Fucoidan alleviates dyslipidemia and modulates gut microbiota in high-fat diet-induced mice

Therapeutic Potential of Fucoidan in Alleviating Histamine-Induced Liver Injury: Insights from Mice Studies

Histamine, a bioactive component in certain foods such as Huangjiu has been associated with liver injury and disrupted intestinal balance. This study explored the potential therapeutic effects of fucoidan (FCD) in mitigating histamine-induced imbalances in mice. We found that FCD mitigated liver injury, reducing transaminases, oxidative stress, and inflammation. Histological improvements included decreased cell infiltration and necrosis. FCD restored tight junction proteins and suppressed inflammation-related genes. Western blot analysis revealed FCD's impact on TGF-β1, p-AKT, AKT, CYP2E1, Grp78, NLRP3, Cas-1, and GSDMD. Gut LPS levels decreased with FCD. Gut microbiota analysis showed FCD's modulation effect, reducing Firmicutes and increasing Bacteroides. FCD demonstrates potential in alleviating histamine-induced liver injury, regulating inflammation, and influencing gut microbiota. Further research exploring higher dosages and additional parameters is warranted.

Potential prebiotic and antibacterial activities of fucoidan from Laminaria japonica

Fucoidan from Laminaria japonica became sterilized with an autoclave and ultraviolet (UV) radiation. Potential prebiotic and antibacterial activities of sterilized fucoidans (SF) were the subject of investigation. Molecular weight, monosaccharide composition, FTIR, and NMR spectra of SF underwent evaluations to elucidate the relationship between the structure and activities of SF. The growth of Lactobacillus rhamnosus GG and L. acidophilus with autoclave sterilized fucoidan (ASF) and the growth of L. plantarum, L. gasseri, L. paracasei, and L. reuteri with UV sterilized fucoidan (USF) increased significantly. Also, fucoidan was vastly more effective than fructooligosaccharides in improving the growth of L. gasseri, L. reuteri, and L. paracasei. The growth of Escherichia coli and Bacillus cereus decreased at each SF concentration. ASF was more effective against E. coli, B. cereus, and Staphylococcus aureus than the USF efficiency. However, USF exhibited more inhibitory effects on the growth of Enterobacteriaceae compared to the ASF efficiency. When comparing the ASF and USF, autoclave caused a considerable decrease in molecular weight and uronic acid content, increased fucose and galactose, and made no significant changes in NMR spectra. Fucoidan effectively promoted probiotic bacterial growth and reduced pathogenic outbreaks in the medium. Therefore, it can occur as a new algal prebiotic and antibacterial agent.

Unraveling the bioactive interplay: seaweed polysaccharide, polyphenol and their gut modulation effect

Seaweed is rich in many unique bioactive compounds such as polyphenols and sulfated polysaccharides that are not found in terrestrial plant. The discovery of numerous biological activities from seaweed has made seaweed an attractive functional food source with the potential to be exploited for human health benefits. During food processing and digestion, cell wall polysaccharide and polyphenols commonly interact, and this may influence the nutritional properties of food. Interactions between cell wall polysaccharide and polyphenols in plant-based system has been extensively studied. However, similar interactions in seaweed have received little attention despite the vast disparity between the structural and chemical composition of plant and seaweed cell wall. This poses a challenge in extracting seaweed bioactive compounds with intact biological properties. This review aims to summarize the cell wall polysaccharide and polyphenols present in brown, red and green seaweed, and current knowledge on their potential interactions. Moreover, this review gives an overview of the gut modulation effect of seaweed polysaccharide and polyphenol.

Combination of Lycium barbarum L. and Laminaria japonica polysaccharides as a highly efficient prebiotic: Optimal screening and complementary regulation of gut probiotics and their metabolites

The combination of polysaccharides is an effective way to develop prebiotics with stable performance during processing and digestion for human wellness. However, there is little information on optimal screening and complementary regulation of compound polysaccharides. This study aimed to optimally select a combination of Lycium barbarum L. polysaccharide (LBP) and Laminaria japonica polysaccharide (LJP) as a highly efficient prebiotic to regulate the gut probiotics and their metabolites. Two LBPs characterized as rhamnogalacturonan I enriched pectins and two LJPs characterized as fucoidans were obtained by enzyme-assisted acid extraction at moderate and dramatic temperatures and combined in pairs to obtain 4 groups containing 4 proportional combinations. All combinations showed better prebiotic effects than individual LJP. The combination of LBP and LJP extracted at 50 °C at a ratio of 4:1 exhibited the strongest prebiotic effect. The optimal compound polysaccharide achieved superior effect and complementary function via LBP-targeted proliferation of Bifidobacterium, Lactobacillus, and Bacteroides and production of SCFAs and non-SCFA health-associated metabolites, LJP-targeted accumulation of butyrate-producing bacteria and corresponding metabolites, as well as synergistic effect of LJP and LBP at exact proportion. Our study provided theoretical and methodological guidance for optimal screening of compound polysaccharides as new prebiotics.

Effect of fucoidan on gut microbiota and its clinical efficacy in Helicobacter pylori eradication: A randomized controlled trial

OBJECTIVE

To assess the clinical efficacy of fucoidan-assisted standard quadruple therapy (SQT) in Helicobacter pylori (H. pylori) eradication and the improvement of gut microbiota.

METHODS

An open-label randomized controlled trial was conducted at the Affiliated Hospital of Qingdao University in Shandong Province, China. Ninety patients who tested positive for H. pylori were randomized to the standard quadruple therapy (SQT) group (SQ), SQT + fucoidan combination group (SF), and fucoidan + sequential SQT group (FS), respectively. Stool samples were collected for gut microbiota composition at baseline and after treatment.

RESULTS

After H. pylori eradication, the relative abundances of most conditional pathogens in the SQ decreased, while those of several beneficial bacteria increased or decreased (P < 0.05). In FS, the abundances of most beneficial bacteria increased gradually from baseline to week 12, while those of the conditional pathogens decreased (P < 0.05). The abundance of Bifidobacterium had a decreasing trend in SQ, but remained unchanged in SF and increased in FS (P < 0.05). The abundances of most beneficial bacteria were significantly higher in FS than in SQ and SF (P < 0.05). Addition of fucoidan enhanced symptom improvement during H. pylori eradication compared with SQT alone.

