Quantification and comparison of acidic polysaccharides in edible fish intestines and livers using HPLC-MS/MS.

Fish intestines and livers are usually considered as delicious and nutritious food in China. Acidic polysaccharides are important nutrients in these food of animal origin, but there is currently little information regarding their quantitative distributions. The present study demonstrated a method to quantify acidic polysaccharides simultaneously by analyzing their disaccharides produced from the acid hydrolysis using high-performance liquid chromatography (HPLC) coupled with triple quadrupole mass spectrometry. The recoveries for these acidic polysaccharides were all 97%-115% with relative standard deviation of 3.0%-9.0%. All of the acidic polysaccharides had good linearities. Then this method was applied to determine the composition of acidic polysaccharides in 5 edible fish livers and intestines. Besides well-known glycosaminoglycans (GAGs) including hyaluronic acid (HA), Chondroitin sulfate (CS), dermatan sulfate (DS) and heparin (HP), 4 novel acidic polysaccharides including 2 GAGs and 2 non-GAGs comprised of hexose-hexuronic acid repeating units were also found. CS and HP were the major acidic polysaccharides components in fish intestines and livers, respectively. The absolute amounts of acidic polysaccharides differed greatly in these fish tissues, but their proportions showed similarity in the same type of tissues. The present study demonstrated an effective method for acidic polysaccharides quantification, and revealed acidic polysaccharides compositions of edible fish livers and intestines.

Polyelectrolyte complex formation of alginate and chito oligosaccharide is influenced by their proportion and alginate molecular weight.

Sodium alginate (SA) and chito oligosaccharide (COS) are widely used food additives in the food industry, and exploring their interaction to form polyelectrolyte complexes (PECs) may provide insights into food development. In the present study, the effects of viscosity-average molecular weight (Mv) and relative amounts of SA on the formation of sodium alginate/chito oligosaccharide polyelectrolyte (SCP) complexes were investigated. The results showed that the electrostatic interaction between -COOH and -NH2 and the hydrogen bonding between OH, were attributed to the formation of the SCP complexes. Then the formation and properties of SCP complexes were greatly dependent on the Mv and the relative amount of SA. SA with Mv of ≥2.16 × 106 Da could form spherical SCP complexes, while the SA/COS ratio (w/w) ≥ 0.8 was not conducive to the formation of SCP complexes. Moreover, the SCP complexes were more stable in the gastric environment than in the intestinal condition. In addition, 1.73 × 107 Da was the optimal Mv of SA for SCP complexes formation. This study contributed to a comprehensive understanding of the interaction between SA and COS, and shed light on the potential application of SA and COS formulation to develop new food products.

Modulation effect of sulfated polysaccharide from Sargassum fusiforme on gut microbiota and their metabolites in vitro fermentation.

The present study demonstrated the digestion behavior and fermentation characteristics of a sulfated polysaccharide from Sargassum fusiforme (SFSP) in the simulated digestion tract environment. The results showed that the molecular weight of two components in SFSP could not be changed by simulated digestion, and no free monosaccharide was produced. This indicates that most of SFSP can reach the colon as prototypes. During the fermentation with human intestinal flora in vitro, the higher-molecular-weight component of SFSP was utilized, the total sugar content decreased by 16%, the reducing sugar content increased, and the galactose content in monosaccharide composition decreased relatively. This indicates that SFSP can be selectively utilized by human intestinal flora. At the same time, SFSP also changed the structure of intestinal flora. Compared with the blank group, SFSP significantly increased the abundance of Bacteroidetes and decreased the abundance of Firmicutes. At the genus level, the abundances of Bacteroides and Megamonas increased, while the abundances of Shigella, Klebsiella, and Collinsella decreased. Moreover, the concentrations of total short-chain fatty acids (SCFAs), acetic, propionic and n-butyric acids significantly increased compared to the blank group. SFSP could down-regulate the contents of trimethylamine, piperidone and secondary bile acid in fermentation broth. The contents of nicotinic acid, pantothenic acid and other organic acids were increased. Therefore, SFSP shows significant potential to regulate gut microbiota and promote human health.

