Effect of Supplementing Seaweed Extracts to Pigs until d35 Post-Weaning on Performance and Aspects of Intestinal Health.

The objective of this study was to examine the effects of feeding laminarin (LAM) and fucoidan (FUC) enriched seaweed extracts up to d35 post-weaning on measures of animal performance, intestinal microbial and transcriptome profiles. 75 pigs were assigned to one of three groups: (1) basal diet; (2) basal diet + 250 ppm fucoidan; (3) basal diet + 300 ppm laminarin with 7 replicates per treatment group. Measures of performance were collected weekly and animals sacrificed on d35 post-weaning for the sampling of gastrointestinal tissue and digesta. Animal performance was similar between the basal group and the groups supplemented with FUC and LAM (P > 0.05). Pigs fed the basal diet had higher alpha diversity compared to both the LAM and FUC supplemented pigs (P < 0.05). Supplementation with LAM and FUC increased the production of butyric acid compared to basal fed pigs (P < 0.05). At genus level pigs fed the LAM supplemented diet had the greatest abundance of Faecalbacterium, Roseburia and the lowest Campylobacter of the three experimental treatments (P< 0.05). While neither extract had beneficial effects on animal performance, LAM supplementation had a positive influence on intestinal health through alterations in the gastrointestinal microbiome and increased butyrate production.

Synthesis of alternan-stabilized zinc nanoparticles: morphological, thermal, antioxidant and antimicrobial characterization.

This study aimed to synthesize zinc nanoparticles with antimicrobial and antioxidant activities using alternan (ZnNPs-Alt) produced by Lactobacillus reuteri E81 as the stabilizing agent. For the characterization of the ZnNPs-Alt, UV-vis spectroscopy, SEM, TEM and EDX analysis, XRD, FTIR and DSC analysis were applied. The functional role of ZnNPs-Alt was tested by determination of their antioxidant activities by DPPH and CUPRAC methodologies and their antibacterial and antifungal activities. Results of this study demonstrated that alternan was utilized as a successful stabilizer to produce crystalline, thermally stabile ZnNPs-Alt with a particle size of ∼ 100 nm. Importantly, strong antioxidant and antimicrobial activities were observed for ZnNPs-Alt in a concentration dependent manner. These findings confirmed the role of alternan as a stabilizing agent for the production of ZnNPs-Alt with functional roles.

Optimization and characterization of pullulan production by a newly isolated high-yielding strain Aureobasidium melanogenum.

Pullulan is an extracellular water-soluble polysaccharide with wide applications. In this study, we screened strains that could selectively produce high molecular weight pullulan for application in industrial pullulan production. A new fungus strain A4 was isolated from soil and identified as Aureobasidium melanogenum based on colony characteristics, morphology, and internally transcribed spacer analysis. Thin-layer chromatography, Fourier-transform infrared spectroscopy, and nuclear magnetic resonance analysis suggested that the dominant exopolysaccharide produced by this strain, which presented a molecular weight of 1.384 × 106 Dalton in in-gel permeation chromatography, was pullulan. The culture conditions for A. melanogenum A4 were optimized at 30 °C and 180 rpm: carbon source, 50 g/L maltose; initial pH 7; and 8 g/L Tween 80. Subsequently, batch fermentation was performed under the optimized conditions in a 5-L stirred-tank fermentor with a working volume of 3 L. The fermentation broth contained 303 g/L maltose, which produced 122.34 g/L pullulan with an average productivity of 1.0195 g/L/h and 82.32 g/L dry biomass within 120 h. The conversion efficiency of maltose to pullulan (Y%) and specific production rate (g/h/g dry cells) (Qs) reached 40.3% and 0.0251 g/L/g dry cells, respectively. The results showed strain A4 could be a good candidate for industrial production.

Extraction and Yield Optimisation of Fucose, Glucans and Associated Antioxidant Activities from Laminaria digitata by Applying Response Surface Methodology to High Intensity Ultrasound-Assisted Extraction.