CONCLUSIONS

Fucoidan considerably improved gut dysbiosis during SQT for H. pylori eradication. Gut microbiota can be maintained by the addition of fucoidan before eradication therapy with SQT rather than by concomitant addition with therapy. Fucoidan-assisted SQT could relieve gastrointestinal symptoms during H. pylori eradication.

Dietary fiber modulates gut microbiome and metabolome in a host sex-specific manner in a murine model of aging

Emerging evidence reveals the fundamental role of the gut microbiome in human health. Among various factors regulating our gut microbiome, diet is one of the most indispensable and prominent one. Inulin is one of the most widely-studied dietary fiber for its beneficial prebiotic effects by positively modulating the gut microbiome and microbial metabolites. Recent research underscores sexual dimorphism and sex-specific disparities in microbiome and also diet-microbiome interactions. However, whether and how the prebiotic effects of dietary fiber differ among sexes remain underexplored. To this end, we herein examine sex-specific differences in the prebiotic effects of inulin on gut microbiome and metabolome in a humanized murine model of aging i.e., aged mice carrying human fecal microbiota. The findings demonstrate that inulin exerts prebiotic effects, but in a sex-dependent manner. Overall, inulin increases the proportion of Bacteroides, Blautia, and glycine, while decreasing Eggerthella, Lactococcus, Streptococcus, trimethylamine, 3-hydroxyisobutyrate, leucine and methionine in both sexes. However, we note sex-specific effects of inulin including suppression of f_Enteroccaceae:_, Odoribacter, bile acids, malonate, thymine, valine, acetoin, and ethanol while promotion of Dubosiella, pyruvate, and glycine in males. Whereas, suppression of Faecalibaculum, Lachnoclostridium, Schaedlerella, phenylalanine and enhancement of Parasutterella, Phocaeicola, f_Lachnospiraceae;_, Barnesiella, Butyricimonas, glycine, propionate, acetate and glutamate are observed in females. Altogether, the study reveals that prebiotic mechanisms of dietary fiber vary in a sex-dependent manner, underscoring the importance of including both sexes in preclinical/clinical studies to comprehend the mechanisms and functional aspects of dietary interventions for effective extrapolation and translation in precision nutrition milieus.

Beneficial effects of seaweed-derived components on metabolic syndrome via gut microbiota modulation

Metabolic syndrome comprises a group of conditions that collectively increase the risk of abdominal obesity, diabetes, atherosclerosis, cardiovascular diseases, and cancer. Gut microbiota is involved in the pathogenesis of metabolic syndrome, and microbial diversity and function are strongly affected by diet. In recent years, epidemiological evidence has shown that the dietary intake of seaweed can prevent metabolic syndrome via gut microbiota modulation. In this review, we summarize the current in vivo studies that have reported the prevention and treatment of metabolic syndrome via seaweed-derived components by regulating the gut microbiota and the production of short-chain fatty acids. Among the surveyed related articles, animal studies revealed that these bioactive components mainly modulate the gut microbiota by reversing the Firmicutes/Bacteroidetes ratio, increasing the relative abundance of beneficial bacteria, such as Bacteroides, Akkermansia, Lactobacillus, or decreasing the abundance of harmful bacteria, such as Lachnospiraceae, Desulfovibrio, Lachnoclostridium. The regulated microbiota is thought to affect host health by improving gut barrier functions, reducing LPS-induced inflammation or oxidative stress, and increasing bile acid production. Furthermore, these compounds increase the production of short-chain fatty acids and influence glucose and lipid metabolism. Thus, the interaction between the gut microbiota and seaweed-derived bioactive components plays a critical regulatory role in human health, and these compounds have the potential to be used for drug development. However, further animal studies and human clinical trials are required to confirm the functional roles and mechanisms of these components in balancing the gut microbiota and managing host health.

Analysis of gut microbiotal diversity in healthy young adults in Sunan County, Gansu Province, China

Objective

To examine gut microbiotal diversity in the Han Chinese and Yugur populations of Sunan County, Gansu Province, living in the same environmental conditions, and to analyze possible causes of differences in diversity.

Methods

We selected 28 people, ages 18-45 years old, all of whom were third-generation pure Yugur or Han Chinese from Sunan County. Fresh fecal samples were collected, and total bacterial deoxyribonucleic acid (DNA) was extracted. We performed 16S ribosomal ribonucleic acid (16S rRNA) high-throughput sequencing (HTS) and bioinformatics to study the relationships among between gut microbiota structure, genetics, and dietary habits in Yugur and Han Chinese subjects.

Results

We found 350 differential operational taxonomic units (OTUs) in Han Chinese and Yugur gut microbiota, proving that gut microbiota differed between the two populations. That were less abundant among Yugurs than Han Chinese were Prevotella_9 and Alloprevotella. That were more abundant among Yugurs than Han Chinese were Anaerostipes and Christensenellaceae_R-7_group. And they were significantly associated with a high-calorie diet In addition. we found differences in predicted gut microbiota structural functions (The main functions were metabolic and genetic information) between the two populations.

Conclusion

Yugur subjects demonstrated differences in gut microbiotal structure from Han Chinese subjects, and this difference influenced by dietary and may be influenced by genetic influences. This finding will provide a fundamental basis for further study of the relationships among gut microbiota, dietary factors, and disease in Sunan County.

