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Our study revealed that different polysaccharides promote gut immunity in different ways and provided a guideline for the development of superior intestinal immunomodulatory polysaccharides.

As potential candidates for treating ulcerative colitis (UC), polysaccharides from natural Cordyceps sinensis inhibited the activation of the NF-κB pathway, enhanced the intestinal barrier, increased the content of sIgA and modulated the gut microbiota in colitis mice.

Pectin with various esterification degrees showed differential effects on the metabolic disorder and inflammation induced by a long-term high-fat diet and low-dose antibiotic exposure, which were possibly related to the enrichment of Lactobacillus.

Human gut microbiota played a key role in maintaining and regulating host health. Gut microbiota composition could be altered by daily diet and related nutrients. Diet polysaccharide, an important dietary nutrient, was one kind of biological macromolecules linked by the glycosidic bonds. Galactans were widely used in foods due to their gelling, thickening and stabilizing properties. Recently, effects of different galactans on gut microbiota have attracted much attention. This review described the structural characteristics of 4 kinds of galactans, including porphyran, agarose, carrageenan, and arabinogalactan, along with the effects of different galactans on gut microbiota and production of short-chain fatty acids. The ability of gut microbiota to utilize galactans with different structural characteristics and related degradation mechanism were also summarized. All these four galactans could be used by gut

Polygonatum sibiricum has been used as food and medicine for thousands of years, and P. sibiricum polysaccharides (PSPs) have become the hot research spot due to their various health-promoting functions. Numerous studies have shown that PSPs possess huge potential in the application of functional food and medicine fields. However, the research status and features of the preparation process, molecular structure, and bioactivities of PSPs are unclear. Therefore, this review makes a comprehensive summary and proposes new insights and guidelines for the extraction, purification, structural features, biosynthesis, and multiple bioactivities of PSPs. Notably, it is concluded that PSPs mainly contain several types of polysaccharides, including fructan, pectin, galactomannan, glucomannans, arabinogalactan, and galactan, and multiple bioactivates, including osteogenic activity, anti-obesity, anti-diabetes, anti-depression, antioxidant, antiglycation, and protective effect against neurotoxicity and gut microbiota regulating activity. This review contributes to the structure–function study and resource utilization of P. sibiricum and its polysaccharides in food fields.

To understand the mechanisms of immunomodulatory effect, Dendrobium Officinale polysaccharides (DOP) were treated by ultrasound and mild base separately to generate fractions of various weight-average molecular weight (Mw) and degrees of acetylation (DA). The structural features, conformational properties, functional properties and immunomodulatory activities of original and modified DOPs were investigated. Ultrasonic treatment decreased the Mw and apparent viscosity and improved the water solubility of DOP. Mild base treatment remarkably reduced the DA and the water solubility, while the overall apparent viscosity was increased. Conformational analysis by triple-detector high performance size-exclusion chromatography showed that the molecular chain of DOP turned more compact coil conformation with decreased DA. Results from the macrophages RAW 264.7 analysis showed that samples sonicated for 200 min (Mw 34.2 kDa) showed the highest immune-regulation effects. However, the immunomodulatory effects of the samples after de-acetylation were all compromised compared to the original DOP. This study inspires further research to establish the structural-immunomodulatory relationships, which promote the application of DOP in both the food and medicine fields.

The purpose was to investigate the contents of heat-induced hazards by liquid chromatography-tandem mass spectrometry (LC-MS/MS) in 44 commercial nuts. Results showed that content ranges of Acrylamide (AA), 5-hydroxymethylfurfural (5-HMF), N

