Consumption of polysaccharides from Auricularia auricular modulates the intestinal microbiota in mice

A review of the fungal polysaccharides as natural biopolymers: Current applications and future perspective

As a unique natural resource, fungi are a sustainable source of lipids, polysaccharides, vitamins, proteins, and other nutrients. As a result, they have beneficial medicinal and nutritional properties. Polysaccharides are among the most significant bioactive components found in fungi. Increasing research has revealed that fungal polysaccharides (FPS) contain a variety of bioactivities, including antitumor, antioxidant, immunomodulatory, anti-inflammatory, hepatoprotective, cardioprotective, and anti-aging properties. However, the exact knowledge about FPS and their applications related to their future possibilities must be thoroughly examined to enhance a better understanding of this sustainable biopolymer source. Therefore, FPS' biological applications and their role in the food and feed industry, agriculture, and cosmetics applications were all discussed in this work. In addition, this review highlighted the mode of action of FPS on human diseases by regulating gut microbiota and discussed the mechanism of FPS as antioxidants in the living cell. The structure-activity connections of FPS were also highlighted and explored. Moreover, future perspectives were listed to pave the way for future studies of FPS applications. Hence, this study can be a scientific foundation for future FPS research and industrial applications.

Therapeutic Potential of Fungal Polysaccharides in Gut Microbiota Regulation: Implications for Diabetes, Neurodegeneration, and Oncology

This review evaluates the therapeutic effects of polysaccharides derived from mushroom species that have medicinal and edible properties. The fungal polysaccharides were recently studied, focusing on their modulation of the gut microbiota and their impact on various diseases. The study covers both clinical and preclinical studies, detailing the results and highlighting the significant influence of these polysaccharides on gut microbiota modulation. It discusses the potential health benefits derived from incorporating these polysaccharides into the diet for managing chronic diseases such as diabetes, neurodegenerative disorders, and cancer. Furthermore, the review emphasizes the interaction between fungal polysaccharides and the gut microbiota, underscoring their role in modulating the gut microbial community. It presents a systematic analysis of the findings, demonstrating the substantial impact of fungal polysaccharides on gut microbiota composition and function, which may contribute to their therapeutic effects in various chronic conditions. We conclude that the modulation of the gut microbiota by these polysaccharides may play a crucial role in mediating their therapeutic effects, offering a promising avenue for further research and potential applications in disease prevention and treatment.

Evaluation of Physicochemical Properties and Prebiotics Function of a Bioactive Pleurotus eryngii Aqueous Extract Powder Obtained by Spray Drying

A bioactive Pleurotus eryngii aqueous extract powder (SPAE) was obtained by spray drying and its performance in terms of physicochemical properties, in vitro digestion, inflammatory factors, and modulation of the intestinal microbiota was explored. The results indicated that the SPAE exhibited a more uniform particle size distribution than P. eryngii polysaccharide (PEP). Meanwhile, a typical absorption peak observed at 843 cm-1 in the SPAE FTIR spectra indicated the existence of α-glycosidic bonds. SPAE exhibited higher antioxidant abilities and superior resistance to digestion in vitro. In addition, SPAE supplementation to mice significantly reduced the release of factors that promote inflammation, enhanced the secretion of anti-inflammatory factors, and sustained maximum production of short-chain fatty acids (SCFAs). Additionally, it significantly enhanced the relative abundance of SCFAs-producing Akkermansia and reduced the abundance of Ruminococcus and Clostridiides in intestines of mice. These results show the potential of SPAE as a novel material with prebiotic effects for the food and pharmaceutical industries.

Shaping human gut community assembly and butyrate production by controlling the arginine dihydrolase pathway

The arginine dihydrolase pathway (arc operon) present in a subset of diverse human gut species enables arginine catabolism. This specialized metabolic pathway can alter environmental pH and nitrogen availability, which in turn could shape gut microbiota inter-species interactions. By exploiting synthetic control of gene expression, we investigated the role of the arc operon in probiotic Escherichia coli Nissle 1917 on human gut community assembly and health-relevant metabolite profiles in vitro and in the murine gut. By stabilizing environmental pH, the arc operon reduced variability in community composition across different initial pH perturbations. The abundance of butyrate producing bacteria were altered in response to arc operon activity and butyrate production was enhanced in a physiologically relevant pH range. While the presence of the arc operon altered community dynamics, it did not impact production of short chain fatty acids. Dynamic computational modeling of pH-mediated interactions reveals the quantitative contribution of this mechanism to community assembly. In sum, our framework to quantify the contribution of molecular pathways and mechanism modalities on microbial community dynamics and functions could be applied more broadly.