The intervention effects of konjac glucomannan with different molecular weights on high-fat and high-fructose diet-fed obese mice based on the regulation of gut microbiota

Konjac is a high-quality dietary fiber rich in β-glucomannan, which has been reported to possess anti-obesity effects. To explore the effective components and the structure-activity relationships of konjac glucomannan (KGM), three different molecular weight components (KGM-1 (90 kDa), KGM-2 (5 kDa), KGM-3 (1 kDa)) were obtained, and systematical comparisons of their effects on high-fat and high-fructose diet (HFFD)-induced obese mice were investigated in the present study. Our results indicated that KGM-1, with its larger molecular weight, reduced mouse body weight and improved their insulin resistance status. KGM-1 markedly inhibited lipid accumulation in mouse livers induced by HFFD by downregulating Pparg expression and upregulating Hsl and Cpt1 expressions. Further investigation revealed that dietary supplementation with konjac glucomannan at different molecular weights caused β-diversity changes in gut microbes. The potential weight loss effect of KGM-1 maybe attributed to the abundance of changes in Coprobacter, Streptococcus, Clostridium IV, and Parasutterella. The results provide a scientific basis for the in-depth development and utilization of konjac resources.

Intestinal Microbiota in Children with Anemia in Southern Peru through Next-Generation Sequencing Technology

Knowledge of the sequencing of the 16S rRNA gene constitutes a true revolution in understanding the composition of the intestinal microbiota and its implication in health states. This study details microbial composition through next-generation sequencing (NGS) technology in children with anemia. Anemia is the most frequent hematological disorder that affects human beings. In Peru, it is one of the conditions that presents the most significant concern due to the adverse effects that cause it, such as delayed growth and psychomotor development, in addition to a deficiency in cognitive development.

Metagenomic Analysis of Gut Microbiome in Gout Patients with Different Chinese Traditional Medicine Treatments

Introduction

Changes in eating habits have made gout a metabolic disease of increasing concern. Previous studies have indicated that there are significant differences in species composition and abundance of gut microbiome in gout patients compared with average. Considering that traditional Chinese medicine has a momentous effect in treating gout, the research study aimed to explore the differences of genomic and metabolomics of gut microbiome before and after traditional Chinese medicine treatment in patients with gout.

Method

30 patients with gout and 29 matched controls were recruited of which 16 patients took H treatment and 14 patients took T treatment. Stools were collected twice for patients before and after treatment and only once for controls. A total of 89 samples were annotated with metagenomic species and functions, and the enrichment analysis of differential genes and KO pathway was carried out.

Result

The results showed a decrease in the diversity of gut microbiome in gout patients and the gene abundance and metabolomics had great differences among study groups. The number of bacterial genera also had significant differences among treatment groups. Moreover, among different groups, the regulation of different species was variously correlated. The correlation between species and clinical laboratory indicators in the rising group was stronger than that in the decreasing group and the upregulation of some strain was related to the content of urea nitrogen.

Conclusion

After the traditional Chinese medicine treatment, the glutathione pathway was significantly enriched and some pathogenic bacteria were significantly inhibited. The study suggests that traditional Chinese medicine treatment may exert its therapeutic effect by inhibiting relevant pathways.

High Molecular Weight Fucoidan Restores Intestinal Integrity by Regulating Inflammation and Tight Junction Loss Induced by Methylglyoxal-Derived Hydroimidazolone-1

Fucoidan from brown seaweeds has several biological effects, including preserving intestinal integrity. To investigate the intestinal protective properties of high molecular weight fucoidan (HMWF) from Undaria pinnatifida on intestinal integrity dysfunction caused by methylglyoxal-derived hydroimidazolone-1 (MG-H1), one of the dietary advanced-glycation end products (dAGEs) in the human-colon carcinoma-cell line (Caco-2) cells and ICR mice. According to research, dAGEs may damage the intestinal barrier by increasing gut permeability. The findings of the study showed that HMWF + MG-H1 treatment reduced by 16.8% the amount of reactive oxygen species generated by MG-H1 treatment alone. Furthermore, HMWF + MGH-1 treatment reduced MG-H1-induced monolayer integrity disruption, as measured by alterations in transepithelial electrical resistance (135% vs. 75.5%) and fluorescein isothiocyanate incorporation (1.40 × 10^-6 cm/s vs. 3.80 cm/s). HMWF treatment prevented the MG-H1-induced expression of tight junction markers, including zonula occludens-1, occludin, and claudin-1 in Caco-2 cells and mouse colon tissues at the mRNA and protein level. Also, in Caco-2 and MG-H1-treated mice, HMWF plays an important role in preventing receptor for AGEs (RAGE)-mediated intestinal damage. In addition, HMWF inhibited the nuclear factor kappa B activation and its target genes leading to intestinal inflammation. These findings suggest that HMWF with price competitiveness could play an important role in preventing AGEs-induced intestinal barrier dysfunction.

Research Progress on the Protective Effect of Brown Algae-Derived Polysaccharides on Metabolic Diseases and Intestinal Barrier Injury

In the human body, the intestine is the largest digestive and immune organ, where nutrients are digested and absorbed, and this organ plays a key role in host immunity. In recent years, intestinal health issues have gained attention and many studies have shown that oxidative stress, inflammation, intestinal barrier damage, and an imbalance of intestinal microbiota may cause a range of intestinal diseases, as well as other problems. Brown algae polysaccharides, mainly including alginate, fucoidan, and laminaran, are food-derived natural products that have received wide attention from scholars owing to their good biological activity and low toxic side effects. It has been found that brown algae polysaccharides can repair intestinal physical, chemical, immune and biological barrier damage. Principally, this review describes the protective effects and mechanisms of brown algae-derived polysaccharides on intestinal health, as indicated by the ability of polysaccharides to maintain intestinal barrier integrity, inhibit lipid peroxidation-associated damage, and suppress inflammatory cytokines. Furthermore, our review aims to provide new ideas on the prevention and treatment of intestinal diseases and act as a reference for the development of fucoidan as a functional product for intestinal protection.

