In vitro fecal fermentation properties of polysaccharides from Tremella fuciformis and related modulation effects on gut microbiota

Study of Lactobacillus plantarum coated with Tremella polysaccharides to improve its intestinal adhesion

BACKGROUND

The adhesion of probiotics to the intestine is crucial for their probiotic function. In previous studies, Tremella polysaccharides (TPS) (with sodium casein) have shown the potential to encapsulate probiotics and protect them in a simulated gastrointestinal tract. This study explored the effect of TPS (with sodium casein) on the adhesion of probiotics.

RESULTS

Lactobacillus plantarum was coated with TPS and sodium casein in different proportions, and was freeze-dried. The rheological properties of the mixture of probiotics powder and mucin solution were determined by static and dynamic rheological analysis. Aqueous solutions of probiotic powder and mucin mixture exhibited pseudoplastic fluid rheological properties. The higher the proportion of TPS content, the higher the apparent viscosity and yield stress. The mixed bacterial powder and mucin fluid displayed thixotropy and was in accordance with the Herschel-Bulkley model. The TPS increased the bio-adhesive force of the probiotic powder and mucin. When using TPS as the only carbon source, the adhesion of L. plantarum to Caco-2 cells increased by 228% in comparison with glucose in vitro. Twelve adhesive proteins were also detected in the whole-cell proteome of L. plantarum. Among them, ten adhesive proteins occurred abundantly when grown with TPS as a carbon source.

CONCLUSION

Tremella polysaccharides therefore possess probiotic properties and can promote the intestinal adhesion of L. plantarum. © 2024 Society of Chemical Industry.

Comparison of different longan polysaccharides during gut Bacteroides fermentation

The bioactivity of polysaccharide was closely related to its fermentation utilization by gut Bacteroides, and its utilization degree was determined by various gut Bacteroides species and different polysaccharides characteristics. The effects of longan polysaccharide (LP) and LP treated by ultrasonic-assisted hydrogen peroxide for 8 h (DLP-8) on gut Bacteroides growth, and their fermentation utilization were compared. The results of LP and DLP-8 on the proliferation of six Bacteroides species showed that Bacteroides uniformis had the highest proliferation index. In fermentation by B. uniformis, DLP-8 (with a lower molecular weight), the viable count of which was higher than that of LP, was degraded more and especially utilized more glucose and glucuronic acid. The microstructure of the two polysaccharides changed differently during fermentation. Moreover, DLP-8 promoted greater short-chain fatty acids production than LP. These results indicated that the fermentation properties of DLP-8 by B. uniformis were superior to those of LP.

In vivo absorption, in vitro simulated digestion, and fecal fermentation properties of Imperata cylindrica polysaccharides and their effects on gut microbiota

Recently we have investigated polysaccharide from Imperata cylindrica (ICP) for its physicochemical structure and biological activities. However, the digestion characteristics have yet to be understood. This study investigated the digestion and metabolism characteristics of ICP through in vivo fluorescence tracking, in vitro simulated digestion, fecal fermentation experiments, and microbial sequencing. The results showed that ICP significant distribution in the gastrointestinal tract and kidneys. ICP underwent slight degradation during simulated gastric and intestinal digestion. During fecal fermentation, the utilization degree of ICP and the concentration of short-chain fatty acids (SCFAs) increased. ICP promoted the increase of beneficial microbial abundance. To understand the impact of ICP on the integrity and health of intestinal tissues, molecular docking was employed to preliminarily predict the interaction between ICP and key proteins. The results revealed that ICP could recognize and bind to key proteins through high-affinity targeting binding sites.

Applications of polysaccharides in enzyme-triggered oral colon-specific drug delivery systems: A review

Enzyme-triggered oral colon-specific drug delivery system (EtOCDDS1) can withstand the harsh stomach and small intestine environments, releasing encapsulated drugs selectively in the colon in response to colonic microflora, exerting local or systematic therapeutic effects. EtOCDDS boasts high colon targetability, enhanced drug bioavailability, and reduced systemic side effects. Polysaccharides are extensively used in enzyme-triggered oral colon-specific drug delivery systems, and its colon targetability has been widely confirmed, as their properties meet the demand of EtOCDDS. Polysaccharides, known for their high safety and excellent biocompatibility, feature modifiable structures. Some remain undigested in the stomach and small intestine, whether in their natural state or after modifications, and are exclusively broken down by colon-resident microbiota. Such characteristics make them ideal materials for EtOCDDS. This article reviews the design principles of EtOCDDS as well as commonly used polysaccharides and their characteristics, modifications, applications and specific mechanism for colon targeting. The article concludes by summarizing the limitations and potential of ETOCDDS to stimulate the development of innovative design approaches.

In vitro human gut microbiota fermentation of litchi pulp polysaccharides as affected by Lactobacillus pre-treatment

In this study, litchi polysaccharides were obtained from unfermented or fermented pulp by Lactobacillus fermentum (denoted as LP and LPF, respectively). The differences between LP and LPF in the colonic fermentation characteristics and modulatory of gut microbiota growth and metabolism were investigated with an in vitro fecal fermentation model. Results revealed that the strategies of gut bacteria metabolizing LP and LPF were different and LPF with lower molecular weight (Mw) was readily utilized by bacteria. The monosaccharide utilization sequence of each polysaccharide was Ara > Gla > GalA > GlcA ≈ Glu ≈ Man. Moreover, LPF promoted stronger proliferation of Bifidobacterium, Megamonas, Prevotella, and Bacteroides and higher SCFAs production (especially acetic and butyric acids) than LP. Correlation analysis further revealed that Mw could represent an essential structural feature of polysaccharides associated with its microbiota-regulating effect. Overall, Lactobacillus fermentation pre-treatment of litchi pulp promoted the fermentation characteristics and prebiotic activities of its polysaccharide.

The effects of inulin on solubilizing and improving anti-obesity activity of high polymerization persimmon tannin

High polymerization persimmon tannin has been reported to have lipid-lowering effects. Unfortunately, the poor solubility restricts its application. This research aimed to investigate the effect and mechanism of inulin on solubilizing of persimmon tannin. Furthermore, we examined whether the addition of inulin would affect the attenuated obesity effect of persimmon tannin. Transmission electron microscope (TEM), Isothermal titration calorimetry (ITC) and Fourier transform infrared spectroscopy (FT-IR) results demonstrated that inulin formed a gel-like network structure, which enabled the encapsulation of persimmon tannin through hydrophobic and hydrogen bond interactions, thereby inhibiting the self-aggregation of persimmon tannin. The turbidity of the persimmon tannin solution decreased by 56.2 %, while the polyphenol content in the supernatant increased by 60.0 %. Furthermore, biochemical analysis and 16s rRNA gene sequencing technology demonstrated that persimmon tannin had a significant anti-obesity effect and improved intestinal health in HFD-fed mice. Moreover, inulin was found to have a positive effect on enhancing the health benefits of persimmon tannin, including improving hepatic steatosis and gut microbiota dysbiosis. it enhanced the abundance of beneficial core microbes while decreasing the abundance of harmful bacteria. Our findings expand the applications of persimmon tannin in the food and medical sectors.

In Vitro Digestion and Fermentation of Different Ethanol-Fractional Polysaccharides from Dendrobium officinale: Molecular Decomposition and Regulation on Gut Microbiota

Polysaccharides from Dendrobium officinale have garnered attention for their diverse and well-documented biological activities. In this study, we isolated three ethanol-fractionated polysaccharides from Dendrobium officinale (EPDO) and investigated their digestive properties and effects on gut microbiota regulation in vitro. The results indicated that after simulating digestion in saliva, gastric, and small intestinal fluids, three EPDOs, EPDO-40, EPDO-60 and EPDO-80, with molecular weights (Mw) of 442.6, 268.3 and 50.8 kDa, respectively, could reach the large intestine with a retention rate exceeding 95%. During in vitro fermentation, the EPDOs were broken down in a "melting" manner, resulting in a decrease in their Mw. EPDO-60 degraded more rapidly than EPDO-40, likely due to its moderate Mw. After 24 h, the total production of short-chain fatty acids (SCFAs) for EPDO-60 reached 51.2 ± 1.9 mmol/L, which was higher than that of EPDO-80. Additionally, there was an increase in the relative abundance of Bacteroides, which are capable of metabolizing polysaccharides. EPDO-60 also promoted the growth of specific microbiota, including Prevotella 9 and Parabacteroides, which could potentially benefit from these polysaccharides. Most notably, by comparing the gut microbiota produced by different fermentation carbon sources, we identified the eight most differential gut microbiota specialized in polysaccharide metabolism at the genus level. Functional prediction of these eight differential genera suggested roles in controlling replication and repair, regulating metabolism, and managing genetic information transmission. This provides a new reference for elucidating the specific mechanisms by which EPDOs influence the human body. These findings offer new evidence to explain how EPDOs differ in their digestive properties and contribute to the establishment of a healthy gut microbiota environment in the human body.

