Review of the relationships among polysaccharides, gut microbiota, and human health

Research Progress on the Therapeutic Effect of Polysaccharides on Non-Alcoholic Fatty Liver Disease through the Regulation of the Gut-Liver Axis

Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disease affecting global public health at present, which can induce cirrhosis and liver cancer in serious cases. However, NAFLD is a multifactorial disease, and there is still a lack of research on its mechanism and therapeutic strategy. With the development of the gut-liver axis theory, the association between the gut-liver axis and the pathogenesis of NAFLD has been gradually disclosed. Polysaccharides, as a kind of natural product, have the advantages of low toxicity, multi-target and multi-pathway action. It has been reported that polysaccharides can affect the gut-liver axis at multiple interrelated levels, such as maintaining the ecological balance of gut microbiota (GM), regulating the metabolites of GM and improving the intestinal barrier function, which thereby plays a protective role in NAFLD. These studies have great scientific significance in understanding NAFLD based on the gut-liver axis and developing safe and effective medical treatments. Herein, we reviewed the recent progress of polysaccharides in improving nonalcoholic fatty liver disease (NAFLD) through the gut-liver axis.

Recent progress of Lycium barbarum polysaccharides on intestinal microbiota, microbial metabolites and health: a review

Intestinal microbiota is symbiotically associated with host health, learning about the characteristics of microbiota and the factors that modulate it could assist in developing strategies to promote human health and prevent diseases. Polysaccharides from Lycium barbarum (LBPs) are found beneficial for enhancing the activity of gut microbiota, as a potential prebiotic, which not only participates in improving body immunity, obesity, hyperlipidemia and systemic inflammation induced by oxidative stress, but also plays a magnificent role in regulating intestinal microenvironment and improving host health and target intestinal effects via its biological activities, as well as gut microbiota and metabolites. To highlight the internal relationship between intestinal microbiota and LBPs, this review focuses on the latest advances in LBPs on the intestinal microbiota, metabolites, immune regulation, intestinal barrier protection, microbiota-gut-brain axis and host health. Moreover, the preparation, structure, bioactivity and modification of LBPs were also discussed. This review may offer new perspective on LBPs improving health of gut and host via intestinal microbiota, and provide useful guidelines for the application of LBPs in the food industry.

Polysaccharide-based nanocomposites for biomedical applications: a critical review

Polysaccharides (PSA) have taken specific position among biomaterials for advanced applications in medicine. Nevertheless, poor mechanical properties are known as the main drawback of PSA, which highlights the need for PSA modification. Nanocomposites PSA (NPSA) are a class of biomaterials widely used as biomedical platforms, but despite their importance and worldwide use, they have not been reviewed. Herein, we critically reviewed the application of NPSA by categorizing them into generic and advanced application realms. First, the application of NPSA as drug and gene delivery systems, along with their role in the field as an antibacterial platform and hemostasis agent is discussed. Then, applications of NPSA for skin, bone, nerve, and cartilage tissue engineering are highlighted, followed by cell encapsulation and more critically cancer diagnosis and treatment potentials. In particular, three features of investigations are devoted to cancer therapy, i.e., radiotherapy, immunotherapy, and photothermal therapy, are comprehensively reviewed and discussed. Since this field is at an early stage of maturity, some other aspects such as bioimaging and biosensing are reviewed in order to give an idea of potential applications of NPSA for future developments, providing support for clinical applications. It is well-documented that using nanoparticles/nanomaterials above a critical concentration brings about concerns of toxicity; thus, their effect on cellular interactions would become critical. We compared nanoparticles used in the fabrication of NPSA in terms of toxicity mechanism to shed more light on future challenging aspects of NPSA development. Indeed, the neutralization mechanisms underlying the cytotoxicity of nanomaterials, which are expected to be induced by PSA introduction, should be taken into account for future investigations.

Effects of Auricularia auricula Polysaccharides on Gut Microbiota and Metabolic Phenotype in Mice

Personalized diets change the internal metabolism of organisms, which, in turn, affects the health of the body; this study was performed to explore the regulatory effects of polysaccharides extracted from Auricularia auricula on the overall metabolism and gut microbiota in normal C57BL/6J mice. The study was conducted using metabolomic and microbiomic methods to provide a scientific basis for further development and use of Auricularia auricula resources in the Qinba Mountains and in nutritional food with Auricularia auricula polysaccharides (AAP) as the main functional component. Based on LC-MS/MS metabolomic results, 51 AAP-regulated metabolites were found, mainly enriched in the arginine biosynthesis pathway, which had the highest correlation, followed by the following metabolisms: arginine and proline; glycine, serine and threonine; and glycerophospholipid, along with the sphingolipid metabolism pathway. Furthermore, supplementation of AAP significantly changed the composition of the mice intestinal flora. The relative abundance levels of Lactobacillus johnsonii, Weissella cibaria, Kosakonia cowanii, Enterococcus faecalis, Bifidobacterium animalis and Bacteroides uniformis were markedly up-regulated, while the relative abundance of Firmicutes bacterium M10-2 was down-regulated. The bioactivities of AAP may be related to the regulatory effects of endogenous metabolism and gut microbiota composition.

Therapeutic potential of non-starch polysaccharides on type 2 diabetes: from hypoglycemic mechanism to clinical trials

Non-starch polysaccharides (NSPs) have been reported to exert therapeutic potential on managing type 2 diabetes mellitus (T2DM). Various mechanisms have been proposed; however, several studies have not considered the correlations between the anti-T2DM activity of NSPs and their molecular structure. Moreover, the current understanding of the role of NSPs in T2DM treatment is mainly based on in vitro and in vivo data, and more human clinical trials are required to verify the actual efficacy in treating T2DM. The related anti-T2DM mechanisms of NSPs, including regulating insulin action, promoting glucose metabolism and regulating postprandial blood glucose level, anti-inflammatory and regulating gut microbiota (GM), are reviewed. The structure-function relationships are summarized, and the relationships between NSPs structure and anti-T2DM activity from clinical trials are highlighted. The development of anti-T2DM medication or dietary supplements of NSPs could be promoted with an in-depth understanding of the multiple regulatory effects in the treatment/intervention of T2DM.