Coix Seed-Based Milk Fermented With Limosilactobacillus reuteri Improves Lipid Metabolism and Gut Microbiota in Mice Fed With a High-Fat Diet

The aim of this study was to investigate the effects of coix seed-based milk (CSM) fermented with Limosilactobacillus reuteri (L. reuteri) on dyslipidemia and the composition of the intestinal microbiota in high fat diet (HFD)-fed mice. Changes in the body weight, serum lipid levels, activities of hepatic oxidative stress factors, expression of lipid-related genes, and composition of the intestinal microbiota of HFD-fed mice after supplementation with CSM were determined. The results showed that intake of CSM reduced the body weight gain as well as serum total cholesterol (TC), triglyceride (TG), and low-density lipoprotein cholesterol (LDL-C) levels, and increased the high-density lipoprotein cholesterol (HDL-C) levels in the mice. Meanwhile, supplementation with CSM could relieve liver oxidative stress, down-regulate the expression of genes related to lipid synthesis, and prevent liver fat accumulation in mice fed with HFD. The 16S rRNA sequencing of the intestinal microbiota showed that CSM regulated the gut microbiota community structure at different taxonomic levels, and reversed gut dysbiosis induced by HFD. The relative abundance of Muribaculaceae, Lachnospiraceae, Dubosiella and Akkermansia which are negatively correlated with blood lipid levels were significantly increased by the intervention of CSM, while the relative abundance of Desulfovibrionaceae, Ruminococca-ceae_UCG-014, Psychrobacter, and Staphylococcus which have positive correlation with blood lipid levels were significantly decreased. These results indicated that CSM might serve as a novel and promising dietary supplement for ameliorating hyperlipidemia and intestinal microbiota disorders caused by HFDs.

Fucoidan Is Not Completely Dependent on Degradation to Fucose to Relieve Ulcerative Colitis

Recently, fucoidan has been proposed for use as a potential anti-inflammatory drug. The purpose of this study was to investigate the mechanism of fucoidan in the treatment of ulcerative colitis. We compared the anti-inflammatory effects of fucoidan and fucose induced by dextran sulfate sodium, and the effects of fucoidan and fucose on the gut microbiota of mice. Our results showed that low-dose fucoidan significantly improved weight loss, disease activity index scores, colonic shortening, colonic histopathological damage, intestinal fatty acid binding protein 2 levels, and the expression of Occludin, Claudin-4, and Claudin-1. However, both high-dose fucoidan and fucose did not perform as well as low-dose fucoidan as described above. In addition, 16S rDNA high-throughput sequencing showed that low-dose fucoidan significantly increased the abundance of Alloprevotella, and fucose significantly increased Ruminococcaceae, but neither significantly reversed the imbalance in the gut microbiota. Therefore, we inferred that the regulation of fucoidan on colitis has a unique and complex mechanism, and it is not completely dependent on degradation to fucose to relieve ulcerative colitis, nor is it achieved only by regulating the gut microbiota. The mechanism by which fucoidan treats colitis may also include reducing inflammatory cell infiltration and increasing intestinal barrier function.

Antidiabetic Effects of Bifidobacterium longum subsp. longum BL21 through Regulating Gut Microbiota Structure in Type 2 Diabetic Mice

Bifidobacterium longum subsp. longum BL21 (BL21) possess hypoglycemic activity, but its anti-diabetic mechanism has rarely been illustrated. In the present work, the effect of BL21 on type 2 diabetes mellitus...

Fucoidan Protects Against High-Fat Diet-Induced Obesity and Modulates Gut Microbiota in Institute of Cancer Research Mice

Fucoidan possesses various biological activities, such as anticoagulant, immunomodulatory, anti-inflammatory, potential antioxidant, and others. In this study, we investigated the effect of fucoidan on high-fat diet-induced obesity, inflammation, and gut microbiota in Institute of Cancer Research mice. Mice were gavaged with 50 mg/(kg·d) (Fuc0.5 group) or 250 mg/(kg·d) (Fuc2.5 group) of fucoidan for 5 weeks. Fucoidan alleviated obesity and tissue damage by decreasing body weight and body mass index, decreasing body weight gain, improved organ index, liver steatosis, and improved the structure of the small intestine. In addition, fucoidan decreased total cholesterol, triglyceride, and low-density lipoprotein cholesterol, and increased high-density lipoprotein cholesterol. Moreover, fucoidan reduced serum lipopolysaccharide concentrations, tumor necrosis factor-α, and total bile acid. Furthermore, fucoidan improved the structure of gut microbiota and significantly increased the abundance (Shannon diversity index, evenness, and Faecalibacterium prausnitzii) determined by denaturing gradient gel electrophoresis and quantitative PCR. In conclusion, our study provides a scientific basis for fucoidan as a functional food for modulating the gut microbiota and protecting against obesity.

Fucose Ameliorates Tritrichomonas sp.-Associated Illness in Antibiotic-Treated Muc2-/- Mice

The mucus layer in the intestine plays a critical role in regulation of host–microbe interactions and maintaining homeostasis. Disruptions of the mucus layer due to genetic, environmental, or immune factors may lead to inflammatory bowel diseases (IBD). IBD frequently are accompanied with infections, and therefore are treated with antibiotics. Hence, it is important to evaluate risks of antibiotic treatment in individuals with vulnerable gut barrier and chronic inflammation. Mice with a knockout of the Muc2 gene, encoding the main glycoprotein component of the mucus, demonstrate a close contact of the microbes with the gut epithelium which leads to chronic inflammation resembling IBD. Here we demonstrate that the Muc2^−/− mice harboring a gut protozoan infection Tritrichomonas sp. are susceptible to an antibiotic-induced depletion of the bacterial microbiota. Suppression of the protozoan infection with efficient metronidazole dosage or L-fucose administration resulted in amelioration of an illness observed in antibiotic-treated Muc2^−/− mice. Fucose is a monosaccharide presented abundantly in gut glycoproteins, including Mucin2, and is known to be involved in host–microbe interactions, in particular in microbe adhesion. We suppose that further investigation of the role of fucose in protozoan adhesion to host cells may be of great value.