The objectives of this study were to employ response surface methodology (RSM) to investigate and optimize the effect of ultrasound-assisted extraction (UAE) variables, temperature, time and amplitude on the yields of polysaccharides (fucose and total glucans) and antioxidant activities (ferric reducing antioxidant power (FRAP) and 1,1-diphenyl-2-picryl-hydrazyl radical scavenging activity (DPPH)) from Laminariadigitata, and to explore the suitability of applying the optimum UAE conditions for L.digitata to other brown macroalgae (L.hyperborea and Ascophyllumnodosum). The RSM with three-factor, four-level Box-Behnken Design (BBD) was used to study and optimize the extraction variables. A second order polynomial model fitted well to the experimental data with R² values of 0.79, 0.66, 0.64, 0.73 for fucose, total glucans, FRAP and DPPH, respectively. The UAE parameters studied had a significant influence on the levels of fucose, FRAP and DPPH. The optimised UAE conditions (temperature = 76 °C, time = 10 min and amplitude = 100%) achieved yields of fucose (1060.7 ± 70.6 mg/100 g dried seaweed (ds)), total glucans (968.6 ± 13.3 mg/100 g ds), FRAP (8.7 ± 0.5 µM trolox/mg freeze-dried extract (fde)) and DPPH (11.0 ± 0.2%) in L.digitata. Polysaccharide rich extracts were also attained from L.hyperborea and A. nodosum with variable results when utilizing the optimum UAE conditions for L.digitata.

Interaction studies of lead(II) ion with cyclic ß-(1→3),(1→6) glucans extracted from Bradyrhizobium japonicum based on 'chelation enhanced fluorescence' (CHEF) effect.

Cyclic ß-(1→3),(1→6) glucans (CBGs) isolated from Bradyrhizobium japonicum bacteria are the periplasmic oligosaccharides having cyclic structures. This paper presents the isolation of CBGs from the bacteria cultured using optimized medium that improved yields to 350-450 mg per gram of cellular dry weight along with analytical interaction with lead(II) ions in the range 33.0-2.0 ppm with CBG as a binding ligand, using constant wavelength synchronous fluorescence spectroscopy. The binding ability of CBGs towards lead(II) is clearly evident from the scanning electron microscopy (SEM) images. The theoretical calculations using HEX 8.0 gave an insight about the interaction between CBG and lead(II) to be in the ratio of 3:1. The method displayed the sensitivity and selectivity towards lead(II) ions up to 2.0 ppm. This observed property of CBGs can potentially hold an application in bioremediation of the soil contaminated with lead.

Biotinylated Cyclooligosaccharides for Paclitaxel Solubilization.

The poor water solubility of paclitaxel causes significant problems in producing cancer therapeutic formulations. Here, we aimed to solubilize paclitaxel using biocompatible cyclic carbohydrates. Generally recognized as safe, labeled ß-cyclodextrin (ß-CD), a cyclic α-1,4-glucan consisting of seven glucoses, was prepared, and bio-sourced cyclosophoraoses (CyS), which are unbranched cyclic ß-1,2-glucans with 17-23 glucose units, were purified using various chromatographic methods from Rhizobium leguminosarum cultural broth. For effective targeting, CyS and ß-CD were modified with a biotinyl moiety in a reaction of mono-6-amino CyS and mono-6-amino-ß-CD with N-hydroxysuccinimide ester of biotinamidohexanoic acid. Interestingly, the aqueous solubility of paclitaxel was enhanced 10.3- and 3.7-fold in the presence of biotinyl CyS and biotinyl ß-CD, respectively. These findings suggest that biotin-appended cyclooligosaccharides can be applied to improve the delivery of paclitaxel.

Economic co-production of poly(malic acid) and pullulan from Jerusalem artichoke tuber by Aureobasidium pullulans HA-4D.