Polysaccharide from Boletus aereus ameliorates DSS-induced colitis in mice by regulating the MANF/MUC2 signaling and gut microbiota

Inflammatory bowel diseases (IBD) are chronic inflammatory conditions characterized by disruptions in the colonic mucus barrier and gut microbiota. In this study, a novel soluble polysaccharide obtained from Boletus aereus (BAP) through water extraction was examined for its structure. The protective effects of BAP on colitis were investigated using a DSS-induced mice model. BAP was found to promote the expression of intestinal mucosal and tight junction proteins, restore the compromised mucus barrier, and suppress the activation of inflammatory signaling. Moreover, BAP reshape the gut microbiota and had a positive impact on the composition of the gut microbiota by reducing inflammation-related microbes. Additionally, BAP decreased cytokine levels through the MANF-BATF2 signaling pathway. Correlation analysis revealed that MANF was negatively correlated with the DAI and the level of cytokines. Furthermore, the depletion of gut microbiota using antibiotic partially inhabited the effect of BAP on the activation of MANF and Muc2, indicating the role of gut microbiota in its protective effect against colitis. In conclusion, BAP had an obvious activation on MANF under gut inflammation. This provides new insights into the prospective use of BAP as a functional food to enhance intestinal health.

Characterization, antioxidant activity and in vitro digestion of hawthorn pectin prepared by gradient ethanol precipitation

Four modified hawthorn pectin fractions (MHPs), named MHP-30, MHP-50, MHP-70 and MHP-90, were obtained by ultrasonic-assisted pectin methyl esterase modification and gradient ethanol precipitation. The results indicated that all four MHPs were composed of galacturonic acid, galactose, xylose, arabinose, glucose and mannose in different proportions. With the increase of the ethanol concentration, the molecular weight, esterification degree and galacturonic acid content of MHPs all decreased, whereas the arabinose content and branching degree increased. The structural characterization from XRD, SEM, and FT-IR showed that four MHPs exhibited amorphous structure, similar functional groups, diverse surface morphologies. Besides, in vitro antioxidant assays confirmed that MHP-70 and MHP-90 exhibited stronger total antioxidant activities than MHP-30 and MHP-50. The results of simulated saliva-gastrointestinal digestion showed that the molecular weight of MHP-70 and MHP-90 remained stable, yielded small amounts of reducing sugars, and were resistant to digestion in the human upper digestive tract. Overall, MHP-70 and MHP-90 shown great potential as novel natural antioxidants, which are expected to be good carbon sources for the utilization of intestinal microorganisms.

Structure characterization of an agavin-type fructan isolated from Polygonatum cyrtonema and its effect on the modulation of the gut microbiota in vitro

The herbal medicine Polygonatum cyrtonema is highly regarded in China for its medicinal and dietary properties. However, further research is needed to elucidate the structure of its polysaccharide and understand how it promotes human health by modulating the gut microbiota. This study aims to investigate a homogeneous polysaccharide (PCP95-1-1) from Polygonatum cyrtonema and assess its susceptibility to digestion as well as its utilization by intestinal microbiota. The results confirmed that PCP95-1-1 is an agavin-type fructan, which possesses two fructose chains, namely β-(2 → 6) and β-(2 → 1) fructosyl-fructose, attached to the sucrose core, and has branches of β-D-Fruf residues. Moreover, PCP95-1-1 demonstrated resistance to digestion and maintained its reducing sugar content throughout the digestive system, indicating it could reach the gut without being digested. In vitro fermentation of PCP95-1-1 significantly decreased the pH value (p < 0.05) while notably increasing the production of short-chain fatty acids (SCFAs), confirming its utilization by human gut microbiota. Additionally, PCP95-1-1 exhibited a significant ability (p < 0.05) to beneficial bacteria such as Megamonas and Bifidobacterium, while reducing the presence of facultative or conditional pathogens such as Escherichia-Shigella and Klebsiella at the genus level. Consequently, PCP95-1-1 has the potential to positively influence physical well-being by modulating the gut microbiota environment and can be developed as a functional food.

Comparison of soluble dietary fibers from various quinoa microgreens: Structural characteristics and bioactive properties

Quinoa (Chenopodium quinoa Willd.) microgreens are widely consumed as healthy vegetables around the world. Although soluble dietary fibers exist as the major bioactive macromolecules in quinoa microgreens, their structural characteristics and bioactive properties are still unclear. Therefore, the structural characteristics and bioactive properties of soluble dietary fibers from various quinoa microgreens (QMSDFs) were investigated in this study. The yields of QMSDFs ranged from 38.82 to 52.31 mg/g. Indeed, all QMSDFs were predominantly consisted of complex pectic-polysaccharides, e.g., homogalacturonan (HG) and rhamnogalacturonan I (RG I) pectic domains, with the molecular weights ranged from 2.405 × 104 to 5.538 × 104 Da. In addition, the proportions between RG I and HG pectic domains in all QMSDFs were estimated in the range of 1: 2.34-1: 4.73 (ratio of galacturonic acid/rhamnose). Furthermore, all QMSDFs exhibited marked in vitro antioxidant, antiglycation, prebiotic, and immunoregulatory effects, which may be partially correlated to their low molecular weights and low esterification degrees. These findings are helpful for revealing the structural and biological properties of QMSDFs, which can offer some new insights into further development of quinoa microgreens and related QMSDFs as value-added healthy products.

Exopolysaccharides from Enterococcus faecium and Streptococcus thermophilus: Bioactivities, gut microbiome effects, and fermented milk rheology

Exopolysaccharides (EPSs) are carbohydrate polymers that can be produced from probiotic bacteria. This study characterized the EPSs from Enterococcus faecium (EPS-LB13) and Streptococcus thermophilus (EPS-MLB10) and evaluated their biological and technological potential. The EPSs had high molecular weight and different monosaccharide compositions. The EPSs exhibited various biological activities at 250 mg/L, such as scavenging free radicals (10 % to 88.8 %), enhancing antioxidant capacity (714 to 2848 µg/mL), inhibiting pathogens (53 % to 74 %), and suppressing enzymes and cancer cells (2 % to 83 %), etc. The EPSs supported the growth of beneficial gut bacteria from Proteobacteria, Bacteroidetes, Firmicutes, and Acinetobacter in fecal fermentation with total Short-chain fatty acids production from 5548 to 6023 PPM. Moreover, the EPSs reduced the gelation time of fermented skimmed bovine milk by more than half. These results suggest that the EPSs from LB13 and MLB10 have promising applications in the dairy and pharmaceutical industries.

Efficient extraction of pectic polysaccharides from thinned unripe kiwifruits by deep eutectic solvent-based methods: Chemical structures and bioactivities

To promote the potentially industrial applications of thinned unripe kiwifruits, two deep eutectic solvent-based methods, including deep eutectic solvent-assisted extraction (DAE) and microwave-assisted deep eutectic solvent extraction (MDE), were optimized for the extraction of polysaccharides from thinned unripe kiwifruits (YKP). Results showed that the yields of YKP-D prepared by DAE and YKP-DM prepared by MDE were extremely higher than YKP-H prepared by hot water extraction. Furthermore, YKP-H, YKP-D, and YKP-DM were mainly composed of pectic polysaccharides, including homogalacturonan (HG) and rhamnogalacturonan I (RG I) domains. Besides, both YKP-D and YKP-DM exhibited stronger antioxidant, anti-glycosylation, and immunomodulatory effects than those of YKP-H, and their higher contents of uronic acids and bound polyphenols as well as lower molecular weights could partially contribute to their bioactivities. Overall, these results revealed that the developed MDE method could be utilized as a promising method for highly efficient extraction of YKP with superior beneficial effects.