Lactobacillus casei LC89 exerts antidiabetic effects through regulating hepatic glucagon response and gut microbiota in type 2 diabetic mice

Previous study suggests that Lactobacillus casei exhibits antihyperglycemic activity, however, the molecular mechanism of this has yet to be elucidated. Here, the anti-diabetic effects and underlying mechanisms of Lactobacillus casei LC89 are investigated in type 2 diabetes mellitus (T2DM) mice, which was induced by a high-fat diet (HFD) with streptozotocin (100 mg per kg BW). The results show that LC89 at a dose of 109 CFU day-1 decreases fasting blood glucose (FBG) and insulin levels by 35.12% and 28.37%, respectively, compared to the diabetes control (DC) group. Moreover, LC89 treatment improved the insulin resistance index (HOMA-IR), serum lipid profiles and inflammation cytokines. The real-time polymerase chain reaction indicated that LC89 markedly downregulates the mRNA expression of hepatic glucagon (GCG), glucagon receptor (GCGR), phosphoenolpyruvate carboxykinase (PEPCK) and glucose-6-phosphatase (G6Pase). Meanwhile, LC89 significantly decreases the abundance of Odoribacter, but increases the Alloprevotella, Bacteroides, Parabacteroides and Ruminococcus content. Therefore, LC89 plays a positive role in alleviating T2DM by regulating gut microbiota and glucagon signal pathway-related genes, and it may be a beneficial dietary supplement to regulate glucose metabolism in T2DM.

Health effects of dietary sulfated polysaccharides from seafoods and their interaction with gut microbiota

Various dietary sulfated polysaccharides (SPs) have been isolated from seafoods, including edible seaweeds and marine animals, and their health effects such as antiobesity and anti-inflammatory activities have attracted remarkable interest. Sulfate groups have been shown to play important roles in the bioactivities of these polysaccharides. Recent in vitro and in vivo studies have suggested that the biological effects of dietary SPs are associated with the modulation of the gut microbiota. Dietary SPs could regulate the gut microbiota structure and, accordingly, affect the production of bioactive microbial metabolites. Because of their differential chemical structures, dietary SPs may specifically affect the growth of certain gut microbiota and associated metabolite production, which may contribute to variable health effects. This review summarizes the latest findings on the types and structural characteristics of SPs, the effects of different processing techniques on the structural characteristics and health effects of SPs, and the current understanding of the role of gut microbiota in the health effects of SPs. These findings might help in better understanding the mechanism of the health effects of SPs and provide a scientific basis for their application as functional food.

Polysaccharides and glycosides from Aralia echinocaulis protect rats from arthritis by modulating the gut microbiota composition

ETHNOPHARMACOLOGICAL RELEVANCE

Aralia echinocaulis has been used in traditional medicines in China and exhibits good effects on rheumatoid arthritis (RA).

AIM OF THE STUDY

Aralia echinocaulis is rich in polysaccharides and glycosides. This study aims to explore the effect of total polysaccharide and glycoside (TPG) from A. echinocaulis on an RA rat model and the role of alterations in gut microbes mediated by TPG.

MATERIALS AND METHODS

In this study, a collagen-induced arthritis (CIA) rat model was constructed and used to evaluate the effects of TPG in vivo. 16S rRNA sequencing was used to detect the changes in the gut microbiota. A cooccurrence analysis was conducted by calculating Spearman's rank correlations. Microbial functions were predicted using PICRUSt with the KEGG and COG databases.

RESULTS

The results showed that TPG from A. echinocaulis could inhibit arthritis, reduce serum IL-1β and TNF-α levels, and improve synovial pathology in the RA rat model but failed to produce the same results in a pseudoaseptic RA rat model. 16S rRNA sequencing verified that TPG could modulate the gut microbiota community structure of RA rats. The cooccurrence analysis found 19 out of the 50 most abundant genera in a cooccurrence network, of which 16 showed a positive correlation and 3 showed a negative correlation. KEGG pathway and COG function analyses found that TPG-induced alterations in the gut microbiota might be correlated with the circulatory system, excretory system, metabolic diseases, signaling molecules and interactions, coenzyme transport and metabolism, and nucleotide transport and metabolism.

CONCLUSIONS

TPG from A. echinocaulis had significant effects on the RA rat model, which are related to the modulation of the gut microbiota. These results are useful to better understanding the mechanisms of TPG in RA.

The lignan-rich fraction from Sambucus Williamsii Hance ameliorates dyslipidemia and insulin resistance and modulates gut microbiota composition in ovariectomized rats

Menopausal women are susceptible to have high risk of cardiovascular diseases, type II diabetes and osteoporosis due to the metabolic disorder caused by estrogen deficiency. Accumulating evidence supports that gut microbiota is a key regulator of metabolic diseases. Our previous metabolomics study interestingly demonstrated that the anti-osteoporotic effects of lignan-rich fraction (SWCA) from Sambucus wialliamsii Hance were related to the restoration of a series of lipid and glucose metabolites. This study aims to investigate how SWCA modulates lipid and glucose metabolism and the underlying mechanism. Our results show that oral administration of SWCA (140 mg/kg and 280 mg/kg) for 10 weeks alleviated dyslipidemia, improved liver functions, prevented glucose tolerance and insulin actions, attenuated system inflammation and improved intestinal barrier in OVX rats. It also induced a high abundance of Actinobacteria, and restored microbial composition. We are the first to report the protective effects of the lignan-rich fraction from S. williamsii on dyslipidemia and insulin resistance. Our findings provide strong evidence for the application of this lignan-rich fraction to treat menopausal lipid disorder and insulin resistance-related diseases.

