內(nèi)容: Laminarin oligosaccharides (LOSs) with a specific degree of polymerization prepared through the laminarin degradation via laminarinase present more significant nutritional functions and application values. Human intestinal bacteria are promising potential producers of novel carbohydrate-active enzymes with unique properties. Here, a novel glycoside hydrolase family 128 (GH128) laminarinase OUC-BsLam26 from the intestinal bacterium Bacteroides sp. CBA7301 was heterologously expressed and characterized. The recombinant OUC-BsLam26 with a molecular mass of 49.86 kDa exhibits highest activity (6.60 U/mg) at 45 °C and pH 6.0, which shows noticeable temperature and pH stability. The purified OUC-BsLam26 could degrade laminarin via an endo-type mode with the generation of laminaripentaose, laminaritetraose, laminaritriose, and laminaribiose, among them, laminaritetraose is the principal product, which accounts for 45.25% of the total products, which is significantly different from the reported GH128 laminarinases. The minimum recognition substrate of OUC-BsLam26 is laminarihexaose. Furthermore, OUC-BsLam26 also could catalyze the transglycosylation process with the production of some novel glycosides. Altogether, the intestinal bacterium Bacteroides sp. CBA7301 contains laminarinase with unique product composition and OUC-BsLam26 is a hopeful bio-catalyst with the potential to produce laminaritetraose and some novel glycosides.

內(nèi)容: The high incidence of postpartum hypogalactia hinders the healthy development of postpartum women and the next generation. Lacquer seed oil (LSO), extracted from the seeds of the lacquer tree, has been traditionally used as a dietary supplement for promoting postpartum lactation and recovery in some districts of China. However, its physiological effects have not been verified, and the mechanism and active components of LSO have not been analyzed. Thus, we applied LSO to bromocriptine-induced postpartum hypogalactia rats. The results showed that LSO supplement effectively improves bromocriptine-induced postpartum hypogalactia. LSO also increased prolactin levels reduced by bromocriptine, promoted JAK2/STAT5 and PI3K/AKT pathways and several gene expression levels of milk synthesis in mammary gland. Moreover, metabolomic and network pharmacological analysis further revealed that JAK2/STAT5, PI3K/AKT, and estrogen signaling pathway are the potential main regulatory sites for the beneficial effects of LSO on postpartum hypogalactia, and that quercetin, kaempferol, arachidonic acid, epicatechin, and β-sitosterol are the top 5 main active ingredients of LSO. Our results suggested that LSO has great potential in the application of the improvement of postpartum hypogalactia.

內(nèi)容: Cadmium ion (Cd2+) detection technology plays a prominent role in food safety and human health. Herein, we designed and constructed an 2-aminoethyl dihydrogen phosphate (AEP)@upconversion nanoparticles (UCNPs) fluorescence sensor for quantitative detection of Cd2+ in paddy rice based on inner filter effect (IFE) combined with enzyme inhibition mechanism.?The AEP modification UCNPs can offer a stable fluorescence donor at 658 nm and be quenched by the oxidized tetramethylbenzidine (oxTMB) catalyzed by horseradish peroxidase (HRP) enzymes. Without addition of Cd2+, the fluorescence of AEP@UCNPs fluorescence sensor was weaken due to the IFE between AEP@UCNPs and oxTMB. With addition of Cd2+, HRP enzyme activity was inhibited by Cd2+, leading to the decreased oxTMB, resulting in the enhance upconversion fluorescence intensity. As a result, the fluorescence intensity signal at 658 nm of the IFE-based AEP@UCNPs fluorescence sensor increased linearly with the increase in Cd2+ in a wide range from 0.5 μmol/L to 6 μmol/L and the limit of detection (LOD) was 24.6 nmol/L. In addition, our proposed IFE-based AEP@UCNPs fluorescence sensor can achieve Cd2+ detection in paddy rice in 30 min.

