Pectic oligosaccharides ameliorate high-fat diet-induced obesity and hepatic steatosis in association with modulating gut microbiota in mice.

Accumulating evidence has shown that gut microbiota and its metabolites have important significance in the etiology of obesity and related disorders. Prebiotics prevent and alleviate obesity by modulating the gut microbiota. However, how pectin oligosaccharides (POS) derived from pectin degradation affect gut microbiota and obesity remains unclear. To investigate the potential anti-obesity effects of POS, mice were fed a high-fat diet (HFD) for 12 weeks and a POS supplement with drinking water during the last 8 weeks. The outcomes demonstrated that POS supplementation in HFD-fed mice decreased body weight (P < 0.01), improved glucose tolerance (P < 0.001), reduced fat accumulation (P < 0.0001) and hepatic steatosis, protected intestinal barrier, and reduced pro-inflammatory cytokine levels. After fecal metagenomic sequencing, the POS corrected the gut microbiota dysbiosis caused by the HFD, as shown by the increased populations of Bifidobacterium, Lactobacillus taiwanensis, and Bifidobacterium animalis, and decreased populations of Alistipes and Erysipelatoclostridium, which were previously considered harmful bacteria. Notably, the changed gut microbiota was associated with the obesity prevention of POS. These findings demonstrate that POS regulates particular gut microbiota, which is essential owing to its ability to prevent disorders associated with obesity.

Preventive effect of pectic oligosaccharides on acute colitis model mice: modulating epithelial barrier, gut microbiota and Treg/Th17 balance.

Pectin as a dietary fiber supplement has shown emerging potential in clinical ulcerative colitis (UC) adjuvant therapy. In this study, the preventive and prebiotic effects of enzymatically degraded pectic oligosaccharides (POS) were further explored in dextran sodium sulfate (DSS)-induced colitis mice. The POS supplement (400 mg kg-1) was significantly effective at improving preventive efficacy, promoting colonic epithelial barrier integrity and reducing inflammatory cytokines. Meanwhile, the changes in T regulatory (Treg) cells and T helper 17 (Th17) cells indicated that POS treatment regulated the Treg/Th17 balance. Gut microbiota analysis showed that the POS supplement reshaped the dysfunctional gut microbiota. Further Spearman's correlation coefficient analysis indicated that the changes of the gut microbiota were highly associated with modulating the epithelial barrier, promoting the development of Treg cells and suppressing the differentiation of pro-inflammatory Th17 cells. All of these results suggest that enzymatically- degraded POS is a promising therapeutic agent for UC prevention and adjuvant treatment by maintaining intestinal homeostasis.

Characterization and Application of a New ß-Galactosidase Gal42 From Marine Bacterium Bacillus sp. BY02.

ß-Galactosidase plays an important role in medicine and dairy industry. In this study, a new glycoside hydrolase family 42 (GH42) ß-galactosidase-encoding gene, gal42, was cloned from a newly isolated marine bacterium Bacillus sp. BY02 and expressed in Escherichia coli. Structural characterization indicated that the encoding ß-galactosidase, Gal42, is a homotrimer in solution, and homology modeling indicated that it retains the zinc binding sites of the Cys cluster. The reaction activity of Gal42 was significantly increased by Zn2+ (229.6%) and other divalent metal ions (Mn2+, Mg2+, and Co2+), while its activity was inhibited by EDTA (53.9%). Meanwhile, the thermo-stability of the Gal42 was also significantly enhanced by 5 and 10 mM of zinc ion supplement, which suggested that the "Cys-Zn" motif played important roles in both structural stability and catalytic function. Furthermore, Gal42 showed effective lactose hydrolysis activity, which makes the enzyme hydrolyze the lactose in milk effectively. These properties make Gal42 a potential candidate in food technology.

Polyguanidine-modified adsorbent to enhance marine applicability for uranium recovery from seawater.

The marine applicability of adsorbents intended for recovering uranium from seawater is crucial. For such applicability, the materials must exhibit anti-biofouling properties, seawater pH adaptability (pH~8), and salt tolerance. Extracting uranium from seawater is a long-term project; hence, biofouling, high salt concentrations, and weak alkaline environments negatively affect the adsorption of uranium and damage the recovered materials. Most studies on the extraction of uranium from seawater focus on increasing the adsorption capacity of the employed adsorbent, while its marine applicability is neglected. In the present study, three types of guanidine polymer (GP)-modified acrylic fibers were prepared to investigate the impact of the introduced structure on the marine applicability of the fibers. After screening, the introduction of polyhexamethylene biguanidine (PHMB) is observed to produce PAO-PHMB-A, characterized by excellent marine applicability. The enhanced properties include high antimicrobial activity (109 CFU/mL, 99.71%), good salt tolerance, and optimal adsorption at a pH of 8. Owing to the synergistic effect of its functional groups, the PAO-PHMB-A material exhibits excellent adsorption performance (525.89 mg/g), as well as high selectivity and durability. More importantly, long-term marine tests revealed that PAO-PHMB-A shows a remarkable uranium adsorption capacity (30 d, 3.19 mg/g) and excellent antibacterial activity. Considering its excellent marine applicability and good adsorption performance, the PAO-PHMB-A material developed in this work could serve as a potential adsorbent for engineering applications associated with uranium recovery from seawater.