The protective effect of Enteromorpha prolifera polysaccharide on alcoholic liver injury in C57BL/6 mice.

An alcohol-induced liver injury model was induced in C57BL/6 mice to assess the protective efficacy of Enteromorpha prolifera polysaccharides (EP) against liver damage. Histological alterations in the liver were examined following hematoxylin-eosin (H&E) staining. Biochemical assay kits and ELISA kits were employed to analyze serum and liver biochemical parameters, as well as the activity of antioxidant enzymes and alcohol metabolism-related enzymes. The presence of oxidative stress-related proteins in the liver was detected using western blotting. Liquid chromatography and mass spectrometry were used to profile serum metabolites in mice. The findings demonstrated that EP-H (100 mg/Kg) reduced serum ALT and AST activity by 2.31-fold and 2.32-fold, respectively, when compared to the alcohol-induced liver injury group. H&E staining revealed a significant attenuation of microvesicular steatosis and ballooning pathology in the EP-H group compared to the model group. EP administration was found to enhance alcohol metabolism by regulating metabolite-related enzymes (ADH and ALDH) and decreasing CYP2E1 expression. EP also modulated the Nrf2/HO-1 signaling pathway to bolster hepatic antioxidant capacity. Furthermore, EP restored the levels of lipid metabolites (Glycine, Butanoyl-CoA, and Acetyl-CoA) to normalcy. In summary, EP confers protection to the liver through the regulation of antioxidant activity and lipid metabolites in the murine liver.

Fucoidan alleviates the inhibition of protein digestion by chitosan and its oligosaccharides.

Chitosan (CTS) and chitosan oligosaccharides (COS) have been widely applied in food industry due to their bioactivities and functions. However, CTS and COS with positive charges could interact with proteins, such as whey protein isolate (WPI), influencing their digestion. Interaction among CTS/COS, FUC, and WPI/enzymes was studied by spectroscopy, chromatography, and chemical methods in order to reveal the role of FUC in relieving the inhibition of protein digestibility by CTS/COS and demonstrate the action mechanisms. As shown by the results, the addition of FUC increased degree of hydrolysis (DH) and free protein in the mixture of CTS and WPI to 3.1-fold and 1.8-fold, respectively, while raise DH value and free protein in the mixture of COS and WPI to 6.7-fold and 1.2-fold, respectively. The interaction between amino, carboxyl, sulfate, and hydroxyl groups from carbohydrates and protein could be observed, and notably, FUC could interact with CTS/COS preferentially to prevent CTS/COS from combining with WPI. In addition, the addition of FUC could also relieve the combination of CTS to trypsin, increasing the fluorescence intensity and concentration of trypsin by 83.3 % and 4.8 %, respectively. Thus, the present study demonstrated that FUC could alleviate the inhibitory effect of CTS/COS on protein digestion.

Structure-activity relationship of Caulerpa lentillifera polysaccharide in inhibiting lipid digestion.

Caulerpa lentillifera polysaccharide (CLP) has been characterized as a sulfated polysaccharide which can effectively inhibit lipid digestion. However, little information was known regarding its inhibitory mechanisms. In the present study, desulfation and degradation were conducted to prepare the derivatives of CLP, and a series of chemical and spectroscopic methods were used to elucidate the structure-activity relationship of CLP on the inhibitory effect of lipid digestion. Results revealed that CLP possessed excellent binding capacities for sodium cholate, sodium glycocholate, and sodium taurocholate. In addition, CLP can effectively inhibit lipase activity by quenching the fluorescence intensity, changing the secondary structure, and decreasing the UV-Vis absorbance. Of note, sulfate groups in CLP took a vital role in inhibiting lipase activity, while the molecular weight of CLP showed a positive correlation with the binding activities of bile acids. Furthermore, adding CLP into the whey protein isolate (WPI) emulsion system also impeded lipid digestion, indicating that CLP can be a potential reduced-fat nutraceutical used in food emulsion systems.