The function and application of edible fungal polysaccharides

Edible fungi, commonly known as mushrooms, are precious medicinal and edible homologous gifts from nature to us. Edible fungal polysaccharides (EFPs) are a variety of bioactive macromolecular which isolated from fruiting bodies, mycelia or fermentation broths of edible or medicinal fungus. Increasing researches have confirmed that EFPs possess multiple biological activities both in vitro and in vivo settings, including antioxidant, antiviral, anti-inflammatory, immunomodulatory, anti-tumor, hypoglycemic, hypolipidemic, and regulating intestinal flora activities. As a result, they have emerged as a prominent focus in the healthcare, pharmaceutical, and cosmetic industries. Fungal EFPs have safe, non-toxic, biodegradable, and biocompatible properties with low immunogenicity, bioadhesion ability, and antibacterial activities, presenting diverse potential applications in the food industries, cosmetic, biomedical, packaging, and new materials. Moreover, varying raw materials, extraction, purification, chemical modification methods, and culture conditions can result in variances in the structure and biological activities of EFPs. The purpose of this review is to provide comprehensively and systematically organized information on the structure, modification, biological activities, and potential applications of EFPs to support their therapeutic effects and health functions. This review provides new insights and a theoretical basis for prospective investigations and advancements in EFPs in fields such as medicine, food, and new materials.

In vitro digestion and fecal fermentation of basidiospore-derived exopolysaccharides from Naematelia aurantialba

Mushroom polysaccharides exhibit numerous health-enhancing attributes that are intricately linked to the breakdown, assimilation, and exploitation of polysaccharides within the organism. Naematelia aurantialba polysaccharides (NAPS-A), highly prized polysaccharides derived from mushrooms, remain shrouded in uncertainty regarding their characteristics pertaining to gastrointestinal digestion and gut microbial fermentation. The study aimed to understand the digestion and fecal fermentation patterns of NAPS-A. After simulated digestion, NAPS-A's physicochemical properties remained unchanged. However, during in vitro fecal fermentation, indigestible NAPS-A underwent significant changes in various properties, such as reducing sugar, chemical composition, constituent monosaccharides, Molecular weight, apparent viscosity, FT-IR spectra, and microscopic morphology. Notably, NAPS-A was effectively utilized by the gut microbiota, with unchanged properties after digestion but altered after fermentation. It influenced gut microbe composition by increasing beneficial bacteria (Lactobacillus, Faecalibacterium, and Roseburia), lowering pH, and producing short-chain fatty acids. NAPS-A fermentation enriches carbohydrate, fatty acid, and amino acid metabolic pathways through PICRUSt prediction analysis. Overall, these findings emphasize NAPS-A's role in regulating gut bacteria and their metabolic functions, despite its challenging digestibility.

Effect of polysaccharide concentration on heat-induced Tremella fuciformis polysaccharide-soy protein isolation gels: Gel properties and interactions

The formation of a single soybean protein isolate (SPI) gel is limited by the processing conditions, and has the disadvantages of poor gel property, and it is usually necessary to add other biomacromolecules to improve its property. In this study, we investigated the effects of polysaccharide concentration on gel properties and interaction mechanisms of Tremella fuciformis polysaccharide (TFP)-SPI complexes. It was found that (1) the rheological properties, texture properties, water-holding properties, and thermal stability of TFP-SPI composite gels were improved with the addition of TFP (0.25-2.0 %, w/v) in a concentration-dependent manner; (2) hydrogen bond, the electrostatic interaction, hydrophobic interaction, and disulfide bond in the gel system increased with the increase of TFP concentration; (3) the electrostatic and hydrophobic interactions played an important role in the formation of the TFP-SPI composite gel while hydrogen bond formation was the least contributor to the binary composite gel network. Overall, TFP is not only a critical health food but also a promising structural component for improving the gel properties of SPI.

Glycosidic linkages of fungus polysaccharides influence the anti-inflammatory activity in mice

INTRODUCTION

Over decades, the source-function relationships of bioactive polysaccharides have been progressively investigated, however, it is still unclear how a defined structure may conduce to the bioactivities of polysaccharides.

OBJECTIVES

To explore the structure-function relationship of fungus polysaccharides, we employed a dextran sulfate sodium (DSS)-induced colitis mouse model to compare the anti-inflammatory activity of two fungus polysaccharides from Dictyophora indusiata (DIP) and Tremella fuciformis (TFP), which exhibit distinct glycosidic linkages.

METHODS

The structures of DIP and TFP were characterized through molecular weight detection, molecular morphology analysis, methylation analysis, and NMR analysis. Subsequently, we employed a DSS-induced colitis model to assess the anti-inflammatory efficacy of DIP and TFP. The colitis symptoms, histological morphology, intestinal inflammatory cytokines, and the composition and function of gut microbiota before and after polysaccharides treatment in colitis mice were also investigated.

RESULTS

DIP, l,3-β-D-glucan with 1,4-β and 1,6-β-D-Glcp as branched chains, exhibited superior therapeutic effect than that of TFP consisted of a linear 1,3-α-D-mannose backbone with D-xylose and L-fucose in the side chains. Both DIP and TFP relieved DSS-induced colitis in a gut microbiota-dependent manner. Furthermore, metagenomics showed that DIP and TFP could partially reverse the bacterial function in colitis mice. Glycoside Hydrolase 1 (GH1) and GH3 were identified as being involved in hydrolyzing the glucose linkages in DIP, while GH92 and GH29 were predicted to be active in cleaving the α-1,3-linked mannose linkages and the glycosidic bonds of L-fucose residues in TFP.

CONCLUSION

Our findings highlight the pivotal role of glycosidic linkages in anti-inflammatory activities of fungus polysaccharides and would promote the design and discovery of polysaccharides with designated activity to be used as functional foods and/or therapeutics.

Structural characterization and in vitro fermentation properties of polysaccharides from Polygonatum cyrtonema

Polysaccharides, the major active ingredient and quality control indicator of Polygomatum cyrtonema are in need of elucidation for its in vitro fermentation characteristics. This study aimed to investigate the structural characteristics of the homogeneous Polygomatum cyrtonema polysaccharide (PCP-80 %) and its effects on human intestinal bacteria and short chain fatty acids (SCFAs) production during the in vitro fermentation. The results revealed that PCP-80 % was yielded in 10.44 % and the molecular weight was identified to be 4.1 kDa. PCP-80 % exhibited a smooth, porous, irregular sheet structure and provided good thermal stability. The analysis of Gas chromatograph-mass spectrometer (GC-MS) suggested that PCP-80 % contained six glycosidic bonds, with 2,1-linked-Fruf residues accounted for a largest proportion. Nuclear magnetic resonance (NMR) provided additional evidence that the partial structure of PCP-80 % probably consists of →1)-β-D-Fruf-(2 → as the main chain, accompanied by side chains dominated by →6)-β-D-Fruf-(2→. Besides, PCP-80 % promoted the production of SCFAs and increased the relative abundance of beneficial bacteria such as Megamonas, Bifidobacterium and Phascolarctobacterium during in vitro colonic fermentation, which changed the composition of the intestinal microbiota. These findings indicated that Polygomatum cyrtonema polysaccharides were able to modulate the structure and composition of the intestinal bacteria flora and had potential probiotic properties.

Preparation, Structural Analysis, and Intestinal Probiotic Properties of a Novel Oligosaccharide from Enzymatic Degradation of Huangshui Polysaccharide

Huangshui polysaccharide (HSP) has attracted more and more interest due to its potential health benefits. Despite being an excellent source for the preparation of oligosaccharides, there are currently no relevant research reports on HSP. In the present study, a novel oligosaccharide (HSO) with a molecular weight of 1791 Da and a degree of polymerization of 11 was prepared through enzymatic degradation of crude HSP (cHSP). Methylation and NMR analyses revealed that the main chain of HSO was (1 → 4)-α-d-glucose with two O-6-linked branched chains. Morphological observations indicated that HSO exhibited smooth surface with lamellar and filamentary structure, and the glycan size ranged from 0.03 to 0.20 μm. Notably, HSO significantly promoted the proliferation of Bifidobacterium, Bacteroides, and Phascolarctobacterium, thereby making positive alterations in intestinal microbiota composition. Moreover, HSO markedly increased the content of short-chain fatty acids during in vitro fermentation. Metabolomics analysis illustrated the important metabolic pathways primarily involving glucose metabolism, amino acid metabolism, and fatty acid metabolism.