Firmicutes and Bacteroidetes are the predominant bacterial phyla colonizing the healthy human gut. Accumulating evidence suggests that dietary fiber plays a crucial role in host health, yet most studies have focused on how the dietary fiber affects health through gut Bacteroides. More recently, gut Firmicutes have been found to possess many genes responsible for fermenting dietary fiber, and could also interact with the intestinal mucosa and thereby contribute to homeostasis. Consequently, the relationship between dietary fiber and Firmicutes is of interest, as well as the role of Firmicutes in host health. In this review, we summarize the current knowledge regarding the molecular mechanism of dietary fiber degradation by gut Firmicutes and explain the communication pathway of the dietary fiber-Firmicutes-host axis, and the beneficial effects of dietary fiber-induced Firmicutes and their metabolites on health. A better understanding of the dialogue sustained by the dietary fiber-Firmicutes axis and the host could provide new insights into probiotic therapy and novel dietary interventions aimed at increasing the abundance of Firmicutes (such asDietary fiber-induced gut Firmicutes and their metabolites exhibit relevant health-promoting functions.Most of dietary fiber have a great effect on gut Firmicutes.Mechanisms of dietary fiber uptake by gut Firmicutes are outlined.Mechanisms of dietary fiber- gut Firmicutes-host interactions require more investigation for the development of dietary fiber in food production and host health.

Food nutrients plays a crucial role in human health, especially in gastrointestinal (GI) health. The effect of food nutrients on human health mainly depends on the digestion and fermentation process in the GI tract. In vitro GI digestion and fermentation models had the advantages of reproducibility, simplicity, universality, and could integrally simulate the in vivo conditions to mimic oral, gastric, small intestinal and large intestinal digestive processes. They could not only predict the relationship among material composition, structure and digestive characteristics, but also evaluate the bioavailability of material components and the impact of digestive metabolites on GI health. This review systematicly summarized the current state of the in vitro simulation models, and made detailed descriptions for their applications, advantages and disadvantages, and specially their applications in food carbohydrates. In addition, it also provided the suggestions for the improvement of in vitro models and firstly proposed to establish a set of standardized methods of in vitro dynamic digestion and fermentation conditions for food carbohydrates, which were in order to further evaluate more effects of the nutrients on human health in future.

Fructans such as fructo-oligosaccharides (FOS) and inulin have been reported to directly regulate ileal inflammatory responses in lipopolysaccharide (LPS)-induced endotoxemic mice, without alterations in the colonic microbiota. Firstly, we replicated this model and found that a single gavage of 10 mg g-1 of fructans directly promoted caecal acetate and propionate production. Thus, the previous understanding of microbiota-independent effects of prebiotic fructans in endotoxemic mice has been challenged. In parallel, we performed a daily gavage of 160 mg kg-1 of inulin, xylan, or Dendrobium officinale polysaccharides (DOP) for two weeks prior to LPS injection. The long-term intake of prebiotic fibres reduced the bacterial load in the spleen and mesenteric lymph nodes (MLNs), and in comparison, a single gavage of fructans increased that. However, the long-term intake was unable to improve the short-chain fatty acid (SCFA) synthesis and epithelial barrier function that were impaired by LPS. Notably, the three fibre types consistently reduced the expression of mucin 2 (MUC2) and variously modulated critical mediators (IL-18, IL-22, and HIF-1α) to regulate the host-commensal microbiota interactions in the ileum. In addition, the three fibre types consistently inhibited the inflammatory T helper (Th) cell response in the ileum, while they diversely modulated the peripheral and systemic Th cell responses. Overall, the prebiotic fibres displayed microbiota-related changes in endotoxemic mice, and the potential associations with the in vivo anti-inflammatory effects of prebiotic fibres need further investigation.

The release of lysosomal hydrolase into the cytoplasm is accompanied by several systems of apoptosis signal transduction, and the imbalance between cell viability and apoptosis induces tumorigenesis. Tea polysaccharides (TPs) are the main bioactive components in green tea with hopeful anti-tumor efficacy, while their mechanism is still unclear. Here, TPs significantly promoted the death of colon cancer cell line CT26. RNA-seq results showed that the signal pathways up-regulated by TPs included lysosome pathways, apoptosis, the release of mitochondrial pigment c and programmed cell death. Among them, the results of AO-EB and annexin V-FITC/PI double staining indicated that TPs significantly up-regulated apoptosis. In addition, TPs significantly disrupted the function of lysosomes, which would cause mitochondrial damage. Intriguingly, TPs treatment increased the expression of Bak1, cleaved caspase-9 and cleaved caspase-3, but decreased the level of Bcl-2 and mitochondrial membrane potential, which indicated that TPs induced mitochondrial-mediated apoptosis. Moreover, TPs ameliorated the reduced lysosomal numbers by Baf A1 (lysosomal inhibitor). Therefore, our data indicated that TPs targeted lysosomes and induced apoptosis by a lysosomal-mitochondrial pathway mediated caspase cascade, thereby inhibiting the proliferation of CT26 cells. In short, the data would help the development of TPs as potential cancer drug therapeutics.

