Similar hypoglycemic effects of glucomannan and its enzyme degraded products from Amorphophallus albus on type 2 diabetes mellitus in mice and potential mechanisms

Regulation of glycose and lipid metabolism and application based on the colloidal nutrition science properties of konjac glucomannan: A comprehensive review

The physicochemical properties of dietary fiber in the gastrointestinal tract, such as hydration properties, adsorption properties, rheological properties, have an important influence on the physiological process of host digestion and absorption, leading to the differences in satiety and glucose and lipid metabolisms. Based on the diversified physicochemical properties of konjac glucomannan (KGM), it is meaningful to review the relationship of structural characteristics, physicochemical properties and glycose and lipid metabolism. Firstly, this paper bypassed the category of intestinal microbes, and explained the potential of dietary fiber in regulating glucose and lipid metabolism during nutrient digestion and absorption from the perspective of colloidal nutrition. Secondly, the modification methods of KGM to regulate its physicochemical properties were discussed and the relationship between KGM's molecular structure types and glycose and lipid metabolism were summarized. Finally, based on the characteristics of KGM, the application of KGM in the main material and ingredients of fat reduction food was reviewed. We hope this work could provide theoretical basis for the study of dietary fiber colloid nutrition science.

Effects of Glucomannan Supplementation on Type II Diabetes Mellitus in Humans: A Meta-Analysis

The hypoglycemic and lipid-lowering effects of glucomannan are widely known, and it is a potential effective treatment for type II diabetes. In this study, we evaluated the effects of glucomannan supplementation on blood-lipid-related indicators, blood-glucose-related indicators, blood pressure (BP), and body weight (BW) in patients suffering from type II diabetes. We searched databases including PubMed, Cochrane, the comprehensive biomedical research database (Embase), Web of Science, and China National Knowledge Infrastructure (CNKI) for literature on glucomannan and type II diabetes. Six randomized controlled trials (RCTs) were eligible (n = 440 participants) to be included in our analysis. Glucomannan not only reduced the total cholesterol (TC) (MD -0.38 [95% CI: -0.61, -0.15], p = 0.001) and low-density lipoprotein (LDL) levels (MD -0.35 [95% CI: -0.52, -0.17], p < 0.0001) compared with the control group, but also reduced the fasting blood glucose (FBG) (MD -1.08 [95% CI: -1.65, -0.50], p = 0.0002), 2 h postprandial blood glucose (P2hBG) (MD -1.92 [95% CI: -3.19, -0.65], p = 0.003), fasting insulin (FINS) (MD -1.59 [95% CI: -2.69, -0.50], p = 0.004), and serum fructosamine (SFRA) levels (SMD -1.19 [95% CI: -1.74, -0.64], p < 0.0001). Our analysis indicates that glucomannan is an effective nutritional intervention for type II diabetes.

Effects of sulfur-fumigated ginseng on the global quality of Si-Jun-Zi decoction, a traditional ginseng-containing multi-herb prescription, evaluated by metabolomics and glycomics strategies

Si-Jun-Zi decoction (SJZD) with ginseng as the principal medicinal herb is a traditional Chinese Medicine multi-herb prescription that commonly employed to treat colorectal cancer etc. Previous studies showed that nearly half of the commercial ginseng was sulfur-fumigated, one of the postharvest processing methods that commonly causes sulfur-dioxide (SO₂) residue and chemical composition transformation in medical herbs. In this study, the effect of sulfur-fumigated ginseng on global quality of SJZD was evaluated by UPLC-QTOF-MS/MS based metabolomics and multiple chromatographic techniques based glycomics strategies. For non-saccharides components, sulfur-fumigated ginseng led to the emergence of sulfur-containing derivatives and alteration of saponins and flavonoids in SJZD. For saccharide components, sulfur-fumigated ginseng decreased the total contents and molecular weights of polysaccharides, changed the monosaccharide composition of polysaccharides, and increased the contents of oligosaccharides and free monosaccharides of SJZD. The alterations of SJZD were aggravated with the sulfur-fumigated content of ginseng. Those phenomena might be attributed to 1) sulfur-fumigation caused the generation of sulfur-containing derivatives in ginseng, which further transferred to SJZD, and 2) sulfur-fumigation caused the residue of SO₂ in ginseng, which reduced the pH value and further changed the dissolution of saponins and flavonoids and accelerated the degradation of the polysaccharides to oligosaccharides and/or monosaccharides in SJZD. Furthermore, although storage reduced the SO₂ residue in sulfur-fumigated ginseng, it couldn't recover the alterations of chemical profiles in SJZD. In conclusion, sulfur-fumigated ginseng altered the global quality of SJZD, which promoted that extra attention must be paid during the application of herbal formulas that containing sulfur-fumigated herbs.

Effects of L-arabinose by hypoglycemic and modulating gut microbiome in a high-fat diet- and streptozotocin-induced mouse model of type 2 diabetes mellitus

L-arabinose is a good and healthy food additive. This study was conducted to investigate the effect of L-arabinose in a mouse model of type 2 diabetes mellitus (T2DM) induced by exposure to a high-fat diet (HFD) and streptozotocin (STZ). The model mice received L-arabinose at 20 and 60 mg (kg body weight [bw])^-1 d^-1 , metformin at 300 mg (kg bw)^-1 d^-1 (positive control) or sterile water (control) via oral gavage. Compared with the model group, mice treated with L-arabinose exhibited attenuated symptoms of diabetes mellitus, including a slower rate of body weight loss, increased homeostasis model assessment of β-cell function index levels, decreased blood glucose, alleviation of steatosis, and repair of pancreatic islet cells. L-arabinose also exerted an anti-inflammatory effect and partially mitigated dyslipidemia. A 16S-rRNA sequence analysis of the gut microbiota revealed that at the phylum level, treatment with L-arabinose significantly reduced the ratio of Firmicutes to Bacteroidetes due to a decreased relative abundance of Firmicutes; at the genus level, it reversed the increase in the relative abundance of Allobaculum and the decrease abundance of Oscillospira caused by exposure to an HFD and STZ. And the model mice received L-arabinose at 20 mg (kg bw)^-1 d^-1 had a better effect on improving T2DM than the high-dose group supplemented L-arabinose at 60 mg (kg bw)^-1 d^-1 . These results strongly suggest L-arabinose as an excellent candidate supplement to prevent or treat T2DM. PRACTICAL APPLICATIONS: L-arabinose, xylitol and sucralose are well-known substitutes for sucrose. L-arabinose has been reported to have beneficial effects on hyperglycemia, glycemic index, and fat accumulation. In this study, we found that low-dose (20 mg (kg bw)^-1 d^-1 ) supplementation of L-arabinose significantly improved glucose intolerance and gut microbiota incoordination in T2DM caused by HFD and STZ.