Production, structural and functional characteristics of soluble dietary fiber from fermented okara by Penicillium expansum

Soluble dietary fiber (SDF), an important prebiotic, has attracted growing attention, due to its great health effects and wide application. This study focused on the preparation of SDF from fermented okara. The yield of SDF obtained through Penicillium expansum fermentation (FSDF) reached 45.63 % (w/w) under the optimal conditions (pH 6.7, inoculum size 9.5 %, and time 29 h) by response surface methodology, which were 1.92 and 4.43 times higher than those of phosphate-citric acid treatment and untreated okara. Infrared spectra and X-ray diffraction indicated that three SDFs had similar spectral distribution and crystalline region. Moreover, FSDF displayed looser and more porous microstructures. Meanwhile, the composition ratio of monosaccharides has changed. FSDF exhibited higher water solubility (97.46 %), glucose adsorption capacity (203.73 mg/g), sodium cholate adsorption capacity (13.07 mg/g), cholesterol adsorption capacity (6.69- 7.62 mg/g) and radical (ABTS+, hydroxyl and DPPH) scavenging capacity. Additionally, three SDFs didn't degrade by upper gastrointestinal tract and could improve the proportion of beneficial intestinal flora in vitro, such as Lactobacillus and Bifidobacterium. Overall, the FSDF prepared in this study was a functional ingredient with great potential in foods.

Structural properties and biological activities of soluble dietary fibers rich in pectic-polysaccharides from different buckwheat green leaves

Buckwheat green leaves are commonly consumed as functional tea materials due to their various beneficial effects. Although buckwheat green leaves have abundant soluble dietary fibers (SDFs), the information about their structural properties and functional properties remains unknown, largely hindering their applications as functional/health products. Hence, to enhance the usage and application of SDFs from buckwheat green leaves as value-added health products, the structures and biological activities of SDFs derived from different buckwheat green leaves were investigated and compared. Results revealed that SDFs derived from Tartary buckwheat green leaves (TBSDF) and common buckwheat green leaves (CBSDF) were rich in complex pectic-polysaccharides, mainly composing of homogalacturonan (HG) and rhamnogalacturonan I (RG I) pectic domains. Besides, TBSDF had higher proportion of RG I pectic domains than that of CBSDF. Furthermore, the existence of a high content of complex pectic-polysaccharides in TBSDF and CBSDF could contribute to their various biological activities, such as antioxidant, antiglycation, fat/bile acid binding, anticancer, and prebiotic effects. These results can provide some new insights into further development of buckwheat green leaves and related SDFs as value-added health products.

Effect of in vitro digestion and fermentation of kiwifruit pomace polysaccharides on structural characteristics and human gut microbiota

Kiwifruit pomace is abundant in polysaccharides that exhibit diverse biological activities and prebiotic potential. This study delves into the digestive behavior and fermentation characteristics of kiwifruit pomace polysaccharides (KFP) through an in vitro simulated saliva-gastrointestinal digestion and fecal fermentation. The results reveal that following simulated digestion of KFP, its molecular weight reduced by 4.7%, and the reducing sugar (CR) increased by 9.5%. However, the monosaccharide composition and Fourier transform infrared spectroscopy characteristics showed no significant changes, suggesting that KFP remained undigested. Furthermore, even after saliva-gastrointestinal digestion, KFP retained in vitro hypolipidemic and hypoglycemic activities. Subsequently, fecal fermentation significantly altered the physicochemical properties of indigestible KFP (KFPI), particularly leading to an 89.71% reduction in CR. This indicates that gut microbiota could decompose KFPI and metabolize it into SCFAs. Moreover, after 48 h of KFPI fecal fermentation, it was observed that KFPI contributed to maintaining the balance of gut microbiota by promoting the proliferation of beneficial bacteria like Bacteroides, Lactobacillus, and Bifidobacterium, while inhibiting the unfavorable bacteria like Bilophila. In summary, this study offers a comprehensive exploration of in vitro digestion and fecal fermentation characteristics of KFP, providing valuable insights for potential development of KFP as a prebiotic for promoting intestinal health.

A novel exopolysaccharide from Weissella cibaria FAFU821: Structural characterization and cryoprotective activity

Exopolysaccharides produced by Weissella cibaria has attracted increasing attention owing to their biological activity. Here, a strain was isolated from the home-made fermented octopus, which was identified as W. cibaria FAFU821. In addition, the polysaccharide were isolated and purified by cellulose DE-52 column and Sephadex G-100 column, and named EPS821-1. In this work, the structure of EPS821-1 and its cryoprotective activity on Bifidobacterium longum subsp. longum F2 were investigated in vitro. These results suggested that the EPS821-1 is a novel glucan, which mainly consists of α-(1 → 6) linkage with α-(1 → 4), α-(1 → 4,6) and α-(1 → 3,6) residue as branches. In addition, EPS821-1 existed the three-dimensional network structure and exhibited the excellent cryoprotective activities for B. longum subsp. longum F2, which was 2.75 folds higher than that of the controls. This study provided scientific evidence and insights for the application of EPS821-1 as cryoprotection in food field.

The Prebiotic Activity of a Novel Polysaccharide Extracted from Huangshui by Fecal Fermentation In Vitro

A novel polysaccharide, HSP80-2, with an average molecular weight of 13.8 kDa, was successfully isolated by the gradient ethanol precipitation (GEP) method from Huangshui (HS), the by-product of Chinese Baijiu. It was mainly composed of arabinose, xylose, and glucose with a molar ratio of 4.0:3.1:2.4, which was completely different from the previous reported HS polysaccharides (HSPs). Morphological observations indicated that HSP80-2 exhibited a smooth but uneven fragmented structure. Moreover, HSP80-2 exerted prebiotic activity evaluated by in vitro fermentation. Specifically, HSP80-2 was utilized by gut microbiota, and significantly regulated the composition and abundance of beneficial microbiota such as Phascolarctobacterium, Parabacteroides, and Bacteroides. Notably, KEGG pathway enrichment analysis illustrated that HSP80-2 enriched the pathways of amino sugar and nucleotide sugar metabolism (Ko00520), galactose metabolism (ko00052), and the citrate cycle (TCA cycle) (ko00020). Meanwhile, the contents of short-chain fatty acids (SCFAs) mainly including acetic acid, propionic acid, and butyric acid in the HSP80-2 group were remarkably increased, which was closely associated with the growth of Lachnoclostridium and Parabacteroides. These results showed that HSP80-2 might be used as a potential functional factor to promote human gut health, which further extended the high value utilization of HS.

Effects of ultrasonic-enzymatic-assisted ethanol precipitation method on the physicochemical characteristics, antioxidant and hypoglycemic activities of Tremella fuciformis polysaccharides

This investigation involved the extraction of a novel polysaccharide from the spore fermentation broth of Tremella fuciformis using a method that combined ultrasonic and enzymatic assistance with ethanol precipitation. It was then compared with enzymatic and ultrasonic extraction methods. The objective of this research is to offer a reference point for expanding the application of ultrasonic-assisted enzymatic extraction technology in T. fuciformis polysaccharides (TFPs). Based on single-factor experiments, Box-Behnken was used to optimize the extraction conditions of TFPs by ultrasonic-enzymatic-assisted ethanol precipitation extraction. The results revealed an optimal combination of enzymes, with a cellulase-to-papain ratio of 2:1, an enzyme addition of 4000U/100 mL, an enzymolysis temperature of 49 °C, ultrasonicpower at 3 W/mL and an ultrasonictime of 20 min. The extraction rate of TFPs and α- amylase inhibition rates were 23.94 % and 61.44 %, respectively. Comparing the physicochemical properties, structural characterization and in vitro activity of TFPs extracted through different methods, the results showed that ultrasonic treatment significantly influences the apparent morphology of polysaccharide and could enhance its in vitro biological activity. However, different extraction techniques exhibit insubstantial impact on the chemical composition, glycosidic bonds or glycosidic ring configurations within the polysaccharides. Among them, ultrasonic-enzymatic-assisted ethanol precipitation extraction of polysaccharide has the highest extraction rate and the lowest viscosity. It has significant effects on ABTS+ scavenging activity, α- amylase inhibition rate and glucose dialysis retardation index, polysaccharide treated with ultrasonic-enzymatic showed the best performance. These findings suggest that ultrasonic-enzymatic-assisted ethanol precipitation extraction can enhance the activities of TFPs, thereby providing a valuable insight for their future development and application.