Taxonomic Composition and Diversity of the Gut Microbiota in Relation to Habitual Dietary Intake in Korean Adults

We investigated associations of habitual dietary intake with the taxonomic composition and diversity of the human gut microbiota in 222 Koreans aged 18-58 years in a cross-sectional study. Gut microbiota data were obtained by 16S rRNA gene sequencing on DNA extracted from fecal samples. The habitual diet for the previous year was assessed by a food frequency questionnaire. After multivariable adjustment, intake of several food groups including vegetables, fermented legumes, legumes, dairy products, processed meat, and non-alcoholic beverages were associated with major phyla of the gut microbiota. A dietary pattern related to higher α-diversity (HiαDP) derived by reduced rank regression was characterized by higher intakes of fermented legumes, vegetables, seaweeds, and nuts/seeds and lower intakes of non-alcoholic beverages. The HiαDP was positively associated with several genera of Firmicutes such as Lactobacillus, Ruminococcus, and Eubacterium (all p < 0.05). Among enterotypes identified by principal coordinate analysis based on the β-diversity, the Ruminococcus enterotype had higher HiαDP scores and was strongly positively associated with intakes of vegetables, seaweeds, and nuts/seeds, compared to the two other enterotypes. We conclude that a plant- and fermented food-based diet was positively associated with some genera of Firmicutes (e.g., Lactobacillus, Ruminococcus, and Eubacterium) reflecting better gut microbial health.

Sulfated polysaccharides from Undaria pinnatifida improved high fat diet-induced metabolic syndrome, gut microbiota dysbiosis and inflammation in BALB/c mice

Undaria pinnatifida was shown to reduce serum lipids and fat accumulation and produce beneficial effect on type 2 diabetes, but its effect on intestinal micro-ecology remains unclear. This study showed that sulfated polysaccharides from U. pinnatifida (UPSP) reduced weight gain, fat accumulation and metabolic disorders in mice fed with high fat diet (HFD). UPSP not only alleviated HFD-induced microbiota dysbiosis indicated as increased abundances of some Bacteroidales members that had positive correlations with the improvement of physiological indexes, but also maintained gut barrier integrity and reduced metabolic endotoxemia. A dose-effect relationship was observed between the dose of UPSP and its effect on some physiological indexes, gut microbiota community and nutrient utilization. The in vitro result showed that the use of Bacteroides species within Bacteroidales on UPSP was species-dependent, and the dose of UPSP affected the growth properties of some Bacteroides species. It implied that UPSP can be considered as prebiotic agent to prevent gut dysbiosis and obesity-related diseases in obese individuals.

Probiotic-fermented black tartary buckwheat alleviates hyperlipidemia and gut microbiota dysbiosis in rats fed with a high-fat diet

Natural plants fermented with probiotics exert beneficial effects on hyperlipidemia and gut microbiota disorders. This study aimed to investigate the hypolipidemic activity of fermented black tartary buckwheat (FBTB) in rats with hyperlipidemia induced by a high-fat diet (HFD) in association with the regulation of gut microbiota. Probiotic fermentation by Bacillus sp. DU-106 obviously increased the contents of tyrosine, lysine, total flavonoids, total polyphenols, quercetin, and kaempferol in black tartary buckwheat (BTB) and significantly decreased the rutin content. FBTB treatment for 8 weeks significantly decreased the levels of serum total cholesterol, triglycerides, and low-density lipoprotein cholesterol in HFD-induced hyperlipidemic rats. Western blot analysis further confirmed that the protein expression levels of FXR, SREBP1, and PPARα were altered after FBTB treatment. Moreover, FBTB intervention altered the gut microbiota of HFD-fed rats by increasing the relative abundances of Lactobacillus, Faecalibaculum, and Allobaculum and decreasing the relative abundance of Romboutsia. The relative abundance of Allobaculum was positively correlated with the levels of tyrosine, total flavonoids, total polyphenols, quercetin and kaempferol and negatively correlated with that of rutin. These results suggested that FBTB could alleviate hyperlipidemia and gut microbiota dysbiosis in HFD-fed rats.

Supplementation of Bacillus sp. DU-106 reduces hypercholesterolemia and ameliorates gut dysbiosis in high-fat diet rats

Gut microbiota modulation by a probiotic is a novel therapy for hypercholesterolemia mitigation. This study initially investigated the potential hypocholesterolemic effect of Bacillus sp. DU-106 in hypercholesterolemic rats and explored its potential relation with gut microbiota. Sprague-Dawley rats received a high-fat diet, or a high-fat diet supplemented with 7.5 × 10⁹ and 1.5 × 10¹⁰ CFU/kg bw/day Bacillus sp. DU-106 (low-dose and high-dose groups). At the end of 9 weeks, Bacillus sp. DU-106 treatment significantly decreased the body weight, liver index, and total cholesterol. 16S rRNA sequencing showed that Bacillus sp. DU-106 intervention significantly increased bacterial richness and particularly increased the genus abundance of Turicibacter, Acinetobacter, Brevundimonas, and Bacillus and significantly decreased the abundance of Ralstonia. Metabolomic data further indicated that the supplementation of Bacillus sp. DU-106 remarkably changed the gut metabolic profiles of hypercholesterolemic rats and, in particular, elevated the metabolites of indole-3-acetate, methylsuccinic acid, creatine, glutamic acid, threonine, lysine, ascorbic acid, and pyridoxamine. Spearman's correlation analysis showed the close relation between the different genera and metabolites. In conclusion, Bacillus sp. DU-106 supplement ameliorated high-fat diet-induced hypercholesterolemia and showed potential probiotic benefits for the intestine. KEY POINTS: • A novel potential probiotic Bacillus sp. DU-106 ameliorated hypercholesterolemia in rats. • Bacillus sp. DU-106 supplement regulated gut microbiome structure and richness. • Bacillus sp. DU-106 supplement changed metabolic profiles in high-fat diet rats. • Significant correlations were observed between differential genera and metabolites.