Therapeutic approaches to colorectal cancer via strategies based on modulation of gut microbiota

Colorectal cancer (CRC) ranks third in terms of global incidence and second in terms of death toll among malignant tumors. Gut microbiota are involved in the formation, development, and responses to different treatments of CRC. Under normal physiological conditions, intestinal microorganisms protect the intestinal mucosa, resist pathogen invasion, and regulate the proliferation of intestinal mucosal cells via a barrier effect and inhibition of DNA damage. The composition of gut microbiota and the influences of diet, drugs, and gender on the composition of the intestinal flora are important factors in the early detection of CRC and prediction of the results of CRC treatment. Regulation of gut microbiota is one of the most promising new strategies for CRC treatment, and it is essential to clarify the effect of gut microbiota on CRC and its possible mechanisms to facilitate the prevention and treatment of CRC. This review discusses the role of gut microbiota in the pathogenesis of CRC, the potential of gut microbiota as biomarkers for CRC, and therapeutic approaches to CRC based on the regulation of gut microbiota. It might provide new ideas for the use of gut microbiota in the prevention and treatment of CRC in the near future and thus reduce the incidence of CRC.

A balanced gut microbiota is essential to maintain health in captive sika deer

Certain animals harbor a high proportion of pathogens, particular the zoonotic pathogens, in their gut microbiome but are usually asymptomic; however, their carried pathogens may seriously threaten the public health. By understanding how the microbiome overcomes the negative effects of pathogens to maintain host health, we can develop novel solutions to control animal-mediated pathogen transmission including identification and application of beneficial microbes. Here, we analyzed the gut microbiota of 10 asymptomic captive sika deer individuals by full-length 16S rDNA sequencing. Twenty-nine known pathogens capable of infecting humans were identified, and the accumulated proportions of the identified pathogens were highly variable among individuals (2.33 to 39.94%). The relative abundances of several beneficial bacteria, including Lactobacillus and Bifidobacterium, were found to be positively correlated with the relative abundances of accumulated pathogens. Whole-genome metagenomic analysis revealed that the beneficial- and pathogenic-associated functions, such as genes involved in the synthesis of short chain fatty acids and virulence factors, were also positively correlated in the microbiome, indicating that the beneficial and pathogenic functions were maintained at a relatively balanced ratio. Furthermore, the bacteriophages that target the identified pathogens were found to be positively correlated with the pathogenic content in the microbiome. Several high-quality genomes of beneficial bacteria affiliated with Lactobacillus and Bifidobacterium and bacteriophages were recovered from the metagenomic data. Overall, this study provides novel insights into the interplay between beneficial and pathogenic content to ensure maintenance of a healthy gut microbiome, and also contributes to discovery of novel beneficial microbes and functions that control pathogens. KEY POINTS: • Certain asymptomic captive sika deer individuals harbor relatively high amounts of zoonotic pathogens. • The beneficial microbes and the beneficial functions are balanced with the pathogenic contents in the gut microbiome. • Several high-quality genomes of beneficial bacteria and bacteriophages are recovered by metagenomics.

Current advances and potential trends of the polysaccharides derived from medicinal mushrooms sanghuang

For thousands of years, sanghuang is distinctive as a general designation for a group of precious and rare Chinese medicinal mushrooms. Numerous investigations have revealed that polysaccharide is one of the important biological active ingredients of sanghuang with various excellent biological activities, including antioxidant, anti-aging, anti-tumor, immunomodulatory, anti-inflammatory, anti-diabetic, hepatoprotective, and anti-microbial functionalities. For the past two decades, preparation, structural characterization, and reliable bioactivities of the polysaccharides from fruiting bodies, cultured mycelia, and fermentation broth of sanghuang have been arousing extensive interest, and particularly, different strains, sources, and isolation protocols might result in obvious discrepancies in structural features and bioactivities. Therefore, this review summarizes the recent reports on preparation strategies, structural features, bioactivities, and structure-activity relationships of sanghuang polysaccharides, which will enrich the knowledge on the values of natural sanghuang polysaccharides and support their further development and utilization as therapeutic agents, vaccines, and functional foods in tonic and clinical treatment.

Codonopsis pilosula oligosaccharides modulate the gut microbiota and change serum metabolomic profiles in high-fat diet-induced obese mice

Obesity has become a major health problem worldwide, linked to gut microbiota imbalance and chronic inflammation. This study aims to evaluate whether Codonopsis pilosula oligosaccharides (CPOs) can alleviate obesity and related metabolic complications in high-fat diet (HFD) induced obese mice. Male C57BL/6J mice were fed with a HFD for 16 weeks and treated daily with CPOs (500 mg kg^-1). CPO supplementation decreased body weight and fat accumulation and improved glucose tolerance in HFD-fed mice. CPOs also reversed the effects of the HFD on inflammatory markers and improved macrophage infiltration. The results of gut microbiota analysis showed that CPOs could also regulate gut microbiota composition, significantly increasing the abundance of the beneficial bacteria Muribaculaceae spp., Alistipes and Clostridium and decreasing the abundance of the harmful bacteria Rikenella, Enterobacteriaceae spp., Collinsella and Megasphaera in HFD mice. Based on serum non-targeted metabolomics analysis, 20 key metabolites responding to CPO treatment were identified, and their biological functions were mainly related to tryptophan and bile acid metabolism. The results demonstrate that CPO supplementation can ameliorate HFD-induced obesity and obesity-related metabolic disorders. It can be used as a novel gut microbiota modulator to prevent HFD-induced gut dysbiosis.