BACKGROUND: poly(L-malic acid) (PMA) is a water-soluble polyester with many attractive properties in medicine and food industries, but the high cost of PMA fermentation has restricted its further application for large-scale production. To overcome this problem, PMA production from Jerusalem artichoke tubers was successfully performed. Additionally, a valuable exopolysaccharide, pullulan, was co-produced with PMA by Aureobasidum pullulans HA-4D. RESULTS: The Jerusalem artichoke medium for PMA and pullulan co-production contained only 100 g/L hydrolysate sugar, 30 g/L CaCO3 and 1 g/L NaNO3. Compared with the glucose medium, the Jerusalem artichoke medium resulted in a higher PMA concentration (114.4 g/L) and a lower pullulan concentration (14.3 g/L) in a 5 L bioreactor. Meanwhile, the activity of pyruvate carboxylase and malate dehydrogenas was significantly increased, while the activity of α-phosphoglucose mutase, UDP-glucose pyrophosphorylase and glucosyltransferase was not affected. To assay the economic-feasibility, large-scale production in a 1 t fermentor was performed, yielding 117.5 g/L PMA and 15.2 g/L pullulan. CONCLUSIONS: In this study, an economical co-production system for PMA and pullulan from Jerusalem artichoke was developed. The medium for PMA and pullulan co-production was significantly simplified when Jerusalem artichoke tubers were used. With the simplified medium, PMA production was obviously stimulated, which would be associated with the improved activity of pyruvate carboxylase and malate dehydrogenas.

Extraction, selenylation modification and antitumor activity of the glucan from Castanea mollissima Blume.

The present study aimed to characterize the glucan from C. mollissima Blume fruits and its selenium derivative, then investigate their antitumor activity in vitro. A glucan, designated as CPA, was firstly isolated from the fruits of C. mollissima Blume. Structure analysis indicated that CPA was a linear 1,6-α-D-glucan with the average molecular weight about 2.0 × 103 kDa. The selenylation modification derivative of CPA (sCPA), exhibited a stronger antiproliferative effect on tumor cells than CPA in vitro. CPA and sCPA could induce HeLa cells apoptosis and decrease mitochondrial membrane potential. sCPA could also arrest HeLa cells in S phase, promote reactive oxygen species generation and activate caspase-3 activity in HeLa cells. These results manifest that CPA and sCPA inhibit the proliferation of HeLa cells via different mechanisms, which is meaningful for their potential use as antitumor drugs.

Olive Mill Waste Enhances α-Glucan Content in the Edible Mushroom Pleurotus eryngii.

Mushroom polysaccharides are edible polymers that have numerous reported biological functions; the most common effects are attributed to ß-glucans. In recent years, it became apparent that the less abundant α-glucans also possess potent effects in various health conditions. Here we explore several Pleurotus species for their total, ß and α-glucan content. Pleurotus eryngii was found to have the highest total glucan concentrations and the highest α-glucans proportion. We also found that the stalks (stipe) of the fruit body contained higher glucan content then the caps (pileus). Since mushrooms respond markedly to changes in environmental and growth conditions, we developed cultivation methods aiming to increase the levels of α and ß-glucans. Using olive mill solid waste (OMSW) from three-phase olive mills in the cultivation substrate. We were able to enrich the levels mainly of α-glucans. Maximal total glucan concentrations were enhanced up to twice when the growth substrate contained 80% of OMSW compared to no OMSW. Taking together this study demonstrate that Pleurotus eryngii can serve as a potential rich source of glucans for nutritional and medicinal applications and that glucan content in mushroom fruiting bodies can be further enriched by applying OMSW into the cultivation substrate.

Lignin-carbohydrate complexes from sisal (Agave sisalana) and abaca (Musa textilis): chemical composition and structural modifications during the isolation process.