Inhibitory effects of fucoidan from Laminaria japonica against some pathogenic bacteria and SARS-CoV-2 depend on its large molecular weight.

Fucoidan is a highly sulfated polysaccharide with a wide range of bioactivities, including anti-pathogenic activity. However, the relationship between structure and activity of fucoidan in inhibiting pathogen infections remains unclear. Here, different-molecular-weight fucoidans were prepared by photocatalytic degradation followed by membrane ultrafiltration, and their chemical structures and anti-pathogenic microbiota activity were compared. Results showed that photocatalytic degradation could effectively degrade fucoidan while its structure block and sulfate groups were not destroyed obviously. Fucoidan (90.8 kDa) of 5 mg/mL could inhibit the growth of S. aureus, S. typhimurium and E. coli, but its degradation products, Dfuc1 (19.2 kDa) and Dfuc2 (5.5 kDa), demonstrated lower inhibitory effect. In addition, compared to Dfuc1 and Dfuc2, fucoidan showed stronger capability to prevent the adhesion of S. aureus, L. monocytogenes, V. parahaemolyticus and S. typhimurium to HT-29 cells. Moreover, the inhibitory effect against SARS-CoV-2 and the binding activity to S protein were also positively correlated to molecular weight. These results indicate that natural fucoidan with higher molecular weight are more effective to inhibit these pathogenic bacteria and SARS-CoV-2, providing a better understanding of the relationship between structure and activity of fucoidan against pathogenic microbiota.

Characterization and Gel Properties of Low-Molecular-Weight Carrageenans Prepared by Photocatalytic Degradation.

Low-molecular-weight carrageenan has attracted great interest because it shows advantages in solubility, absorption efficiency, and bioavailability compared to original carrageenan. However more environment-friendly and efficient methods to prepare low-molecular-weight carrageenan are still in great need. In the present study, a photocatalytic degradation method with only TiO2 has been developed and it could decrease the average molecular weight of κ-carrageenan to 4 kDa within 6 h. The comparison of the chemical compositions of the degradation products with those of carrageenan by FT-IR, NMR, etc., indicates no obvious removement of sulfate group, which is essential for bioactivities. Then 20 carrageenan oligosaccharides in the degradation products were identified by HPLC-MSn, and 75% of them possessed AnGal or its decarbonylated derivative at their reducing end, indicating that photocatalysis is preferential to break the glycosidic bond of AnGal. Moreover, the analysis results rheology and Cryo-SEM demonstrated that the gel property decreased gradually. Therefore, the present study demonstrated that the photocatalytic method with TiO2 as the only catalyst has the potential to prepare low-molecular-weight carrageenan with high sulfation degree and low viscosity, and it also proposed the degradation rules after characterizing the degradation products. Thus, the present study provides an effective green method for the degradation of carrageenan.

Effect of ultrasound-assisted resting on the quality of surimi-wheat dough and noodles.

In this study, the influence of ultrasound-assisted resting at different power on the rheological properties, water distribution and structural characteristics of dough with 50 % surimi as well as the texture, cooking and microstructure characteristics of the surimi-wheat noodles were investigated. Compared with the fermentation control (FC) noodles, the microstructure, cooking and texture characteristics of noodles (≤24.00 W/L) were significantly (p < 0.05) improved after ultrasonic treating. As the increasing of ultrasonic power, compared to FC, the creep strain, recovery strain, semi-bound water, and free sulfhydryl (SH) contents of surimi-wheat dough decreased at first and then increased significantly (p < 0.05). The α-helix and ß-turn content of dough increased at first and then decreased after ultrasonic treatment, while the ß-sheet was reversed. The surimi-wheat dough network structure was improved by ultrasonic treatment, with the densest and continuous pore size in 21.33 W/L, but the dough structure was broken and loose (>21.33 W/L), which consisted of the hardness, elasticity, chewiness, resistant and cooked quality of surimi-wheat noodles. This work elucidated the effect of ultrasonic power on the performance of surimi-wheat dough, and the optimal ultrasound power was obtained, thereby improving the nutritional properties and the quality of surimi-wheat noodles.