The crude guava polysaccharides ameliorate high-fat diet-induced obesity in mice via reshaping gut microbiota

Guava is a popular fruit consumed worldwide with beneficial effects in regulation of glucose and lipid metabolism. Although polysaccharides are a major phytochemical component of guava, to date, the alleviative effects of polysaccharides from the guava fruit against diet-induced obesity remain unclear. The relationship between the anti-obesity effects of guava polysaccharide (GP) and gut microbiota is unknown. In current study, seven-week-old C57BL/6 mice were fed high-fat diet (HFD) supplemented with GP (100 mg/kg) by oral gavage for 11 weeks. GP supplementation alleviated HFD-induced body weight gain and visceral obesity, and reduced serum cholesterol, triglyceride, and LDL-C levels. In addition, GP ameliorated insulin resistance and prevented hepatic lipid accumulation and meta-inflammation in both liver and adipose tissues in obese mice. Remarkably, GP treatment restored the Firmicutes/Bacteroidetes ratio, induced growth of beneficial bacteria including Clostridium XlVa, Parvibacter, and Enterorhabdus, and decreased in inflammation-related bacteria Mucispirillum in mice fecal samples, accompanied with enhanced production of colonic short chain fatty acids especially butyric acid. However, the metabolic benefits of GP diminished in antibiotics-treated HFD-fed mice. Overall, GP improved metabolic profiles in HFD-induced obese mice via the mediation of gut microbiota-dependent pathways. GP might be developed and utilized as prebiotics in nutraceutical and food industry.

Extraction, purification, structural characterization, and gut microbiota relationship of polysaccharides: A review

Intestinal dysbiosis is one of the major causes of the occurrence of metabolic syndromes, such as obesity, diabetes, nonalcoholic fatty liver disease, and cardiovascular diseases. Polysaccharide-based microbial therapeutic strategies have excellent potential in the treatment of metabolic syndromes, but the underlying regulatory mechanisms remain elusive. Identification of the internal regulatory mechanism of the gut microbiome and the interaction mechanisms involving bacteria and the host are essential to achieve precise control of the gut microbiome and obtain valuable clinical data. Polysaccharides cannot be directly digested; the behavior in the intestinal tract is considered a "bridge" between microbiota and host communication. To provide a relatively comprehensive reference for researchers in the field, we will discuss the polysaccharide extraction and purification processes and chemical and structural characteristics, focusing on the polysaccharides in gut microbiota through the immune system, gut-liver axis, gut-brain axis, energy axis interactions, and potential applications.

Purple red rice anthocyanins alleviate intestinal damage in cyclophosphamide-induced mice associated with modulation of intestinal barrier function and gut microbiota

The regulatory effects of purple red rice bran anthocyanins (PRBA) on intestinal barrier function and gut microbiota in mice were investigated. Results showed that PRBA had an ameliorative effect on intestinal barrier damage, including restoration of villus length, improvement in the number of cupped cells and promotion of sIgA secretion. PRBA stimulated the production of cytokines, reduced the levels of endotoxin (ET) and lipopolysaccharide binding protein (LBP) in serum, as well as upregulated the expression of tight junction proteins (TJs) and NF-κB pathway proteins. Furthermore, PRBA not only promoted the production of short-chain fatty acids (SCFAs), but also regulated the intestinal microbiota by increasing beneficial bacteria (Lachnospiraceae, Bacteroidaceae, Ruminococcaceae) and reducing pathogenic bacteria (Shigella) to maintained intestinal homeostasis. Above results indicated that PRBA could ameliorate cyclophosphamide-induced impairment of intestinal barrier function and dysregulation of the gut microbiota, which provides a new idea for broadening the exploitation of PRBA.

Effect of Gan Cao (Glycyrrhiza uralensis Fisch) polysaccharide on Growth Performance, Immune Function, and Gut microflora of Broiler Chickens

Glycyrrhiza uralensis Fisch, also called Gan Cao, is a commonly prescribed herb in traditional Chinese medicine. Gan Cao is associated with immune-modulation and antitumor potential though its mechanism of action is not well-known. To explore the effects of different dietary levels of Gan Cao polysaccharide (GCP) on broilers, a total of 400 Avian broiler chickens were randomly divided into 4 groups with 10 replicates of 10 broilers each. The broilers in the control group were fed a basal diet, while those in the experimental groups were fed the basal diet supplemented with 0.5%, 1.0%, and 1.5% GCP, respectively, for 42 d. The results showed a significant increase in the growth performance in the GCP groups. The antibody titer of NDV and the phagocytosis index was higher in the birds with GCP treatment than in the control group, with the 1% GCP addition displaying the highest titer. The Lactobacillus and Bifidobacteria count in the cecum content of the birds in the 1% GCP group was higher compared to the other groups. In conclusion, dietary supplementation with GCP had a substantial impact on the growth performance, immune response, and microflora population in the cecum of the birds, especially at a level of 1% addition.

Polysaccharides from Cordyceps militaris prevent obesity in association with modulating gut microbiota and metabolites in high-fat diet-fed mice

Improved gut microbes and nutritious metabolites have been considered as the mediators of health benefits from indigestible polysaccharides, but their role in the anti-obesity effect of polysaccharides from Cordyceps militaris (CMP) remains elusive. This study aims to explore the potential mediators of the anti-obesity effects of CMP in high-fat diet (HFD)-fed mice using 16S rRNA sequencing and untargeted metabolomics analysis. The results showed that CMP supplementation in HFD-fed mice reduced body weight, fat accumulation, pro-inflammatory cytokine levels, and impaired glucose tolerance as well as gut barrier. Moreover, the CMP reversed the HFD-induced gut microbiota dysbiosis, as indicated by the elevated population of Alloprevotella, Parabacteroides, Butyricimonas, and Alistipes; and decreased population of Negativebacillus, in addition to altered levels of metabolites, such as brassicasterol and 4'-O-methylkanzonol W. Notably, CMP prevented obesity in association with the altered gut microbes and metabolites. These findings suggest that CMP may serve as a potential prebiotic agent to modulate specific gut microbes and related metabolites, which play a critical role in its preventing obesity-related diseases.

