Gut microbiota plays a predominant role in affecting hypolipidemic effect of Deacetylated Konjac Glucomannan (Da-KGM)

Integration of Lipidomics and Transcriptomics Identifies the Regulation of Lipid Homeostasis as Potential Mechanisms of Konjac Glucomannan against Hepatic Steatosis

Hepatic steatosis is characterized by substantial disruption in the liver's lipid level regulation. Konjac glucomannan (KGM) is acknowledged as a nutritious food that has the potential to prevent hyperlipidemia. This study utilized lipidomics and transcriptomics to investigate the efficacy of KGM in alleviating high-fat diet-induced hepatic steatosis by regulating lipid homeostasis. The findings indicated that supplementation of KGM for a duration of 10 weeks led to significant decreases in body weight, liver weight, and epididymal fat tissue weight. Furthermore, improvements in lipid concentrations in plasma and liver samples were observed, along with enhancements in glucose tolerance and the mitigation of liver damage. Additionally, lipidomics analysis revealed that the primary differential lipid metabolites were mainly associated with fatty acid metabolism pathways. Transcriptomic analysis showed that KGM significantly altered the gene expression of the peroxisome proliferator-activated receptor (PPAR) signaling pathway in the liver. Moreover, KGM demonstrated a significant regulatory impact on the hepatic expression of PPARγ, potentially mitigating hepatic steatosis through modulation of the PPARγ-mediated lipid metabolism pathway. In conclusion, these findings suggest that KGM effectively mitigates steatosis by modulating hepatic lipid metabolites and controlling PPARγ-mediated genes in the liver.

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.

Protective Effects of Different Selenium Green Tea Polysaccharides on the Development of Type 2 Diabetes in Mice

Selenium polysaccharides have attracted significant interest due to their superior function to that of individual polysaccharides. However, limited research has compared the protective effects of different selenium polysaccharides from different selenization methods on diabetes. This work aims to compare the preventive effects of natural selenium-enriched green tea polysaccharides (NSe-TPS), synthetic selenized green tea polysaccharides (PCSe-TPS), and a mixture of sodium selenite and green tea polysaccharides (ordinary tea polysaccharides (Ord-TPS)+Se) on the development of diabetes. While establishing a diabetes model induced by a high-sugar, high-fat diet combined with streptozotocin, different selenium polysaccharides were administered daily by gavage for nine weeks. Our findings indicate that PCSe-TPS exhibited superior preventive effects on developing type 2 diabetes compared to NSe-TPS and Ord-TPS+Se. PCSe-TPS effectively regulated glucose metabolism and insulin resistance by activating the PI3K/Akt pathway, thereby preventing elevated blood glucose levels. Additionally, PCSe-TPS mitigated oxidative damage and inflammatory responses in liver tissues. Notably, PCSe-TPS intervention reversed the decline in bacterial species richness and the abundance of unclassified_Oscillospiraceae during the development of diabetes in mice. These results provide valuable insights into the protective effects of PCSe-TPS against diabetes development, highlighting its advantages over NSe-TPS and Ord-TPS+Se.

Composition of gut microbiota involved in alleviation of dexamethasone-induced muscle atrophy by whey protein

Skeletal muscle atrophy is a condition associated with increased morbidity and mortality. While the concept of the gut-muscle axis has been proposed, the role of gut microbiota in dexamethasone (DEX)-induced skeletal muscle atrophy remains largely unknown, limiting its clinical applications. In this study, we found that administration of DEX caused a shift in the gut microbiota of mice, characterized by an increased ratio of Firmicutes/Bacteroidota and a reduction in alpha diversity. We also identified 480 new operational taxonomic units (OTUs), while 1168 specific OTUs were lost. Our Spearman correlation analysis revealed 28 key taxonomic genera of bacteria that were positively or negatively associated with skeletal muscle strength and weight (r: -0.881 to 0.845, p < 0.05). Moreover, supplementation with whey protein reshaped the gut microbiota structure in DEX-treated mice, making it more similar to that of the control group. Importantly, we further utilized a stepwise regression model to identify two enterotypes capable of predicting skeletal muscle function and weight. Notably, Ileibacterium and Lachnospiraceae_UCG-001 played significant roles in predicting both skeletal muscle function and weight. Our findings suggest that DEX causes shifts in the gut microbiota, which can be reversed by whey protein intervention. The enterotypes identified by our stepwise regression models predict muscle function and weight, underscoring the potential role of gut microbiota in modulating muscle atrophy and emphasizing the therapeutic opportunities of microbiota-altering interventions.