Crude polysaccharides extracted from red kidney bean (RK) display significant antidiabetic activity in type 2 diabetic mice, but the underlying mechanism and the core functional component has not been elucidated. In this study, the antidiabetic effect and mechanism of RK are investigated by serum metabolomics and high-throughput sequencing. In addition, the key component was identified by evaluating the improvement on glucose and lipid homeostasis in type 2 diabetic rats. Our data indicated that RK relieved the symptoms of hyperglycemia, hyperlipidemia in STZ-induced diabetic rats. RK not only improved the metabolic disturbance by regulating the biosynthesis of unsaturated fatty acids, but also modified gut microbiota composition by selectively enriching in key genera of Bacteroides, Phascolarctobacterium, Succinivibrio, Blautia. We further found the purified polysaccharides (RKP) were identified as the core biofunctional component in RK. Our present studies provide evidence that RKP are potential effective dietary supplement for type 2 diabetic individuals.

Bifidobacteria are considered as probiotics due to their role in promoting intestinal health, including regulating intestinal flora, controlling glycolipid metabolism, anti-colitis effects. Dietary fiber is considered as prebiotic favoring gut health. It also can be used as carbon source to support the growth and colonization of probiotics like bifidobacteria. However, because of genetic diversity, different bifidobacterial species differ in their ability to utilize dietary fiber. Meanwhile, dietary fiber with different structural properties has different effects on the bifidobacteria proliferation. The interaction between dietary fiber and bifidobacteria will consequently lead to a synergistic or antagonistic function in promoting intestinal health, therefore affecting the application of combined use of dietary fiber and bifidobacteria. In this case, we summarize the biological function of bifidobacteria, and their interaction with different dietary fiber in promoting gut health, and finally provide several strategies about their combined use.

Carbohydrates, including monosaccharides, oligosaccharides and polysaccharides, are widely distributed in food resources. Matrix-assisted laser desorption/ionization (MALDI), a soft ionization technique, is extensively applied in carbohydrates analysis. MALDI mass spectrometers are capable to generate spectra rapidly and record mass profiles or fingerprints from foods, usually with simple sample preparation or pretreatment. Therefore, this review described recent research progress on MALDI mass spectrometry (MS) detection in food carbohydrates, especially for the improvement of ionization efficiency and their application in structure characterization of polysaccharides from food and edible herbs. Furthermore, the quantitative study and mass spectrometry imaging were also briefly summarized.

Background Pectin exists in a broad range of plants, and acts as functional food additives with modulatory effects on colonic inflammation and metabolism dysfunctions, which underscores its promising prospects in commercialization. Moreover, food ingredients like pectin can impact the gut microbiota, and the degradation capabilities of these commensals may in turn determine the efficacy of dietary intervention. Scope and approach In this review, the pectin-host axis was figured by summarizing the physiological functions of pectin and the associated mechanisms; The pectin-gut microbiota axis was described via discussing the impact of pectin on intestinal microbiota composition; And the gut microbiota-host axis was discussed through describing the beneficial functions of pectinolytic commensals and their metabolites. Key findings and conclusions The structure properties of pectin including degree of esterification and branched chains played critical roles in their physiological functions of metabolism regulation, inflammation modulation, and carcinogen prevention. Meanwhile, distinct diversity, enterotypes or composition of gut microbiota can be developed under interventions of pectin with various structure characteristics, and pectin-induced dominant bacteria like Ruminococcaceae, Succinivibrionaceae, Lachnospiraceae and Bacteroidaceae and their metabolites exhibited relevant health-promoting functions. All these data are fundamental to establish the precise networks and further discover underlying mechanisms of pectin-gut microbiota-host interactions and can optimize the development of pectin in food and health care products.