內(nèi)容: Fructose consumption has risen dramatically in recent decades due to the use of sucrose and high fructose corn syrup in beverages and processed foods, contributing to rising rates of hyperuricemia. The purpose of this experiment was to explore the anti-hyperuricemia effects of an active oligopeptide (GPSGRP) derived from sea cucumber in fructose induced hyperuricemia mouse model, and to clarify the underlying mechanism in sight of gut microbiota and serum metabolites. Peptide GPSGRP treatment rebalanced uric acid metabolism and alleviated inflammatory response in mice. In addition, treatment with GPSGRP decreased the abundance of Bacteroides and Proteobacteria at the phylum level, Muribaculum, Prevotella and Bacteroides at the genus level, and inhibited the related pathways of purine metabolism and glycolysis/gluconeogenesis metabolism. Moreover, serum metabolites, including linoleic acid, indole and its derivatives, arachidonic acid and uridine, as well as related metabolic pathways, such as tricarboxylic acid cycle, ketone production and sugar production, were altered in response to GPSGRP treatment. This study provides a valuable reference for the application and development of marine biological peptides in uric acid management.

內(nèi)容: Punicalagin has been demonstrated to exhibit anti-oxidant and anti-inflammatory properties, but whether and how it could impact hypercholesterolemia remains not fully explored. The aim of this study was to investigate the influence of punicalagin on hypercholesterolemia in mice and its related mechanisms. After 6 weeks’ intervention, punicalagin significantly reduced serum total cholesterol and low-density lipoprotein cholesterol (LDL-C) levels in mice fed a high-fat high-cholesterol (HFHC) diet. Meanwhile, punicalagin supplementation lowered hepatic cholesterol level, which corresponded to the down-regulation of cholesterol synthesis genes (Fdps, Cyp51) and up-regulated bile acid synthesis genes (Cyp7a1, Cyp27a1). In addition, bile acid reabsorption was retarded in punicalagin-fed mice through down-regulating ileal apical sodium-dependent BA transporter (ASBT). Furthermore, intestinal farnesoid X receptor (FXR)-fibroblast growth factor 15 (Fgf15) pathway was inhibited while hepatic FXR-small heterodimeric partner (SHP) pathway was activated in punicalagin group. Microbiota analysis and targeted metabolomics showed that punicalagin decreased the abundance of bile-salt hydrolase (BSH)-producing bacteria (Clostridiaceae and Bifidobacteriaceae) and the ratio of primary BAs to secondary BAs. In conclusion, the cholesterol-lowering effect of punicalagin partly through down-regulating cholesterol synthesis and increasing cholesterol catabolism, which could be achieved by regulating gut microbiota, altering bile acid composition and modulating FXR signaling pathway. These findings indicate the potential application of punicalagin-related products as an alternative strategy for hypercholesterolemia prevention and mitigation.

內(nèi)容: Mold spoilage and nutrition enrichment are major concerns of Chinese steamed bread, and using functional lactic acid bacteria as starter to play the role of in-situ preservation and nutritional fortification was a promising alternative. Hence, Lactiplantibacillus plantarum P10 capable of inhibiting spoilage microorganisms and producing γ-aminobutyric acid (GABA) (380 mg/L) was screened from Chinese pickle. Metabolomics analysis showed that P10 produced key antimicrobial metabolites mainly including ten organic acids, aldehyde, alkaloid. Besides, P10 might exhibit health beneficial effects such as degrading cholesterol, lowering blood glucose and reducing uric acid due to the production of deoxycholic acid and Ile-Pro-Ile, and the degradation of purine. Finally, the promising application potential of P10 was evidenced in steamed bread with extended shelf life, excellent anti-aging effect, and 24.5-fold enrichment of GABA. Conclusively, this investigation could provide scientific basis for the application of P10 as a functional starter in steamed bread.

內(nèi)容: This study was performed to investigate the changes in microbial communities and metabolites during the long-term fermentation of commercially manufactured anchovy sauce. Samples of commercial anchovy sauce were collected from large-scale fermentation tanks with fermentation periods of up to 7.87 years. The complex bacterial community was simplified to two genera, Tetragenococcus and Halanaerobium, after approximately 0.55 years of fermentation. Although genera, such as Saccharomyces, Cladosporium, Candida, and Aspergillus, were relatively dominant, no clear pattern was identified in fungal community analysis. The longitudinal metabolite profile demonstrated that approximately half (55.8%) of the metabolites present in anchovy sauce were produced within a year of fermentation due to rapid fermentation. Despite the static microbial community, the contents of several metabolites including amino acids and biogenic amines changed continuously during the long-term fermentation of anchovy sauce. This study provides novel insights into the changes in microbiota and metabolites in fish sauce produced without any starter inoculation.