Active pullulan-based coatings incorporated with Auricularia auricular extracts for preserving potato fresh-cuts

In the present study, Auricularia auricular polysaccharides (AAP) and Auricularia auricular proteins (AAPR) obtained from the waste products of Auricularia auricular were incorporated into pullulan (PUL) to obtain active packaging films/coatings. Results showed that incorporating AAP/AAPR into PUL-based films decreased their transparency, but increased the compactness, thermal stability, antioxidant, and antimicrobial properties. Adding 2% PUL films with 10%:10% of AAP/AAPR exhibiting good mechanical properties were applied to fresh-cut potatoes to avoid spoilage during eight days of storage, with significantly decreased in browning index, weight loss, microbial growth prevention and the total soluble solids was maintained. These results substantiated that pullulan containing AAP/AAPR as an active film/coating with antioxidant and antimicrobial properties has significant potential for maintaining safety and quality of fresh-cut potatoes and extending their shelf life.

Impact of polyphenol-loaded edible starch nanomaterials on antioxidant capacity and gut microbiota

Starch nanoparticles (SNPs) have the capability to adsorb polyphenol components from apple pomace efficiently, forming bound polyphenols (P-SNPs). These bound polyphenols may have potential bioactivities to affect human health positively. Therefore, in-depth in vivo observation of the antioxidant activity and evaluation of its gut microbiota regulatory function are essential. The results revealed that P-SNPs indicated significant scavenging abilities against DPPH, ABTS, and hydroxyl radicals. Furthermore, the nanomaterials exhibited non-toxic properties, devoid of hepatorenal and intestinal damage, while concurrently stimulating the production of short-chain fatty acids (SCFAs) within the gastrointestinal tract. Notably, P-SNPs significantly enhanced antioxidant capacity in serum, liver, and kidney tissues, fostering the proliferation of beneficial bacteria (Lactobacillus, Bacillus, norank_f__Muribaculaceae) while suppressing pathogenic bacterial growth (Helicobacter, Odoribacter). This study proposes a novel research concept for the scientific use of polyphenols in promoting gut health.

The function and application of edible fungal polysaccharides

Edible fungi, commonly known as mushrooms, are precious medicinal and edible homologous gifts from nature to us. Edible fungal polysaccharides (EFPs) are a variety of bioactive macromolecular which isolated from fruiting bodies, mycelia or fermentation broths of edible or medicinal fungus. Increasing researches have confirmed that EFPs possess multiple biological activities both in vitro and in vivo settings, including antioxidant, antiviral, anti-inflammatory, immunomodulatory, anti-tumor, hypoglycemic, hypolipidemic, and regulating intestinal flora activities. As a result, they have emerged as a prominent focus in the healthcare, pharmaceutical, and cosmetic industries. Fungal EFPs have safe, non-toxic, biodegradable, and biocompatible properties with low immunogenicity, bioadhesion ability, and antibacterial activities, presenting diverse potential applications in the food industries, cosmetic, biomedical, packaging, and new materials. Moreover, varying raw materials, extraction, purification, chemical modification methods, and culture conditions can result in variances in the structure and biological activities of EFPs. The purpose of this review is to provide comprehensively and systematically organized information on the structure, modification, biological activities, and potential applications of EFPs to support their therapeutic effects and health functions. This review provides new insights and a theoretical basis for prospective investigations and advancements in EFPs in fields such as medicine, food, and new materials.