The antidiabetic function of polysaccharides prepared from six legumes: soybean, white kidney bean, red kidney bean, small black soybean, field bean, lentil were studied. Six legume polysaccharides' antidiabetic function in high-fat diet and streptozotocin-induced type II diabetic mice were compared. Their effects on body weight, fasting blood glucose (FBG), glycosylated serum protein (GSP), serum insulin levels (HOMA-IR), blood lipids (including total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-c), and high-density lipoprotein cholesterol (HDL-c)) were tested. Results showed that red kidney bean polysaccharides (RK) could alleviate the symptoms of emaciation, decreased the levels of FBG, GSP, TC, LDL-c and obviously reduced the concentration of TG and HOMA-IR (p

Background Glucomannans (GMs) are a group of hydrophilic polysaccharides, which have been produced from different parts of natural plants. Studies on plant-derived GMs contribute to wide applications of GMs or GMs-added products that have desirable quality and health characteristics. Among those popular GMs, konjac glucomannan (KGM) and acemannan are the most famous ones that have been widely reviewed from various points in recent years. However, there is a lack of a comprehensive review to introduce the sources, extraction and purification methods, structural features, and other aspects of GMs from common natural plants such as Aloe, Dendrobium, Bletilla, and so on. Scope and approach This review firstly presents the extraction and purification technologies of GMs from different plant sources, aiming at optimizing more effective production methods with specific treatments for special plant origins. After that, structural features, biological properties, as well as structure-function relationship are summarized. Key findings and conclusions GMs have been widely isolated from different sectors (leaf, stem, and roots) of many plant resources. A general extraction and purification procedure together with several suggestions is put forward to prepare GMs. Although the β-(1 → 4)-linked main chain has been confirmed, detailed structural characteristics of GMs such as side chain and functional group related properties need further studies. Molecular weights, monosaccharide composition, and acetyl group of GMs are key factors that have been identified to affect plentiful biological properties such as immunomodulatory, anti-tumor, anti-diabetic activities. However, the inherent action mechanisms remain unclear. Several research interests in the future are recommended.

Background Food-derived natural polysaccharides are attracting increasing attention in fields of food and healthy product, and the purification of polysaccharide is indispensable for the study. Currently, purification process mostly focuses on crude polysaccharide, while the importance of polysaccharide purification in the processes of raw material and polysaccharide extraction are easily ignored. Scope and approach This review aims to develop an understanding and practical suggestions on polysaccharide purification. Numerous methods on polysaccharide purification were summarized, and their advantages and disadvantages have been discussed. Finally, current challenges and perspectives on polysaccharide purification were pointed out. Key findings and conclusions Polysaccharide purification should be emphasized and performed based on three consecutive and progressive stages: polysaccharide in raw material, polysaccharide in crude extract and the crude polysaccharide. Besides, the purification of crude polysaccharide comprises the enrichment of polysaccharide and isolation of fractions having different structural or conformational characteristics. However, how to prepare polysaccharide with high purity in large scale and simultaneously preserving its native structure and bioactivity, remains a demanding and important task for future work.

Polysaccharide derived from natural products has a wide range of sources and mild properties, and exhibit various bioactivities. Ascorbic acid is one of the most important nutrients in fruits and vegetables, as well as their products. Ascorbic acid and polysaccharide coexist in many systems during food production and processing. Many studies have found that ascorbic acid at low concentrations degrades polysaccharide derived from natural products via hydroxyl radical. In this paper, the research progress on ascorbic acid induced polysaccharide degradation is summarized from four aspects: mechanism of action, analytical methods, influencing factors and bioactivity of degradation products. It is expected to provide a theoretical basis for further research.

