced constipation in ICR (Institute of Cancer Research) mice. ICR mice were orally administered with lactic acid bacteria for 9 days. Body weight, diet intake, drinking amount, defecation status, gastrointestinal transit and defecation time, and the serum levels of MTL (motilin), Gas (gastrin), ET (endothelin), SS (somatostatin), AChE (acetylcholinesterase), SP (substance P), VIP (vasoactive intestinal peptide) were used to evaluate the preventive effects of LF-Suo on constipation. Bisacodyl, a laxative drug, was used as a positive control. The normal, control, 100 mg/kg bisacodyl treatment, LB (Lactobacillus bulgaricus)-, LF-Suo (L)- and LF-Suo (H)-treated mice showed the time to the first black stool defecation at 90, 218, 117, 180, 155 and 137 min, respectively. By the oral administration of LB-, LF-Suo (L), LF-Suo (H) or bisacodyl (100 mg/kg), the gastrointestinal transit was reduced to 55.2%, 72.3%, 85.5% and 94.6%, respectively, of the transit in normal mice, respectively. In contrast to the control mice, the serum levels of MTL, Gas, ET, AChE, SP and VIP were significantly increased and the serum levels of SS were reduced in the mice treated with LF-Suo (p < 0.05). By the RT-PCR (reverse transcription–polymerase chain reaction) and western blot assays, LF-Suo increased the c-Kit, SCF (stem cell factor), GDNF (glial cell line-derived neurotrophic factor) and decreased TRPV1 (transient receptor potential vanilloid 1), NOS (nitric oxide synthase) expressions of small intestine tissue in mice. These results demonstrate that lactic acid bacteria has preventive effects on mouse constipation and LF-Suo demonstrated the best functional activity.

The present study investigated the effects of cajanonic acid A (CAA), extracted from the leaves of Cajanus cajan (L.) Millsp with a purity of 98.22%, on the regulatory mechanisms of glucose and lipid metabolism. HepG2 cells transfected with a protein-tyrosine phosphatase 1B (PTP1B) overexpression plasmid were established. The cells, induced with insulin resistance by dexamethasone (Dex) treatment, together with type 2 diabetes mellitus (T2DM) model rats and ob/ob mice, were used in the present study. The effects of CAA treatment on the differentiation of 3T3-L1 adipocytes were determined using Oil Red O. The expression levels of insulin signaling factors were detected via reverse transcription-quantitative polymerase chain reaction and western blot analyses. The results revealed that the overexpression of PTP1B contributed to insulin resistance, which was reversed by CAA treatment via inhibiting the activity of PTP1B and by regulating the expression of associated insulin signaling factors. The treatment of cell lines with Dex led to increased expression of PTP1B but decreased glucose consumption, and decreased tyrosine phosphorylation of insulin receptor, insulin receptor substrate 1, and phosphoinositide 3-kinase. Treatment with CAA not only reduced the fasting blood glucose levels and protected organs from damage, but also reduced the serum fasting levels of total cholesterol, triglycerides and low-density lipoprotein cholesterol in the T2DM rats. CAA treatment also inhibited adipocyte differentiation and decreased the mRNA levels of various adipogenic genes. Furthermore, CAA treatment restored the transduction of insulin signaling by regulating the expression of PTP1B and associated insulin signaling factors. Treatment with CAA also reduced the problems associated with hyperglycemia and hyperlipidemia. In conclusion, CAA may be used to cure T2DM via restoring insulin resistance and preventing obesity.

Natural products generally contain complex and multiple bioactive compounds that are responsible for the effects on health through complicated synergistic and/or suppressive actions. As an important raw material of local ethnic minority tea, ethnomedicines and food supplements in southwestern areas of China, Docynia indica (Wall.) Decne (DID) mainly consists of phlorizin (PHZ), which is the main active component. In this study, the holistic activities and the interactions of components of PHZ, non-phlorizin (NP) in the DID extract (DIDE) were evaluated. A rapid and effective high-speed counter-current chromatography (HSCCC) was performed to knock out PHZ from DIDE and the purity of PHZ was 96.01% determined by HPLC, with a recovery rate of 96.76%. After 13 weeks of treatment course in a high-fat diet (HFD)-induced obese mice model, the results revealed that the DIDE and PHZ significantly decreased weight gain, blood lipid levels, hyperplasia of adipocytes and alleviated inflammation (p < 0.05). Both DIDE and PHZ improves insulin resistance (p < 0.001). Meanwhile, the intestinal barrier function was improved compared to HFD group, through the determination of serum lipopolysaccharides (LPS), glucagon-likepeptide-2 (GLP-2) and hematoxylin-eosin staining of jejunum. Interestingly, after NP treatment, the metabolic syndrome of the HFD-induced obesity appeared to have a similar improvement. All the experiments showed that there is a synergistic weakening phenomenon when PHZ and NP interact with each other in the mixed state. In conclusion, for the PHZ and NP showing a good effect on anti-obesity, anti-inflammation, and intestinal barrier function, DIDE could be a good source of functional food to prevent obesity.

Tibetan kefir grains are the traditional starter for fermented milk products in Tibet, China. To gain a deeper understanding of their bacterial and fungal community diversities, we compared kefir grains from three different regions, Nyingchi, Lhasa and Yangbajing, using high-throughput sequencing. The results of sequence analysis grouped the reads into four bacterial and four fungal phyla, comprising 34 bacterial and 139 fungal genera, and 44 bacterial and 195 fungal species. Firmicutes and Proteobacteria were two dominant bacterial phyla, and Lactobacillus and Acetobacter were the dominant bacterial genera. Basidiomycota and Ascomycota were the dominant fungal phyla. There was significant difference in the Basidiomycota and Ascomycota among three regions (P < 0.05). A significant difference in genera was observed in the percentage of Saccharomyces, Trichosporon, Aspergillus and Candida between the samples from Nyingchi, Lhasa and Yangbajing (P < 0.05). Based on principal component analysis (PCA), the Tibetan kefir grain samples from Nyingchi could be distinctly differentiated from the other two regions in term of fungal community, but no obvious difference existed in the bacterial population of samples from the three regions.