Ultrasonic effects on the degradation kinetics, structural characteristics and protective effects on hepatocyte lipotoxicity induced by palmitic acid of Pueraria Lobata polysaccharides

In this study, a high-molecular-weight Pueraria lobata polysaccharide (PLP) with a molecular weight of 273.54 kDa was degraded by ultrasound, and the ultrasonic degradation kinetics, structural characteristics and hepatoprotective activity of ultrasonic degraded PLP fractions (PLPs) were evaluated. The results showed that the ultrasonic treatment significantly reduced the Mw and particle size of PLP, and the kinetic equation of ultrasonic degradation of PLP followed to the midpoint fracture model (the fist-order model). The monosaccharide composition analysis, FT-IR, triple helix structure and XRD analysis all indicated that the ultrasound degradation did not destroy the primary structure of PLP, but the thermal stability of degraded fractions improved. Additionally, the scanning electron microscopy analysis demonstrated that the surface morphology of PLP was altered from smooth, flat, compact large flaky structure to a sparse rod-like structure with sparse crosslinking (PLP-7). The degraded PLP fractions (0.5 mg/mL) with lower Mw exhibited better antioxidant activities and protective effects against palmitic acid-induced hepatic lipotoxicity, which may be due to the increased exposure of active groups such as hydroxyl groups of PLP after ultrasound. Further investigation showed that PLPs not only increased Nrf2 phosphorylation and its nuclear translocation, thereby activating Nrf2/Keap1 signaling pathway, but also enhanced HO-1, NQO-1, γ-GCL gene expressions and promoted superoxide dismutase and catalase activities, which protected hepatocytes against PA-induced oxidative stress and lipotoxicity. Overall, our research might provide an in-depth insight into P. Lobata polysaccharide in ameliorating lipid metabolic disorders, and the results revealed that ultrasonic irradiation could be a promising degradation method to produce value-added polysaccharide for use in functional food.

Effects of Persimmon (Diospyros kaki L. cv. Mopan) Polysaccharide and Their Carboxymethylated Derivatives on Lactobacillus Strains Proliferation and Gut Microbiota: A Comparative Study

Persimmon is a fruit that contains sugars, vitamins, phenolic compounds, and various other nutrients. The aim of this study was to explore the structure of carboxymethylated persimmon polysaccharide (CM-PFP) and its interaction with the human gut microbiota. Carboxymethyl modification of the persimmon polysaccharide (PFP) increased both the Mw and Mn, enhanced dispersion stability, and decreased thermal stability. Both PFP and CM-PFP promoted the proliferation of Lactobacillus while inhibiting the proliferation of Staphylococcus aureus and Escherichia coli. In the simulated fecal fermentation, the pH of PFP- and CM-PFP-containing media decreased, the content of short-chain fatty acids increased, and the abundance of intestinal flora at the phylum and genus levels changed. The relative abundance of harmful intestinal bacteria was significantly reduced in both PFP and CM-PFP groups. Furthermore, it was found that CM-PFP was more easily metabolized than PFP, glucose, and fructo-oligosaccharide (FOS) and had a proliferation increase effect on Lactobacillus. Therefore, CM-PFP has a significant positive effect on both Lactobacillus proliferation and the human gut microbiota.

Fecal fermentation and high-fat diet-induced obesity mouse model confirmed exopolysaccharide from Weissella cibaria PFY06 can ameliorate obesity by regulating the gut microbiota

Obesity associated with diet and intestinal dysbiosis is a worldwide public health crisis, and exopolysaccharides (EPS) produced by lactic acid bacteria (LAB) have prebiotic potential to ameliorate obesity. Therefore, the present study obtained LAB with the ability to produce high EPS, examined the structure of EPS, and explained its mechanism of alleviating obesity by in vivo and in vitro models. The results showed that Weissella cibaria PFY06 with a high EPS yield was isolated from strawberry juice, and pure polysaccharide (PFY06-EPS) was purified by Sephadex G-100. The structural characteristics of PFY06-EPS showed that the molecular weight was 8.08 × 10⁶ Da and composed of α-(1,6)-D glucosyl residues. An in vitro simulated human colon fermentation test demonstrated that PFY06-EPS increased the abundance of Prevotella and Bacteroides. Cell tests confirmed that PFY06-EPS after fecal fermentation inhibited fat accumulation by promoting the secretion of endogenous gastrointestinal hormones and insulin and inhibiting the secretion of inflammatory factors. Notably, PFY06-EPS reduced weight gain, fat accumulation, inflammatory reactions and insulin resistance in a high-fat diet-induced obesity mouse model and improved glucolipid metabolism. PFY06-EPS intervention reversed obesity-induced microflora disorders, such as reducing the Firmicutes/Bacteroides ratio and increasing butyrate-producing bacteria (Roseburia and Oscillibacter), and reduced endotoxemia to maintain intestinal barrier integrity. Therefore, in vivo and in vitro models showed that PFY06-EPS had potential as a prebiotic that may play an anti-obesity role by improving the function of the gut microbiota.

Preparation of low molecular weight polysaccharides from Tremella fuciformis by ultrasonic-assisted H2O2-Vc method: Structural characteristics, in vivo antioxidant activity and stress resistance

Different methods were used to degrade Tremella fuciformis polysaccharides (TFP) and prepare low molecular weight polysaccharides of Tremella fuciformis (TFLP) to improve their bioavailability. It was found that the TFLP prepared by ultrasonic-assisted H2O2-Vc method showed the highest level of antioxidant activity and stress resistance in C. elegans. The structural characteristics, in vivo antioxidant and stress resistance of TFLP-1 were evaluated after isolation and purification of TFLP, it was found that TFLP-1 was an acid polysaccharide with a molecular weight of 75770 Da, which mainly composed of mannose. Meanwhile, it could regulate the antioxidant activity and stress resistance in C. elegans by upregulating the transcription of fat-5, fat-7, acs-2, glp-1, hsf-1, hsp-1, mtl-1, nhr-49, skn-1 and sod-3 mRNA. The improvement effects were closely related to the significant regulation of galactose metabolism, alpha linolenic acid metabolism, and pantothenate and CoA biosynthesis metabolic pathways. These results provided insights into the high value application of Tremella fuciformis in the food industry and the development of antioxidant related functional foods.

Relationship among Chinese herb polysaccharide (CHP), gut microbiota, and chronic diarrhea and impact of CHP on chronic diarrhea

Chronic diarrhea, including diarrhea-predominant irritable bowel syndrome (IBS-D), osmotic diarrhea, bile acid diarrhea, and antibiotic-associated diarrhea, is a common problem which is highly associated with disorders of the gut microbiota composition such as small intestinal bacterial overgrowth (SIBO) and so on. A growing number of studies have supported the view that Chinese herbal formula alleviates the symptoms of diarrhea by modulating the fecal microbiota. Chinese herbal polysaccharides (CHPs) are natural polymers composed of monosaccharides that are widely found in Chinese herbs and function as important active ingredients. Commensal gut microbiota has an extensive capacity to utilize CHPs and play a vital role in degrading polysaccharides into short-chain fatty acids (SCFAs). Many CHPs, as prebiotics, have an antidiarrheal role to promote the growth of beneficial bacteria and inhibit the colonization of pathogenic bacteria. This review systematically summarizes the relationship among gut microbiota, chronic diarrhea, and CHPs as well as recent progress on the impacts of CHPs on the gut microbiota and recent advances on the possible role of CHPs in chronic diarrhea.

