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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

Regeneration of epithelia is crucial for maintaining the intestinal barrier and homeostasis. Our previous work showed that exopolysaccharides from Lactobacillus plantarum NCU116 (EPS116) regulated the barrier function and homeostasis of the intestine; however, the relevant mechanisms remain obscure. Therefore, we sought to explore the role of EPS116 in promoting intestinal epithelial regeneration. Our data showed that the administration of EPS116 markedly ameliorated inflammatory bowel disease-related phenotypes and promoted the regeneration of crypts in the colon of colitis mice. The results of immunofluorescence and reverse transcription-quantitative polymerase chain reaction experiments indicated that EPS116 strikingly increased the number of intestinal stem cells (ISCs) and the expression of differentiation markers for goblet cells, enterocytes, and enteroendocrine cells in the mouse colon. Intestinal microbiota analysis showed that EPS116 increased microbial populations associated with intestinal regeneration and glycan metabolism. Therefore, the present study revealed a novel model that EPS116 promoted the intestinal homeostasis through modulating the proliferation and differentiation of ISCs and altering the gut microbiota profile.

Polysaccharides were extracted by hot water and alkali in sequence from Dolichos lablab L. hull, and further purified by ion-exchange and gel columns. Hot water extracted D. lablab hull polysaccharide (DLHP) was rich in glucuronoxylan and pectin, and alkali extracted polysaccharide (DLHAP) mostly embraced glucuronoxylan. The structures of purified glucuronoxylans from DLHP and DLHAP were mainly analyzed by HPAEC-PAD, methylation combined with GC–MS, NMR and SEC-MALLS. DLHP-1 was identified as acetylated glucuronoxylan containing →4)-β-Xylp-(1→ backbone with substitution at O-2 site by α-GlcpA/4-O-methyl-α-GlcpA. The molar ratio of β-Xylp to α-GlcpA was 6.9:1, and acetylation was mainly at O-3 site of β-Xylp with acetylation degree of 21.5%. DLHP-1 and DLHP-2 had similar physicochemical properties, except for molecular weight (Mw). DLHAP-1 was the non-methylated glucuronoxylan almost without acetylation, and it had the molar ratio of β-Xylp to α-GlcpA of 5.6:1. Besides, DLHP-1 (Mw of 20.0 × 103 g mol−1) adopted semi-flexible chain, while DLHAP-1 (Mw of 15.4 × 103 g mol−1) showed flexible chain. These results provided a structural basis for study on polysaccharides from D. lablab hull, which was benefit for understanding biological activities and developing functional food or pharmaceuticals of D. lablab.

The interaction between gut microbiota and polysaccharide is being paid more and more attention. Galactan is a kind of polysaccharide mainly composed of galactose, and it has been shown to play a significant role in regulating gut microbiota. Bacteroides thetaiotaomicron is considered as the best degrader of polysaccharides. The purpose of this paper was to investigate the utilization of four different galactans, including agarose, carrageenan, arabinogalactan, and glucofucogalactan, by our own isolated B. thetaiotaomicron A4. Samples of cultures grown on either four galactans groups or control groups were collected. The change of OD600, pH, and short‐chain fatty acids (SCFAs) during fermentation were determined, and growth curve and transcriptome of B. thetaiotaomicron A4 were studied. B. thetaiotaomicron A4 could utilize the four galactans and grew well on them, with carrageenan being most utilized, followed by arabinogalactan, glucofucogalactan, and agarose. SCFAs (mainly acetic acid and propionic acid) produced along with the decreased pH during fermentation. A large number of genes of B. thetaiotaomicron A4 were upregulated and functioned in different pathways during the degradation of the four galactans. The carbohydrate metabolism‐related pathways of B. thetaiotaomicron A4 were enriched after feeding the four galactans, although the specific pathways were different among four galactans groups. The different structural characteristics of four galactans required that B. thetaiotaomicron A4 could excrete corresponding enzymes to degrade them. These results help to understand the interaction between galactans and gut microbe.

Graphical abstract, Highlights • Plasma urea was increased along with erythrocyte Na+/K+ -ATPase activity reduced and abnormal erythrocyte morphologies appeared during 14-day high relative humidity (90 ± 2%) exposure. • Shortly after 12-h and 24-h exposures, urea influx and ammonia level were increased in the colon of mice, respectively. • Colonic urea-nitrogen metabolism was influenced by the increased levels of ammonia, amino acids and short-chain fatty acids during 14-day exposure. • Gut bacteria related to urease production, amino acids metabolism and SCFAs production was enriched during the exposure., Introduction Colonic urea-nitrogen metabolites have been implicated in the pathogenesis of certain diseases which can be affected by environmental factors. Objectives We aimed to explore the influence of ambient humidity on colonic urea-nitrogen metabolism. Methods Blood biochemical indexes, metabolites of intestinal tract, and gut microbiota composition of mice (n = 10/group) exposed to high relative humidity (RH, 90 ± 2%) were analyzed during the 14-day exposure. Results After 12-h exposure, plasma blood urea nitrogen (BUN) level increased along with a decrease in the activity of erythrocyte Na+/K+ -ATPase. Moreover, abnormal erythrocyte morphologies appeared after 3 days of exposure. The colonic BUN and ammonia levels increased significantly after the 12-h and 24-h exposure, respectively. The colonic level of amino acids, partly synthesized by gut microbiota using ammonia as the nitrogen source, was significantly higher on the 7th day. Furthermore, the level of fecal short-chain fatty acids was significantly higher after 3-day exposure and the level of branched-chain fatty acids increased on the 14th day. Overall, gut microbiota composition was continuously altered during exposure, facilitating the preferential proliferation of urea-nitrogen metabolism bacteria. Conclusion Our findings suggest that short-term high RH exposure influences colonic urea-nitrogen metabolism by increasing the influx of colonic urea and altering gut microbiota, which might further impact the host health outcomes.

