內容: Bone collagen hydrolysates (peptides) derived from byproduct of animal product processing have been used to produce commercially valuable products due to their potential antioxidant activity. Maillard glycosylated reaction is considered as a promising method to enhance the antioxidant activity of peptides. Hence, this research aims at investigating the Maillard glycosylation activity and antioxidant activity of bone collagen hydrolysates from different sources. In this study, 3 glycosylated bone collagen hydrolysates were prepared and characterized, and cytotoxicity and antioxidant activity were analyzed and evaluated. The free amino groups loss, browning intensity, and fluorescence intensity of G-Cbcp (glycosylated chicken bone collagen hydrolysates (peptides)) were the heaviest, followed by G-Pbcp (glycosylated porcine bone collagen hydrolysates (peptides)) and G-Bbcp (glycosylated bovine bone collagen hydrolysates (peptides)). The results of amino acid analysis showed that amino acid composition of different bone collagen hydrolysates was significantly different and the amino acid decreased to different degrees after Maillard glycosylated reaction, which may lead to differences in Maillard glycosylated reaction activity. Furthermore, the 3 glycosylated hydrolysates showed no significant cytotoxicity. The results showed that glycosylation process significantly increased the antioxidant activity of bone collagen hydrolysates, and G-Cbcp showed the strongest antioxidant activity, followed by G-Pbcp and G-Bbcp. Therefore, compared with the bone collagen hydrolysates, 3 glycosylated hydrolysates showed significant characteristic and structural changes, and higher antioxidant activity.

內容: Highland barley (HB) is a high-altitude cereal with rich nutritional components and potential health benefits. To clarify its hypoglycemic effect and mechanism, we investigated the effect of whole grain HB and fecal microbiota transplantation (FMT) on glucose metabolism and gut microbiota in high-fat diet and streptozotocin (HFD/STZ)-induced diabetic mice. The results showed that HB (40%) significantly decreased fasting blood glucose and the area under the glucose tolerance curve, significantly increased insulin secretion and improved insulin resistance in HFD/STZ-induced diabetic mice (P < 0.05). Inflammatory factors and blood lipid indices were also significantly alleviated after 12 weeks of 40% HB intervention (P < 0.05). Additionally, beneficial bacteria, such as Bifidobacterium and Akkermansia, were significantly enriched in the gut of diabetic mice after whole grain HB intervention. Meanwhile, the results of further FMT experiments verified that the fecal microbiota after the 40% HB intervention not only significantly increased the relative abundance of Bifidobacterium and Akkermansia but also effectively improved glucose metabolism and alleviated the inflammatory state in HFD/STZ-induced diabetic mice. Collectively, our study confirmed the bridge role of gut microbiota in improving glucose metabolism of whole grain HB, which could promote the development of precision nutrition.

內容: Sensitive detection of Staphylococcus aureus enterotoxin B (SEB) is of importance for preventing food poisoning from threatening human health. In this work, an electrochemical and colorimetric dual-signal detection assay of SEB was developed. The probe (Ab2/AuPt@Fe-N-C) was bound to SEB captured by Ab1, where the Ab2/AuPt@Fe-N-C triggered methylene blue degradation and resulted in the decrease of electrochemical signal. Furthermore, the probe catalyzed the oxidation of 3,3’,5,5’-tetramethyl biphenyl to generate a colorimetric absorbance at 652 nm. Once the target was captured and formed a sandwich-like complex, the color changed from colorless to blue. SEB detection by colorimetric and electrochemical methods showed a linear relationship in the concentration ranges of 0.000 2–10.000 0 and 0.000 5–10.000 0 ng/mL, with limits of detection of 0.066 7 and 0.167 0 pg/mL, respectively. The dual-signal biosensor was successfully used to detect SEB in milk and water samples, which has great potential in toxin detection in food and the environment.