The viability of probiotic bacteria is always questionable when they exposed to the harsh environment and thus microencapsulation of probiotic bacteria is generally applied to enhance the viability during processing, storage, and also for the target delivery in gastrointestinal tract. Polysaccharide is one of the most widely used wall material in the area of probiotic microencapsulation. However, with the increasing demand and new application areas for probiotic microcapsules, traditionally used polysaccharides can barely satisfy such challenges. Therefore, seeking for new kinds of polysaccharides with preponderant properties that suitable for probiotic microencapsulation is now catching the interest of researchers and has important implication. This review focuses on the application of polysaccharides in the area of probiotic microencapsulation, including to classify the traditional polysaccharides according to their characteristic properties used especially for microencapsulation of probiotics, as well as to give a critical perspective on emerging polysaccharides applied as wall materials to encapsulate probiotic bacteria.

Lactic acid bacteria strain (LAB) NCU116 fermented Asparagus officinalis polysaccharides (FAOP) have been proven to cause substantial changes in physicochemical properties such as monosaccharide composition and molecular weight, accounting for their enhanced immune activity than unprocessed Asparagus officinalis polysaccharides (AOP). In the current study, the hepatoprotective effects of FAOP in mice with cyclophosphamide (CTX)-induced hepatotoxicity were investigated. FAOP were more effective than AOP in alleviating CTX-induced hepatic damage, including inhibition of hepatic biochemical markers (ALT, AST, AKP and LDH) and pro-inflammatory cytokines (TNF-α and IL-1β) as well as reinforcement of antioxidant systems (T-AOC, SOD, CAT, and MDA). In particular, compared with AOP, FAOP showed superior performance by promoting GSH biosynthesis, and normalizing the expression level of bile acid receptors (FXR and SHP) and key enzymes in bile acid synthesis (CYP7A1, CYP8B1 and CYP27A1). Modulation of disordered homeostasis of bile acids by FAOP can be attributed to the upregulation of hepatic short chain fatty acid (SCFA) receptors GPR41 and GPR109A as well as intestinal SCFA production. Furthermore, serum metabolomics study validated the hepatoprotective superiority of FAOP than AOP with evidence from variations in bile acid compositions and the construction of related metabolic pathways. Therefore, LAB NCU116 fermentation of Asparagus officinalis was practical and effective to obtain promising hepatoprotective polysaccharides, which might arise from enhanced SCFA production than unprocessed AOP.

This work investigated the physiochemical characteristics and preventive effects of purified pectin (H121, L13 and L102) with different esterification degrees on dextran sulfate sodium (DSS)-induced colitis in mice. Three doses of each type of pectin were administered to C57BL/6J mice for 7 days before the DSS treatment, with dextran and mesalazine as positive controls. Results showed that pathological factors including the body weight, the disease activity index (DAI), the colonic weight/length ratio and the organ index of the spleen were improved with pre-intervention of a high dose of L13 or L102. Further studies showed that administration of a low dose of L13, low dose and medium dose of L102 or dextran improved intestinal permeability and tight junction function in colitis mice. Treatments of L13 of all doses and L102 of a high dose downregulated the oxidative stress-associated factors, while L102 of a low dose and H121 ameliorated the inflammatory cytokine production in serum and the colon. The above results suggested that pectin could attenuate DSS-induced intestinal epithelial injury, inflammation and oxidative stress. Specifically, compared to high esterified pectin, low esterified pectin displayed better protective effects in acute colitis mice.

Maillard reaction during food processing contributes to the formation of some unpleasant heat-induced toxicants including advanced glycation end products (AGEs) and 5-hydroxymethylfurfural (HMF), which have been linked to various health risks. The effects of baking factors and recipes, such as baking temperature (130°C-180 °C) and time (8 min-15 min), sucrose levels (0 g-20 g), butter levels (0 g-20 g) and egg liquid levels (0 g-12 g) on the formation of free N

Maillard reaction during food processing contributes to the formation of some unpleasant heat-induced toxicants including advanced glycation end products (AGEs) and 5-hydroxymethylfurfural (HMF). The current study prepared butter cookies fortified with two dietary natural antioxidants (catechins and curcumin) and two dietary hydrocolloids (pectin and chitosan), and investigated their effects on formation of free Nε-(carboxymethyl)lysine (CML)/Nε-(carboxyethyl)lysine (CEL), protein-bound CML/CEL and HMF and on the sensory qualities of butter cookies. Meanwhile, three typical α-dicarbonyl compounds were also determined to identify possible correlations between α-dicarbonyl intermediates and formation of these harmful heat-induced products in butter cookies. Experimental data showed that catechin exhibited the strongest inhibitory effects on formation of AGEs and HMF, but its addition would impair the color and taste of cookies. On the other hand, chitosan was not so effective in inhibiting AGEs and HMF as compared to catechin, but its addition could increase the sensory qualities of butter cookies.