Improving the digestive stability and prebiotic effect of carboxymethyl chitosan by grafting with gallic acid: In vitro gastrointestinal digestion and colonic fermentation evaluation

Carboxymethyl chitosan (CMCS) is a useful polysaccharide with potential applications in food, cosmetic and biomedical industries. Nonetheless, CMCS is unfavorable for maintaining intestinal flora balance. In this study, gallic acid (GA) was grafted with CMCS through ascorbic acid/hydrogen peroxide initiated graft copolymerization reaction, producing GA grafted CMCS (GA-g-CMCS). The digestive and fermentative behavior of CMCS and GA-g-CMCS were investigated by using in vitro simulated gastrointestinal digestion and colonic fermentation models. Results showed that the average molecular weight (M_w) of CMCS gradually decreased during saliva-gastro-intestinal digestion, changing from original sheet-like morphology to porous and rod-like fragments. However, the M_w and morphology of GA-g-CMCS were almost unchanged under saliva-gastro-intestinal digestion. Meanwhile, the grafted GA moiety was not released from GA-g-CMCS during saliva-gastro-intestinal digestion. As compared with CMCS fermentation, GA-g-CMCS fermentation significantly suppressed the relative abundance of Escherichia-Shigella, Paeniclostridium, Parabacteroides, Lachnoclostridium, Clostridium_sensu_stricto_1, UBA1819 and Butyricimonas, while facilitated the relative abundance of Enterobacter, Enterococcus, Fusobacterium and Lachnospira. In addition, GA-g-CMCS fermentation significantly enhanced the production of short-chain fatty acids. These findings suggested that the digestive stability and prebiotic effect of CMCS were improved by grafting with GA.

Fecal fermentation characteristics of Rheum tanguticum polysaccharide and its effect on the modulation of gut microbial composition

Background

Rheum tanguticum is utilized as one of the well known traditional Chinese medicine for the treatment of gastrointestinal diseases. Recently, R. tanguticum polysaccharides (RP) have received increasing attention due to their diversely pharmacological activities. Usually, the pharmacological activities of polysaccharides are closely correlated to their metabolic properties from the stomach to the intestine. However, the digestive behavior and fecal fermentation characteristics of RP are unknown, which need to be fully investigated.

Methods

In this study, an in vitro simulated gastrointestinal model was carried out for the investigation of the digestive behavior and fecal fermentation characteristics of RP. The possible changes in physicochemical properties of RP, such as molecular weight, monosaccharide composition, reducing sugar released, chemical composition, pH value, and short chain fatty acids, were determined during in vitro simulated digestion and human fecal fermentation, and its effect on the modulation of gut microbial composition was also evaluated.

Results

The results revealed that RP was indigestible under the in vitro simulated digestion conditions according to its stabilities in physicochemical properties. Conversely, the indigestible RP (RPI) could be notably utilized by colonic microbiota in human feces after the in vitro fermentation, especially, at the initial fermentation stage (0–6 h). The fecal fermentation characteristics of RPI were revealed. Results showed that the content of reducing sugars obviously increased from 0.177 to 0.778 mg/mL at the initial stage of fermentation, and its molecular weight notably declined from 2.588 × 10⁵ to 0.828 × 10⁵ Da at the end stage of fermentation. Notably, the utilization of arabinose and galactose in RPI by colonic bacteria was faster than that of galacturonic acid. Besides, RPI could obviously modulate gut microbial composition via promoting the relative abundances of several beneficial bacteria, such as genera Bacteroides, Bifidobacterium, and Megamonas, resulting in the promoted production of several short-chain fatty acids, such as acetic, propionic, and butyric acids.

Conclusions

Results from this study showed that RP was indigestible in the human upper gastrointestinal tract in vitro, but could be easily utilized by colonic microbiota in human feces at the initial stage of fermentation. RP could be used as potential prebiotics for the improvement of intestinal health.

Tracking the gastrointestinal digestive and metabolic behaviour of Dendrobium officinale polysaccharides by fluorescent labelling

Recently, Dendrobium officinale polysaccharide (DOP), a typical acetylated glucomannan, has been widely applied in functional foods owing to its excellent bioactivity. However, the insufficiency of studies on in vivo process severely limits the further utilization of DOP. The aim of this study was to systematically investigate the gastrointestinal digestive behaviour of DOP after oral administration by labelling it with two fluorescein aminopyrene-1,3,6-trisulfonic acids, trisodium salt (APTS) and cyanine 7.5 (Cy7.5). Combining the results of NIR imaging and HPGPC, we found that DOP was poorly absorbed directly in the prototype form; instead, DOP moved with the intestinal contents to the distal part of the intestine, where Bacteroides aggregated for a prolonged time and was metabolized to oligosaccharide-like substances. In contrast, the digestive degradation of DOP in pseudo-sterile mice with a targeted clearance of Bacteroides significantly weakened, which provided the basis and direction for the subsequent search for more specific metabolic pathways of DOP in vivo.

Multi-Omics Integration Analysis Identifies Lipid Disorder of a Non-Alcoholic Fatty Liver Disease (NAFLD) Mouse Model Improved by Zexie–Baizhu Decoction

Non-alcoholic fatty liver disease (NAFLD) is an increasingly epidemic metabolic disease with complex pathogenesis. Multi-target therapy may be an effective strategy for NAFLD treatment, and traditional Chinese medicine (TCM) characterized by multi-ingredients and multi-targets has unique advantages in long-term clinical practice. Zexie–Baizhu (ZXBZ) decoction is a Chinese classical formula to treat body fluid disorders initially. Although many bioactive monomers from Zexie and Baizhu had been discovered to improve lipid disorders, limited research studies were focused on the aqueous decoction of ZXBZ, the original clinical formulation. In the current study, we identified 94% chemical composition of ZXBZ decoction and first discovered its hepaprotective effect in a gubra-amylin NASH (GAN) diet-induced NAFLD mouse model. Based on metabolomics and transcriptomics analyses, we speculated that lipid and glucose metabolisms might be regulated by ZXBZ decoction, which was further confirmed by improved dyslipidemia and hepatic steatosis in ZXBZ groups. Consistently with cross-omics analysis, we discovered ZXBZ decoction could influence two energy sensors, Sirt1 and AMPK, and subsequently affect related proteins involved in lipid biosynthesis, catabolism, and transport. In conclusion, ZXBZ decoction regulated energy sensors, consequently impeded lipogenesis, and promoted fatty acid oxidation (FAO) to alleviate lipid disorders and protect the liver in NAFLD models, which suggested ZXBZ decoction might be a promising treatment for NAFLD.