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.

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.

Diabetes mellitus is a serious threat to human health. Cyclocarya paliurus (Batal.) Iljinskaja (C.paliurus) is one of the traditional herbal medicine and food in China for treating type 2 diabetes, and the C. paliurus polysaccharides (CP) were found to be one of its major functional constituents. This research aimed at investigating the hypoglycemic mechanism for CP. It was found that CP markedly attenuated the symptoms of diabetes, and inhibited the protein expression of Bax, improved the expression of Bcl-2 in pancreas of diabetic rats, normalized hormones secretion and controlled the inflammation which contributed to the regeneration of pancreatic β-cell and insulin resistance. CP treatment increased the beneficial bacteria genus Ruminococcaceae UCG-005 which was reported to be a key genus for protecting against diabetes, and the fecal short-chain fatty acids levels were elevated. Uric metabolites analysis showed that CP treatment helped to protect with the diabetes by seven significantly improved pathways closely with the nutrition metabolism (amino acids and purine) and energy metabolism (TCA cycle), which could help to build up the intestinal epithelial cell defense for the inflammation associated with the diabetes. Our study highlights the specific mechanism of prebiotics to attenuate diabetes through multi-path of gut microbiota and host metabolism.

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.

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 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.

Water-soluble β-d-glucan was obtained from wild Cordyceps sinensis by alkali solution and ethanol precipitation. The structure characteristics were determined using high-performance anion-exchange chromatography coupled with pulsed amperometric detection (HPAEC-PAD), methylation combined with gas chromatography-mass spectrometry, and one-/two-dimensional nuclear magnetic resonance spectroscopy. Results showed that β-d-glucan had a structure of every seven (1→3)-β-d-Glcp backbone residues with two (1→6)-β-d-Glcp branches. Additionally, conformation properties in different solvents were investigated by static light scattering, dynamic light scattering, and HPSEC with multiple detectors. It was found that β-d-glucan in 0.5 M NaOH had a narrow unimodal distribution of hydrodynamic radius displaying a spherical coil conformation, whereas it formed severe aggregation in dimethyl sulfoxide. In 0.1 M NaNO3, β-d-glucan mainly existed as a rod-like conformation corresponding to a helical structure together with small aggregates (10%). This work added more information to the understanding of C. sinensis polysaccharides.

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.

Previous studies have proven that polysaccharide obtained from the seeds of Plantago asiatica L. (PLCP) could induce maturation of murine dendritic cells, promote defecation, and possess a...

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.

Momordica charantia L. has been consumed as a vegetable for thousands of years, and its fruit has various bioactive compounds. The aim of this study was to investigate the effect of fermentation with Lactobacillus plantarum (L. plantarum) NCU116 on the chemical composition, antioxidant activity, and volatile profile of M. charantia juice. Fermentation and sterilization increased the concentrations of short-chain fatty acids, while the total saponins in the juice was reduced. Fermentation increased lactic acid, total phenolics, and total flavonoids. Fermentation improved the phenolic composition of the juice, such as decreased caffeic and p-coumaric acids, and increased dihydrocaffeic and phloretic acids. Furthermore, the antioxidant properties of the juice and phenolic extracts increased after fermentation. Fermentation altered the aroma profile of the juice to confer a more desirable flavor by reducing aldehydes and ketones, while increasing alcohols and acids. Sterilization decreased lactic acid, total phenolic content, phenolic composition, antioxidant activities, and the aroma profile. These results suggested that L. plantarum fermentation had a beneficial effect on the physico-chemical properties, bioactive compounds, antioxidant property, as well as aroma composition of M. charantia.

Inflammatory bowel disease (IBD), including Crohn's disease and ulcerative colitis, has gradually emerged as a public health challenge worldwide. Morinda citrifolia (noni) has been used to treat various ailments by Pacific Islanders for centuries. In this work, noni fruit polysaccharide (NFP) was obtained by hot water extraction, and its structure was initially explored. The molecular weight of NFP was approximately 456 kDa, and its monosaccharide components predominantly consisted of Gala (58.44%), Gal (4.44%), Glu (21.13%), Rha (4.84%), and Ara (2.16%) to form galacturonic acid, rhamnogalacturonan-I, arabinogalactan, and arabinan. The protective effect of NFP on the intestinal mucosal barrier was then investigated using DSS-induced IBD model mice. Whereas DSS treatment inhibited intestinal mucosal expression and destroyed the tight junction of epithelial cells, by contrast, NFP promoted mucosal and tight junction protein (zonula occludens-1 and occludin) expression. In conclusion, NFP improved the clinical diagnosis of acute colitis in IBD mice and may present a potential source of IBD treatment.

Polysaccharide is one of the main bioactive substances in Cordyceps sinensis (C. sinensis). The aim of this study was to investigate the effect of polysaccharide from natural C. sinensis (CSP) on intestinal mucosal immunity and antioxidant activity in cyclophosphamide (Cy)-induced intestinal immunosuppressed mice, further to explore the potential mechanism. Results showed that in mice with Cy-induced intestinal injury, the supplement of CSP (25, 50, 100 mg/kg·bw) significantly increased the levels of goblet cells and mucus in intestine in a dose-dependent manner. The formation of immunoglobulin A (IgA)-secreting cells and the secretory IgA (sIgA) contents were promoted obviously in CSP groups. Furthermore, CSP significantly promoted the secretion or mRNA expression of T helper (Th) 1 style cytokines, including interleukin-2 (IL-2), IL-12 p40, interferon-γ (IFN-γ) and tumor necrosis factor-α (TNF-α), in addition to Th1 style transcription factor T-bet. Besides, the levels of Th2 style cytokines, including IL-4, IL-10 and transcription factor GATA-3, were also improved. The value of T-bet/GATA-3, as well as IFN-γ/IL-4 was increased obviously. These results indicated that CSP effectively enhanced intestinal mucosal immunity and regulated polarization of Th1/Th2 cells. The total antioxidant capacity (T-AOC), and the activities of superoxidase dismutase (SOD), glutathione peroxidase (GSH-Px) and catalase (CAT) in liver were increased significantly, and the content of malondialdehyde (MDA) was decreased dose-dependently. In conclusion, CSP effectively ameliorated Cy-induced intestinal injury in mice, which provided a good suggestion of the potential utilization of CSP as a natural immunopotentiator and antioxidant.

