Beneficial Effects of Holothuria leucospilota Polysaccharides on Fermentability In Vivo and In Vitro

Flammulina velutipes residue Polysaccharide Alleviates Immunosuppression and Intestinal Injury by Modulating Gut Microbiota and Associated Metabolites

This study elucidated the mechanisms underlying the immunoregulatory and gut-microbiota-modulating effects of Flammulina velutipes residue polysaccharide (FVRP) using cyclophosphamide (CTX)-induced mouse models. FVRP supplementation alleviated CTX-induced intestinal damage and boosted antioxidant enzyme activity and cytokine secretion. Additionally, FVRP enhanced the diversity and total species richness of the gut microbiota, promoting the proliferation of beneficial bacteria (e.g., Prevotellaceae), while reducing the abundance of CTX-derived bacteria (Lachnospiraceae and Rikenellaceae). FVRP facilitates the accumulation of short-chain fatty acids. Untargeted metabolomic analyses of cecal content revealed that FVRP treatment notably restored the levels of 32 endogenous metabolites altered by CTX. Based on a pseudosterility mice model, fecal microbiota transplantation (FMT), and fecal filtrate transplantation (FFT), gut microbiota and associated metabolites were demonstrated to play a crucial role in the immunomodulatory and protective effects of FVRP against intestinal injury. In conclusion, FVRP exhibits significant potential as an immune enhancer and natural therapeutic agent for alleviating intestinal inflammatory conditions.

Fucoidan from Apostichopus japonicus enhances intestinal barrier function and promotes intestinal immunity via regulating the gut microbiota and tryptophan metabolism

Apostichopus japonicus is one of the most popular types of sea cucumber among consumers in Southeast Asia. Fucoidan from Apostichopus japonicus (Aj-FUC) has attracted considerable attention because of its immunomodulatory activities. Aj-FUC is indigestible in the human upper gastrointestinal tract but can be utilized by the gut microbiota. Thus, we suspect that Aj-FUC interacts with the gut to enhance immunefunction. This study showed that after a three-week intervention with Aj-FUC (100 mg/kg/d), the gut microbiota in mice developed a new homeostasis. Subsequently, in the condition of intestinal flora homeostasis, the effects of Aj-FUC on intestinal health in normal mice and the prevention of intestinal mucosal damage in cyclophosphamide-induced mice were investigated. Aj-FUC preserved intestinal structural integrity, increased the number of goblet cells, upregulated the expression of ZO-1 and Occludin, stimulated the secretion of sIgA and IgA, and maintained the Th1/Th2 balance. Importantly, beneficial bacteria were enriched, and tryptophan metabolism-related metabolites such as 5-hydroxyindole-3-acetic acid, and indole-3-lactic acid were upregulated following Aj-FUC administration. In summary, a three-week Aj-FUC intervention could result in the formation of a new homeostasis in intestinal flora, while the effect of Aj-FUC on intestinal immunity was related to the regulation of tryptophan metabolism by gut microbiota.

Effects of Holothuria leucospilota polysaccharide on alleviating diabetic kidney disease through regulating inflammation

Diabetic kidney disease (DKD) is a severe metabolic disorder that typically results from diabetes mellitus and culminates in chronic kidney disease and renal failure. It has been reported that Holothuria leucospilota polysaccharide (HLP) has an improvement effect on type 2 diabetes mellitus (T2DM) rats. This study aimed to explore the impact of HLP on DKD further and reveal its mechanism. The spontaneous Goto-Kakizaki (GK) rats were used as a model of the DKD group, and Wistar rats were used as a normal control group, treated with intragastric administration for 4 weeks. The results showed that after HLP intervention, the renal index was reduced. Scr, BUN, and UA levels increased in the DKD group, and the HLP-H group was significantly decreased by 15.44 μmol/L, 1.11 mmol/L, and 0.08 mmol/L (p < 0.05). HLP also alleviated renal pathological damage and kidney fibrosis, decreased MIF, CD74, and IL-6 mRNA expression levels, enhanced PI3K, AKT, and PCX levels. These results indicated that HLP effectively relieved DKD by regulating inflammation and metabolism.