Tea is a popular beverage with a long history of safe and healthy use. Tea polysaccharide is a bioactive component extracted from tea, which has attracted more and more attention in recent decades. In this article, an acidic polysaccharide Gougunao tea polysaccharide (GPS) was isolated from Gougunao green tea by hot water extraction and ethanol precipitation. After purification by a diethylaminoethyl (DEAE) Sepharose Fast Flow column and a Sephacryl S-400 column, several homogalacturonan (HG) and rhamnogalacturonan-I (RG-I) fractions were obtained. Fraction GPS2b with the highest yield was selected for structural characterization by methylation and nuclear magnetic resonance (NMR) analysis. GPS2b was found to be an HG-type pectic polysaccharide (degree of methyl esterification [DE], 51.6%) with low molecular weight (Mw, 36.8 kDa). It was mainly composed of →4)-α-GalpA- (1→ and →4)-α-GalpA-6-OMe-(1→. In addition, a minor highly branched RG-I domain was identified in this fraction. The investigation of structural features of tea polysaccharides can provide insights to understand their structure-bioactivity relationship.

In our previous study, two crude polysaccharides from red kidney bean and small black soybean (RK, SB) have shown the alleviative effect on type 2 diabetic mice. Meanwhile, hepatic dysfunction usually accompanied with type 2 diabetes mellitus (T2DM), and closely related to glucose and lipid homeostasis. Therefore, this time we further investigated the protective effect on hepatic dysfunction of RK and SB. Results found that both crude polysaccharides had the protective effects. In addition, investigation on purified polysaccharides identified that the polysaccharide was the biofunctional component basis in crude RK and SB. Subsequently, further research investigated the regulating mechanism of two pure polysaccharides (RKPH and SBPH) on hepatic metabolism and lipid metabolism. The results showed the improved different metabolites of phosphatidylcholine (PC) and phosphatidylethanolamine (PE) by RKPH and SBPH to affect glycerophospholipid metabolism pathway might be involved in the improvement of the glucose, lipids homeostasis and liver function in T2DM.

Highlights • Functional properties of polysaccharides depend on their structural features. • IR spectroscopy is widely used in polysaccharide structural analysis. • Classical applications of IR spectroscopy in polysaccharide are reviewed. • IR integrating techniques can considerably expand its application scope., Polysaccharides are important biomacromolecules with numerous beneficial functions and a wide range of industrial applications. Functions and properties of polysaccharides are closely related to their structural features. Infrared (IR) spectroscopy is a well-established technique which has been widely applied in polysaccharide structural analysis. In this paper, the principle of IR and interpretation of polysaccharide IR spectrum are briefly introduced. Classical applications of IR spectroscopy in polysaccharide structural elucidation are reviewed from qualitative and quantitative aspects. Some advanced IR techniques including integrating with mass spectrometry (MS), microscopy and computational chemistry are introduced and their applications are emphasized. These emerging techniques can considerably expand application scope of IR, thus exert a more important effect on carbohydrate characterization. Overall, this review seeks to provide a comprehensive insight to applications of IR spectroscopy in polysaccharide structural analysis and highlights the importance of advanced IR-integrating techniques.