Screening of Microbes Associated With Swine Growth and Fat Deposition Traits Across the Intestinal Tract

Pigs, as one of the most common livestock species worldwide, are expected to have a fast growth rate and lower subcutaneous fatness but higher intramuscular fat ("marbling meat"). Nowadays, it is believed that not only host genetics but also its gut microbiomes can modulate farm animal phenotypes, however, many of the mechanisms remain elusive. We measured the body weight (BW), average daily gain (ADG), backfat thickness (BFT), and intramuscular fatness (IMF) of 91 Enshi pigs at 260 days of age, then genotyped each one individually using a 50K single nucleotide polymorphism array and performed 16S ribosomal RNA gene sequencing on 455 microbial samples from the jejunum, ileum, cecum, colon, and rectum. The microbial diversity showed notable spatial variation across the entire intestinal tract, with the cecum and colon having the highest α-diversity. The cecal and colonic microbiotas made greater contributions to BW and ADG and accounted for 22-37% of the phenotypic variance. The jejunal and cecal microbiotas contributed more (13-31%) to the BFT and IMF than the other segments. Finally, from cecum, colon, and jejunum, we identified eight microbial taxa that were significantly correlated with the target traits. The genera Alloprevotella and Ruminococcaceae UCG-005 were highly positively correlated with BW and ADG. The genera Prevotellaceae UCG-001 and Alistipes in the cecum and Clostridium sensu stricto 1 in the jejunum were highly positively correlated with BFT and IMF. The genera Stenotrophomonas, Sphaerochaeta, and Desulfovibrio were negatively associated with the mentioned traits. These findings could aid in developing strategies for manipulating the gut microbiota to alter production performance in pigs.

The Pros and Cons of Using Algal Polysaccharides as Prebiotics

Macroalgae stand out for their high content of dietary fiber (30–75%) that include soluble, sulfated (fucoidan, agaran, carrageenan, and ulvan) and non-sulfated (laminaran and alginate) polysaccharides. Many studies indicate that these compounds exert varied biological activities and health-promoting effects and for this reason, there is a growing interest for using them in food products. The aim of this review was to critically evaluate prebiotic properties of algal polysaccharides, i.e., their ability to exert biological activities by modulating the composition and/or diversity of gut microbiota (GM). Pre-clinical studies show that the non-sulfated alginate and laminaran are well-fermented by GM, promoting the formation of short chain fatty acids (SCFAs) including butyrate, and preventing that of harmful putrefactive compounds (NH₃, phenol, p-cresol, indole and H₂S). Alginate increases Bacteroides, Bifidobacterium, and Lactobacillus species while laminaran mostly stimulates Bacteroides sp. Results with sulfated polysaccharides are more questionable. Agarans are poorly fermentable but agarose-oligosaccharides exhibit an interesting prebiotic potential, increasing butyrate-producing bacteria and SCFAs. Though carrageenan-oligosaccharides are also fermented, their use is currently limited due to safety concerns. Regarding fucoidan, only one study reports SCFAs production, suggesting that it is poorly fermented. Its effect on GM does not indicate a clear pattern, making difficult to conclude whether it is beneficial or not. Notably, fucoidan impact on H₂S production has not been evaluated, though some studies report it increases sulfate-reducing bacteria. Ulvan is badly fermented by GM and some studies show that part of its sulfate is dissimilated to H₂S, which could affect colonic mitochondrial function. Accordingly, these results support the use of laminaran, alginate and agaro-oligosaccharides as prebiotics while more studies are necessary regarding that of fucoidan, carrageenan and ulvan. However, the realization of clinical trials is necessary to confirm such prebiotic properties in humans.

Ursolic acid alleviates hypercholesterolemia and modulates the gut microbiota in hamsters

Ursolic acid (UA) is a triterpenoid acid widely abundant in fruits and vegetables such as apple, blueberry and cranberry. The present study was carried out to investigate the effect of UA supplementation in diet on blood cholesterol, intestinal cholesterol absorption and gut microbiota in hypercholesterolemic hamsters. A total of thirty-two hamsters were randomly assigned to four groups and given a non-cholesterol diet (NCD), a high-cholesterol diet containing 0.1% cholesterol (HCD), an HCD diet containing 0.2% UA (UAL), or an HCD diet containing 0.4% UA (UAH) for 6 weeks. Results showed that UA supplementation reduced plasma cholesterol by 15-16% and inhibited intestinal cholesterol absorption by 2.6-9.2%. The in vitro micellar cholesterol solubility experiment clearly demonstrated that UA could displace 40% cholesterol from micelles. In addition, UA decreased the ratio of Firmicutes to Bacteroidetes, whereas it enhanced the growth of short chain fatty acid (SCFA)-producing bacteria in the intestine. In conclusion, UA possessed a cholesterol-lowering activity and could favorably modulate the gut microbiota.

Polysaccharides isolated from Cordyceps Sinensis contribute to the progression of NASH by modifying the gut microbiota in mice fed a high-fat diet

Various dietary fibers are considered to prevent obesity by modulating the gut microbiota. Cordyceps sinensis polysaccharide (CSP) is a soluble dietary fiber known to have protective effects against obesity and related diseases, but whether these effects induce any side effects remains unknown. The function and safety of CSP were tested in high-fat diet (HFD)-feding C57BL/6J mice. The results revealed that even though CSP supplementation could prevent an increase in body weight, it aggravated liver fibrosis and steatosis as evidenced by increased inflammation, lipid metabolism markers, insulin resistance (IR) and alanine aminotransferase (ALT) in HFD-induced obesity. 16S rDNA gene sequencing was used to analyze the gut microbiota composition, and the relative abundance of the Actinobacteria phylum, including the Olsenella genus, was significantly higher in CSP-treated mice than in HFD-fed mice. CSP supplementation may increase the proportion of Actinobacteria, which can degrade CSP. The high level of Actinobacteria aggravated the disorder of the intestinal flora and contributed to the progression from obesity to nonalcoholic steatohepatitis (NASH) and related diseases.

Supplementation with Sea Vegetables Palmaria mollis and Undaria pinnatifida Exerts Metabolic Benefits in Diet-Induced Obesity in Mice

BACKGROUND

Sea vegetables are rich sources of nutrients as well as bioactive components that are linked to metabolic health improvement. Algal polysaccharides improve satiety and modulate gut microbiota while proteins, peptides, and phenolic fractions exert anti-inflammatory, antioxidant, and antidiabetic effects.

OBJECTIVE

We tested the hypothesis that dietary supplementation with either Pacific dulse (Palmaria mollis, red algae) or wakame (Undaria pinnatifida, brown algae) could remediate metabolic complications in high-fat diet-induced obesity.