Effects of fucoidans and alginates from Sargassum graminifolium on allergic symptoms and intestinal microbiota in mice with OVA-induced food allergy

Food allergy has been one of the main problems threatening people's health in recent years. However, there is still no way to completely cure it at present. Therefore, the development of food allergy related drugs is still necessary. Sargassum graminifolium (SG) is a kind of polysaccharide rich marine brown alga used in food and medicine. Sargassum graminifolium polysaccharides (SGP) is mainly composed of fucoidans and alginic acid. In our study, we compared the activity of fucoidans and alginates from SG against OVA-induced food allergy in a mouse model, observed the regulatory effects of fucoidans and alginates from SG on the intestinal microbiota and summarized the possible role of the intestinal microbiota in the anti-food allergy process because polysaccharides can further act on the body through the intestinal microbiota. The results showed that fucoidans and alginates from SG could relieve the symptoms of allergy, diarrhea and jejunum injury significantly in mice with food allergy (p < 0.05). Furthermore, fucoidans at 500 mg kg-1 could reduce OVA-specific IgE and TNF-α levels significantly in the serum of food allergic mice (p < 0.05), while alginates could only significantly down-regulate serum OVA-specific IgE (p < 0.05). The results also showed that fucoidans had a stronger regulatory effect on the richness and diversity of the intestinal microbiota in food allergic mice compared to alginates at the same dose. In addition, fucoidans at 500 mg kg-1 had the most significant regulatory effect on Firmicutes, Lactobacillus and Alistipes in food allergic mice. These results suggested that fucoidans and alginates might regulate food allergy in mice through different pathways. Together, this study enriched the research on the action of alga-derived polysaccharides against food allergy.

Aconitum carmichaelii Debeaux: A systematic review on traditional use, and the chemical structures and pharmacological properties of polysaccharides and phenolic compounds in the roots

ETHNOPHARMACOLOGICAL RELEVANCE

Aconitum carmichaelii, belonging to the Ranunculaceae family, is a widely used traditional herbal plant in Asian countries, especially in China. The lateral ("Fuzi") and mother ("Chuanwu") roots are the two main plant parts used in Traditional Chinese Medicine (TCM), where they are used in the treatment of acute myocardial infarction, heart failure, rheumatoid arthritis, and as analgesics.

AIM OF THE STUDY

In order to further guide the research direction and application of A. carmichaelii, this study aims to give a systematic and in-depth overview on the phytochemical and pharmacological studies of non-alkaloid natural products with focus on polysaccharides and phenolic compounds.

MATERIALS AND METHODS

A comprehensive search in the literature was conducted based on the databases Google Scholar, SciFinder (American Chemical Society), Springer Link, PubMed Science, Science Direct and China National Knowledge Internet, Wanfang Data, in addition to books, doctoral and master's dissertations, and official website. The main keywords were: "Aconitum carmichaelii", "Aconiti Lateralis Radix Praeparata", "Fuzi", "Chuanwu", "Aconiti Radix", "monkshood" and "Bushi".

RESULTS

A. carmichaelii is known for the use of its different root parts, including "Fuzi" and "Chuanwu". Different types of polysaccharides, both neutral and acidic, and 39 phenolic compounds like flavonoids, phenylpropanoids, lignans, neolignans, and benzoic acid derivatives have been isolated and identified from the roots. Pharmacological studies of the isolated polysaccharides have demonstrated various biological effects such as hypoglycemic, hypolipidemic, cardiovascular, immunomodulatory, anti-tumor, and neuropharmacological activities. Studies on pharmacological effects of the phenolic compounds isolated from the roots are however limited.

CONCLUSIONS

This review shows that polysaccharides could be one of the active components in the roots of A. carmichaelii, and they are promising for future applications due to their pharmacological properties. In addition, polysaccharides are generally non-toxic, biocompatible, and biodegradable. This review also sheds light on new research directions for A. carmichaelii. A more detailed structural characterization of polysaccharides from different root parts of A. carmichaelii, and their structure-activity relationships are required. Additionally, their pharmacological properties as immunomodulators in the intestinal system should be investigated. Further, more knowledge about the pharmacological effects and molecular mechanisms of the phenolic compounds that have been identified are needed.

Anti-obesity effects of Laminaria japonica fucoidan in high-fat diet-fed mice vary with the gut microbiota structure

Previous studies have indicated that fucoidan could resist high-fat-diet (HFD)-induced obesity by modulating the composition of gut microbiota. However, the outcome of dietary intervention may differ between individuals due to large inter-individual variability in gut microbiota. Thus, the present study aimed to investigate the possible discrepancy of the anti-obesity effects of fucoidan supplementation in HFD-fed mice models with different gut microbiota communities. In the present study, the anti-obesity effects of fucoidan isolated from Laminaria japonica (FucLj) on normal mice and microbiota-altered mice treated with penicillin or metronidazole were compared and investigated. The 16S rRNA sequencing revealed the differences of gut microbiota among penicillin-treated, metronidazole-treated and normal groups, and mice treated with penicillin were characterized by greater relative abundance of the phylum Bacteroidetes and the families Muribaculaceae and Bacteroidaceae. Furthermore, FucLj ameliorated HFD-induced body weight gain, fat accumulation, serum lipid profiles, insulin resistance, hepatic steatosis and adipocyte hypertrophy in penicillin-treated and untreated mice, while no effects were observed in metronidazole-treated mice. Overall, mice with different initial gut microbiota responded differently to FucLj supplementation on a high-fat diet, and metronidazole-sensitive gut bacteria negatively correlated with obesity symptoms and were required for the anti-obesity effects of FucLj. Moreover, the anti-obesity effects were not dependent on the utilization of FucLj by gut microbiota to produce SCFAs. These findings indicate that evaluation of the gut microbiota structure before dietary interventions is helpful for enhancing the beneficial outcomes of dietary fiber supplementation and provide a rationale for the further application of dietary fucoidan in a personalized way.

Plant Polysaccharides Modulate Immune Function via the Gut Microbiome and May Have Potential in COVID-19 Therapy

Plant polysaccharides can increase the number and variety of beneficial bacteria in the gut and produce a variety of active substances, including short-chain fatty acids (SCFAs). Gut microbes and their specific metabolites have the effects of promoting anti-inflammatory activity, enhancing the intestinal barrier, and activating and regulating immune cells, which are beneficial for improving immunity. A strong immune system reduces inflammation caused by external viruses and other pathogens. Coronavirus disease 2019 (COVID-19) is still spreading globally, and patients with COVID-19 often have intestinal disease and weakened immune systems. This article mainly evaluates how polysaccharides in plants can improve the immune system barrier by improving the intestinal microecological balance, which may have potential in the prevention and treatment of COVID-19.