Investigation the nutritional properties of Auricularia auricula pulp fermented with Lactobacillus strains and their effects on gut microbiota

BACKGROUND

Auricularia auricula is rich in bioactive components, and microbial fermentation can further dramatically increase its content and bioavailability. However, there are few studies on the relationship between fermented A. auricula pulp (FAAP) and gut microbiota. In this study, standard strains Lactobacillus plantarum 21801 and 21805 purchased from the China Center of Industrial Culture Collection were used to ferment A. auricula pulp at a ratio of 2:1, with an inoculum of 5%, a fermentation temperature of 31 °C, and a fermentation time of 22 h. The nutritional properties, aroma, and color of FAAP and their effects on the body characteristics of mice and the structure and abundance of gut microbiota are discussed.

RESULTS

The results showed that, compared with A. auricula pulp, FAAP significantly increased the nutritional properties while maintaining favorable sensory quality and flavor profiles. Among them, the content of total polyphenols and total flavonoids reached 22.04 μg mL-1 and 20.56 μg mL-1 respectively, and the 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid free-radical scavenging rate increased to 73.21%. The consumption of FAAP had no negative effects on weight or liver and kidney function in mice and dramatically enhanced the antioxidant capacity in the liver and serum. The production of short-chain fatty acids in the gut was promoted, the relative abundance of beneficial bacteria (Lactobacillus, Bifidobacterium, norank_f__Muribaculaceae and unclassified_f__Lachnospiraceae) increased, and the growth of some pathogenic bacteria (Helicobacter, Mucispirillum, and Alloprevotella) was inhibited.

CONCLUSION

These findings demonstrate that FAAP is rich in nutrients and has unique functional properties that promote host health and regulate the gut microbiota. © 2023 Society of Chemical Industry.

Molecular Mechanism of Polysaccharides Extracted from Chinese Medicine Targeting Gut Microbiota for Promoting Health

The accumulating evidence revealed that gut microbiota plays an important role in pathological process of disease including obesity, type 2 diabetes mellitus, heart failure, and non-alcoholic fatty liver disease. Polysaccharides extracted from Chinese medicine (CM) can not only alleviate pathological status but also promote health by anti-inflammatory, regulating immunity, lowering blood glucose and lipids, anti-cancer, and anti-oxidation. The alterations of gut microbiota composition and metabolism pathways are the potential mechanisms of CM polysaccharides treatment. In addition, they exert functions through gut-organ axis or play an indirect role by synergistic actions with other drugs or components mediated by gut microbiota. This review summarizes the molecular mechanisms of CM polysaccharides interacted with intestinal microbial inhabitants as potential prebiotics for promoting health.

The Influence of Polysaccharides on Lipid Metabolism: Insights from Gut Microbiota

SCOPE

Polysaccharides are complex molecules of more than ten monosaccharide residues interconnected through glycosidic linkages formed via condensation reactions. Polysaccharides are widely distributed in various food resources and have gained considerable attention due to their diverse biological activities. This review presented a critical analysis of the existing research literature on anti-obesity polysaccharides and investigates the complex interplay between their lipid-lowering activity and the gut microbiota, aiming to provide a comprehensive overview of the lipid-lowering properties of polysaccharides and the underlying mechanisms of action.

METHODS AND RESULTS

In this review, the study summarized the roles of polysaccharides in improving lipid metabolism via gut microbiota, including the remodeling of the intestinal barrier, reduction of inflammation, inhibition of pathogenic bacteria, reduction of trimethylamine N-oxide (TMAO) production, and regulation of the metabolism of short-chain fatty acids (SCFAs) and bile acids (BAs).

CONCLUSION

These mechanisms collectively contributed to the beneficial effects of polysaccharides on lipid metabolism and overall metabolic health. Furthermore, polysaccharide-based nanocarriers combined with gut microbiota have broad prospects for developing targeted and personalized therapies for hyperlipidemia and obesity.