MAIN CONCLUSION: Two types of lignins occurred in different lignin-carbohydrate fractions, a lignin enriched in syringyl units, less condensed, preferentially associated with xylans, and a lignin with more guaiacyl units, more condensed, associated with glucans. Lignin-carbohydrate complexes (LCC) were isolated from the fibers of sisal (Agave sisalana) and abaca (Musa textilis) according to a plant biomass fractionation procedure recently developed and which was termed as "universally" applicable to any type of lignocellulosic material. Two LCC fractions, namely glucan-lignin (GL) and xylan-lignin (XL), were isolated and differed in the content and composition of carbohydrates and lignin. In both cases, GL fractions were enriched in glucans and comparatively depleted in lignin, whereas XL fractions were depleted in glucans, but enriched in xylans and lignin. Analysis by two-dimensional Nuclear Magnetic Resonance (2D-NMR) and Derivatization Followed by Reductive Cleavage (DFRC) indicated that the XL fractions were enriched in syringyl (S)-lignin units and ß-O-4' alkyl-aryl ether linkages, whereas GL fractions have more guaiacyl (G)-lignin units and less ß-O-4' alkyl-aryl ether linkages per lignin unit. The data suggest that the structural characteristics of the lignin polymers are not homogeneously distributed within the same plant and that two different lignin polymers with different composition and structure might be present. The analyses also suggested that acetates from hemicelluloses and the acyl groups (acetates and p-coumarates) attached to the γ-OH of the lignin side chains were extensively hydrolyzed and removed during the LCC fractionation process. Therefore, caution must be paid when using this fractionation approach for the structural characterization of plants with acylated hemicelluloses and lignins. Finally, several chemical linkages (phenylglycosides and benzyl ethers) could be observed to occur between lignin and xylans in these plants.

Chemical Structure and Immunomodulating Activities of an α-Glucan Purified from Lobelia chinensis Lour.

A neutral α-glucan, named BP1, with a molecular mass of approximately 9.45 kDa, was isolated from Lobelia chinensis by hot-water extraction, a Q-Sepharose Fast Flow column and Superdex-75 column chromatography. Its chemical structure was characterized by monosaccharide analysis, methylation analysis and analysis of its FT-IR, high performance gel permeation chromatography (HPGPC) and 1D/2D-NMR spectra data. The backbone of BP1 consists of →6α-d-Glcp¹â†’6,3α-d-Glcp¹â†’(6α-d-Glcp¹)x-6,3α-d-Glcp¹-(6α-d-Glcp¹)y→. The side chains were terminal α-d-Glcp¹â†’ and α-d-Glcp¹â†’ (6α-d-Glcp¹)z→4α-d-Glcp¹â†’3α-d-Glcp¹â†’4α-d-Glcp¹â†’ (x + y + z = 5), which are attached to the backbone at O-3 of 3,6α-d-Glcp¹. The results of the effect of BP1 on mouse macrophage cell line RAW 264.7 indicate that BP1 enhances the cell proliferation, phagocytosis, nitric oxide production and cytokine secretion in a dose-dependent manner. Because the inhibitor of Toll-like receptor 4 blocks the BP1-induced secretion of TNF-α and IL-6, we hypothesize that α-glucan BP1 activates TLR4, which mediates the above-mentioned immunomodulating effects.

Selection and characterization of Euglena anabaena var. minor as a new candidate Euglena species for industrial application.

Euglena gracilis is a microalgae used as a model organism. Recently, mass cultivation of this species has been achieved for industrial applications. The genus Euglena includes more than 200 species that share common useful features, but the potential industrial applications of other Euglena species have not been evaluated. Thus, we conducted a pilot screening study to identify other species that proliferate at a sufficiently rapid rate to be used for mass cultivation; we found that Euglena anabaena var. minor had a rapid growth rate. In addition, its cells accumulated more than 40% weight of carbohydrate, most of which is considered to be a euglenoid specific type of beta-1-3-glucan, paramylon. Carbohydrate is stored in E. anabaena var. minor cells during normal culture, whereas E. gracilis requires nitrogen limitation to facilitate paramylon accumulation. These results suggest the potential industrial application of E. anabaena var. minor.