Plants in Amorphophallus genus are rich in soluble dietary fibres and have long been used as food and traditional medicine in Asian countries. In the present investigation, natural O-acetyl-glucomannans were extracted from tubers of Amorphophallus rivirei (konjac), A. albus and two local types of A. bulbifer (wild type M and wild type B), which were designated as KGM, AGM, MGM, and BGM, successively. Comparative studies were conducted on their physicochemical properties and primary structures. The four AcGMs had about 90% (w/w) neutral sugar, 11% (w/w) moisture, and 1%–2% (w/w) ash. Relatively high contents of acetyl groups (17%–24%, w/w) were detected. Mannose and glucose as the main components existed in molar ratios of 1.41, 1.41, 1.21, and 1.58 for KGM, AGM, MGM, and BGM, respectively. Relative molecular weights of AcGMs increased in the order of: KGM

Type 2 diabetes is a complex metabolic and endocrine disorder worldwide, which causes severe health and economic problems. The effects of polysaccharide from Plantago asiatica L. (PLP) on high-fat diet and streptozotocin-induced type 2 diabetic rats were examined. Administration of PLP caused significant decreases in the concentrations of blood glucose, insulin, total cholesterol, triglyceride, non-esterified fatty acid and maleic dialdehyde, and significant increases in the levels of high density lipoprotein-cholesterol and the activities of antioxidant enzymes compared with diabetic rats after 4 weeks’ treatment. The concentrations of short-chain fatty acids (SCFA) were significantly higher in the feces of diabetic rats after treatment with PLP. Moreover, colon bacterial diversity and abundance of bacteria, including Bacteroides vulgatus, Lactobacillus fermentum, Prevotella loescheii and Bacteroides vulgates were significantly increased by PLP treatment. These results indicated that the anti-diabetic effect of PLP in type 2 diabetic rats may be associated with regulation of gut microbiota and increased levels of SCFA.

Caenorhabditis elegans is a well-established laboratory animal model and has been widely used in biological research. However, it is still a challenge to obtain a good amount of quality RNA from a limited number of C. elegans for gene expression studies. To address this issue, the present study has compared different conditions to preserve C. elegans for RNA extraction after the failure of an initial effort to use RNAlater-preserved worms for RNA extraction. The effects of different concentrations of proteinase K, different worm life stages, and different worm numbers on RNA extraction were also investigated. The best results were achieved under the following conditions: 1) adult worms that were either freshly prepared or quickly frozen in liquid nitrogen followed by storage at −80 °C; 2) disruption of C. elegans with proteinase K (1 mg/mL) in a lysis buffer (65 °C for 10 min) prior to extraction with Trizol agent. This method can provide a stable, rapid, and effective means to extract RNA from C. elegans with variable worm numbers from 20 to 200. • RNAlater was inappropriate for preserving C. elegans for effective RNA extraction. • Proteinase K was verified for lysing a limited number of C. elegans for RNA extraction. Method name: Inappropriateness of RNAlater to preserve C. elegans for RNA extraction, Keywords: Caenorhabditis elegans, RNA extraction, RNAlater, Storage conditions, Proteinase K

Aloe barbadensis Miller (Aloe vera) has long been used in food, cosmetic and pharmaceutical industries. The solid wastes such as the spikes and the outer green skins are usually separated from the inner gel and discarded during the process of Aloe vera leaves. Three kinds of polysaccharides (designated as ASP-4N, ASP-6N and ASP-8N) were successfully purified from the leaf skin of Aloe vera in our previous work. The present study aimed to analyze the structural and molecular features of ASP-6N and ASP-8N using methylation and GC-MS, NMR, high performance size-exclusion chromatography coupled with multi-angle laser light scattering (HPSEC-MALLS) and scanning electron microscopy (SEM) techniques. Results showed that ASP-6N and ASP-8N were β-(1→4)-glucomannans with acetyl groups, which may attach to O-2, O-3 or O-6 of mannopyranosyl residues in the backbone as mono-, di-, or tri-acetylated forms. HPSEC-MALLS analysis indicated that the polysaccharide fractions from Aloe leaf skin adopted various conformations in the aqueous solution depending on their molecular mass. The polysaccharides had fibrous, ribbon-like and spherical morphology by SEM observation.

High intake of dietary fibers was found to be inversely associated with type-2 diabetes (T2D), whereas the difference among different dietary fibers on T2D remains unclear. Therefore, we have investigated the effects of different dietary fibers on T2D. Nine types of dietary fibers were used to investigate and evaluate their effects on type-2 diabetic rats via physiology, genomics, and metabolomics. We found that supplementation with β-glucan, arabinogalactan, guar gum, apple pectin, glucomannan, and arabinoxylan significantly reduced the fasting blood glucose, whereas carrageenan, xylan, and xanthan gum did not affect glycemic control in diabetic rats. Also, bioactive dietary fibers (β-glucan, arabinogalactan, guar gum, and apple pectin) associated with the increased butyric acid level and abundance of beneficial bacteria (Lachnobacterium, Parabacteroides, Faecalibacterium, Akkermansia, and some butyric acid-producing bacteria), as well as improved host metabolism by decreasing 12α-hydroxylated bile acids, acylcarnitines, and amino acids (leucine, phenylalanine, citrulline, etc.), thereby exert beneficial effects on T2D. It was also found that β-glucan might attenuate insulin resistance via downregulation of Prevotella copri-mediated biosynthesis of branched-chain amino acids in T2D. Together, our study uncovered the effects of different dietary fibers on T2D, along with their potential mechanism.