Metabolomic analysis reveals the potential of fucosylated chondroitin sulfate from sea cucumber in modulating metabolic homeostasis

In this study, we prepared four derivatives of fucosylated chondroitin sulfate (FCS): full-length FCS (flFCS) from Holothuria leucospilota, low molecular weight FCS (lmFCS) derived from flFCS, and their de-branched counterparts, de-branched flFCS (d-flFCS) and de-branched lmFCS (d-lmFCS) via controlled acid treatment. Following structural verification using various analytical techniques, we applied targeted metabolomics to examine the impact of FCS on nutritional efficacy and its structure-activity relationship. Analysis of 225 plasma and feces samples from 75 mice revealed a positive correlation between metabolomic shifts and increased weight gain, underscoring FCS's potential to enhance nutrient absorption and promote growth. The observed linear relationship between the levels of short-chain fatty acids in plasma and feces suggests that FCS may facilitate catabolic activities in the gastrointestinal tract. The comparative study of different FCS derivatives on mouse growth and metabolic homeostasis regulation led to the conclusion that FCS exhibits greater biological activity with a higher degree of branching and larger molecular weight.

Holothuria leucospilota polysaccharides (HLP) ameliorate colitis rats via regulation of the metabolic profiling and TLR4/NLRP3 signaling pathways

Recently, the development of natural polysaccharides for ameliorating immunity and gut metabolism has attracted extensive attention. This study used Holothuria leucospilota polysaccharides (HLP) to explore the improvement mechanism in ulcerative colitis rats on perspectives of immunity and metabolism. The results showed that HLP increased goblet cells’ number and the content of tight junction proteins (zona occludens 1 and occludin) and improved intestinal barrier permeability. The levels of immune cytokines (IL‐4, IL‐6, IL‐10, IL‐18, TNF‐α, and IL‐1β) and the activity of oxidative stress‐related enzymes (superoxide dismutase, catalase, malondialdehyde, and glutathione peroxidase) were regulated. HLP regulated the related genes and proteins expression of immune cytokines, MAPK, and NLRP3 inflammasome. Furthermore, HLP treatment increased the concentration of short‐chain fatty acids (SCFAs) and regulated serum metabolic disorders by regulating amino acid metabolism, SCFA metabolism, and energy metabolism. These results provide a new perspective for developing HLP as a promising functional food for preventing and mitigating colitis.

UPLC-Q-TOF/MS-based metabonomics reveals mechanisms for Holothuria leucospilota polysaccharides (HLP)-regulated serum metabolic changes in diabetic rats

This study aimed to use metabolomic methods to explore how Holothuria leucospilota polysaccharides (HLP) improved metabolism disorders in the liver of Goto-Kakizaki (GK) rats with spontaneous type 2 diabetes. The results showed that HLP effectively improved the metabolic disorder. Based on KEGG functional analysis, five key biomarkers associated with bile acid metabolism were detected and screened (P < 0.05). The results of serum total bile acid levels and liver damage in diabetic rats further showed the regulatory effects of HLP on bile acid metabolism. The results of bile acid-related gene expression in the liver showed that HLP inhibited liver farnesoid X Receptor - small heterodimer partner (FXR-SHP) signalling and increased the expression of bile acid synthesis genes (P < 0.05). Our results explored the underlying mechanisms by which HLP accelerated cholesterol consumption to anti-hypercholesterolemia and anti-diabetic by inhibiting liver FXR-SHP signaling. HLP's effect on bile acid regulation provides insights into treating T2DM.

Fermentation of Betaphycus gelatinum Using Lactobacillus brevis: Growth of Probiotics, Total Polyphenol Content, Polyphenol Profile, and Antioxidant Capacity

Little information is available regarding polyphenol variations in the food processing of edible and medicinal red seaweed, Betaphycus gelatinum. This study investigated the effects of Lactobacillus brevis fermentation on total polyphenol content (TPC), polyphenol profile, and antioxidant activity in Betaphycus gelatinum pretreated by ultrasound-assisted mild acid hydrolysis for the first time. During 60 h of fermentation, the viable colony number significantly increased, pH significantly decreased, and reducing sugar content significantly decreased initially, then significantly increased. Free TPC significantly increased to 865.42 ± 29.29 μg GAE/g DW (163.09% increase) with increasing antioxidant activity, while bound TPC significantly decreased to 1004.90 ± 87.32 μg GAE/g DW (27.69% decrease) with decreasing antioxidant activity. Furthermore, 27 polyphenol compounds were identified by ultra-high-performance liquid chromatography with Xevo triple quadrupole mass spectrometry. In total, 19 and 23 free polyphenols and 24 and 20 bound polyphenols were identified before and after fermentation, respectively. Before fermentation, bound trans-cinnamic acid (56.75%), bound rosmarinic acid (26.62%), and free trans-cinnamic acid (3.85%) were the main components. After fermentation, free rosmarinic acid (43.57%), bound trans-cinnamic acid (15.19%), bound rosmarinic acid (13.33%), and free trans-cinnamic acid (5.99%) were the main components. These results provide information for the food processing of Betaphycus gelatinum.