Laminarin from Irish Brown Seaweeds Ascophyllum nodosum and Laminaria hyperborea: Ultrasound Assisted Extraction, Characterization and Bioactivity.

Ultrasound assisted extraction (UAE), purification, characterization and antioxidant activity of laminarin from Irish brown seaweeds Ascophyllum nodosum and Laminarina hyperborea were investigated. UAE was carried out using 60% ultrasonic power amplitude and 0.1 M hydrochloric acid for 15 min. Separately, solid-liquid extraction was carried in an orbital shaker using 0.1 M hydrochloric acid at 70 °C for 2.5 h. UAE with hydrochloric acid resulted in the highest concentration of laminarin, 5.82% and 6.24% on dry weight basis from A. nodosum and L. hyperborea, respectively. Purification of all extracts was carried out using molecular weight cut off dialysis at 10 kDa. Characterization of the laminarin fraction was carried out using matrix assisted laser desorption/ionization time-of-flight mass spectrometry. Antioxidant activity of A. nodosum and L. hyperborea extracts had 2,2-diphenyl-1-picrylhydrazyl (DPPH) inhibition levels of 93.23% and 87.57%, respectively. Moreover, these extracts have shown inihibition of bacterial growth of Staphylcoccus aureus, Listeria monocytogenes, Escherichia coli and Salmonella typhimurium.

The immunologically active oligosaccharides isolated from wheatgrass modulate monocytes via Toll-like receptor-2 signaling.

Wheatgrass is one of the most widely used health foods, but its functional components and mechanisms remain unexplored. Herein, wheatgrass-derived oligosaccharides (WG-PS3) were isolated and found to induce CD69 and Th1 cytokine expression in human peripheral blood mononuclear cells. In particular, WG-PS3 directly activated the purified monocytes by inducing the expression of CD69, CD80, CD86, IL-12, and TNF-α but affected NK and T cells only in the presence of monocytes. After further purification and structural analysis, maltoheptaose was identified from WG-PS3 as an immunomodulator. Maltoheptaose activated monocytes via Toll-like receptor 2 (TLR-2) signaling, as discovered by pretreatment of blocking antibodies against Toll-like receptors (TLRs) and also determined by click chemistry. This study is the first to reveal the immunostimulatory component of wheatgrass with well defined molecular structures and mechanisms.

Characterization of hyperbranched glycopolymers produced in vitro using enzymes.

Asymmetrical flow field flow fractionation (AF4) has proven to be a very powerful and quantitative method for the determination of the macromolecular structure of high molar mass branched biopolymers, when coupled with multi-angle laser light scattering (MALLS). This work describes a detailed investigation of the macromolecular structure of native glycogens and hyperbranched α-glucans (HBPs), with average molar mass ranging from 2 × 10(6) to 4.3 × 10(7) g mol(-1), which are not well fractionated by means of classical size-exclusion chromatography. HBPs were enzymatically produced from sucrose by the tandem action of an amylosucrase and a branching enzyme mimicking in vitro the elongation and branching steps involved in glycogen biosynthesis. Size and molar mass distributions were studied by AF4, coupled with online quasi-elastic light scattering (QELS) and transmission electron microscopy. AF4-MALLS-QELS has shown a remarkable agreement between hydrodynamic radii obtained by online QELS and by AF4 theory in normal mode with constant cross flow. Molar mass, size, and dispersity were shown to significantly increase with initial sucrose concentration, and to decrease when the branching enzyme activity increases. Several populations with different size range were observed: the amount of small size molecules decreasing with increasing sucrose concentration. The spherical and dense global conformation thus highlighted was partly similar to native glycogens. A more detailed study of HBPs synthesized from low and high initial sucrose concentrations was performed using complementary enzymatic hydrolysis of external chains and chromatography. It emphasized a more homogeneous branching pattern than native glycogens with a denser core and shorter external chains.