A polysaccharide from Cordyceps sinensis (NCSP) was reported to attenuate intestinal injury and regulate the balance of T helper (Th)1/Th2 cells in immunosuppressed mice. However, whether it influences Th17 and regulatory T (Treg) cells as well as gut ecology remains unknown. In the present study, the intestinal injury mouse model was also established by intraperitoneal injection of cyclophosphamide (Cy) for three consecutive days. NCSP was found to increase the number of CD4+ T cells, stimulate the secretion of interleukins (IL)-17 and IL-21, and the expression of transcription factor (retinoic acid-related orphan receptor (ROR)-γt). The levels of transforming growth factor (TGF)-β3 and transcription factor (forkhead box (Fox)p-3) were increased in NCSP-treated groups. Moreover, NCSP upregulated the mRNA expression of toll like receptors (TLR-2, -6 and -9), while it downregulated the TLR-4 expression. In addition, NCSP modulated the intestinal microbiota composition and increased the levels of SCFAs. These findings indicated that NCSP may enhance intestinal immunity and have the potential to become a prebiotic to regulate intestinal microbiota.

Inflammatory response plays a critical role in the initiation and progression of type 2 diabetes mellitus (T2DM). Myeloperoxidase (MPO), a leukocyte-derived protagonist, exerts its proinflammatory properties in many complications. We explored the associations between serum extracellular vesicle (EV)-derived MPO as well as serum MPO and T2DM.We performed a cross-sectional study in 151 individuals, including 93 patients with T2DM and 58 non-T2DM controls. The concentrations of serum EV-derived MPO and serum MPO were measured by Luminex Assay.Our data showed that serum EV-derived MPO concentrations and serum MPO concentrations were significantly higher in T2DM patients compared with non-T2DM subjects. In addition, multivariate logistic regression analysis revealed that serum EV-derived MPO as well as serum MPO was independently associated with the presence of T2DM even after adjusting for confounding factors (OR = 1.836 /1 ng EV-derived MPO, 95% CI = 1.395-2.417, P 0.001; OR = 4.135 /10 ng serum MPO, 95% CI = 2.285-7.483, P 0.001). Furthermore, serum MPO showed marginally higher discriminatory accuracy than serum EV-derived MPO in screening T2DM (AUC = 0.858; AUC = 0.779).Increased concentrations of the inflammatory marker MPO either in serum or in serum EVs were independently associated with T2DM.

Macrolepiota albuminosa (Berk.) Pegler is abundant in active polysaccharides, but little is known about their structures and solution properties. In this study, water-extracted polysaccharides from M. albuminosa (MAWP) were purified into three fractions with structural heterogeneity, which was attributed to the diversity in molecular weight, monosaccharide composition and linkage patterns, further affecting their solution properties. Methylation and NMR analysis revealed MAWP-60p and MAWP-70 were a 3-O-methylated glucomannogalactan and a previously unreported glucomannogalactan, whereas MAWP-80 was elucidated as a branched galactoglucan. Besides, three fractions exhibited random coil conformation in aqueous solution, while MAWP-60p had the highest viscosity due to its highest molecular weight, mean square radius of gyration (Rg) and O-methyl group attached to the backbone. The molecular weight, monosaccharide composition and glycosidic linkages might be the major contributors to the flexibility, molecular size and stereochemistry of mushroom polysaccharide chains.

Wholegrains have been promoted for human consumption due to their various health benefits. However, different wholegrains vary in nutritional composition and their beneficial impact on health. In this study, we compared the in vitro starch and protein digestibility, as well as dietary fiber content of eight different wholegrains including barley, buckwheat, coix seed, foxtail millet, oat, proso millet, quinoa, and sorghum and their porridges. We found that boiling improved starch digestibility of all grains, and protein digestibility except proso millet and sorghum. Porridges made from oats, quinoa, or buckwheat are considered healthier than others due to their lower glycemic index and glycemic load, higher digestible protein content and amino acid bioaccessibility, and higher dietary fiber content (>12%). This study could provide a comprehensive nutritional composition and digestibility of the eight types of wholegrains and their porridges. Dietary recommendations were also given for different populations based on factor analysis.

This study aimed to investigate the effects of polysaccharide from Artocarpus heterophyllus Lam. pulp (JFP-Ps) on gut microbiota composition and short-chain fatty acids production in mice. The microbial communities of V3 and V4 region 16S rRNA gene was amplified by PCR, then sequenced on an Illumina MiSeq PE250 platform and analyzed by multivariate statistical methods. The concentrations of short-chain fatty acids (SCFAs) were measured using gas chromatography (GC) equipped with a flame ionization detector (FID). The results showed that JFP-Ps significantly affected the levels of intestinal bacteria, including Bacteroidetes, Firmicutes, Proteobacteria, Cyanobacteria, Actinobacteria, Tenericutes, Deferribacteres and TM7. The concentrations of acetic acid, propionic acid, n-butyric acid and total SCFAs in mouse feces were significantly increased by treatment with JFP-Ps for 2 weeks. These results indicate that JFP-Ps is beneficial to the gut health and can be developed as a functional ingredient in relation to gut health.