Holothurian Wall Hydrolysate Ameliorates Cyclophosphamide-Induced Immunocompromised Mice via Regulating Immune Response and Improving Gut Microbiota

Some biologically active compounds isolated from sea cucumbers stimulate the body's immune response by activating immune cells. Immune function is closely related to the integrity intestinal barrier and balanced gut microbiota. However, it is unknown whether the daily administration of holothurian wall hydrolysate (HWH) ameliorated intestinal dysbiosis and barrier injury induced by immunodeficiency. This study aimed to investigate the immunomodulatory effect and the underlying mechanism of HWH in cyclophosphamide (CTX)-induced immunocompromised mice. BALB/c mice received CTX (80 mg/kg, intraperitoneally) once a day for 3 days to induce immunodeficiency, and then they received the oral administration of HWH (80 or 240 mg/kg) or levamisole hydrochloride (LH, 40 mg/kg, positive control), respectively, once a day for 7 days. We utilized 16S rRNA sequencing for microbial composition alterations, histopathological analysis for splenic and colonic morphology, Western blotting for expressions of tight junction proteins (TJs), and quantitative real-time (qRT)-PCR for measurements of pro-inflammatory cytokines. HWH attenuated the immune organ damage induced by CTX, increased the secretions of interleukin (IL)-6, IL-1β, and tumor necrosis factor (TNF)-α, and promoted the recovery of goblet cells and the production of TJs (claudin-1, occludin, and ZO-1) in the colon of the immunocompromised mice. Moreover, HWH promoted the growth of beneficial microorganisms such as Lactobacillus, Lachnospiraceae, Christensenellaceae, and Bifidobacterium, while it suppressed the populations of Ruminococcus, Staphylococcus, and Streptococcus. These results demonstrate that HWH elicits intestinal mucosal immunity, repairs the damage to intestinal mucosal integrity, and normalizes the imbalanced intestinal microbial profiles in immunocompromised mice. It may be helpful to identify the biological activities of HWH to support its potential use in new prebiotics, immunomodulatory agents, and medical additives for intestinal repair.

Polysaccharides from Holothuria leucospilota Relieve Loperamide-Induced Constipation Symptoms in Mice

A vital bioactive component of marine resources is Holothuria leucospilota polysaccharides (HLP). This study examined whether HLP could regulate intestinal flora to treat loperamide-induced constipation. Constipated mice showed signs of prolonged defecation (up by 60.79 min) and a reduced number of bowel movements and pellet water content (decreased by 12.375 and 11.77%, respectively). The results showed that HLP treatment reduced these symptoms, reversed the changes in related protein expression levels in the colon, and regulated the levels of active peptides associated with the gastrointestinal tract in constipated mice, which significantly improved water-electrolyte metabolism and enhanced gastrointestinal motility. Meanwhile, it was found that intestinal barrier damage was reduced and the inflammatory response was inhibited through histopathology and immunohistochemistry. As a means to further relieve constipation symptoms, treatment with low, medium, and high HLP concentrations increased the total short-chain fatty acid (SCFA) content in the intestine of constipated mice by 62.60 μg/g, 138.91 μg/g, and 126.51 μg/g, respectively. Moreover, an analysis of the intestinal flora's gene for 16S rRNA suggested that the intestinal microbiota was improved through HLP treatment, which is relevant to the motivation for the production of SCFAs. In summary, it was demonstrated that HLP reduced loperamide-induced constipation in mice.

Research on the Properties of Polysaccharides, Starch, Protein, Pectin, and Fibre in Food Processing

As food components, polysaccharides, starch, protein, pectin, and fibre are often used in the food industry due to their particular functional properties, as well as their efficient, safe, and green characteristics [...].

Polysaccharide from Patinopecten yessoensis Skirt Boosts Immune Response via Modulation of Gut Microbiota and Short-Chain Fatty Acids Metabolism in Mice

Polysaccharide from marine shellfish has various bioactivities. In this study, the effects of polysaccharide from Patinopecten yessoensis skirt (PS) on boosting immune response in mice were evaluated, and the potential mechanisms were explored. The results showed that PS administration effectively increased the serum IgG and IgM levels, implying that PS had immune response-boosting properties. Moreover, PS administration could modulate the composition of the gut microbiota, and significantly improve short-chain fatty acids (SCFAs) metabolism, especially butyrate metabolism. Of note, the expression of the Tlr2, Tlr7, MyD88, Tnfa, and Il1b genes in toll-like receptor (TLR) signaling pathway was significantly increased. In summary, PS could boost immune response by modulating the gut microbiota and SCFAs metabolism correlating with the activation of the TLR signaling pathway. Therefore, PS can be developed as a special ingredient for functional product.