Preliminary characterization, antioxidant properties and production of chrysolaminarin from marine diatom Odontella aurita.

A new chrysolaminarin, named CL2, with a molecular mass of 7.75 kDa, was purified from the marine diatom, Odontella aurita, using DEAE-52 cellulose anion-exchange chromatography and Sephadex G-200 gel-filtration chromatography. The monosaccharide and structural analysis revealed that CL2 was a glucan mainly composed of glucose, which was linked by the ß-d-(1→3) (main chain) and ß-d-(1→6) (side chain) glycosidic bond, demonstrated by infrared spectroscopy (IR) and nuclear magnetic resonance (NMR). The antioxidant activity tests revealed that the CL2 presented stronger hydroxyl radical scavenging activity with increasing concentrations, but less was effective on reducing power analysis and scavenging 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical. The influences of nitrogen concentration and light intensity on chrysolaminarin production of O. aurita were further investigated in a glass column photobioreactor, and a record high chrysolaminarin productivity of 306 mg L-1 day-1 was achieved. In conclusion, the chrysolaminarin CL2 from O. aurita may be explored as a natural antioxidant agent for application in aquaculture, food and pharmaceutical areas.

Characterization and biocompatibility of glucan: a safe food additive from probiotic Lactobacillus plantarum DM5.

BACKGROUND: Exopolysaccharide produced by lactic acid bacteria are the subject of an increasing number of studies for their potential applications in the food industry as stabilizing, bio-thickening and immunostimulating agents. In this regard, the authors isolated an exopolysaccharide producing probiotic lactic acid bacterium from fermented beverage Marcha of north eastern Himalayas. RESULTS: The isolate Lactobacillus plantarum DM5 showed extracellular glucansucrase activity of 0.48 U mg⁻¹ by synthesizing natural exopolysaccharide glucan (1.87 mg mL⁻¹) from sucrose. Zymogram analysis of purified enzyme confirms the presence of glucosyltransferase of approximately 148 kDa with optimal activity of 18.7 U mg⁻¹ at 30 °C and pH 5.4. The exopolysaccharide was purified by gel permeation chromatography and had an average molecular weight of 1.11 × 106 Da. Acid hydrolysis and structural characterization of exopolysaccharide revealed that it was composed of d-glucose residues, containing 86.5% of α-(1→6) and 13.5% of α-(1→3) linkages. Rheological study exhibited a shear thinning effect of glucan appropriate for food additives. A cytotoxicity test of glucan on human embryonic kidney 293 (HEK 293) and human cervical cancer (HeLa) cell lines revealed its nontoxic biocompatible nature. CONCLUSION: This is the first report on the structure and biocompatibility of homopolysaccharide α-D-glucan (dextran) from probiotic Lactobacillus plantarum strain and its unique physical and rheological properties that facilitate its application in the food industry as viscosifying and gelling agent.

The carrier function and inhibition effect on benign prostatic hyperplasia of a glucan from Epimedium brevicornu Maxim.

Epimedium, a traditional Chinese medicine commonly used as a dietary supplement, contains polysaccharides and flavonoids as its main bioactive ingredients. In this study, a neutral homogeneous polysaccharide (EPSN-1) was isolated from Epimedium brevicornu Maxim. EPSN-1 was identified as a glucan with a backbone of →4)-α-D-Glcp-(1→, branched units comprised α-D-Glcp-(1→6)-α-D-Glcp-(1→, ß-D-Glcp-(1→6)-ß-D-Glcp-(1→ and α-D-Glcp-(1→ connected to the C6 position of backbone. The conformation of EPSN-1 in aqueous solution indicated its potential to form nanoparticles. This paper aims to investigate the carrier and pharmacodynamic activity of EPSN-1. The findings demonstrated that, on the one hand, EPSN-1, as a functional ingredient, may load Icariin (ICA) through non-covalent interactions, improving its biopharmaceutical properties such as solubility and stability, thereby improving its intestinal absorption. Additionally, as an effective ingredient, EPSN-1 could help maintain the balance of the intestinal environment by increasing the abundance of Parabacteroides, Lachnospiraceae UGG-001, Anaeroplasma, and Eubacterium xylanophilum group, while decreasing the abundance of Allobaculum, Blautia, and Adlercreutzia. Overall, this dual action of EPSN-1 sheds light on the potential applications of natural polysaccharides, highlighting their dual role as carriers and contributors to biological activity.