Preventive and Prebiotic Effect of α-Galacto-Oligosaccharide against Dextran Sodium Sulfate-Induced Colitis and Gut Microbiota Dysbiosis in Mice.

ß-Galacto-oligosaccharide (ß-GOS) showed great potential in ulcerative colitis (UC) adjuvant therapy. Herein, the preventive and prebiotic effect of enzymatic-synthesized α-linked galacto-oligosaccharide (α-GOS) was investigated in dextran sodium sulfate-induced colitis and gut microbiota dysbiosis mice. Compared with ß-GOS, the α-GOS supplement was more effective in improving preventive efficacy, promoting colonic epithelial barrier integrity, and alleviating inflammation cytokines. Moreover, the activation of the NOD-like receptor (NLR) family member NLRP3 inflammasome-mediated inflammation was significantly inhibited by both α-GOS and ß-GOS. Gut microbiota analysis showed that α-GOS treatment reshaped the dysfunctional gut microbiota. The subsequent Spearman's correlation coefficient analysis indicated that these gut microbiota changes were significantly correlated with the inflammatory parameters. These results suggested that the enzymatic-synthesized α-GOS is a promising therapeutic agent in UC prevention and adjuvant treatment by maintaining intestinal homeostasis.

Enzymatically synthesized α-galactooligosaccharides attenuate metabolic syndrome in high-fat diet induced mice in association with the modulation of gut microbiota.

The composition and structure of gut microbiota plays an important role in obesity induced by a high-fat diet (HFD) and related metabolic syndrome (MetS). Previous studies have shown that galacto-oligosaccharides (GOSs) have an effective anti-obesity effect. In this study, we aimed to investigate the effect of enzymatically synthesized α-galacto-oligosaccharides (ES-α-GOSs) on MetS and gut microbiota dysbiosis in HFD-fed mice, and to further investigate whether the attenuation of MetS is associated with the modulation of gut microbiota. Our results indicated that ES-α-GOS could notably ameliorate obesity-related MetS, including hyperlipidemia, insulin resistance and mild inflammation. The subsequent analysis of gut microbiota further showed that ES-α-GOS supplements can significantly modulate the overall composition of the gut microbiota and reverse the gut microbiota disorder caused by HFD feeding. Moreover, Spearman correlation analysis showed that 40 key bacteria reversed by ES-α-GOS were highly associated with metabolic parameters. These results suggested that ES-α-GOSs could serve as a potential candidate for preventing obesity-induced MetS in association with the modulation of gut microbiota.

Unsaturated alginate oligosaccharides attenuated obesity-related metabolic abnormalities by modulating gut microbiota in high-fat-diet mice.

Gut microbiota plays an important role in the high-fat diet (HFD)-induced obesity and related metabolic syndrome (MetS). Our previous study has demonstrated that unsaturated alginate oligosaccharides (UAOS) degraded by alginate lyase possess significant anti-obesity effects in HFD-fed mice. Herein, we further established that UAOS could significantly ameliorate obesity-related metabolic abnormalities, including hyperlipidemia, insulin resistance and low-grade inflammation. Particularly, the beneficial effect of UAOS on these metabolic abnormalities could be significantly reversed by antibiotic supplementation. Subsequently, the microbiological analysis has revealed that UAOS treatment can modulate the overall composition of the gut microbiota, which is highly associated with metabolic parameters. UAOS supplementation can partially reverse the gut dysbiosis induced by HFD-diet or antibiotics. Specifically, UAOS treatment selectively increased the relative abundance of beneficial intestinal bacteria (e.g. Lactobacillus and Akkermansia genus) and decreased the abundance of inflammogenic bacteria (e.g. Bacteroides and Parabacteroides). These results suggest that UAOS can attenuate the HFD-induced obesity and related abnormalities through modulating gut microbiota, indicating that UAOS can act as potent prebiotic agents in treating obesity and related metabolic diseases.

Atractylenolide II prevents radiation damage via MAPKp38/Nrf2 signaling pathway.