Influence of Natural Polysaccharides on Intestinal Microbiota in Inflammatory Bowel Diseases: An Overview

The incidence of inflammatory bowel disease (IBD) has increased in recent years. Considering the potential side effects of conventional drugs, safe and efficient treatment methods for IBD are required urgently. Natural polysaccharides (NPs) have attracted considerable attention as potential therapeutic agents for IBD owing to their high efficiency, low toxicity, and wide range of biological activities. Intestinal microbiota and their fermentative products, mainly short-chain fatty acids (SCFAs), are thought to mediate the effect of NPs in IBDs. This review explores the beneficial effects of NPs on IBD, with a special focus on the role of intestinal microbes. Intestinal microbiota exert alleviation effects via various mechanisms, such as increasing the intestinal immunity, anti-inflammatory activities, and intestinal barrier protection via microbiota-dependent and microbiota-independent strategies. The aim of this paper was to document evidence of NP–intestinal microbiota-associated IBD prevention, which would be helpful for guidance in the treatment and management of IBD.

Targeting Gut Microbiota With Natural Polysaccharides: Effective Interventions Against High-Fat Diet-Induced Metabolic Diseases

Unhealthy diet, in particular high-fat diet (HFD) intake, can cause the development of several metabolic disorders, including obesity, hyperlipidemia, type 2 diabetes mellitus (T2DM), non-alcoholic fatty liver disease (NAFLD), and metabolic syndrome (MetS). These popular metabolic diseases reduce the quality of life, and induce premature death worldwide. Evidence is accumulating that the gut microbiota is inextricably associated with HFD-induced metabolic disorders, and dietary intervention of gut microbiota is an effective therapeutic strategy for these metabolic dysfunctions. Polysaccharides are polymeric carbohydrate macromolecules and sources of fermentable dietary fiber that exhibit biological activities in the prevention and treatment of HFD-induced metabolic diseases. Of note, natural polysaccharides are among the most potent modulators of the gut microbiota composition. However, the prebiotics-like effects of polysaccharides in treating HFD-induced metabolic diseases remain elusive. In this review, we introduce the critical role of gut microbiota human health and HFD-induced metabolic disorders. Importantly, we review current knowledge about the role of natural polysaccharides in improving HFD-induced metabolic diseases by regulating gut microbiota.

Spirulina platensis biomass enhances the proliferation rate of Lactobacillus acidophilus 5 (La-5) and combined with La-5 impact the gut microbiota of medium-age healthy individuals through an in vitro gut microbiome model

This study first evaluated the stimulatory effect of S. platensis biomass on the growth of L. acidophilus and the metabolic activity during fermentation (37 °C, 72 h) in a culture medium. The results demonstrated a higher impact of S. platensis biomass than fructooligosaccharide (FOS), an established prebiotic. Higher L. acidophilus proliferation rates and metabolic activity were observed (lower pH values and higher concentrations of acetic, lactic, and propionic acids) in the presence of S. platensis. Then, we evaluated the effects of the S. platensis biomass (1.5 g, twice a day, 5 days) in association with L. acidophilus (10⁶ CFU/g) on the gut microbiota composition of medium-age healthy individuals through the Simulator of Human Intestinal Microbial Ecosystem (SHIME®) and measurement of metabolites. L. acidophilus (La5) and L. acidophilus + S. platensis (Spi-La5) could positively modulate the intestinal microbiota. The administration of La5 resulted in increases in Bacteroides, Megasphaera, Lactobacillus, and Parabacteroides genus abundance, with a consequent decrease in ammonium ions. The administration of Spi-La5 increased the abundance of the genus Erysipelatoclostridium, Roseburia, Enterococcus, Bifidobacterium, Coriobacteriaceae UCG-003, Enterobacter, and Paraclostridium. The results demonstrate that the intestinal microbiota was differently modified by administrating La5 and Spi-La5 and indicate the latter as an alternative for microbiota positive modulation in healthy individuals.

Structural Characterization and In Vitro Fermentation Characteristics of Enzymatically Extracted Black Mulberry Polysaccharides

In this study, we systematically investigated the structural characterization and in vitro fermentation patterns of crude black mulberry fruit polysaccharides (BMPs), either extracted by water (BMP) or by enzymatic treatment. Different enzymatic treatments were pectinase-extracted (PE)-BMP, pectin lyase-extracted (PL)-BMP, cellulase-extracted (CE)-BMP, and compound enzymes-extracted (M)-BMP (pectinase:pectin lyase:cellulase = 1:1:1). Our results show that enzymatic treatment improved the polysaccharide yield and led to a different chemical composition and structure for the polysaccharides. Change dynamics during the in vitro fermentation indicated that BMPs could indeed be degraded and consumed by human fecal microbiota and that different BMPs showed different degrees of fermentability. In addition, BMPs stimulated the growth of Bacteroidetes and Firmicutes, inhibited the growth of Fusobacteria and Proteobacteria (except for CE-BMP), and induced the production of short-chain fatty acids (SCFAs). Furthermore, we found that BMP and PL-BMP exhibited better fermentability and prebiotic potential than the other polysaccharides.

Dietary Supplementation of Auricularia auricula-judae Polysaccharides Alleviate Nutritional Obesity in Mice via Regulating Inflammatory Response and Lipid Metabolism

The incidence of lipid metabolism disorder and obesity that is caused by high-calorie diets is increasing year by year, which has become an urgent global health problem. This study was performed to explore the intervention effects of polysaccharides that were extracted from Auricularia auricula-judae resources in the Qinba Mountain area on nutritional obesity in C57BL/6J mice that was induced by high fat and high fructose diets (HFFD) and to investigate their underlying molecular mechanisms. The results showed that dietary supplementation of Auricularia auricula-judae polysaccharides (AAP) significantly improved mice’s insulin resistance state, altered serum lipid metabolites, and slowed down body weight gain that was induced by HFFD. In addition, AAP supplementation decreased inflammatory factor levels and alleviated liver histomorphology changes. Furthermore, AAP down-regulated liver adipogenic-related gene expressions, suppressed cholesterol synthesis-related gene levels, up-regulated fatty acid β-oxidation-related gene expressions, and promoted cholesterol efflux-related gene expressions, thus improving mice hepatic lipid metabolism homeostasis. Moreover, the intervention effects were closely related to mitochondrial function. These results provide a scientific basis for the further development and utilization of Auricularia auricula-judae resources in the Qinba Mountain area.