內容: Obesity is associated with gut dysbiosis and metabolic endotoxin. Junshanyinzhen tea extract (JSTE) reduced fat accumulation and body weight in obese mice. However, the effects and mechanism of JSTE in preventing obesity were unclear. Therefore, we used different doses of JSTE (75, 150 and 300 mg/(kg?day)) to evaluate the effect on high-fat diet (HFD)-induced rats under 8 weeks of intervention. Here, our results showed that JSTE could significantly reduce body weight gain, blood lipid levels and fat accumulation, improve fatty damage in liver tissue (P < 0.05). In addition, JSTE increased the expression of intestinal tight junction proteins (P < 0.05), relieved metabolic endotoxemia (P < 0.05) and chronic low-grade inflammation in HFD rats. Sequencing of fecal samples showed that JSTE could effectively reverse the microbial diversity and the ratio of Firmicutes to Bacteroidetes to normal levels in HFD-fed rats. Desulfovibrioceae and Erysipelotrichaceae, which are positively related to obesity, were decreased by JSTE intervention (P < 0.05). while Bifidobacteriaceae, Bacteroidaceae, Akkermansia, and Clostridium, which are negatively related to obesity, were increased. Together, these results suggested that JSTE might effectively prevent obesity by modulating gut microbiota dysbiosis, intestinal barrier dysfunction, metabolic endotoxemia and chronic low-grade inflammation in HFD-induced rats.

內容: The application of microorganisms as probiotics is limited due to lack of safety evaluation. Here, a novel multi-stress-tolerant yeast Meyerozyma guilliermondii GXDK6 with aroma-producing properties was identified from marine mangrove microorganisms. Its safety and probiotic properties were assessed in accordance with phenotype and whole-genome sequencing analysis. Results showed that the genes and phenotypic expression of related virulence, antibiotic resistance and retroelement were rarely found. Hyphal morphogenesis genes (SIT4, HOG1, SPA2, ERK1, ICL1, CST20, HSP104, TPS1, and RHO1) and phospholipase secretion gene (VPS4) were annotated. True hyphae and phospholipase were absent. Only one retroelement (Tad1-65_BG) was found. Major biogenic amines (BAs) encoding genes were absent, except for spermidine synthase (JA9_002594), spermine synthase (JA9_004690), and tyrosine decarboxylase (inx). The production of single BAs and total BAs was far below the food-defined thresholds. GXDK6 had no resistance to common antifungal drugs. Virulence enzymes, such as gelatinase, DNase, hemolytic, lecithinase, and thrombin were absent. Acute toxicity test with mice demonstrated that GXDK6 is safe. GXDK6 has a good reproduction ability in the simulation gastrointestinal tract. GXDK6 also has a strong antioxidant ability, β-glucosidase, and inulinase activity. To sum up, GXDK6 is considered as a safe probiotic for human consumption and food fermentation.

內容: Two selenium (Se)-containing peptides from Se-enriched rice, TSeMMM and SeMDPGQQ, possess neuroprotective potency against lead (Pb2+)-induced cytotoxicity. However, the crosstalk between mRNA and microRNAs (miRNA) involved in the neuroprotection mechanism remains to be elucidated. In this study, RNA-sequencing and miRNA-sequencing were used to independently identify differentially expressed mRNAs and small RNAs profiles in Pb2+-treated primary fetal rat cortical neurons and then the correlated miRNA?mRNA target pairs were obtained. It was found that 34 mRNAs related to oxidative phosphorylation could be reversed by pretreatment of TSeMMM and SeMDPGQQ. The protective effect of TSeMMM and SeMDPGQQ was mediated by upregulation of miR-107-3p, which downregulates the ATPase H+ transporting V0 subunit e1 (Atp6v0e1) mRNA level. A zebrafish model was applied to verify the relevance between the targeted mRNA and miRNA by real-time quantitative PCR. The results indicated that miR-107-3p was a potential therapeutic target to achieve neuroprotection of Se-containing peptides via stimulation of Atp6v0e1.

內容: Oxidative stress is one of the main ways to cause alcohol-induced liver injury, and alcoholic liver disease (ALD) has been a common health problem worldwide. Lactic acid bacteria (LAB) is also considered as a potential treatment to alleviate alcohol-induced liver injury. Lactobacillus plantarum J26 is a LAB isolated from Chinese traditional fermented dairy products with excellent probiotic effects. This study aimed to establish a mice model of alcoholic liver injury through acute-on-chronic alcohol feeding and to study the alleviating effect of pre-intake of L. plantarum J26 on alcohol-induced oxidative liver injury and focus on its potential mechanism of alleviating effect. The results showed that pre-intake of L. plantarum J26 could improve liver pathological changes, reduce lipid accumulation, increase mitochondrial ATP and mitochondrial (mtDNA) levels, and alleviate liver injury. In addition, pre-intake L. plantarum J26 can improve the level of short-chain fatty acids (SCFAs) in the intestines in mice, short chain fatty acids can be used as a signaling molecule activation of nuclear factor E2-related factor 2 (Nrf2) signaling pathway to alleviate liver oxidative stress, and maintain mitochondrial homeostasis by regulating the expression of genes related to mitochondrial dynamics and autophagy, thereby reducing cell apoptosis to alleviate alcohol-induced oxidative liver injury.