Role of metal chlorides in the gelation and properties of fucoidan/κ-carrageenan hydrogels.

Metal ions play a crucial role in forming hydrogels, and their effects on fucoidan (FUC): κ-carrageenan (KC) mixed gels were investigated. The results indicated that the FUC: KC mixed gels (FC) were promoted by K+ and Ca2+ but destroyed by Fe3+. The gel strength of FC was enhanced by K+ and Ca2+, with G' and G″ being highest at 50 mmol/L KCl and 25 mmol/L CaCl2, respectively. Water mobility was weakened after the addition of KCl and CaCl2 in accordance with the decrease in T23 relaxation time (free water, 100-1000 ms). After addition of KCl and CaCl2, the FC groups presented a typical three-dimensional network structure in contrast to the lamellar, disordered, and broken structure of FUC. Moreover, the FT-IR spectrum certified the enhancement of hydrogen bonds and the occurrence of electrostatic interactions during gel formation by the red-shift of the OH stretching vibration of the Ca2+ group and the blue-shift of the COS vibrations. The XRD results confirmed that the binding of Ca2+ to FC was tighter than that of K+ at the same charge content. These results provide a theoretical basis for understanding the interaction mechanism of FC with metal ions.

Two Ascophyllum nodosum Fucoidans with Different Molecular Weights Inhibit Inflammation via Blocking of TLR/NF-κB Signaling Pathway Discriminately.

The present study aimed to clarify the potential mechanism of fucoidans found in Ascophyllum nodosum on anti-inflammation and to further explore the relationship between their structures and anti-inflammation. Two novel fucoidans named ANP-6 and ANP-7 and found in A. nodosum, were separated and purified and their structures were elucidated by HPGPC, HPLC, GC-MS, FT-IR, NMR, and by the Congo red test. They both possessed a backbone constructed of →2)-α-L-Fucp4S-(1→, →3)-α-L-Fucp2S4S-(1→, →6)-ß-D-Galp-(1→, and →3,6)-ß-D-Galp4S-(1→ with branches of →2)-α-L-Fucp4S-(1→ and →3)-ß-D-Galp-(1→. Moreover, ANP-6 and ANP-7 could prevent the inflammation of the LPS-stimulated macrophages by suppressing the NO production and by regulating the expressions of iNOS, COX-2, TNF-α, IL-1ß, IL-6, and IL-10. Their inhibitory effects on the TLR-2 and TLR-4 levels suggest that they inhibit the inflammation process via the blocking of the TLR/NF-κB signal transduction. In addition, ANP-6, with a molecular weight (63.2 kDa), exhibited stronger anti-inflammatory capabilities than ANP-7 (124.5 kDa), thereby indicating that the molecular weight has an influence on the anti-inflammatory effects of fucoidans.

Preparation of Low-Molecular-Weight Fucoidan with Anticoagulant Activity by Photocatalytic Degradation Method.