This work established an effective method for kale flavonoids enrichment by resins. Resin screening, adsorption kinetics and isotherms, dynamic adsorption and desorption tests were conducted to optimize the appropriate resins and enrichment conditions. The results showed that NKA-9 was the optimum resin. The best adsorption conditions were 0.2 mg/mL flavonoids concentration, 12.5 bed volume (BV) sample volume and 2 BV/h adsorption rate. The desorption conditions were 3 BV of 80% ethanol at 2 BV/h elution rate. Under these conditions, the product purity was 31.16%. The purified flavonoids extract was mainly comprised of Kaempferol-3-O-sophoroside-7-O-diglucoside, Kaempferol-3,7,4’-O-D-triglucoside, Kaempferol-3-O-feruloyl-sophoroside-7-O-D-glucoside, and Kaempferol-3-O-sinapoyl-sophoroside. Moreover, it presented higher scavenging ability against 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical and hydroxyl (•OH) radical than crude extract. In conclusion, kale flavonoids can be well concentrated by NKA-9 resin and the purified flavonoids extract has good antioxidant activity which can be potentially applied in food, cosmetic or pharmacy industries.

Various structural types of polysaccharides are recognized by toll-like receptor 4 (TLR4). However, the mechanism of interaction between the polysaccharides with different structures and TLR4 is unclarified. This review summarized the primary structure of polysaccharides related to TLR4, mainly including molecular weight, monosaccharide composition, glycosidic bonds, functional groups, and branched-chain structure. The optimal primary structure for interacting with TLR4 was obtained by the statistical analysis. Besides, the dual-directional regulation of TLR4 signaling cascade by polysaccharides was also elucidated from an immune balance perspective. Finally, the 3D interaction model of polysaccharides to TLR4-myeloid differentiation factor 2 (MD2) complex was hypothesized according to the LPS-TLR4-MD2 dimerization model and the polysaccharides solution conformation. The essence of polysaccharides binding to TLR4-MD2 complex is a multivalent non-covalent bond interaction. All the arguments summarized in this review are intended to provide some new insights into the interaction between polysaccharides and TLR4.

Background As an important role of host homeostasis, the glycometabolism was closely related to the process and metabolic pathways of carbohydrates such as glycolysis, hexosamine biosynthetic pathway, and pentose phosphate in the host. Disorders of glycometabolism result in a series of metabolic diseases, such as diabetes, obesity, hypoglycemia, and etc. Scope and approach Polysaccharides, which were widely existing in daily diet and cannot be directly digested by gastrointestinal enzymes in the host, were considered to have beneficial effects on the glycometabolism. Furthermore, the relationship between polysaccharides and gut microbiota, have attracted extensive attention in the researches for glycometabolism-related diseases. Gut microbiota participates in the process of glycometabolism based on the fermentation of dietary polysaccharides and related metabolites. Key findings and conclusions This review aims at summarizing the state of the effects of the polysaccharides on glycometabolism through gut microbiota modification and exploring the underlying mechanisms for the beneficial effects of the polysaccharides on glycometabolism disorders.

Trichoderma viride was utilized to ferment the defatted rice bran (DRB), and soluble dietary fiber was prepared before and after fermentation, named as B-SDF and F-SDF, respectively. Optimum fermentation conditions for yield of F-SDF were determined using response surface methodology (RSM). The yield of F-SDF was significantly increased from 10.5 (w/w, %) to 33.4 (w/w, %) under the optimal conditions (inoculum size = 10%, pH = 5.8 and time = 41 h). Fourier transform infrared spectroscopy (FTIR) demonstrated that both B-SDF and F-SDF had typical characteristics of the infrared spectrum of polysaccharides, and X-ray diffraction (XRD) revealed they were mainly substances of amorphous structure. In addition, F-SDF showed looser structure by scanning electron microscopy (SEM) analysis, increased molecular weight by high-performance gel permeation chromatography (HPGPC) analysis, and more complex monosaccharide composition by high-performance anion exchange chromatography (HPAEC) analysis. Furthermore, functional properties analysis showed that F-SDF exhibited higher water-holding capacity (WHC), oil-holding capacity (OHC), water solubility (WS) and cholesterol absorption capacity (CAC) than B-SDF. In summary, the present study suggested that SDF from defatted rice bran obtained through Trichoderma viride fermentation has a higher potential to be used as a functional ingredient in foods.