Obesity is a chronic disease characterized by overweight resulting from fat accumulation, along with disturbance of metabolism and gut microbiota. Fermentation, as a green processing method, is beneficial for improving the nutrition capacity of food components. Polysaccharides are considered as one of the important components in food and are also potential supplements for anti-obesity treatment. This study aimed to investigate the anti-obesity effects of polysaccharides from fermented and non-fermented Momordica charantia L. with Lactobacillus plantarum NCU116 (FP and NFP) on obese rats by serum metabolomics and gut microbiota analysis. Metabolomics results revealed that abnormal lipid metabolism was formed due to obesity. The supplement of FP and NFP improved the glycerophospholipids, glycosphingolipids, and amino acid metabolism of the obese rats, which alleviated the hypercholesterolemia and overweight in rats. Furthermore, the disorder of gut microbiota was ameliorated by FP and NFP. FP promoted the growth of beneficial bacteria, such as phylum Firmicutes, Actinobacteria, and genera Anaerostipes, Coprococcus, Lactobacillus, and Bifidobacterium. FP also reduced several harmful bacteria belonging to the phylum Proteobacteria and genera Helicobacter. The positive correlation of the weight loss and lowering of serum lipids with the increased beneficial bacteria further elucidated that the anti-obesity effect of FP in obese rats is associated with the regulation of gut microbiota and serum metabolites. The results of this study could provide information for developing probiotic products in the future that may have beneficial effects on the prevention or treatment of obesity.

Type 2 diabetes (T2D) is a worldwide epidemic associated with metabolic disorders and intestinal microbiota alterations. Polysaccharides have been considered to be beneficial to the prevention and alleviation of T2D. In the present study, ultra-performance liquid chromatography-triple-time-of-flight-based metabolomics and proteomics and 16S rRNA sequencing methods were employed to evaluate the effects of glucomannans from Dendrobium officinale stem, konjac, and Aloe vera leaves on host metabolism and intestinal microbiota regulation in type 2 diabetic rats and potential mechanisms. The metabolism of amino acids was significantly disturbed in the type 2 diabetic rats, especially the upregulated branched-chain amino acid (BCAA) metabolism. Host-derived BCAA metabolism was significantly decreased in type 2 diabetic rats. However, the levels of BCAAs in host circulation and gene abundance of BCAA biosynthesis in gut microbiota were significantly increased in diabetic rats, which suggested that the disturbed intestinal microbiota might be responsible for the increased circulation of BCAAs in T2D. Glucomannan treatment decreased the abundance of microbial BCAA biosynthesis-related genes and ameliorated the host BCAA metabolism. Also, glucomannan with a higher molecular weight and a lower ratio of mannose/glucose possessed better antidiabetic effects. In summary, the antidiabetic effects of glucomannans might be associated with the amelioration of BCAA metabolism by modulating intestinal microbiota.

The human gut microbiota respond to particular food components, interact with intestinal mucosa and thereby contribute to health and disease. Key microbiome features are under comprehensive investigation and are likely to be developed as reliable evidence for clinical diagnosis. The underlying mechanisms provide the foundation for assembling bespoke nutritional ingredients, including functional food additives, that may lead to favorable outcomes in facilitating the amelioration of host dysfunction. Functional hydrocolloids serve as multiple food additives with promising application prospects and outstanding adjunctive beneficial characteristics. Therefore, in this review, we introduce the latest advances in the food additives–gut microbiota–host axis by summarizing the physiochemical and physiological properties of a collection of functional hydrocolloids from various sources, describing the functional hydrocolloids-related intestinal commensal markers and deciphering the underlying mechanisms of their beneficial effects, and propose the feasibilities and guidelines for further development of gut microbiota-oriented personalized nutrition.

β- d -glucan is a major type of bioactive polysaccharide commonly found in edible fungi, especially Lentinus, Cordyceps, and Ganoderma, which are among the most popular and treasured edible and medicinal fungi since ancient times in China. The β-glucans isolated from Lentinus, Cordyceps, and Ganoderma were a kind of homopolysaccharide with backbones of β-(1 → 3)-linked, β-(1 → 6)-linked, and/or β-(1 → 4)-linked d -glucan, and the branching point located at O-6, O-3, or O-4 position. Among them, a characteristic structure of linear β-(1 → 3)- d -glucan with (1 → 6)-β- d -Glcp side chains is frequently reported. For example, lentinan from Lentinus edodes (yield 5%, w/w) has been applied in adjuvant therapy for cancer diseases through the enhancement of immune system. In particular, β-(1 → 3)-glucan with triple helical chain conformation was most effective. Other kinds of chemical structures, including β-(1 → 6)- d -glucan, β-(1 → 4)- d -glucan, as well as a mixed β-(1 → 3)(1 → 4)(1 → 6)-backboned d -glucan, were also reported. This chapter aims to summarize the advances in research of β-glucans derived from Lentinus, Cordyceps, and Ganoderma species, focusing on their isolation methods, purification processes, detailed structures, and chain conformation. Besides, a range of functional activities are comprehensively reviewed, including immunomodulatory, antitumor, anticancer, antivirus, antioxidant activities, etc. Potential for further developments and applications is also briefly discussed.