The digestive behavior of pectin in human gastrointestinal tract: a review on fermentation characteristics and degradation mechanism

Pectin is widely spread in nature and it develops an extremely complex structure in terms of monosaccharide composition, glycosidic linkage types, and non-glycosidic substituents. As a non-digestible polysaccharide, pectin exhibits resistance to human digestive enzymes, however, it is easily utilized by gut microbiota in the large intestine. Currently, pectin has been exploited as a novel functional component with numerous physiological benefits, and it shows a promising prospect in promoting human health. In this review, we introduce the regulatory effects of pectin on intestinal inflammation and metabolic syndromes. Subsequently, the digestive behavior of pectin in the upper gastrointestinal tract is summarized, and then it will be focused on pectin's fermentation characteristics in the large intestine. The fermentation selectivity of pectin by gut bacteria and the effects of pectin structure on intestinal microecology were discussed to highlight the interaction between pectin and bacterial community. Meanwhile, we also offer information on how gut bacteria orchestrate enzymes to degrade pectin. All of these findings provide insights into pectin digestion and advance the application of pectin in human health.

The potential cutaneous benefits of Tremella fuciformis

Tremella fuciformis, also known as snow mushroom, is an edible mushroom that has historically been popular in herbal and Asian medicine and cuisine. The main polysaccharide ingredients have been extracted and used as treatment in a variety of conditions, demonstrating positive effects in a range of biological functions including those involved in antioxidation, antitumor, antidiabetic, immunomodulatory, and neuroprotective pathways. Studies have demonstrated the role this extract may play in skin antiaging, photoprotection, wound healing, and barrier protection. Most studies have been limited to in vitro and in vivo animal models. Future clinical research is needed to further understand the role of T. fuciformis in dermatology. This review will discuss the existing research findings and potential future applications for T. fuciformis as a treatment in skin conditions.

From gut to skin: exploring the potential of natural products targeting microorganisms for atopic dermatitis treatment

Atopic dermatitis (AD) is the most common chronic inflammatory skin disease. Recent studies have revealed that interactions between pathogenic microorganisms, which have a tendency to parasitize the skin of AD patients, play a significant role in the progression of the disease. Furthermore, specific species of commensal bacteria in the human intestinal tract can have a profound impact on the immune system by promoting inflammation and pruritogenesis in AD, while also regulating adaptive immunity. Natural products (NPs) have emerged as promising agents for the treatment of various diseases. Consequently, there is growing interest in utilizing natural products as a novel therapeutic approach for managing AD, with a focus on modulating both skin and gut microbiota. In this review, we discuss the mechanisms and interplay between the skin and gut microbiota in relation to AD. Additionally, we provide a comprehensive overview of recent clinical and fundamental research on NPs targeting the skin and gut microbiota for AD treatment. We anticipate that our work will contribute to the future development of NPs and facilitate research on microbial mechanisms, based on the efficacy of NPs in treating AD.

Purification of Polysaccharide Produced by the Haploid Yeast Strain of Tremella sanguinea and Its Antioxidant and Prebiotic Activities

Tremella sanguinea is a traditional Chinese medicinal and edible mushroom. Polysaccharides from Tremella mushrooms have received increasing amounts of research attention due to their diverse pharmacological activities. In this study, via the incubation of basidiospores collected from fresh artificially cultivated basidiocarps of T. sanguinea, a haploid yeast strain of T. sanguinea was obtained, and it was found to be a typical loose-slime-forming yeast capable of producing a large amount of exopolysaccharides (EPS). Using DEAE-52 cellulose column chromatography and Sephadex G-100 gel permeation chromatography, the major polysaccharide, named TSPS-1, was separated and purified from the EPS produced by the haploid yeast strain of T. sanguinea. TSPS-1 was a homogeneous polysaccharide with a molecular weight of 2.5 × 10³ kDa and consisted of rhamnose, glucose, xylose, mannose and glucuronic acid at a molar ratio of 1: 0.7: 62.2: 24.6: 11.5. The bioactivity of the TSPS-1 polysaccharide was evaluated. The results show that TSPS-1 exhibited noticeable antioxidant activity by scavenging hydroxyl radicals (EC₅₀ = 1.92 mg/mL) and superoxide radicals (EC₅₀ = 1.33 mg/mL), and prebiotic activity by promoting the growth of different probiotic strains in the genus Lactobacillus and Bifidobacterium. These results suggest that the cultivation of the haploid yeast strain can be a promising alternative for the efficient production of valuable T. sanguinea polysaccharides with antioxidant and prebiotic potential.

The benefits of edible mushroom polysaccharides for health and their influence on gut microbiota: a review

The gut microbiome is a complex biological community that deeply affects various aspects of human health, including dietary intake, disease progression, drug metabolism, and immune system regulation. Edible mushroom polysaccharides (EMPs) are bioactive fibers derived from mushrooms that possess a range of beneficial properties, including anti-tumor, antioxidant, antiviral, hypoglycemic, and immunomodulatory effects. Studies have demonstrated that EMPs are resistant to human digestive enzymes and serve as a crucial source of energy for the gut microbiome, promoting the growth of beneficial bacteria. EMPs also positively impact human health by modulating the composition of the gut microbiome. This review discusses the extraction and purification processes of EMPs, their potential to improve health conditions by regulating the composition of the gut microbiome, and their application prospects. Furthermore, this paper provides valuable guidance and recommendations for future studies on EMPs consumption in disease management.

Structural characterization of a heteropolysaccharide from the fruit of Crataegus pinnatifida and its bioactivity on the gut microbiota of immunocompromised mice

Crataegus pinnatifida is a common food in China, Europe and North America. In order to confirm polysaccharide was the material basis for C. pinnatifida to exert immune regulation. A polysaccharide (CPP) with a molecular weight of 13.58 kDa was isolated from C. pinnatifida. The structure of CPP was determined to be a backbone composed of → 3,5)-α-l-Araf-(1→, with two branches consisting of → 4)-α-d-Galp-(1 → and → 5)-α-l-Araf-(1→, with α-l-Araf and α-d-Manp as the terminal unit. CPP (10 ∼ 500 μg/mL) could promote the secretion of nitric oxide, interleukin-2, interleukin-6 and tumor necrosis factor-α in vitro. CPP could significantly restore the body weight of immunosuppressive mice and improve the immune organ index and interleukin-2, interleukin-6, and tumor necrosis factor-α secretion. In addition, CPP increased the abundance of Bacteroidetes and Verrucomicrobia and decreased the abundance of Proteobacteria at the phylum level. So CPP can regulate the gut microbiota and play an important role in immune regulation.

Stability and flavor of set yogurt fortified with Tremella fuciformis polysaccharide during cold storage

Tremella fuciformis is an edible and medicinal fungus containing excellent nutritional value. T. fuciformis polysaccharide (TFP) is the important bioactive ingredients of T. fuciformis, which has gained great attention. The aim of this study was to investigate the effect of TFP on the stability and flavor of set yogurt. Our results revealed that the addition of 0.1% TFP had a positive effect on improving the stability of set yogurt including the water holding capacity, texture, rheological properties and microstructure at the cold storage period of 1, 7, 14 and 21 days. It is remarkable that the hardness, gumminess and chewiness of the set yogurt were significantly improved by the addition of TFP during the cold storage. Moreover, the set yogurt containing TFP was able to maintain better stability in the three intervals thixotropy test. In particular, the addition of 0.1% TFP had no adverse effects on the flavor of set yogurt, including sourness, sweetness, umami, bitterness, richness and saltiness. These data suggested that TFP can be used as a natural potential stabilizer for the set yogurt.