Glycolysis characteristics of intracellular polysaccharides from Agaricus bitorquis (Quél.) sacc. Chaidam and its effects on intestinal flora from different altitudes of mice in vitro fermentation

The glycolysis characteristics and effects on intestinal flora of polysaccharides from Agaricus bitorquis (Quél.) Sacc. Chaidam (ABIPs) in vitro fermentation by different altitudes of mice feces was examined, including low, medium, and high altitudes groups (LG, MG, and HG). In vitro, fermentation of ABIPs forty-eight hours resulted in a remarkable decrease in total sugar content and improvement of short-chain fatty acids (SCFAs) (mainly acetate, propionate, and butyrate), which simultaneously induced the composition of monose and uronic acids and SCFAs continuously change. Besides, ABIPs influenced the abundance and composition of the intestinal flora, generally increasing the abundance of probiotic bacteria (such as Bifidobacterium and Faecalibacterium) and decreasing the abundance of harmful bacteria (such as Phenylobacterium and Streptococcus) in all groups, with the highland biology core genus Blautia significantly enriched in LG and MG groups. It was also found that ABIPs enhanced pathways associated with biosynthesis and metabolism. In addition, correlation analysis speculated that the metabolism of SCFAs by ABIPs may be associated with genera such as Anaerostipes, Roseburia, and Weissella. ABIPs may protect organismal health by regulating hypoxic intestinal flora composition and metabolic function, and more superior fermentation performance was observed in MG compared to other groups.

The Effect of Mushroom Dietary Fiber on the Gut Microbiota and Related Health Benefits: A Review

Mushroom dietary fiber is a type of bioactive macromolecule derived from the mycelia, fruiting bodies, or sclerotia of edible or medicinal fungi. The use of mushroom dietary fiber as a prebiotic has recently gained significant attention for providing health benefits to the host by promoting the growth of beneficial microorganisms; therefore, mushroom dietary fiber has promising prospects for application in the functional food industry and in drug development. This review summarizes methods for the preparation and modification of mushroom dietary fiber, its degradation and metabolism in the intestine, its impact on the gut microbiota community, and the generation of short-chain fatty acids (SCFAs); this review also systematically summarizes the beneficial effects of mushroom dietary fiber on host health. Overall, this review aims to provide theoretical guidance and a fresh perspective for the prebiotic application of mushroom dietary fiber in the development of new functional foods and drugs.

Auricularia auricula polysaccharides attenuate obesity in mice through gut commensal Papillibacter cinnamivorans

INTRODUCTION

Auricularia auricula is a well-known traditional edible and medical fungus with high nutritional and pharmacological values, as well as metabolic and immunoregulatory properties. Nondigestible fermentable polysaccharides are identified as primary bioactive constituents of Auricularia auricula extracts. However, the exact mechanisms underlying the effects of Auricularia auricula polysaccharides (AAP) on obesity and related metabolic endpoints, including the role of the gut microbiota, remain insufficiently understood.

METHODS

The effects of AAP on obesity were assessed within high-fat diet (HFD)-based mice through obesity trait analysis and metabolomic profiling. To determine the mechanistic role of the gut microbiota in observed anti-obesogenic effects AAP, faecal microbiota transplantation (FMT) and pseudo-germ-free mice model treated with antibiotics were also applied, together with 16S rRNA genomic-derived taxonomic profiling.

RESULTS

High-fat diet (HFD) murine exposure to AAP thwarted weight gains, reduced fat depositing and enhanced glucose tolerance, together with upregulating thermogenesis proteomic biomarkers within adipose tissue. Serum metabolome indicated these effects were associated with changes in fatty acid metabolism. Intestine-dwelling microbial population assessments discovered that AAP selectively enhanced Papillibacter cinnamivorans, a commensal bacterium with reduced presence in HFD mice. Notably, HFD mice treated with oral formulations of P. cinnamivorans attenuated obesity, which was linked to decreased intestinal lipid transportation and hepatic thermogenesis. Mechanistically, it was demonstrated that P. cinnamivorans regulated intestinal lipids metabolism and liver thermogenesis by reducing the proinflammatory response and gut permeability in a JAK-STAT signaling-related manner.

CONCLUSION

Datasets from the present study show that AAP thwarted dietary-driven obesity and metabolism-based disorders by regulating intestinal lipid transportation, a mechanism that is dependent on the gut commensal P. cinnamivorans. These results indicated AAP and P. cinnamivorans as newly identified pre- and probiotics that could serve as novel therapeutics against obesity.