Lactobacillus are commonly used as probiotics in livestock production to improve animal gut health and performance. We previously reported the selection of Lactobacillus zeae LB1, which was able to reduce Salmonella infection in chickens and pigs, through the life-span assay of Caenorhabditis elegans infected with Salmonella Typhimurium DT104. To understand the molecular mechanisms behind the probiotic effect, the present study used C. elegans as a model to investigate the influence of LB1 on the behavior plasticity and roles of both serotonin and dopamine in C. elegans responding to Salmonella infection and LB1 protection. Pre-exposure to LB1 did not elicit aversive olfactory behavior of both the wild-type nematode (N2) and mutants defective in serotonin (tph-1) or dopamine (cat-2) production towards DT104, although LB1 was much more attractive than DT104 to C. elegans. Life-span studies showed that both the mutants succumbed faster than N2 to DT104 infection. Pre-exposure to LB1 significantly increased the survival level of both N2 and mutant tph-1. However, LB1 provided no protection to mutant cat-2. Supplementation of dopamine restored both the resistance of mutant cat-2 to Salmonella infection and the protection from LB1 to mutant cat-2. These results suggest that both serotonin and dopamine have a role in the host defense of C. elegans to Salmonella infection, and that the LB1 protection effect was not dependent on modifying olfactory preference of the nematode, but mediated by dopamine. Additionally, the p38-mitogen activated protein kinase signaling and IGFR-1/DAF-16 signaling pathways may have also participated in the protection under dopamine regulation.

Salmonellosis is a common foodborne disease. We previously reported the protection of Caenorhabditis elegans from Salmonella Typhimurium DT104 infection by Lactobacillus zeae LB1. However, the mechanism is not fully understood. C. elegans exhibits behavior plasticity when presented with diverse pathogenic or commensal bacteria. Whether it can exert approach avoidance to S. Typhimurium through altering its neurological activity remains to be determined. In the current study, both the wild type and mutants defective in serotonin or dopamine production of C. elegans were used to investigate olfactory preference of the nematode to L. zeae LB1, DT104, and Escherichia coli OP50 by choice assays, and its resistance to DT104 infection and the protection offered by L. zeae LB1 using a life-span assay. The expression of target genes in C. elegans was also examined by real-time quantitative PCR. Results showed that pre-exposure to L. zeae LB1 did not elicit aversive olfactory behavior of the nematode toward DT104. Both mutants tph-1 and cat-2 succumbed faster than the wild type when infected with DT104. While pre-exposure to L. zeae LB1 significantly increased the survival of both the wild type and mutant tph-1, it provided no protection to mutant cat-2. Supplementation of dopamine resulted in both the resistance of mutant cat-2 to S. Typhimurium infection and the protection from L. zeae LB1 to the same mutant. Gene expression data also supported the observations in the life-span assay. These results suggest that both serotonin and dopamine play a positive role in the host defense of C. elegans to S. Typhimurium infection and that the L. zeae LB1 protection is not dependent on modifying olfactory preference of the nematode but mediated by dopamine that may have involved the regulation of p38-mitogen-activated protein kinase and insulin/insulin-like growth factor signaling pathways.

The intervention effect of five Lactobacillus strains on the high-fat diet induced obese C57BL/6J mice was investigated. C57BL/6J mice were randomly divided into normal diet group (ND), high-fat diet group (HFD), HFD with Lactobacillus casei NCU011054 group (LC), HFD with Lactobacillus fermrntum NCU0413 group (LF), HFD with Lactobacillus acidophilus NCU433 group (LA), HFD with Lactobacillus rhamnosus NCU2217 group (LR), HFD with Lactobacillus paracasei NCU622 group (LP), with dosage of 108 colony forming units (CFU)/ml. After intervention for 9 weeks, Lactobacillus strains had the potential ability to decrease body weight and Lee’s index, regulate lipid metabolism levels, and improve the morphology of adipose tissues. In addition, most of these Lactobacillus can significantly alter the levels of serum leptin (LEP) and adiponectin (ADPN). These results suggested that five Lactobacillus strains were able to alleviate obesity in mice induced by high-fat diet via relieving fat accumulation, lipid metabolism and regulating the content of leptin and adiponectin.

Diabetes mellitus is a serious threat to human health. Tea is cultivated around the world, and its polysaccharide components are reported to be an effective approach for managing type 2 diabetes with fewer adverse effects than medication. To examine the therapeutic effect of tea polysaccharides on diabetes, a type 2 diabetic rat model was generated. We showed that tea polysaccharides remarkably decreased fasting blood glucose and the levels of total cholesterol, total triglyceride, low-density lipoprotein cholesterol, and free fatty acid of type 2 diabetic rats. 16S rRNA sequencing and metabolomics were used to investigate the variation of gut microbiota and the metabolites profiles of diabetic rats after intervention of tea polysaccharides. We found that tea polysaccharides maintained the diversity of gut microbiota and restored the relative abundance of some bacterial genera (

The intestinal epithelium is known as an important barrier to protect the body from harmful pathogens or toxic substance that may induce intestinal barrier injury. The aim of this study was to investigate the effects of polysaccharide from the seeds of Plantago asiatica L. (PLP) on nonylphenol (NP) induced intestinal barrier injury in vitro. Caco-2 cells were pretreated with PLP, or co-cultured with PLP and NP simultaneously, and cytotoxicity, LDH leakage, transepithelial electrical resistance (TEER), FITC-dextran flux and tight junction (TJ) proteins were conducted to evaluate the intestinal barrier function. The results suggested that PLP pretreatment or co-culture with NP could significantly attenuated NP induced Caco-2 cytotoxicity, suppressed LDH release, restored the TEER value and paracellular permeability of Caco-2 monolayers, which were attributed to enhancing the TJ protein expressions. In addition, PLP co-cultured with NP possessed better protective effects against NP induced cytotoxicity. This study indicated that PLP assuaged NP induced intestinal barrier injury by increasing TJ, and threw light on the development of a dietary supplementation for preventing exogenous toxic substances induced intestinal barrier injury or improving intestinal TJ barrier function.