Effects of Extraction Methods on the Physicochemical Properties and Biological Activities of Polysaccharides from Polygonatum sibiricum

Polygonatum sibiricum polysaccharides (PSPs) have important biological functions, such as antioxidation, immunomodulatory, and hypolipidemic functions. Different extraction methods have effects on their structures and activities. In this study, six extraction methods, including hot water extraction (HWE), alkali extraction (AAE), ultrasound-assisted extraction (UAE), enzyme-assisted extraction (EAE), microwave-assisted extraction (MAE), and freeze-thaw-assisted extraction (FAE) were used to extract PSPs, and their structure-activity relationships were analyzed. The results showed that all six PSPs had similar functional group compositions, thermal stability, and glycosidic bond compositions. PSP-As (PSPs extracted by AAE) exhibited better rheological properties due to their higher molecular weight (Mw). PSP-Es (PSPs extracted by EAE) and PSP-Fs (PSPs extracted by FAE) had better lipid-lowering activity due to their lower Mw. PSP-Es and PSP-Ms (PSPs extracted by MAE), which do not contain uronic acid and have a moderate Mw, had better 1,1-diphenyl-2-picrylhydrazyl (DPPH)-radical-scavenging activity. On the contrary, PSP-Hs (PSPs extracted by HWE) and PSP-Fs, with the Mw of uronic acid, had the best OH-radical-scavenging activity. The high-Mw PSP-As had the best Fe²⁺-chelating ability. In addition, mannose (Man) may play an important role in the immunomodulatory activity. These results indicate that different extraction methods affect the structure and biological activity of polysaccharides to varying degrees, and these results are helpful for understanding the structure-activity relationship of PSPs.

Integrated microbiota and metabolite profiling analysis of prebiotic characteristics of Phellinus linteus polysaccharide in vitro fermentation

Phellinus linteus polysaccharide (PLP) had received increasing attention due to its multiple biological activities. Herein, the extraction, characterization and in vitro fermentation of PLP were studied to explore its physiochemical properties and the interaction mechanism between the gut microbiota and PLP. The results obtained demonstrated that PLP was mainly composed of 9 monosaccharides, with three gel chromatographic peaks and molecular weights (M_w) of 308.45 kDa, 13.58 kD and 3.33 kDa, respectively. After 48 h fermentation, the M_w, total sugar, reducing sugar, pH and monosaccharides composition were decreased. Furthermore, PLP regulated the composition of gut microbiota, such as promoting the proliferation of beneficial bacteria such as Bacteroides, Prevotella and Butyricimonas, while preventing the growth of pathogenic bacteria such as Escherichia-Shigella, Morganella and Intestinimonas. Gut microbiota metabolites regulated by PLP such as short-chain fatty acids were the main regulators that impact the host health. Bioinformatics analysis indicated that butyrate, bile acid and purine metabolism were the main metabolic pathways of PLP regulating host health, and the Bacteroides was the key genus to regulate these metabolic pathways. In conclusion, our finding suggested that PLP may be used as a prebiotic agent for human health because of its ability to regulate gut microbiota.

Catabolism of Dictyophora indusiata Polysaccharide and Its Impacts on Gut Microbial Composition during In Vitro Digestion and Microbial Fermentation

Dictyophora indusiata is one of the most famous edible mushrooms in China. D. indusiata polysaccharide (DP) has attracted increasing attention because of its multiple beneficial effects. In this study, the in vitro simulated digestion and microbial fermentation were designed to reveal the potential catabolic property of DP and its impacts on the modulation of gut microbial composition. The results showed that the reducing sugar content, total polysaccharides content, molecular weight, and rheological property of DP were not significantly altered under in vitro simulated digestive conditions. However, the molecular weight, apparent viscosity, and total polysaccharides content of indigestible DP (DPI) significantly decreased during in vitro fecal fermentation, and the reducing sugar content and the release of free monosaccharides notably increased, suggesting that DP could be degraded and used by gut microbiota. Additionally, the relative abundances of several beneficial bacteria, such as Bacteroides, Catenibacterium, Parabacteroides, and Megamonas, increased significantly, indicating that DP can regulate the composition and abundance of gut microbiota. Moreover, DP could also promote the production of SCFAs, thus changing the acid-base environment of the large intestine. The results of this study are beneficial for deeply clarifying the catabolic behavior of DP in the gastrointestinal tract, which can provide a theoretical basis for developing microbiota-directed products based on DP.

Structural characteristics of mixed pectin from ginseng berry and its anti-obesity effects by regulating the intestinal flora

Ginseng berry is the mature berry of ginseng and its polysaccharide has hypolipidaemic effect, but its mechanism remains unclear. A pectin (GBPA) with a molecular weight of 3.53 × 10⁴ Da was isolated from ginseng berry, it was mainly composed of Rha (25.54 %), GalA (34.21 %), Gal (14.09 %) and Ara (16.25 %). Structural analysis showed that GBPA is a mixed pectin containing rhamnogalacturonan-I and homogalacturonan domains and has a triple helix structure. GBPA distinctly improved lipid disorders in obese rats, and changed intestinal flora with enrichments of Akkermansia, Bifidobacterium, Bacteroides and Prevotella, improved the levels of acetic acid, propionic acid, butyric acid and valeric acid. Serum metabolites which involved in the lipid regulation-related pathway, including cinnzeylanine, 10-Hydroxy-8-nor-2-fenchanone glucoside, armillaribin, 24-Propylcholestan-3-ol, were also greatly changed after GBPA treatment. GBPA activated AMP-activated protein kinase, phosphorylated acetyl-CoA carboxylase, and reduced the expression of lipid synthesis-related genes sterol regulatory element-binding protein-1c and fatty acid synthases. The regulatory effects of GBPA on lipid disorders in obese rats are related to the regulation of intestinal flora and activation of AMP-activated protein kinase pathway. Ginseng berry pectin could be considered in the future as a health food or medicine to prevent obesity.

Structure and potential anti-fatigue mechanism of polysaccharides from Bupleurum chinense DC

Two polysaccharides, BCP-1 and BCP-2, were obtained from Bupleurum chinense DC. by water extraction and ultrafiltration. BCP-1 (1.04 × 10⁵ Da) and BCP-2 (2.14 × 10⁴ Da) were composed of Mannose, Rhamnose, Glucose, Galactose, Arabinose, and Galacturonic acid in different proportions. They both contained oligogalacturonides in their main chain. Besides, the backbone of BCP-1 was composed of 4-β-Galp and 4,6-β-Glcp, and branched at C4 of 4,6-β-Glcp. While BCP-2 contained a backbone of 3,5-α-Araf residues with branches at C3. BCP-2 effectively extended the forced swimming time, improved the glycogen reserves and antioxidant system, decreased the levels of blood urea nitrogen, lactic acid, lactate dehydrogenase and creatinine kinase expression. It alleviated physical fatigue through regulating 5'-AMP-activated protein kinase (AMPK) and Nuclear Factor erythroid 2-Related Factor 2 (Nrf2) signalling pathway in skeletal muscles. This study demonstrated that BCP-2 exhibited more effective anti-fatigue activity than BCP-1 potentially associated with its primary and higher structures.

Antioxidative and Protective Effect of Morchella esculenta against Dextran Sulfate Sodium-Induced Alterations in Liver

Morchella esculenta is an edible mushroom with special flavor and high nutritional value for humans, primarily owing to its polysaccharide constituents. M. esculenta polysaccharides (MEPs) possess remarkable pharmaceutical properties, including antioxidant, anti-inflammatory, immunomodulatory, and anti-atherogenic activities. The aim of this study was to evaluate the in vitro and in vivo antioxidant potential of MEPs. In vitro activity was determined using free radical scavenging assays, whereas in vivo activity was evaluated through dextran sodium sulfate (DSS)-induced liver injury in mice with acute colitis. MEPs effectively scavenged 1,1-diphenyl-2-picrylhydrazyl and 2,2-azinobis-6-(3-ethylbenzothiazoline sulfonic acid) free radicals in a dose-dependent manner. Additionally, DSS-induced mice showed severe liver damage, cellular infiltration, tissue necrosis, and decreased antioxidant capacity. In contrast, intragastric administration of MEPs showed hepatoprotective effects against DSS-induced liver injury. MEPs remarkably elevated the expression levels of superoxide dismutase, glutathione peroxidase, and catalase. Additionally, it decreased malondialdehyde and myeloperoxidase levels in the liver. These results indicate that the protective effects of MEP against DSS-induced hepatic injury could rely on its ability to reduce oxidative stress, suppress inflammatory responses, and improve antioxidant enzyme activity in the liver. Therefore, MEPs could be explored as potential natural antioxidant agents in medicine or as functional foods to prevent liver injury.