The present work was designed to investigate the effect of bound polyphenols on antioxidant and prebiotics properties of carrot dietary fiber (CDF). The polyphenols were removed from CDF by alkaline extraction to obtain dephenolized dietary fiber (CDF-DF). The optimized conditions of extracting polyphenols from CDF were solid-liquid ratio of 1:8.5, the treat temperature of α-amylase 66 °C, the addition of protease of 0.2% and the treat temperature of amyloglucosidase 60 °C, respectively. The FT-IR spectroscopy illustrated that the major functional group of CDF-DF and CDF shared most of the key features, despite changes in the amplitude of some functional groups. Scanning electron microscopy (SEM) was further performed demonstrating no significant structure differences between CDF-DF and CDF. Moreover, the antioxidant properties, including superoxide anion radical, hydroxyl radical and DPPH radical scavenging activity, of CDF-DF were significantly lower than that of CDF. In addition, CDF was more conducive for the growth of Lactobacillus rhamnosus as compared with the CDF-DF. In summary, the above results concluded that there was no significant change of the dietary fiber after removal of bound polyphenols, and the bound polyphenols contributed significantly to the antioxidant and prebiotics properties of dietary fiber from carrot.

There is growing interest in the antioxidants and antibacterial activity from natural substances. The purpose of the research was to gain and distinguish phenolic substances and organic acids in the Camellia oleifera cake, and to study their antioxidant and antibacterial activities. The extraction and purification of them were achieved by solvent extraction and column separation, respectively. The conclusions displayed that purity of the phenolic substances was 94.1 ± 0.5% w/w and that of organic acid was 96.0 ± 0.3% w/w; Fifteen phenolic substances were certificated using HPLC–ESI–MS technology; oxalic, citric, acetic, malic, and succinic acids are discovered to be main organic acids. In addition, the phenolic substances and organic acids both have good antioxidant activity and obvious inhibition against six species of bacteria. These conclusions can be useful in the reuse of the waste of Camellia oleifera oil industry in the future.

The effect of Lactobacillus plantarum-fermentation on the anti-diabetic functionality of Momordica charantia was examined using a high-fat-diet and low-dose streptozocin-induced type 2 diabetic rat model. Fermented Momordica charantia juice (FMCJ) administration mitigated the hyperglycemia, hyperinsulinemia, hyperlipidemia, and oxidative stress in diabetic rats more favorably than the non-fermented counterpart. Treatments with FMCJ improved ergosterols and lysomonomethyl-phosphatidylethanolamines metabolisms more effectively. Supplement of FMCJ regulated the composition of the gut microbiota, such as increased the abundance of Bacteroides caecigallinarum, Oscillibacter ruminantium, Bacteroides thetaiotaomicron, Prevotella loescheii, Prevotella oralis, and Prevotella melaninogenica, in diabetic rats compared with untreated diabetic rats. Moreover, FMCJ-treated diabetic rats exhibited higher concentrations of acetic acid, propionic acid, butyric acid, total short-chain fatty acids and lower pH values in colonic contents than that in non-fermented juice-treated rats. These results demonstrated that Lactobacillus plantarum-fermentation enhanced the anti-diabetic property of MC juice by favoring the regulation of gut microbiota and the production of SCFAs.

In the light of growing populations, longer life expectancies, the current obesity epidemic, as well as consumer demands for safe and healthy food, there is an ever-growing responsibility for food scientists worldwide to come up with adequate solutions. Cooperation between China and Germany in this research area has developed steadily and successfully for many years and focuses on topics highly relevant for both countries, i.e. nutritional needs of an aging population, food authenticity and safety, and special diets when suffering from malnutrition, adverse food effects, or other food-related health impairments. Functional food ingredients and customized formulations can be instrumental to ensure a balanced and healthy nutrition; especially, if food design and processing takes into account how the food is metabolized. Indeed, the microbiome plays a vital role in that process and therefore was addressed in several presentations during the first German-Chinese Symposium on “Functional and healthy food ingredients generated through state-of-the-art biotechnology”, which took place from September 12–14, 2018 at University of Hohenheim in Stuttgart. More than 35 speakers from 10 German and 5 Chinese Universities shared their current research results, discussed knowledge gaps and challenges related to the topic. This report summarizes the presentations given, highlights the main outcomes of the discussion and concludes with an outlook for further joint research.