Auricularia auricula-judae (Bull.) polysaccharides improve obesity in mice by regulating gut microbiota and TLR4/JNK signaling pathway

Obesity has emerged as a crucial factor impacting people's lives, and gut microbiota disorders contribute to its development and progression. Auricularia auricula-judae (Bull.) polysaccharides (AAPs), a traditional functional food in Asia, exhibit potential anti-obesity effects. However, the specific mechanism still needs to be further confirmed. This study investigated the beneficial effects and specific mechanisms of AAPs on obesity. Firstly, AAPs showed significant improvements in overweight, insulin resistance, glucose and lipid metabolism disorders, and liver damage in obese mice. Additionally, AAPs ameliorated gut microbiota disorders, promoting the proliferation of beneficial bacteria like Lactobacillus and Roseburia, resulting in increased levels of SCFAs, folate, and cobalamin. Simultaneously, AAPs inhibited the growth of harmful bacteria, thereby protecting intestinal barrier function, improving endotoxemia, and decreasing the levels of inflammatory factors such as TNF-α and IL-6. Furthermore, AAPs can inhibit the TLR4/JNK signaling pathway while promoting the activation of AKT and AMPK. Importantly, our study underscored the pivotal role of gut microbiota in the anti-obesity effects of AAPs, as evidenced by fecal microbiota transplantation experiments. In conclusion, our findings elucidated that AAPs improve obesity by regulating gut microbiota and TLR4/JNK signaling pathway, offering novel perspectives for further conclusion the anti-obesity potential of AAPs.

Morel (Morchella spp.) intake alters gut microbial community and short-chain fatty acid profiles in mice

Morels (Morchella spp.) are highly nutritious and consumed as both edible mushrooms and traditional Chinese medicine. This study aimed to investigate the effects of dietary supplementation with morel mushrooms on the gut bacterial microbiota and short-chain fatty acids (SCFAs) profiles in healthy mice. Healthy mice were randomly assigned to five groups: a control group (0% morel) and four intervention groups supplemented with different levels of morel mushrooms (5% for M5, 10% for M10, 15% for M15, and 20% for M20) over a period of 4 weeks. Fecal samples were collected at the end of the experiment to characterize the microbiota and assess the SCFAs levels. The morel intervention significantly altered the bacterial community composition, increasing Bacteroides, Lachnospiraceae NK4A136 group and Parabacteroides, while decreasing Staphylococcus and the Firmicutes to Bacteroidetes ratio (F/B ratio). Moreover, increased morel intake was associated with weight loss. All SCFAs content was upregulated in the morel-intervention groups. Potential SCFAs-producing taxa identified by regression analysis were distributed in the families Muribaculaceae, Lachnospiraceae, and in the genera Jeotgalicoccus, Gemella, Odoribacter, Tyzzerella 3 and Ruminococcaceae UCG-014. The functional categories involved with SCFAs-production or weight loss may contain enzymes such as beta-glucosidase (K05349), beta-galactosidase (K01190), and hexosaminidase (K12373) after morel intervention. The exploration of the impact of morel mushrooms on gut microbiota and metabolites contributes to the development of prebiotics for improving health and reducing obesity.

Impacts of sulfur fumigation on the chemistry and immunomodulatory activity of polysaccharides in ginseng

Ginseng is widely regarded as a panacea in Oriental medicine mainly due to its immunomodulatory activity. We previously found that sulfur fumigation, a commonly used pesticidal and anti-bacterial processing practice, weakened the immunomodulatory activity of ginseng. However, if and how sulfur fumigation affects the polysaccharides in ginseng, the crucial components contributing to the immunomodulatory function, remain unknown. Here we report that polysaccharides extracted from sulfur-fumigated ginseng (SGP) presented different chemical properties with polysaccharides extracted with non-fumigated ginseng (NGP), particularly increased water extraction yield and decreased branching degree. SGP had weaker immunomodulatory activity than NGP in immunocompromised mice, as evidenced by less improved immunophenotypes involving body weight, immune organ indexes, white blood cells, lymphocyte cell populations and inflammation. The different immunomodulatory activities were accompanied by changes in the interaction between the polysaccharides and gut microbiota, in which SGP stimulated the growth of different bacteria but produced less SCFAs as compared to NGP. Fecal microbiota transplantation experiment suggested that gut microbiota played a central role in causing the weakened immunomodulatory activity in vivo. This study provides definite evidence that sulfur fumigation affects the chemistry and bioactivity of ginseng polysaccharides, thereby contributing to understanding how sulfur fumigation weakens the immunomodulatory activity of ginseng.