內(nèi)容: Insomnia is associated with neurotransmitters and intestinal dysbiosis. Though studies have demonstrated the ameliorative effects of milk hydrolysates on insomnia, the underlying mechanisms require further exploration. In this study, we investigated how papain hydrolysates of goat casein (CPH) and whey protein (WPH) affected mice’s sleeplessness. Here, we show that CPH effectively improved the total sleep time in 12 h and restoring neurotransmitters (5-hydroxytryptamine (5-HT), γ-aminobutyric acid (GABA), dopamine (DA), and norepinephrine (NE)) in mice. Further gut microbiota analysis revealed a significant increase in the relative abundance of Helicobacter and Escherichia-Shigella and a decrease in the relative abundance of Lactobacillus in the insomnia model mice (Model). Compared to the Model group, both CPH and WPH significantly increased the relative abundance of Akkermansia and Lactobacillus while lowering the relative abundance of Helicobacter and Escherichia-Shigella. Notably, while diazepam (DZP) increased mouse sleep duration, it also increased the relative abundance of Colidextribacter, Parasutterella, Muribaculaceae, and Prevotella. Additionally, the gene expression and protein expression of GABAA receptor, cAMP-response element binding protein (CREB), and brain-derived neurotrophic factor (BDNF) were upregulated in the hypothalamus. We also discovered a link between intestinal gut microbiota and neurotransmitters. Overall, our results suggest that goat milk hydrolysates, especially CPH, can effectively improve insomnia, providing a theoretical basis for further experimentation and individualized designs.

內(nèi)容: In this work, one-step growth models using hyperspectral imaging (HSI) (400–1 000 nm) were successfully developed in order to estimate the microbial loads, minimum growth temperature (Tmin) and maximum specific growth rate (μmax) of Brochothrix thermosphacta in chilled beef at isothermal temperatures (4–25 °C). Three different methods were compared for model development, particularly using (Model I) the predicted microbial loads from partial least squares regression of the whole spectral variables; (Model II) the selected spectral variables related to microbial loads; and (Model III) the first principal scores of HSI spectra by principal component analysis. Consequently, Model I showed the best ability to predict the microbial loads of B. thermosphacta, with the coefficient of determination (Rv2) and root mean square error in internal validation (RMSEV) of 0.921 and 0.498 (lg (CFU/g)). The Tmin (–12.32 °C) and μmax can be well estimated with R2 and root mean square error (RMSE) of 0.971 and 0.276 (lg (CFU/g)), respectively. The upward trend of μmax with temperature was similar to that of the plate count method. HSI technique thus can be used as a simple method for one-step growth simulation of B. thermosphacta in chilled beef during storage.

內(nèi)容: Fucoxanthin, a kind of exclusively algae-derived carotenoids, could reduce lipid content and regulate gut microbiota composition in obese mice, showing potential in preventing hyperlipidemia. This study aimed to illustrate fucoxanthin efficacy in modulating lipid metabolism in serum and liver of high-fat-induced hyperlipidemia mice, as well as investigate the underlying association with gut microbiota changes. Results showed that fucoxanthin significantly reduced body weight gain and body white fat of the mice. In the serum, total triglycerides (TG), total cholesterol (TC) contents were significantly decreased and high-density-lipoprotein cholesterol levels was significantly upregulated. Moreover, fucoxanthin remarkedly prevented lipid accumulation in the liver. Especially, metabolomics results showed that lipids and lipid-like molecules were significantly downregulated compared with the control, indicating the advance of hepatic lipid metabolism. Bile acids profile in the liver was also greatly changed by fucoxanthin. Meanwhile, fucoxanthin remodeled gut microbiota composition and promoted the relative abundance of Desulfovibrio, Blautia and Clostridia genera. Finally, correlation analysis revealed that these gut microbiota changes were closely related with hepatic metabolites/metabolism and serum lipids. Altogether, this study showed great potential of fucoxanthin in improving serum lipids profile, hepatic lipids and bile acids metabolism of hyperlipidemia mice, which was associated with gut microbiota alteration.