The preventive role of polysaccharide from the seeds of Plantago asiatica L. (PLCP) against reproductive system injury induced by nonylphenol (NP) was investigated. Male Sprague-Dawley rats were exposed orally to NP 1 h after PLCP intragastric administration continuously for 45 days. The results showed that NP induced significant decrease in relative weight of testes and epididymis, changed testicular histomorphology, and disrupted hormone secretions. Moreover, oxidative stress occurred after NP exposure by overproduction of Malondialdehyde, lipid peroxidation, inducible nitric oxide synthase, and low activities of superoxide dismutase and catalase. Furthermore, the induction of apoptosis and disturbance of PI3K/Akt/mTOR pathway by NP were also proved. Interestingly, PLCP alleviated NP toxicity by improving antioxidant enzymes, recovering hormone secretions, inhibiting apoptosis and autophagy, which involves PI3K/Akt/mTOR pathway. These findings provide a good direction that PLCP may be a good candidate to help body defend against toxic substance, particularly endocrine disrupting chemicals induced reproductive toxicity.

Lentinula edodes (L. edodes) is a type of edible mushroom which is known to beneficially support the immune system. In this study, three polysaccharide fractions (F1, F2 and F3) were isolated from L. edodes water extracts. Their molecular weights distribution (F1 > F2 > F3) and their immunomodulatory properties were investigated. Thymus index, thickness of footpad, proliferation of splenocytes, immunoglobulin (Ig) content and cytotoxicity of natural killer (NK) cells were measured to evaluate the immunomodulatory effects of the polysaccharides. All three polysaccharide fractions protected host from immunosuppression. F1 had significant effects in enhancing cellular immunity only, while F2 and F3 improved cellular immunity, humoral immunity and innate immunity. The immunomodulatory effects became more significant in the order F1

Growing attention has been paid to the importance of bound polyphenols in dietary fiber. This study aimed to elucidate the effect of bound polyphenols on the fermentation and antioxidant properties of carrot dietary fiber (CDF) in vivo and in vitro. Compared with CDF treatment, 16S rRNA pyrosequencing of in vivo mice feces and in vitro human fecal fermentation samples showed that dephenolized carrot dietary fiber (CDF-DF) treatment decreases operational taxonomic units (OTUs), ACE and Chao1 indexes, increases Firmicute/Bacteroidetes ratio and relative abundance (RA) of Parabacteroides at phylum, restrains RAs of typical beneficial bacteria as well as improves RAs of various harmful bacteria at genus. Meanwhile, short-chain fatty acid (SCFA) contents were lower, while the pH value was higher in the CDF-DF group than those in the CDF group. Interestingly, the combination of bound polyphenols and CDF-DF (CDDP) could recover these indexes influenced by the removal of bound polyphenols in in vitro fermentation samples. Furthermore, the CDF-DF-fed mice exhibited higher MDA content and lower SOD and GSH-Px activities in the colon. The cellular antioxidant activity (CAA) value of CDF-DF was lower than that of CDF and CDDP. These results revealed that bound polyphenols significantly contribute to the fermentation and antioxidant properties of CDF.

Background: Diabetes mellitus is a serious threat to human health. Tea is cultivated around the world and its polysaccharide components are reported to be an effective approach for managing type 2 diabetes with fewer adverse effects than medication. Methods: To examine the therapeutic effect of tea polysaccharides on diabetes, a type 2 diabetic rat model was generated and 16S rRNA sequencing and metabolomics were used to investigate the variation of gut microbiota and the metabolites profiles of diabetic rats after intervention of tea polysaccharides. Findings: We showed that tea polysaccharides remarkably decreased fasting blood glucose and the levels of total cholesterol, total triglyceride, low-density lipoprotein cholesterol and free fatty acid of type 2 diabetic rats. And tea polysaccharides maintained the diversity of gut microbiota and restored the relative abundance of some bacterial genera (Lachnospira, Victivallis, Roseburia and Fluviicola) which was reduced by diabetes. According to metabolomics analysis, we found that amino acid and other related metabolites was influenced by tea polysaccharides intervention. Interpretation: Correlation analysis among metabolites, gut microbiota, and parameters of hypoglycemic indicated that tea polysaccharides had hypoglycemic and hypolipidemic effect on type 2 diabetes via the modulation of gut microbiota and the improvement of host metabolism. Funding Statement: The financial support from National Natural Science Foundation of China for4 Distinguished Young Scholars (31825020), the Program for National Key R&D Program of China (2017YFD0400203), the Project of Academic Leaders of the Major Disciplines in Jiangxi Province (20162BCB22008), Outstanding Science and Technology Innovation Team Project in Jiangxi Province (20165BCB19001), Collaborative Project in Agriculture and Food Field between China and Canada (2017ZJGH0102001), Graduate Student Innovation Special Fund Support in Jiangxi Province (YC2018-S004), is gratefully acknowledged. Declaration of Interests: The authors declare that no conflict of interests. Ethics Approval Statement: All animals and laboratory conditions in this study were performed according to the National Institutes of Health Guidelines on the Use of Laboratory Animals (NIH publication No. 85-23, revised 1996). All experiments were approved by the Animal Care Review Committee, Nanchang University.

Seaweeds and their derivatives are important bioresources of natural bioactive compounds. Nutritional studies indicate that dietary fibers derived from seaweeds have great beneficial potentials in human health and can be developed as functional food. Moreover, sulfated polysaccharides are more likely to be the main bioactive components which are widely distributed in various species of seaweeds including Phaeophyceae, Rhodophyceae and Chlorophyceae. The catabolism by gut microbiota of the seaweeds-derived dietary fibers (DFs) may be one of the pivotal pathways of their physiological functions. Therefore, in this review, we summarized the latest results of the physiological characteristics of seaweed-derived dietary fiber and highlighted the roles of sulfated polysaccharides in the potential regulatory mechanisms against disorders. Meanwhile, the effects of different types of seaweed-derived dietary fiber on gut microbiota were discussed. The analysis of the structure–function correlations and gut microbiota related mechanisms and will contribute to further better applications in food and biotherapeutics.