It is a challenge to degrade sulfated polysaccharides without stripping sulfate groups. In the present study, a photocatalytic method was applied to degrade fucoidan, a sulfated polysaccharide from brown algae. The degradation with varying addition amounts of H2O2 and TiO2 were monitored by high performance gel permeation chromatography (HPGPC) and thin layer chromatography (TLC), and fucoidan was efficiently degraded with 5% TiO2 and 0.95% H2O2. A comparison of the chemical compositions of 2 products obtained after 0.5 h and 3 h illumination, DF-0.5 (average Mw 90 kDa) and DF-3 (average Mw 3 kDa), respectively, with those of fucoidan indicates the photocatalytic degradation did not strip the sulfate groups, but reduced the galactose/fucose ratio. Moreover, 12 oligosaccharides in DF-3 were identified by HPLC-ESI-MSn and 10 of them were sulfated. In addition, DF-0.5 showed anticoagulant activity as strong as fucoidan while DF-3 could specifically prolong the activated partial thromboplastin time. All samples exerted inhibition effects on the intrinsic pathway FXII in a dose-dependent manner. Thus, photocatalytic degradation demonstrated the potential to prepare sulfated low-molecular-weight fucoidan with anticoagulant activity.

An acidic polysaccharide from Patinopecten yessoensis skirt prevents obesity and improves gut microbiota and metabolism of mice induced by high-fat diet.

The prevention of obesity is an urgent need for worldwide public health. The scallop (Patinopecten yessoensis) skirt is the by-product of adductor processing. In order to explore the value of the scallop skirt, the present study isolated an acidic polysaccharide from the skirt of P. yessoensis (SPYP) and evaluated its anti-obesity effect. SPYP was characterized as an acidic heteropolysaccharide with a molecular weight of 13.58 kDa. Through stepwise acid hydrolysis followed by HPLC-MSn analysis, two core chains in SPYP was determined as heparin-like â†’ 4)ß-GlcA(1 â†’ 4)α-GlcNAc â†’ and chondroitin sulfate-like â†’ 4)ß-GlcA(1 â†’ 3)ß-GalNAc â†’. SPYP could effectively reduce body weight, decrease fat accumulation and prevent high blood lipids induced by a high-fat diet (HFD) in mice. Further 16S ribosomal ribonucleic acid (rRNA) sequencing analysis revealed that the anti-obesity effect of SPYP was notably associated with its modulation on gut microbiota. The short-chain fatty acids were also restored by SPYP supplementation compared to the HFD group. Moreover, liquid chromatography-high resolution accurate mass spectrometry (LC-HRMS) analysis demonstrated that metabolite profiles of HFD-fed mice were altered by SPYP supplementation, especially the lipid metabolism in serum and amino acid metabolism in cecal content, which may contribute to the anti-obesity effect of SPYP. The present study offers the basis for processing and application of P. yessoensis skirt.

Digestion behavior of a polysaccharide from Cyclina sinensis: An explanation for the discrepancy in its immunostimulatory activities in vitro and in vivo.

Although numerous polysaccharides have demonstrated potential immunostimulatory activities in in vitro models, only a few of them successfully stimulate the immune system in vivo. In order to explore the possible reasons for the activity loss of polysaccharides in in vivo models, the immunostimulatory activities in vitro and in vivo and the digestion behavior of a polysaccharide from Cyclina sinensis (CSP) were investigated in the present study. CSP showed obvious immunostimulatory activity in a RAW 264.7 cell model. In in vitro experiment, CSP did not exhibit cytotoxicity at concentrations of ≤10 µg/ml, and significantly increased NO production at concentrations of 0.4-10 µg/ml, suggesting CSP processes immunostimulatory activity in vitro. Further investigation using simulated digestion model indicated that CSP could bind with the protein in the digestive fluids to form precipitate in both the stomach and small intestine, and it could be seriously degraded by amylase during the digestion in the small intestine. Furthermore, the in vivo immunostimulatory activity evaluation demonstrated CSP had no effect on immunosuppressed mice as indicated by the body weight, thymus and spleen indexes, and TNF-α, IL-1ß, IL-6, and IL-10 mRNA expression. Thus, the present study indicates that the degradation and precipitation of CSP in the digestive tract are the possible reasons for the activity loss of CSP after digestion. PRACTICAL APPLICATION: Cyclina sinensis is the common aquatic shellfish in China and plays an important role in the marine aquaculture industry. Cyclina sinensis polysaccharide (CSP) is the main active component of C. sinensis. The structure characterization and immunostimulatory activity of a purified fraction of CSP (CSP-1) and the effect of digestion on CSP and its immunostimulatory activity were studied. The result of this study promotes the understanding of the nutritional function effects and provides a scientific reference for the rational development and high-value utilization of C. sinensis.