Ionizing radiation (IR) can act as a negative factor for human homeostasis, by causing and even aggravating a series of pathological conditions. To protect the intactness of normal tissues, effective anti-radiation drugs are urgently needed for alleviating the outcomes of radioactive damage. In this study, we demonstrate that atractylenolide II (ATR II), a sesquiterpenoid monomer extracted from traditional Chinese medicine atractylodes macrocephala, can markedly suppress IR damage by promoting the expression of antioxidant factors heme oxygenase-1 (HO-1) and NAD(P)H dehydrogenase quinone oxido-reductase 1 (NQO-1), which are mediated by nuclear factor-erythroid 2-like 2 (Nrf2) signaling pathway. Furthermore, here we reveal that ATR II effectively upregulates the expression of mitogen-activated protein kinase p38 (MAPKp38), which also acts as a regulator of Nrf2 signaling cascade. Indeed, treatment with a MAPKp38 inhibitor can significantly downregulate the expression of Nrf2 and its downstream target genes HO-1 and NQO-1 and, consequently, abolish the protective effect of ATR II against IR. Consistently, ATR II also has a protective function against IR-induced damage in animal models. In conclusion, our study provides an unexpected function of ATR II in preventing IR-induced damage by modulating MAPKp38/Nrf2 signaling pathway.

Bifunctional Phosphorylcholine-Modified Adsorbent with Enhanced Selectivity and Antibacterial Property for Recovering Uranium from Seawater.

The recovery of uranium from seawater is of great concern because of the growing demand for nuclear energy. Though amidoxime-functionalized adsorbents as the most promising adsorbents have been widely used for this purpose, their low selectivity and vulnerability to biofouling have limited their application in real marine environments. Herein, a new bifunctional phosphorylcholine-modified adsorbent (PVC-PC) is disclosed. The PVC-PC fiber is found to be suitable for use in the pH range of seawater and metals that commonly coexist with uranium, such as alkali and alkaline earth metals, transition metals, and lanthanide metals, have no obvious effect on its uranium adsorption capacity. PVC-PC shows better selectivity and adsorption capacity than the commonly used amidoxime-functionalized adsorbent. Furthermore, PVC-PC fiber exhibits excellent antibacterial properties which could reduce the effects of biofouling caused by marine microorganisms. Because of its good selectivity and antibacterial property, phosphorylcholine-based material shows great potential as a new generation adsorbent for uranium recovery from seawater.

Efficiently Anti-Obesity Effects of Unsaturated Alginate Oligosaccharides (UAOS) in High-Fat Diet (HFD)-Fed Mice.

Obesity and its related complications have become one of the leading problems affecting human health. However, current anti-obesity treatments are limited by high cost and numerous adverse effects. In this study, we investigated the use of a non-toxic green food additive, known as unsaturated alginate oligosaccharides (UAOS) from the enzymatic degradation of Laminaria japonicais, which showed effective anti-obesity effects in a high-fat diet (HFD) mouse model. Compared with acid hydrolyzed saturated alginate oligosaccharides (SAOS), UAOS significantly reduced body weight, serum lipid, including triacylglycerol (TG), total cholesterol (TC) and free fatty acids (FFA), liver weight, liver TG and TC, serum alanine aminotransferase (ALT), and aspartate aminotransferase (AST) levels, adipose mass, reactive oxygen species (ROS) formation, and accumulation induced in HFD mice. Moreover, the structural differences in ß-d-mannuronate (M) and its C5 epimer α-l-guluronate (G) did not cause significant functional differences. Meanwhile, UAOS significantly increased both AMP-activated protein kinase α (AMPKα) and acetyl-CoA carboxylase (ACC) phosphorylation in adipocytes, which indicated that UAOS had an anti-obesity effect mainly through AMPK signaling. Our results indicate that UAOS has the potential for further development as an adjuvant treatment for many metabolic diseases such as fatty liver, hypertriglyceridemia, and possibly diabetes.

A progressive approach on zebrafish toward sensitive evaluation of nanoparticles' toxicity.

Zebrafish (Danio rerio) possess a great promise in evaluating the toxicity of nanoparticles (NPs). The commonly used method on zebrafish was to calculate mortality and 5 or 6 days postfertilization (dpf) toxicity scores. However, this method could only reveal a general toxic level. To further distinguish the toxicity of NPs in the same general level, a more systematic and sensitive approach needs to be put forward. In this work, we describe a progressive approach toward the evaluation of the toxicity of MSRMs NPs we synthesized. This approach contained traditional and newly created methods. The results from traditional methods such as calculating mortality, recording 6 dpf toxicity scores and malformation types of zebrafish revealed a general low toxic level of MSRMs. Then the newly created method was conducted. By using scoring spectra of early developmental stages such as 2 or 3 dpf, we compared the malformation speeds of zebrafish exposed to different concentrations of MSRMs during the time 1 to 6 dpf. The results allowed more sensitive assessments of the toxicity of MSRMs.