Microbiome-metabolomics insights into the feces of high-fat diet mice to reveal the anti-obesity effects of yak (Bos grunniens) bone collagen hydrolysates

The "crosstalk" between gut microbiota, metabolites and genes in diet-induced hepatic steatosis mice intervened with Cordyceps guangdongensis polysaccharides

Cordyceps guangdongensis, a novel edible mushroom in China, has shown many positive health effects. In this study, we extracted the C. guangdongensis polysaccharides (CGP) from the fruiting bodies, and investigated the mechanism for CGP improved high-fat diet-induced (HFDI) metabolic diseases. We found that CGP notably reduced fat mass, improved blood lipid levels and hepatic damage, and restored the gut microbiota dysbiosis induced by high-fat diet (HFD). Metabolome analyses showed that CGP changed the composition of bile acids, and regulated HFDI metabolic disorder in hepatic tissue. Transcriptome comparison showed that the improvement of hepatic steatosis for CGP was mainly related to lipid and carbohydrate metabolism. Association analysis result revealed that Odoribacter, Bifidobacterium and Bi. pseudolongum were negatively correlated to fat and blood lipid indicators, and were significantly associated with genes and metabolites related to carbohydrate and lipid metabolism. Collectively, these results indicate that CGP may be a promising supplement for the treatment of obesity and related metabolic diseases.

Mechanism of Takifugu bimaculatus Skin Peptides in Alleviating Hyperglycemia in Rats with Type 2 Diabetic Mellitus Based on Microbiome and Metabolome Analyses

In this study, we aimed to explore the hypoglycemic effects of a hydrolysate on Takifugu bimaculatus skin (TBSH). The effect of the dipeptidyl peptidase-IV (DPP-IV) inhibitory activities from different TBSH fractions was investigated on basic indexes, gut hormones, blood lipid indexes, viscera, and the gut microbiota and its metabolites in rats with type 2 diabetes mellitus (T2DM). The results showed that the <1 kDa peptide fraction from TBSH (TBP) exhibited a more potent DPP-IV inhibitory effect (IC50 = 0.45 ± 0.01 mg/mL). T2DM rats were induced with streptozocin, followed by the administration of TBP. The 200 mg/kg TBP mitigated weight loss, lowered fasting blood glucose levels, and increased insulin secretion by 20.47%, 25.23%, and 34.55%, respectively, rectified irregular hormonal fluctuations, lipid metabolism, and tissue injuries, and effectively remedied gut microbiota imbalance. In conclusion, TBP exerts a hypoglycemic effect in rats with T2DM. This study offers the potential to develop nutritional supplements to treat T2DM and further promote the high-value utilization of processing byproducts from T. bimaculatus. It will provide information for developing nutritional supplements to treat T2DM and further promote the high-value utilization of processing byproducts from T. bimaculatus.

Dioscoreae Rhizoma starch improves chronic diarrhea by regulating the gut microbiotas and fecal metabolome in rats

Chinese yam (Dioscorea opposite Thunb.) has been used as food and medicine to treat diarrhea for thousands of years. This article aimed to elucidate the potential mechanism of Dioscoreae Rhizoma starch in alleviating chronic diarrhea induced by rhubarb based on gut microbiotas and fecal metabolome. The administration of the Dioscoreae Rhizoma aqueous extracts, crude polysaccharides, and starch could improve diarrhea and alleviate intestinal injury in chronic diarrhea rats. The Dioscoreae Rhizoma starch displayed the most apparent effect on regulating intestinal microbiotas by increasing the abundance and diversity of microbiotas. At the genus level, there were 17 changed intestinal microbiotas in model rats, and the treatment with Dioscoreae Rhizoma starch regulated 11 microbiotas. Metabolomics analysis revealed that Dioscoreae Rhizoma starch could regulate abnormal fecal metabolites to alleviate diarrhea, and these metabolites are involved in phenylalanine, tyrosine, and tryptophan biosynthesis; tyrosine metabolism; vitamin B6 metabolism; and purine metabolism. This study will contribute to the further research and development of Dioscoreae Rhizoma starch.

Anti-obesity mechanism of Ganpu tea revealed by microbiome, metabolome and transcriptome analyses

In this study, the anti-obesity mechanism of Ganpu tea (GPT) from the perspectives of microbiome, metabolome and transcriptome was investigated. GPT significantly reduced the high-fat-diet (HFD)-induced levels of inflammatory cytokines and the expansion of lipid droplets and white adipose tissue. GPT also improved HFD-induced gut microbiome imbalance by significantly reducing the proportion of Firmicutes to Bacteroidota. Metabolomic data showed that HFD-induced metabolic disorder was regulated by GPT and probably characterised by being related to 4-aminobutyraldehyde and 5-acetylamino-6-amino-3-methyluracil. Transcriptome showed that the improvement of obesity was mainly related to the IL-17 signaling pathway and the metabolism of xenobiotics by cytochrome P450. Spearman's correlation analysis indicated that gut microbiota were significantly correlated with inflammatory factors, genes and metabolites. Metabolome-transcriptome analysis showed that GPT reversed obesity mainly through the carbohydrate metabolism, amino acid metabolism and lipid metabolism.Collectively, GPT may be used as a health drink to prevent or treat obesity.