Chitosan and chitosan oligosaccharide influence digestibility of whey protein isolate through electrostatic interaction.

Chitosan (CTS)/chitosan oligosaccharide (COS) and whey protein isolate (WPI) have been frequently used as food supplements, but notably, the interaction between the carbohydrate and the protein may affect the digestibility of protein. Thus, the present study focused on effects of the interaction between CTS/COS and WPI on the protein digestibility. A series of chemical and spectroscopic techniques including gel electrophoresis, gel permeation chromatography, Fourier transform-infrared (FT-IR) spectroscopy, intrinsic fluorescence (IF) spectroscopy, and circular dichroism (CD) spectroscopy were applied. According to the findings, both CTS and COS dramatically reduced intestinal digestibility of WPI, resulting in a decrease of DH by 43.33 % and 52.31 %, respectively. The substitution degree of WPI on CTS was 0.87 g WPI/g CTS, and the electrostatic interaction between amine groups of CTS and carboxyl groups of WPI caused changes in WPI's stability, microstructure, and fluorescence intensity. Notably, CTS affected the digestibility of WPI by precipitating protein and enzyme, whereas COS altered WPI's digestibility by decreasing or inactivating enzyme activity. The present study offered a solid scientific foundation for the rational formulations of carbohydrates and proteins in food industry.

Effect of konjac glucomannan with different viscosities on the quality of surimi-wheat dough and noodles.

It was investigated that the rheology, starch-gluten-surimi network, thermal properties, and water distribution of surimi-wheat dough, and texture characteristics, cooking properties, and microscopic characteristics of the surimi-wheat noodles with konjac glucomannan (KGM) of different viscosities in different concentrations. The results showed that the storage (G'), loss (G″), and complex (G⁎) moduli of dough increased with adding KGM. With the increase of KGM viscosity, the reduction in the free sulfhydryl (SH) content to 0.84 µmol/g and the increase in the free water content to 8.25 % led to significantly improved enthalpy and the microstructure density. The hardness and tensile length of noodles were substantially increased by adding 3 % KGM. In addition, the KGM enhanced the starch-gluten-surimi network and improved the cooking qualities and textural properties of noodles. More importantly, the application of KGM in the wheat flour composite system also showed better performance. Thus, the introduction of KGM into the surimi-wheat dough had a significant effect on the optimization of the macro- and micro-characteristics of dough and noodles.

Structural characterization and SARS-CoV-2 inhibitory activity of a sulfated polysaccharide from Caulerpa lentillifera.

Caulerpa lentillifera (Bryopsidophyceae, Chlorophyta) is an edible seaweed attracting great attention for its expansion of farming scale and increasing consumption in these years. In the present study, a sulfated polysaccharide (CLSP-2) was isolated and separated from C. lentillifera, and its chemical structure was elucidated by a series of chemical and spectroscopic methods. Among these methods, mild acid hydrolysis and photocatalytic degradation were applied to release mono- and oligo-saccharide fragments which were further identified by HPLC-MSn analysis, affording the information of the sugar sequences and the sulfate substitution in CLSP-2. Results indicated that the backbone of CLSP-2 was constructed of →6)-ß-Manp-(1→ with sulfated branches at C2, which were comprised of prevalent →3)-ß-Galp4S-(1→, →3)-ß-Galp2,4S-(1→, and minor Xyl. In addition, the virus neutralization assay revealed that CLSP-2 could effectively protect HeLa cells against SARS-CoV-2 infection with an IC50 of 48.48 µg/mL. Hence, the present study suggests CLSP-2 as a promising agent against SARS-CoV-2.