Soluble, Diferuloylated Corn Bran Glucuronoarabinoxylans Modulate the Human Gut Microbiota In Vitro

Corn bran is exceptionally rich in substituted glucuronoarabinoxylan polysaccharides, which are monoferuloylated and cross-linked by diferulic acid moieties. Here, we assessed the potential prebiotic activity of three enzymatically solubilized corn bran glucuronoarabinoxylans: medium feruloylated (FGAX-M), laccase cross-linked FGAX-M (FGAX-H), and alkali-treated FGAX-M devoid of feruloyl substitutions (FGAX-B). We examined the influence of these soluble FGAX samples on the gut microbiome composition and functionality during in vitro simulated colon fermentations, determined by 16S rRNA gene amplicon sequencing and assessment of short-chain fatty acid (SCFAs) production. All FGAX samples induced changes in the relative composition of the microbiota and the SCFA levels after 24 h of in vitro fermentation. The changes induced by FGAX-M and FGAX-H tended to be more profound and more similar to the changes induced by inulin than changes conferred by FGAX-B. The microbiota changes induced by FGAX-M and FGAX-H correlated with an increase in the relative abundance of Anaerostipes and with increased butyric acid production, while the changes induced by the FGAX-B sample were less compelling. The results imply that solubilized, substituted diferuloylated corn bran glucuronoarabinoxylans may be potential prebiotic candidates and that both single feruloylations and diferuloyl cross-links influence the prebiotic potential of these arabinoxylan compounds.

Starch from Pueraria lobata and the amylose fraction alleviates dextran sodium sulfate induced colitis in mice

Starch from Pueraria lobata (PLS) had polyhedral or spherical granules, displaying a bimodal size distribution within 0.6-30 μm. It showed a trimodal distribution of different molecular weight peaks, with amylose fraction of 18.2 %. PLS had a high crystallinity degree of 37.76 % and consisted of C-type starch, which gelatinized at 64.46-79.61 °C, with a high range of gelatinization (15.15 °C) and high enthalpy (13.98 J/g). A 21-day supplementation of PLS presented a regulative effect on gut microbiota in normal mice, and alleviated DSS-induced murine colitis through attenuating colonic inflammation, maintaining barrier function, preventing gut dysbiosis, increasing the short-chain fatty acids production and inhibiting NF-κB/IL-1β axis. The protective effect of PLS against colitis was in a gut microbiota-dependent manner. Notably, the amylose fraction was responsible for the prebiotic effect of PLS. The results would potentiate new application of PLS and the amylose fraction as functional prebiotics for prevention of colitis.

In Vitro Fecal Fermentation of Euphorbia humifusa-Derived Polysaccharides and Their Protective Effect against Ulcerative Colitis in Mice

Euphorbia humifusa is a plant species with medicinal and food characteristics used to treat diarrhea and other intestinal diseases. This study investigated the prebiotic effects of E. humifusa-derived polysaccharides (EHPs) on human colonic microbiota and their regulatory effects on ulcerative colitis (UC). Structural characterization showed that EHPs mainly consisted of galactose, glucose, and glucuronic acid and were heteropolysaccharides having molecular weights of 7.70 × 10³ and 1.76 × 10² kDa, respectively. EHPs were identified as poorly absorbed macromolecules, verified by the apparent permeability coefficient values (Papp < 1.0 × 10^-6 cm/s) and cellular uptake by Caco-2 cell monolayers. During in vitro fermentation studies, the contents of acetic, propionic, and valeric acids increased significantly in EHP-supplemented samples after 24 h compared to that in the control sample. Moreover, EHPs could alter the intestinal microbiota composition by increasing the relative abundance of Bifidobacterium and Holdemanella and reducing that of Escherichia-Shigella, Tyzzerella, and Parasutterella at the genus level. In a dextran sulfate sodium (DSS)-induced UC mouse model, EHPs alleviated UC symptoms by increasing the colon length, reversing the colon tissue damage and inhibiting pro-inflammatory cytokines. Overall, these results suggest that EHPs could be utilized as a potential prebiotic or a promising nutritional strategy for UC management.

Physicochemical Properties and In Vivo Hepatoprotective Effect of Polysaccharides from Grape Pomace

Here, the polysaccharides from grape pomace, a by-product in the wine industry, were characterized and evaluated in vitro and in vivo. The polysaccharides were extracted and studied using spectroscopic and chemical methods. The results revealed that GPPs are rich in arabinose, galactose and glucuronic acid and are heteropolysaccharides without protein and nucleic acid, containing α-glycoside bonds with irregular clusters on the surface. In vitro antioxidant activity assays indicated that GPPs have concentration-dependent antioxidant activity. In vivo, GPPs markedly decreased the levels of TNF-a, IL-6, ALT, AST and MDA in serum and liver tissues and restored the levels of SOD, CAT and GSH. Additionally, further histopathological examination confirmed that GPPs could mitigate the injury of liver induced by CCl₄. Our results demonstrate that GPPs had antioxidant and hepatoprotective effects, and they are expected to be a potential ingredient for functional foods or hepatoprotective drugs.

Metagenomic Insights into the Anti-Obesity Effect of a Polysaccharide from Saccharina japonica

Saccharina japonica polysaccharides exhibit great potential to be developed as anti-obesity and prebiotic health products, but the underlying mechanism has not been adequately addressed. In this study, we investigated the potential mechanism of a S. japonica polysaccharide fraction (SjC) in preventing high-fat-diet (HFD)-induced obesity in mice using 16S rRNA gene and shotgun metagenomic sequencing analysis. SjC was characterized as a 756 kDa sulfated polysaccharide and 16 weeks of SjC supplementation significantly alleviated HFD-induced obesity, insulin resistance, and glucose metabolism disorders. The 16S rRNA and metagenomic sequencing analysis demonstrated that SjC supplementation prevented gut microbiota dysbiosis mainly by regulating the relative abundance of Desulfovibrio and Akkermansia. Metagenomic functional profiling demonstrated that SjC treatment predominantly suppressed the amino acid metabolism of gut microbiota. Linking of 16S rRNA genes with metagenome-assembled genomes indicated that SjC enriched at least 22 gut bacterial species with fucoidan-degrading potential including Desulfovibrio and Akkermansia, which showed significant correlations with bodyweight. In conclusion, our results suggest that SjC exhibits a promising potential as an anti-obesity health product and the interaction between SjC and fucoidan-degrading bacteria may be associated with its anti-obesity effect.

Quantitative estimation of enzymatic released specific oligosaccharides from Hericium erinaceus polysaccharides using CE-LIF

Polysaccharides exhibit multiple pharmacological activities which are closely related to their structural features. Therefore, quantitatively quality control of polysaccharides based on their chemical characteristics is important for their application in biomedical and functional food sciences. However, polysaccharides are mixed macromolecular compounds that are difficult to isolate and lack standards, making them challenging to quantify directly. In this study, we proposed an improved saccharide mapping method based on the release of specific oligosaccharides for the assessment of Hericium erinaceus polysaccharides from laboratory cultured and different regions of China. Briefly, a polysaccharide from H. erinaceus was digested by β-(1-3)-glucanase, and the released specific oligosaccharides were labeled with 8-aminopyrene-1,3,6-trisulfonic-acid (APTS) and separated by using micellar electrokinetic chromatography (MEKC) coupled with laser induced fluorescence (LIF), and quantitatively estimated. MEKC presented higher resolution compared to polysaccharide analysis using carbohydrate gel electrophoresis (PACE), and provided great peak capacity between oligosaccharides with polymerization degree of 2 (DP2) and polymerization degree of 6 (DP6) in a dextran ladder separation. The results of high performance size exclusion chromatography coupled with multi-angle laser light scattering and refractive index detector (HPSEC-MALLS-RI) showed that 12 h was sufficient for complete digestion of polysaccharides from H. erinaceus. Laminaritriose (DP3) was used as an internal standard for quantification of all the oligosaccharides. The calibration curve for DP3 showed a good linear regression (R ² > 0.9988). The limit of detection (LOD) and limit of quantification (LOQ) values were 0.05 μg/mL and 0.2 μg/mL, respectively. The recovery for DP3 was 87.32 (±0.03)% in the three independent injections. To sum up, this proposed method is helpful for improving the quality control of polysaccharides from H. erinaceus as well as other materials.