Type 2 diabetes (T2D) is a metabolic disease characterized by hyperglycemia. Intake of dietary fiber is inversely associated with risks of T2D. Here, metabolomics and 16S rRNA gene sequencing were employed to investigate the effects of arabinoxylan on gut microbiota and their metabolites in type 2 diabetic rats. T2D increased the abundance of opportunistic pathogens (such as Desulfovibrio and Klebsiella) and the levels of 12α-hydroxylated bile acids and acylcarnitines (C3) in diabetic rats, which eventually contribute to insulin resistance and hyperglycemia. Supplementation with arabinoxylan promoted the growth of fiber-degrading bacteria to increase short-chain fatty acids (SCFAs), as well as decreased the abundance of opportunistic pathogens. Arabinoxylan treatment also decreased the concentrations of 12α-hydroxylated bile acids, and increased the levels of equol, indolepropionate, and eicosadienoic acid. This study indicated that the beneficial effects of arabinoxylan on T2D may be partially attributed to the modification of gut microbiota and related metabolites.

The application of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI TOF MS) in glycan was limited due to their poor ionization efficiency, compared with biomolecules such as proteins and peptides. Aiming to improve the ionization efficiency and simplify preparation procedure simultaneously during MALDI MS analysis, an on-target derivatization method using 3-aminoquinoline (3-AQ)/α-cyano-4-hydroxycinnamic acid (CHCA) as matrix was employed and it was conducted both in the positive and negative ion MALDI TOF MS. Results indicated that after on-target derivatization, the ions generated had substantially improved S/N ratios and sensitivity in the tandem mass spectra. The B/Y− type ions of 3-AQ-labeled glycans could be easily recognized, and cross-ring A− type ions provided additional information to reveal the linkage patterns. Specifically, positive ion mass spectra with protonated adduct as precursor ion produced a simple fragmentation pattern benefited for sequencing and observation of branches. Furthermore, this method was successfully applied in polysaccharides analysis, including arabinoxylan, xylan, arabinogalactan and dextran after enzymatic or acid degradation. This study demonstrated that it was feasible to analyze higher molecular weight polysaccharides by MALDI TOF MS using 3-AQ/CHCA matrix through appropriate hydrolysis, and it allowed much efficient structural interpretation with increased sensitivity and characteristic fragment ions.

A homogeneous galactoglucan was purified from the alkali-extracted polysaccharides from the basidioma of Macrolepiota albuminosa by gradient ethanol precipitation, whose proposed structure was given for the first time. Results showed it had a molecular weight of 210 kDa, and mainly consisted of glucose and galactose. There were abundant filaments, randomly distributed sheet-like and flaky appearance in its surface by SEM observation. Its backbone comprised β-(1 → 6)-Glcp, α-(1 → 6)-Galp and β-(1 → 3,6)-Glcp residues at 4:1:1, terminated by β-(1 → 3)-Glcp and T-Glcp residues. Rheological measurements suggested its steady flow behavior was highly dependent on concentrations. Newtonian behavior was evident at low concentrations, whereas pseudoplastic behavior was observed at high concentrations. Besides, the X-ray diffraction patterns proved the presence of amorphous structure. The conformational parameters were detected by HPSEC-MALLS-RI, revealing a random coil conformation in NaNO3 aqueous solution. This work provides a theoretical basis for the application of polysaccharides from M. albuminosa in food- and drug-based therapies.

Diabetes mellitus (DM) and its complications are major public health concerns which strongly influence the quality of humans' life. Modification of gut microbiota has been widely used for the management of diabetes. In this review, the relationship between diabetes and gut microbiota, as well as the effects of different dietary components and traditional Chinese medicine (TCM) on gut microflora are summarized. Dietary compounds and TCM possessing bioactive components (fiber and phytochemicals) first change the composition of gut microbiota (inhibiting pathogens and promoting the beneficial bacteria growth) and then influence the production of their metabolites, which would further modify the intestinal environment through inhibiting the production of detrimental compounds (such as lipopolysaccharide, hydrogen sulfide, indol, etc.). Importantly, metabolites (short chain fatty acids and other bioactive components) fermented/degraded by gut microbiota can target multiple pathways in intestine, liver, pancreas, etc., resulting in the improvement of gut health, glycemic control, lipids profile, insulin resistance and inflammation. Furthermore, understanding the interaction between different dietary components and gut microbiota, as well as underlying mechanisms would help design different diet formula for the management of diabetes. Further researches could focus on the combination of different dietary components for preventing and treating diabetes, based on the principle of "multiple components against multiple targets" from the perspective of gut microbiota.

Aloe barbadensis Miller (Aloe vera) is a kind of popular medicinal and horticultural crops widely cultivated around the world. Polysaccharides with different structural features and bioactivities have been isolated from the pulp of Aloe vera. In the current study, a novel polysaccharide fraction (AGP40) isolated and purified from gel juice of Aloe vera was subjected to structural and conformational analysis. AGP40 had a backbone consisting of major →4)-β-Manp-(1 → residues and minor →3)-β-Manp-(1 → and →4)-β-Glcp-(1 → residues. Low degree of branches distributed at O-6 of 4-linked mannose in the main chain. The acetyl groups in AGP40 presented as mono- or di-substituents (O-2, O-3, O-6, O-2,3, O-2,6 and O-3,6). AGP40 performed as random coil conformation in 0.1 M NaNO3 solution, and had fibrous filaments and irregular spherical structures in solid state. Detailed structural and conformational analysis of AGP40 in the present study may greatly improve the bioactive function investigation and mechanism explanation of acetyl glucomannans in the future.