METHODS

Individually caged C57BL/6J mice (n = 8) were fed ad libitum with either a low-fat diet (LFD), 10% kcal fat; high-fat diet (HFD), 60% kcal fat; HFD + 5% (wt:wt) dulse (HFD + D); or HFD + 5% (wt:wt) wakame (HFD + W) for 8 weeks. Food intake and weight gain were monitored weekly. Glucose tolerance, hepatic lipids, fecal lipids, and plasma markers were evaluated, and the gut microbiome composition was assessed.

RESULTS

Despite the tendency of higher food and caloric intake than the HFD (P = 0.04) group, the HFD + D group mice did not exhibit higher body weight, indicating lower food and caloric efficiency (P < 0.001). Sea vegetable supplementation reduced plasma monocyte chemotactic protein (MCP-1) (P < 0.001) and increased fecal lipid excretion (P < 0.001). Gut microbiome analysis showed that the HFD + D group had higher alpha-diversity than the HFD or LFD group, whereas beta-diversity analyses indicated that sea vegetable-supplemented HFD-fed mice (HFD + D and HFD + W groups) developed microbiome compositions more similar to those of the LFD-fed mice than those of the HFD-fed mice.

CONCLUSION

Sea vegetable supplementation showed protective effects against obesity-associated metabolic complications in C57BL/6J male mice by increasing lipid excretion, reducing systemic inflammatory marker, and mitigating gut microbiome alteration. While the obese phenotype development was not prevented, metabolic issues related to lipid absorption, inflammation, and gut microbial balance were improved, showing therapeutic promise and warranting eventual mechanistic elucidations.

The protective mechanisms of macroalgae Laminaria japonica consumption against lipid metabolism disorders in high-fat diet-induced hyperlipidemic rats

Macroalgae Laminaria japonica (MLJ) has been reported to exhibit various biological activities including improving immunity, anti-aging, anti-tumor, anti-atherosclerosis and anti-diabetic, but the protective mechanisms of MLJ consumption against non-alcoholic fatty liver disease (NAFLD) associated with hyperlipidemia remain poorly understood. This study demonstrated that MLJ consumption prevented high-fat diet (HFD)-induced NAFLD associated with hyperlipidemia in a rat model, and improved hyperlipidemia-related parameters, e.g. serum and hepatic lipid profiles. Moreover, histological analysis showed that MLJ reduced lipid deposition in adipocytes and hepatocytes compared with the HFD group. Such beneficial effects may be associated with the modulation of the intestinal microbiota, especially some key microbial phylotypes involved in lipid metabolism homeostasis. The underlying protective mechanisms of MLJ consumption against HFD-induced NAFLD associated with hyperlipidemia were also studied by ultra-high performance liquid chromatography with quadruple-time of flight mass spectrometry (UPLC-QTOF/MS)-based liver metabolomics coupled with pathway analysis. The metabolic pathway enrichment analysis of the differentially abundant hepatic metabolites indicated that primary bile acid biosynthesis metabolism and cysteine and methionine metabolism were the two main metabolic pathways altered by MLJ consumption when compared with the model group. The analysis of the transcription levels of liver-related genes by RT-qPCR and the expressions of liver-related proteins by immunohistochemistry (IHC) showed that MLJ consumption could regulate the levels of mRNA transcription and protein expression related to hepatic lipid metabolism. In short, this study indicates that MLJ could be developed as functional food supplement for the prevention or treatment of NAFLD associated with hyperlipidemia.

Hypolipidemic Effects of β-Glucans, Mannans, and Fucoidans: Mechanism of Action and Their Prospects for Clinical Application

The search for lipid-lowering drugs is important for clinical medicine. This review summarizes our research findings regarding the hypolipidemic activity of polysaccharides. There are several validated agents altering lipid levels which reduce the risk of atherosclerotic cardiovascular events. Nonetheless, for many people, the risk of such an event remains unacceptably high despite treatment with these agents. This situation has prompted the search for new therapies to reduce the residual cardiovascular risk. The lipid-lowering effect of β-glucans consumed with food was demonstrated in patients with atherosclerosis. The mechanism of the protective effect of β-glucans is poorly studied. The effects of β-glucans are mediated by Toll-like receptors, by dectin-1, and possibly by other receptors. Nevertheless, the mechanism of the protective action of β-glucan in lipemic mice has been studied insufficiently. This review will present up-to-date information regarding experimental hypolipidemic polysaccharide compounds that hold promise for medicine. Phagocyte-specific chitotriosidase in humans contributes to innate immune responses against chitin-containing fungi. This enzyme has been first described in patients with Gaucher disease and serves as an important diagnostic biomarker. It has been reported that, in mice, chitin particles of certain size are recognized by macrophages through Toll-like receptors, dectin-1, and to a lesser extent through mannose receptor.

Hepatoprotective effect of a fucoidan extract from Sargassum fluitans Borgesen against CCl4-induced toxicity in rats

The in vivo antifibrotic effect of a fucoidan extract (FE) from Sargassum fluitans Borgesen was evaluated in a carbon tetrachloride-induced liver damage model in rats over twelve weeks. Chemical analysis showed the FE to contain carbohydrates, sulfates, uronic acids, protein, phenols, and to have a molecular weight of ~60 kDa. Physiological, biochemical, histological and genetic assays were done. Daily oral administration of FE (50 mg/kg) reduced liver enzymatic activity, liver infiltration of inflammatory cells, collagen fiber deposition and gene expression cytokines such as interleukin beta 1 (IL-β1), tumor necrosis factor alpha (TNF-α), transforming growth factor beta 1 (TGF-β1), Smad-3, Smad-2, collagen 1 alpha 1 (col1α1) and tissue inhibitor of metalloproteinase 1 (TIMP-1). It also increased RNA expression of Smad-7 and metalloproteinase 2 and 9 (MMP2 and MMP9). The fucoidan extract exhibited an antifibrotic effect mediated by the inhibiting TGF-β1/Smad pathway, as well as anti-inflammatory effects.