In vitro digestion and fermentation combined with microbiomics and metabolomics reveal the mechanism of superfine yak bone powder regulating lipid metabolism by altering human gut microbiota

The effects of superfine yak bone powder (YBP) on human gut microbiota (HGM) were investigated by in vitro digestion and fermentation combined with microbiomics and metabolomics. Results showed that size reduction and protein structural degradation during digestion allowed superfine YBP to release more Ca²⁺ than CaCO₃ powders with similar particle size. Moreover, the indigestible YBP further influenced HGM and was associated with increased occurrence of beneficial bacteria such as Megasphaera spp., Megamonas spp., Acidaminococcus spp., and Prevotella spp. The altered HGM was associated with greater production of short-chain fatty acids with 4-6 carbon atoms. Furthermore, the indigestible YBP was associated with up-regulation of many lipid-related metabolites, including taurine, secondary bile acids, saturated long-chain fatty acids, and ω-3/ω-6 polyunsaturated fatty acids, which modulated favorably lipid metabolic pathways. These findings implied the potential activity of superfine YBP as a food fortifier in favorably altering HGM community structure and regulating lipid metabolism.

The Bioaccessibility of Yak Bone Collagen Hydrolysates: Focus on Analyzing the Variation Regular of Peptides and Free Amino Acids

The lack of a bioaccessibility test for yak bone collagen hydrolysates (YBCH) limits their development as functional foods. In this study, simulated gastrointestinal digestion (SD) and absorption (SA) models were utilized to evaluate the bioaccessibility of YBCH for the first time. The variation in peptides and free amino acids was primarily characterized. There was no significant alteration in the concentration of peptides during the SD. The transport rate of peptides through the Caco-2 cell monolayers was 22.14 ± 1.58%. Finally, a total of 440 peptides were identified, more than 75% of them with lengths ranging from 7 to 15. The peptide identification indicated that about 77% of the peptides in the beginning sample still existed after the SD, and about 76% of the peptides in the digested YBCH could be observed after the SA. These results suggested that most peptides in the YBCH resist gastrointestinal digestion and absorption. After the in silico prediction, seven typical bioavailable bioactive peptides were screened out and they exhibited multi-type bioactivities in vitro. This is the first study to characterize the changes in peptides and amino acids in the YBCH during gastrointestinal digestion and absorption, and provides a foundation for analyzing the mechanism of YBCH's bioactivities.

Innovative Application of Metabolomics on Bioactive Ingredients of Foods

Metabolomics, as a new omics technology, has been widely accepted by researchers and has shown great potential in the field of nutrition and health in recent years. This review briefly introduces the process of metabolomics analysis, including sample preparation and extraction, derivatization, separation and detection, and data processing. This paper focuses on the application of metabolomics in food-derived bioactive ingredients. For example, metabolomics techniques are used to analyze metabolites in food to find bioactive substances or new metabolites in food materials. Moreover, bioactive substances have been tested in vitro and in vivo, as well as in humans, to investigate the changes of metabolites and the underlying metabolic pathways, among which metabolomics is used to find potential biomarkers and targets. Metabolomics provides a new approach for the prevention and regulation of chronic diseases and the study of the underlying mechanisms. It also provides strong support for the development of functional food or drugs. Although metabolomics has some limitations such as low sensitivity, poor repeatability, and limited detection range, it is developing rapidly in general, and also in the field of nutrition and health. At the end of this paper, we put forward our own insights on the development prospects of metabolomics in the application of bioactive ingredients in food.

Flavonoids from Lycium barbarum leaves attenuate obesity through modulating glycolipid levels, oxidative stress, and gut bacterial composition in high-fat diet-fed mice

Traditional herbal therapy made from Lycium barbarum leaves has been said to be effective in treating metabolic diseases, while its exact processes are yet unknown. Natural flavonoids are considered as a secure and reliable method for treating obesity. We thus made an effort to investigate the processes by which flavonoids from L. barbarum leaves (LBLF) reduce obesity. To assess the effectiveness of the intervention following intragastric injection of various dosages of LBLF (50, 100, and 200 mg/kg⋅bw), obese model mice developed via a high-fat diet were utilized. Treatment for LBLF may decrease body weight gain, Lee’s index, serum lipids levels, oxidative stress levels, and hepatic lipids levels. It may also enhance fecal lipids excretion and improve glucose tolerance. Additionally, LBLF therapy significantly restored gut dysfunction brought on by a high-fat diet by boosting gut bacterial diversities and altering the composition of the gut bacterial community by elevating probiotics and reducing harmful bacteria.

Fu brick tea alleviates alcoholic liver injury by modulating the gut microbiota-liver axis and inhibiting the hepatic TLR4/NF-κB signaling pathway

This study first evaluated the protective effects of Fu brick tea water extracts (FTE) on alcoholic liver injury and its underlying mechanism in C57BL/6J mice. Oral administration of FTE by oral gavage (400 mg per kg bw) for 12 weeks significantly alleviated lipid metabolism disorder, reduced the activities of serum ALT and AST, decreased the expression of the liver CYP2E1 gene, and enhanced the antioxidant capacities of the livers in alcohol-fed mice (p < 0.05). FTE also relieved alcohol-induced gut microbiota dysbiosis by promoting the proliferation of probiotics such as Muribaculaceae and Lactobacillus, and subsequently increased the cecal levels of short-chain fatty acids (SCFAs) and decreased the tryptophan content of alcohol-fed mice (p < 0.05). Importantly, FTE was found to improve the alcohol-impaired gut barrier function by up-regulating the expression of the epithelial tight junction protein. Accordingly, FTE decreased the circulating lipopolysaccharide (LPS) and thus inhibited the hepatic TLR4/NF-κB signaling pathway to ameliorate alcoholic liver injury. Cumulatively, these findings shed light on the important role of the gut microbiota-liver axis behind the protective efficacy of FTE on alcoholic liver injury.