Glucan polysaccharides isolated from Lactarius hatsudake Tanaka mushroom: Structural characterization and in vitro bioactivities.

Commercially available mushroom polysaccharides have found widespread use as adjuvant tumor treatments. However, the bioactivity of polysaccharides in Lactarius hatsudake Tanaka (L. hatsudake), a mushroom with both edible and medicinal uses, remains relatively unexplored. To address this gap, five L. hatsudake polysaccharides with varying molecular weights were isolated, named LHP-1 (898 kDa), LHP-2 (677 kDa), LHP-3 (385 kDa), LHP-4 (20 kDa), and LHP-5 (4.9 kDa). Gas chromatography-mass spectrometry, nuclear magnetic resonance, and atomic force microscopy, etc., were employed to determine their structural characteristics. The results confirmed that spherical aggregates with amorphous flexible fiber chains dominated the conformation of the LHP. LHP-1 and LHP-2 were identified as glucans with α-(1,4)-Glcp as the main chain; LHP-3 and LHP-4 were classified as galactans with varying molecular weights but with α-(1,6)-Galp as the main chain; LHP-5 was a glucan with ß-(1,3)-Glcp as the main chain and ß-(1,6)-Glcp connecting to the side chains. Significant differences were observed in inhibiting tumor cell cytotoxicity and the antioxidant activity of the LHPs, with LHP-5 and LHP-4 identified as the principal bioactive components. These findings provide a theoretical foundation for the valuable use of L. hatsudake and emphasize the potential application of LHPs in therapeutic tumor treatments.

Structural properties of glucan from Russula griseocarnosa and its immunomodulatory activities mediated via T cell differentiation.

The polysaccharide, RGP2, was isolated from Russula griseocarnosa and its immunostimulatory effects were confirmed in cyclophosphamide (CTX)-induced immunosuppressed mice. Following purification via chromatography, structural analysis revealed that RGP2 had a molecular weight of 11.82 kDa and consisted of glucose (Glc), galactose (Gal), mannose, glucuronic acid and glucosamine. Bond structure analysis and nuclear magnetic resonance characterization confirmed that the main chain of RGP2 was formed by →6)-ß-D-Glcp-(1→, →3)-ß-D-Glcp-(1→ and →6)-α-D-Galp-(1→, which was substituted at O-3 of →6)-ß-D-Glcp-(1→ by ß-D-Glcp-(1→. RGP2 was found to ameliorate pathological damage in the spleen and enhance immune cell activity in immunosuppressed mice. Based on combined multiomics analysis, RGP2 altered the abundance of immune-related microbiota (such as Lactobacillus, Faecalibacterium, and Bacteroides) in the gut and metabolites (uridine, leucine, and tryptophan) in the serum. Compared with immunosuppressed mice, RGP2 also restored the function of antigen-presenting cells, promoted the polarization of macrophages into the M1 phenotype, positively affected the differentiation of helper T cells, and inhibited regulatory T cell differentiation through the protein kinase B (AKT)/mechanistic target of rapamycin (mTOR) pathway, ultimately exerting an immune boosting function. Overall, our findings highlight therapeutic strategies to alleviate CTX-induced immunosuppression in a clinical setting.