Polysaccharides, Next Potential Agent for the Treatment of Epilepsy?

Epilepsy is a chronic neurological disorder. Current pharmacological therapies for epilepsy have limited efficacy that result in refractory epilepsy (RE). Owing to the limitations of conventional therapies, it is needed to develop new anti-epileptic drugs. The beneficial effects of polysaccharides from Chinese medicines, such as Lycium barbarum polysaccharides (COP) and Ganoderma lucidum polysaccharides (GLP), for treatment of epilepsy include regulation of inflammatory factors, neurotransmitters, ion channels, and antioxidant reactions. Especially, polysaccharides could be digested by intestinal microbial flora, referred as “intestinal brain organ” or “adult’s second brain”, may be the target for treatment of epilepsy. Actually, polysaccharides can effectively improve the type and quantity of intestinal flora such as bifidobacteria and lactic acid bacteria and achieve the purpose of treating epilepsy. Therefore, polysaccharides are hypothesized and discussed as potential agent for treatment of epilepsy.

Polysaccharides and Metal Nanoparticles for Functional Textiles: A Review

Nanotechnology is a powerful tool for engineering functional materials that has the potential to transform textiles into high-performance, value-added products. In recent years, there has been considerable interest in the development of functional textiles using metal nanoparticles (MNPs). The incorporation of MNPs in textiles allows for the obtention of multifunctional properties, such as ultraviolet (UV) protection, self-cleaning, and electrical conductivity, as well as antimicrobial, antistatic, antiwrinkle, and flame retardant properties, without compromising the inherent characteristics of the textile. Environmental sustainability is also one of the main motivations in development and innovation in the textile industry. Thus, the synthesis of MNPs using ecofriendly sources, such as polysaccharides, is of high importance. The main functions of polysaccharides in these processes are the reduction and stabilization of MNPs, as well as the adhesion of MNPs onto fabrics. This review covers the major research attempts to obtain textiles with different functional properties using polysaccharides and MNPs. The main polysaccharides reported include chitosan, alginate, starch, cyclodextrins, and cellulose, with silver, zinc, copper, and titanium being the most explored MNPs. The potential applications of these functionalized textiles are also reported, and they include healthcare (wound dressing, drug release), protection (antimicrobial activity, UV protection, flame retardant), and environmental remediation (catalysts).

Can Supplemented Skim Milk (SKM) Boost Your Gut Health?

The incorporation of functional ingredients, such as prebiotics and probiotics in food matrices, became a common practice in the human diet to improve the nutritional value of the food product itself. Worldwide, skim milk (SKM) is one of the most consumed food matrices, comprising all the essential nutrients desired for a balanced diet. Thus, the modulation of the human gut microbiota by SKM supplemented with different well-known functional ingredients was evaluated. Four well-studied prebiotics, fructo-oligosaccharides (FOS), galacto-oligosaccharides (GOS), mannan-oligosaccharides (MOS) and inulin, and one probiotic product, UL-250® (Saccharomyces boulardii) were added at 1% (w/v) to SKM and subjected to a gastrointestinal in vitro model. The impact of each combination on gut microbiota profile and their fermentation metabolites (i.e., short-chain fatty acids–SCFA) was assessed by quantitative polymerase chain reaction (qPCR) and high-performance liquid chromatography (HPLC), respectively. The addition of FOS to SKM had promising results, showing prebiotic potential by promoting the growth of Lactobacillus, Bifidobacterium, and Clostridium cluster IV. Moreover, the increment of SCFA levels and the decrease of total ammonia nitrogen were observed throughout colonic fermentation. Overall, these results demonstrate that the combination SKM + FOS was the most beneficial to the host’s health by positively modulating the gut microbiota.

The Algal Polysaccharide Ulvan and Carotenoid Astaxanthin Both Positively Modulate Gut Microbiota in Mice

The intestinal microbial community (microbiota) is dynamic and variable amongst individuals and plays an essential part in gut health and homeostasis. Dietary components can modulate the structure of the gut microbiota. In recent years, substantial efforts have been made to find novel dietary components with positive effects on the gut microbial community structure. Natural algal polysaccharides and carotenoids have been reported to possess various functions of biological relevance and their impact on the gut microbiota is currently a topic of interest. This study, therefore, reports the effect of the sulfated polysaccharide ulvan and the carotenoid astaxanthin extracted and purified from the aquacultured marine green macroalgae Ulva ohnoi and freshwater green microalgae Haematococcus pluvialis, respectively, on the temporal development of the murine gut microbiota. Significant changes with the increase in the bacterial classes Bacteroidia, Bacilli, Clostridia, and Verrucomicrobia were observed after feeding the mice with ulvan and astaxanthin. Duration of the treatments had a more substantial effect on the bacterial community structure than the type of treatment. Our findings highlight the potential of ulvan and astaxanthin to mediate aspects of host-microbe symbiosis in the gut, and if incorporated into the diet, these could assist positively in improving disease conditions associated with gut health.

