Oat Dietary Fiber Delays the Progression of Chronic Kidney Disease in Mice by Modulating the Gut Microbiota and Reducing Uremic Toxin Levels.

Chronic kidney disease (CKD) has emerged as a significant public health concern. In this article, we investigated the mechanism of oat dietary fiber in regulating CKD. Our findings indicated that the gut microbiota of CKD patients promoted gut microbiota dysbiosis and kidney injury in CKD mice. Intervention with oat-resistant starch prepared by ultrasonic combined enzymatic hydrolysis (ORSU) and oat ß-glucan with a molecular weight of 5 × 104 Da (OBGM) elevated the levels of short-chain fatty acids (SCFAs) and regulated gut dysbiosis in the gut-humanized CKD mice. ORSU and OBGM also reduced CKD-related uremic toxins such as creatinine, indoxyl sulfate (IS), and p-cresol sulfate (PCS) levels; reinforced the intestinal barrier function of the gut-humanized CKD mice; and mitigated renal inflammation and fibrosis via the NF-κB/TGF-ß pathway. Therefore, ORSU and OBGM might delay the progression of CKD by modulating the gut microbiota to reduce uremic toxins levels. Our results explain the mechanism of oat dietary fiber aimed at mitigating CKD.

Different multi-scale structural features of oat resistant starch prepared by ultrasound combined enzymatic hydrolysis affect its digestive properties.

In this research, oat resistant starch (ORS) was prepared by autoclaving-retrogradation cycle (ORS-A), enzymatic hydrolysis (ORS-B), and ultrasound combined enzymatic hydrolysis (ORS-C). Differences in their structural features, physicochemical properties and digestive properties were studied. Results of particle size distribution, XRD, DSC, FTIR, SEM and in vitro digestion showed that ORS-C was a B + C-crystal, and ORS-C had a larger particle size, the smallest span value, the highest relative crystallinity, the most ordered and stable double helix structure, the roughest surface shape and strongest digestion resistance compared to ORS-A and ORS-B. Correlation analysis revealed that the digestion resistance of ORS-C was strongly positively correlated with RS content, amylose content, relative crystallinity and absorption peak intensity ratio of 1047/1022 cm-1 (R1047/1022), and weakly positively correlated with average particle size. These results provided theoretical support for the application of ORS-C with strong digestion resistance prepared by ultrasound combined enzymatic hydrolysis in the low GI food application.

Tectorigenin ameliorated high-fat diet-induced nonalcoholic fatty liver disease through anti-inflammation and modulating gut microbiota in mice.

Nonalcoholic fatty liver disease (NAFLD) is a complex pathogenesis of liver disease combined with liver inflammation and gut microbiota dysbiosis. Tectorigenin (Tg) is derived from many plants with excellent anti-inflammation activity. However, the beneficial effect of Tg on NAFLD associated with gut microbiota remained unclear. This study aimed to investigate the underlying beneficial effect of Tg on NAFLD in high-fat diet (HFD)-fed mice. Results showed that Tg alleviated lipid profiles and liver steatosis, and reduced serum lipopolysaccharide (LPS) and total bile acid (TBA) levels. Besides, RT-qPCR and Western blot suggested that Tg alleviated hepatic lipid accumulation through inhibiting the lipogenesis and promoting the lipolysis, prevented gut-derived LPS-induced liver inflammatory via restoring intestinal barrier and restraining pro-inflammatory cytokines release, meanwhile, promoted the BA circulation via activating BA receptor and promoting BA synthesis. Moreover, Tg reverted the HFD-induced gut microbial dysbiosis by promoting the growth of beneficial Akkermansia, and inhibiting the proportions of harmful microbes, including Blautia, Lachnoclostridium, Lachnospiraceae_UCG-006, Roseburia, Romboutsia and Faecalibaculum, which were highly correlated with NAFLD-related parameters in serum and liver. Thus, Tg could attenuate NAFLD through mediating the liver-gut axis, and it could be used as a dietary supplement for NAFLD treatment via its anti-inflammatory and prebiotic effects.

Flavonoids from Whole-Grain Oat Alleviated High-Fat Diet-Induced Hyperlipidemia via Regulating Bile Acid Metabolism and Gut Microbiota in Mice.

A high-fat diet (HFD) causes hyperlipidemia, which worsens disturbances in bile acid (BA) metabolism and gut microbiota. This study aimed to investigate the regulation of flavonoids from whole-grain oat (FO) on BA metabolism and gut microbiota in HFD-induced hyperlipidemic mice. The experiment results showed that FO improved serum lipid profiles and decreased body weight and lipid deposition in HFD-fed mice. Through real-time qualitative polymerase chain reaction (RT-qPCR) and Western blot assays, by up-regulating the expression of PPARα, CPT-1, CYP7A1, FXR, TGR5, NTCP, and BSTP, and down-regulating those of SREBP-1c, FAS, and ASBT, FO suppressed lipogenesis, promoted lipolysis and BA synthesis, and efflux to faeces via the FXR pathway. 16s rRNA sequencing revealed that FO significantly increased Akkermansia and significantly decreased Lachnoclostridium, Blautia, Colidextribacter, and Desulfovibrio. Spearman's correlation analysis showed that these bacteria were strongly correlated with hyperlipidemia-related parameters. Therefore, our results indicated that FO possessed an antihyperlipidemic effect via regulating the gut-liver axis, i.e., BA metabolism and gut microbiota.

Purification and characterization of antioxidant peptides from enzymatic hydrolysate of mungbean protein.

In this study, the antioxidant activity of mungbean protein hydrolysate (MPH) was systematically investigated. MPH was fractionated by ultrafiltration into two major fractions (MPH-1 <3 kDa, MPH-2 >3 kDa). Fraction MPH-1, which exhibited the highest antioxidant activity, was further fractionated by gel column into three fractions (MPH-1A, MPH-1B, and MPH-1C). The antioxidant activity of the MPH-1B fraction was stronger than that of the other fractions. Eight mungbean peptides (P1-P8) were identified in fraction MPH-1B by UPLC-Q-TOF-MS. Among them, peptides Trp-Gly-Asn (WGN, P2), Ala-Trp (AW, P4), Arg-Gly-Trp-Tyr-Glu (RGWYE, P5), and Gly-Val-Pro-Phe-Trp (GVPFW, P7) had high antioxidant activity. Moreover, these four peptides exerted protective effects against H2 O2 -induced cytotoxicity and regulated the MDA content, CAT activity, and total GSH content in HepG2 cells with specific observation. This study demonstrated the potential of MPH as a source of antioxidant peptides. This provides a scientific basis for the preparation of antioxidant peptides from mungbean protein. PRACTICAL APPLICATION: This study demonstrated the potential of the hydrolysate of mungbean protein as a source of antioxidant peptides and provided a scientific basis for the preparation of antioxidant peptides from mungbean protein.