Integrated Transcriptomics and Metabolomics Reveal the Mechanism of Alliin in Improving Hyperlipidemia

This research aims to assess the anti-hyperlipidemia effects of alliin in vivo and its potential mechanisms through transcriptomics and metabolomics analysis. A hyperlipidemia mode was established in C57BL/6 mice fed a high-fat diet, and the related physiological parameters of the animals were recorded. Serum TC and MDA in livers significantly decreased by 12.34% and 29.59%, respectively, and SOD and CAT in livers significantly increased by 40.64% and 39.05%, respectively, after high doses of alliin interventions. In total, 148 significantly different genes, particularly Cel, Sqle, Myc, and Ugt1a2, were revealed for their potential roles in HFD-induced alliin, mainly through steroid biosynthesis, triglyceride metabolism, drug metabolism-cytochrome P450, and the PI3K-Akt signaling pathway, according to transcriptomics analysis. Metabolomics results revealed 18 significantly different metabolites between the alliin group and HFD group, which were classified as carboxylic acids, such as N-undecanoylglycine, adipic acid, D-pantothenic acid, cyprodenate, and pivagabine. We found pantothenic acid played a vital role and was effective through pantothenic acid and CoA biosynthesis metabolism. The "steroid biosynthesis pathway" was identified as the most significant metabolic pathway by integrated transcriptomics and metabolomics analysis. This work offered a theoretical framework for the mechanism of alliin lipid lowering in the future. The development and utilization of alliin will be a viable strategy to improve the health status of people with hyperlipidemia, suggesting prospective market opportunities.

Oral konjac glucomannan for prevention of ionizing radiation-induced injury by regulating gut microbiota and increasing short chain fatty acids

Ionizing radiation-induced injury commonly happens in radiotherapy, leading to damages of the hematopoietic and gastrointestinal systems. Radioprotective medications are mainly applied in hospitals, although only injections are available and their gut protection is limited. Here, oral konjac glucomannan (KGM), a natural macromolecule and soluble dietary fiber, was used against ionizing radiation-induced injury. The mice were fed with KGM (0.4 g/kg) for 3 days or injected with a clinical medication amifostine before 6.5 Gy γ-ray whole body irradiation (WBI) or 13 Gy whole abdominal irradiation (WAI). In the WBI experiments, KGM improved blood cell recovery and bone marrow cell proliferation in the femur and spleen, though its effect was weaker than or similar to that of amifostine. In the WBI experiments, the gut protection of KGM was similar to or a little better than that of amifostine, involving regenerated crypts numbers, villus length, and gut permeability. Moreover, KGM remarkably enhanced the survival rates of WBI and WAI mice, consistent with amifostine. KGM, as a prebiotic, enhanced gut microbiota abundance, probiotic numbers, and short chain fatty acid production, maintaining gut homeostasis. Moreover, KGM inhibited the apoptosis of irradiated human intestinal epithelial cells. KGM is a promising natural macromolecule against ionizing radiation-induced injury.

CM3-SII polysaccharide obtained from Cordyceps militaris ameliorates hyperlipidemia in heterozygous LDLR-deficient hamsters by modulating gut microbiota and NPC1L1 and PPARα levels

Accumulating evidence has demonstrated that polysaccharides derived from edible fungi have lipid-lowering effects in mice. However, the lipid metabolism mechanisms in mice and humans are different. We have previously elucidated the structural characteristics of the alkali-extracted polysaccharide CM3-SII obtained from Cordyceps militaris. This study aimed to investigate whether CM3-SII could ameliorate hyperlipidemia in a heterozygous low-density lipoprotein receptor (LDLR)-deficient hamster model of hyperlipidemia. Our data demonstrated that CM3-SII significantly decreased total plasma cholesterol, non-high-density lipoprotein cholesterol, and triglyceride levels in heterozygous LDLR-deficient hamsters. Unlike ezetimibe, CM3-SII could enhance the concentration of plasma apolipoprotein A1 and the expression of liver X receptor α/ATP-binding cassette transporter G8 mRNA pathway and suppress the expression of Niemann-Pick C1-like 1, which help to reduce cholesterol levels further. Moreover, the results of molecular docking analysis demonstrated that CM3-SII could directly bind to Niemann-Pick C1-like 1 with high affinity. The triglyceride-lowering mechanisms of CM3-SII were related to its downregulation of sterol regulatory element-binding protein 1c and upregulation of peroxisome proliferator-activated receptor α. Importantly, CM3-SII increased the abundance of Actinobacteria and Faecalibaculum and the ratio of Bacteroidetes/Firmicutes. Thus, CM3-SII attenuated hyperlipidemia by modulating the expression of multiple molecules involved in lipid metabolism and the gut microbiota.

Phytosterols Alleviate Hyperlipidemia by Regulating Gut Microbiota and Cholesterol Metabolism in Mice

Phytosterols (PS) have been shown to regulate cholesterol metabolism and alleviate hyperlipidemia (HLP), but the mechanism is still unclear. In this study, we investigated the mechanism by which PS regulates cholesterol metabolism in high-fat diet (HFD) mice. The results showed that PS treatment reduced the accumulation of total cholesterol (TC), triglycerides (TG), and low-density lipoprotein cholesterol (LDL-C) in the serum of HFD mice, while increasing the serum levels of high-density lipoprotein cholesterol (HDL-C). Compared with HFD mice, PS not only increased the antioxidant activity of the liver but also regulated the mRNA expression levels of enzymes and receptors related to cholesterol metabolism. The hypolipidemic effect of PS was abolished by antibiotic (Abx) intervention and reproduced by fecal transplantation (FMT) intervention. The results of 16S rRNA sequencing analysis showed that PS modulated the gut microbiota of mice. PS reduced the relative abundance of Lactobacillus and other bile salt hydrolase- (BSH-) producing gut microbiota in HFD mice, which are potentially related to cholesterol metabolism. These findings partially explain the mechanisms by which PS regulates cholesterol metabolism. This implies that regulation of the gut microbiota would be a potential target for the treatment of HLP.