Optimization of ultrasound assisted extraction of abalone viscera protein and its effect on the iron-chelating activity.

This study aims to investigate effects of ultrasound assisted extraction on the abalone viscera protein extraction rate and iron-chelating activity of peptides. The optimal conditions for ultrasound assisted extraction by response surface methodology was at sodium hydroxide concentration 14 g/kg, ultrasonic power 428 W and extraction time 52 min. Under the optimal conditions, protein extraction rate was 64.89%, compared with alkaline extraction of 55.67%. The iron-chelating activity of peptides affected by ultrasound technology was further evaluated by iron-chelating rate, FTIR spectroscopy and LC-HRMS/MS. Alcalase was the suitable enzyme for the preparation of iron-chelating peptides from two abalone viscera proteins, showing no significant difference between their iron-chelating rate of 16.24% (ultrasound assisted extraction) and 16.60% (alkaline extraction). Iron binding sites from the two hydrolysates include amino and carboxylate terminal groups and peptide bond of the peptide backbone as well as amino, imine and carboxylate from side chain groups. Moreover, 24 iron-chelating peptides were identified from hydrolysate (alcalase, ultrasound assisted extraction), which were different from the 27 iron-chelating peptides from hydrolysate (alcalase, alkaline extraction). This study suggests the application of ultrasound technology in the generation of abalone viscera-derived iron-chelating peptides which have the ability to combat iron deficiency.

Fucoidan hydrogels induced by κ-carrageenan: Rheological, thermal and structural characterization.

Fucoidan (FUC) is a non-gelling polysaccharide but could interact with κ-carrageenan (KC) to form a stable gel blend. However, their interaction mechanism is unclear. Herein, FUC and KC blended gels are prepared by mixing FUC (10 and 20 mg/mL) and KC (6, 7 and 8 mg/mL) solutions, and characterized through LF-NMR, rheology, DSC, Cryo-SEM, and FTIR. The FTIR analysis confirms the formation of hydrogen bonds between FUC and KC chains. The KC addition to FUC significantly improves the water retention and frost resistance. The viscoelastic measurements reveal higher gelling nature of the FUC-KC binary mixtures, and the DSC results confirm the higher thermal stability. The Cryo-SEM images clearly reveal the gel network structure. The outcome of this study deemed to further the FUC use in food and non-food applications.

Gut microbiota response to sulfated sea cucumber polysaccharides in a differential manner using an in vitro fermentation model.

Sea cucumber Stichopus japonicus has been consumed as high-valued seafood in Asian, and its sulfated polysaccharide (SCSPsj) has been inferred to benefit the host health via modulating gut microbiota composition. The present study compared the responses of gut microbiota communities from different donors to SCSPsj, and the key bacteria were identified by 16S rRNA gene sequencing analysis and in vitro fermentation with specific bacteria. Gut microbiota communities from 6 donors (A ~ F) utilized the polysaccharides to different degrees in vitro fermentation. Further comparison of Samples A and C demonstrated that Sample C with the relatively strong SCSPsj utilization capability possessed more Parabacteroides while Sample A contained more Bacteroides. Further in vitro fermentation of SCSPsj with 10 Parabacteroides and Bacteroides species suggests that Parabacteroides distasonis, enriched in Sample C, plays a critical role in the utilization of the polysaccharides. Moreover, short chain fatty acids and the metabolite profiles of Samples A and C were also compared, and the results showed that more beneficial metabolites were accumulated by the microbiota community consuming more sulfated sea cucumber polysaccharides. Our findings revealed that certain key members of gut microbiota, such as Parabacteroides distasonis, are critical for SCSPsj utilization in gut so as to influence the benefits of the polysaccharide supplement for host. Thus, to obtain better functional outcome for sulfated sea cucumber polysaccharides and sea cucumber, more attention needs to be paid to the effects of inter-individual differences in microbiota community structure.