Effects of sulfation and carboxymethylation on Cyclocarya paliurus polysaccharides: Physicochemical properties, antitumor activities and protection against cellular oxidative stress

The Cyclocarya paliurus polysaccharide (CP) was chemically modified to produce sulfated derivatives (S-CP) and carboxymethylated derivatives (CM-CP). Subsequently, the antioxidant activity, cytoprotective effect and antitumor activity of these derivatives were investigated to establish the relationship between their structure and functional activity. The results found that chemical modifications resulted in remarkable variations in the chemical compositions and apparent structures of CP. S-CP with the highest amount of glucose had the strongest antioxidant capacity to scavenge DPPH• and HO•, but CM-CP was lower than CP in terms of HO• scavenging. More importantly, S-CP and CM-CP more effectively protected RAW264.7 from H₂O₂-induced damage compared to CP by reducing the secretion of lactate dehydrogenase (LDH), intracellular reactive oxygen species (ROS) and malondialdehyde (MDA), enhancing phagocytosis and superoxide dismutase (SOD) levels, and suppressing abnormal apoptosis. Further experiments showed that the anti-apoptotic effect of S-CP and CM-CP was in intimate association with down-regulation of Caspase-9/3 activities and alleviation of cell cycle arrest in the S phase. In addition, S-CP and CM-CP decreased the cell viability of tumor cells. These findings suggest that the type of functional group plays important roles in the biological function of the derivatives and provide a theoretical basis for the development of novel natural anti-oxidants or low-toxicity anti-tumor drugs.

Modulatory effects of polysaccharides from plants, marine algae and edible mushrooms on gut microbiota and related health benefits: A review

Naturally occurring carbohydrate polymers containing non-starch polysaccharides (NPs) are a class of biomacromolecules isolated from plants, marine algae, and edible mushrooms, and their biological activities has shown potential uses in the prevention and treatment of human diseases. Importantly, NPs serve as prebiotics to provide health benefits to the host through stimulating the proliferation of beneficial gut microbiota (GM) and enhancing the production of short-chain fatty acids (SCFAs). The composition and diversity of GM play a critical role in regulating host health and have been extensively studied in recent years. In this review, the extraction, isolation, purification, and structural characterization of NPs derived from plants, marine algae, and edible mushrooms are outlined. Importantly, the degradation and metabolism of these NPs in the intestinal tract, the effects of NPs on the microbial community and SCFAs generation, and the beneficial effects of NPs on host health by modulating GM are systematically highlighted. Overall, we hope that this review can provide some theoretical references and a new perspective for applications of NPs as prebiotics in functional food and drug development.

Plant polysaccharides utilized by gut microbiota: New players in ameliorating cognitive impairment

Considerable evidence indicates the important role of gut microbiota in human health. Through the interaction with the host and diet, it secretes a myriad of metabolites to modulate biological processes essential for health. Cognitive impairment is a common feature of psychiatric and neurological disorders, which may seriously damage the quality of patients' life. Studies have found that cognitive impairment has a close relationship with gut microbiota, and plant polysaccharides intervention to maintain intestinal micro-ecological balance has a great impact on ameliorating cognitive impairment. This review introduced the interaction between gut microbiota and plant polysaccharides, and focused on signaling pathogenesis of gut microbiota in cognitive impairment. The effect of plant polysaccharides intervention on regulation of gut microbiota was also discussed, so as to provide a promising strategy for ameliorating cognitive impairment.

Hypoglycemic effect of polysaccharide from Astragalus membranaceus on type 2 diabetic mice based on “gut microbiota-mucosal barrier”

Astragalus membranaceus polysaccharide (APP), the main active constituent possesses numerous bioactivities. In this research, the T2DM model mice was combined with streptozotocin to study the hypoglycemic effect and mechanism of...

In vitro digestive characteristics and microbial degradation of polysaccharides from lotus leaves and related effects on the modulation of intestinal microbiota

Polysaccharides exist as one of the most abundant components in lotus leaves, which attract increasing attention owing to their promising health-promoting benefits. In this study, the digestive and microbial degradation characteristics of lotus leaf polysaccharides (LLP) were studied by using an in vitro gastrointestinal model. The results suggested that LLP was stable in the human upper gastrointestinal tract in vitro according to its digestive stabilities at different simulated digestion stages. Conversely, the indigestible LLP (LLPI) could be remarkably utilized by intestinal microbiota in human feces during in vitro fermentation, and its fermentability was 58.11% after the in vitro fermentation of 48 h. Indeed, the microbial degradation characteristics of LLPI during in vitro fermentation by human fecal inoculum were revealed. The results showed that the content of reducing sugars released from LLPI obviously increased from 0.498 to 2.176 mg/mL at the initial fermentation stage (0–6 h), and its molecular weight sharply decreased from 4.08 × 10⁴ to 2.02 × 10⁴ Da. Notably, the molar ratios of arabinose (Ara), galactose (Gal), and galacturonic acid (GalA) in LLPI decreased from 2.89 to 1.40, from 5.46 to 3.72, and from 21.24 to 18.71, respectively, suggesting that the utilization of arabinose and galactose in LLPI by intestinal microbiota was much faster than that of galacturonic acid at the initial fermentation stage. Additionally, LLPI could remarkably regulate gut microbial composition by increasing the abundances of several beneficial microbes, including Bacteroides, Bifidobacterium, Megamonas, and Collinsella, resulting in the promoted generation of several short-chain fatty acids, especially acetic, propionic, and butyric acids. The findings from the present study are beneficial to better understanding the digestive and microbial degradation characteristics of LLP, which indicate that LLP can be used as a potential prebiotic for the improvement of intestinal health.

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LLP was stable in the human upper gastrointestinal tract in vitro.

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The indigestible LLP could be remarkably utilized by intestinal microbiota.

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Arabinose and galactose were quickly utilized at the initial fermentation stage.

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Bacteroides, Bifidobacterium, Megamonas, and Collinsella obviously increased.

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SCFAs, especially acetic, propionic, and butyric acids, remarkably promoted.

A Review on the Structure and Anti-Diabetic (Type 2) Functions of β-Glucans

Type 2 diabetes, a long-term chronic metabolic disease, causes severe and increasing economic and health problems globally. There is growing evidence that β-glucans can function as bioactive macromolecules that help control type 2 diabetes with minimal side effects. However, conflicting conclusions about the antidiabetic activities of β-glucans have been published, potentially resulting from incomplete understanding of their precise structural characteristics. This review aims to increase clarity on the structure-function relationships of β-glucans in treating type 2 diabetes by examining detailed structural and conformational features of naturally derived β-glucans, as well as both chemical and instrumental methods used in their characterization, and their underlying anti-diabetic mechanisms. This may help to uncover additional structure and function relationships and to expand applications of β-glucans.