內容: Recent studies indicated that vitamin A (VA) might be involved in the pathology of type 2 diabetes mellitus (T2DM). This cross-sectional study was conducted to explore the association between circulating VA level and T2DM. A total of 1 818 subjects aged 50 years old and above were recruited from the community. Binomial logistic regression and restricted cubic spline (RCS) were applied to analyze the association of plasma VA level with the risk of T2DM. Serum VA and lipid-adjusted VA levels of T2DM patients were significantly higher than that of non-T2DM subjects (P < 0.05). The ratios of plasma VA/total cholesterol (TC), VA/high-density lipoprotein cholesterol (HDL-c) and VA/low-density lipoprotein cholesterol (LDL-c) were positively associated with the risk of T2DM in the aging population (P < 0.05). Compared with the Q1 level, subjects with Q2 to Q3 levels of plasma VA/triglyceride (TG) have decreased risk of T2DM (odds ratio (OR)Q2 = 0.68, PQ2 = 0.021; ORQ3 = 0.59, PQ3 < 0.01). Our results indicated that the imbalance of circulating lipids and VA might affect the relationship between VA and T2DM. The middle and aging subjects with higher ratios of plasma VA/TC, VA/HDL-c, and VA/LDL-c displayed increased risk for T2DM, but the moderate ratio of VA/TG might protect against risk of T2DM.

內容: The effects of 5 lactic acid bacteria (LAB) fermentation on the pasting properties of glutinous rice flour were compared, and suitable fermentation strains were selected based on the changes of viscosity, setback value, and breakdown value to prepare LAB compound starter cultures. The results revealed that Latilactobacillus sakei HSD004 and Lacticaseibacillus rhamnosus HSD005 had apparent advantages in increasing the viscosity and reducing the setback and breakdown values of glutinous rice flour. In particular, the compound starter created using the two abovementioned LAB in the ratio of 3:1 had better performance than that using a single LAB in improving the pasting properties and increasing the water and oil absorption capacity of glutinous rice flour. Moreover, the gelatinization enthalpy of the fermented samples increased significantly. For frozen glutinous rice dough stored for 28 days, the viscoelasticity of frozen dough prepared by compound starter was better than that of control dough, and the freezable water content was lower than that of control dough. These results indicate that compound LAB fermentation is a promising technology in the glutinous rice-based food processing industry, which has significance for its application.

內容: Autoimmune hepatitis (AIH) is a chronic inflammatory liver disease that threatens human health worldwide. The aim of this study was to detect the protective effect of a fermented Lentinus edodes extract containing α-glucan (FLA), in a concanavalin A (ConA)-induced AIH mouse model and to determine the underlying liver-protective mechanism. The results showed that compared with the model group, the level of proinflammatory cytokines in serum of FLA pretreated mice was significantly decreased, and the degree of inflammatory cell infiltration in liver, thymus and spleen was significantly reduced. Quantitative polymerase chain reaction, immunohistochemistry, and Western blotting showed that FLA pre-treatment inhibited the ConA-induced apoptosis of hepatocytes by down-regulating the expression of BAX and up-regulating the expression of BCL-2. Further research found that FLA may improve liver injury in mice by activating NRF2 signaling pathway and inhibiting TRAF6/NF-κB signaling pathway. Thus, FLA may improve liver injury in mice by shifting gut microbial composition to reduce the release of inflammatory cytokines in the serum and prevent the necrosis of hepatocytes. Up-regulation of NRF2 signaling pathway, down-regulation of TRAF6/NF-κB signaling pathway, and an increase in the relative abundance of Lactobacillus_johnsonii and Ligilactobacillus_murinus play a protective role in liver.