The polysaccharides from Auricularia auricula alleviate non-alcoholic fatty liver disease via modulating gut microbiota and bile acids metabolism

The polysaccharides from Auricularia auricula (AAPs), containing a large number of O-acetyl groups that are related to the physiological and biological properties, seem to be potential prebiotics like other edible fungus polysaccharides. In the present study, therefore, the alleviating effects of AAPs and deacetylated AAPs (DAAPs, prepared from AAPs by alkaline treatment) on nonalcoholic fatty liver disease (NAFLD) induced by high-fat and high-cholesterol diet combined with carbon tetrachloride were investigated. The results revealed that both AAPs and DAAPs could effectively relieve liver injury, inflammation and fibrosis, and maintain intestinal barrier function. Both AAPs and DAAPs could modulate the disorder of gut microbiota and altered the composition of gut microbiota with enrichment of Odoribacter, Lactobacillus, Dorea and Bifidobacterium. Further, the alteration of gut microbiota, especially enhancement of Lactobacillus and Bifidobacterium, was contributed to the changes of bile acids (BAs) profile with increased deoxycholic acid (DCA). Farnesoid X receptor could be activated by DCA and other unconjugated BAs, which participated the BAs metabolism and alleviated the cholestasis, then protected against hepatitis in NAFLD mice. Interestingly, it was found that the deacetylation of AAPs negatively affected the anti-inflammation, thereby reducing the health benefits of A. auricula-derived polysaccharides.

Fermented Wheat Bran Polysaccharides Improved Intestinal Health of Zebrafish in Terms of Intestinal Motility and Barrier Function

Intestinal barrier dysfunction and gut microbiota disorders have been associated with various intestinal and extraintestinal diseases. Fermented wheat bran polysaccharides (FWBP) are promising natural products for enhancing the growth performance and antioxidant function of zebrafish. The present study was conducted, in order to investigate the effects of FWBP on the intestinal motility and barrier function of zebrafish, which could provide evidence for the further potential of using FWBP as a functional food ingredient in the consideration of gut health. In Experiment 1, the normal or loperamide hydrochloride-induced constipation zebrafish larvae were treated with three concentrations of FWBP (10, 20, 40 μg/mL). In Experiment 2, 180 one month-old healthy zebrafish were randomly divided into three groups (six replicates/group and 10 zebrafish/tank) and fed with a basal diet, 0.05% FWBP, or 0.10% FWBP for eight weeks. The results showed that FWBP treatment for 6 h can reduce the fluorescence intensity and alleviate constipation, thereby promoting the gastrointestinal motility of zebrafish. When compared with control group, zebrafish fed diets containing FWBP showed an increased villus height (p < 0.05), an up-regulated mRNA expression of the tight junction protein 1α, muc2.1, muc5.1, matrix metalloproteinases 9 and defensin1 (p < 0.05), an increased abundance of the phylum Firmicutes (p < 0.05), and a decreased abundance of the phylum Proteobacteria, family Aeromonadaceae, and genus Aeromonas (p < 0.05). In addition, 0.05% FWBP supplementation up-regulated the intestinal mRNA expression of IL-10 and Occludin1 (p < 0.05), enhanced the Shannon and Chao1 indexes (p < 0.05), and increased the abundance of Bacteroidota and Actinobacteriota at the phylum level (p < 0.05). Additionally, 0.1% FWBP supplementation significantly improved the villus height to crypt depth ratio (p < 0.05) and increased the mRNA expression of IL-17 (p < 0.05). These findings reveal that FWBP can promote the intestinal motility and enhance the intestinal barrier function, thus improving the intestinal health of zebrafish.

Simulated gastrointestinal digestion and gut microbiota fermentation of polysaccharides from Agaricus bisporus

Agaricus bisporus, an edible mushroom, is grown and consumed worldwide for its delicious taste and multiple health benefits. A. bisporus polysaccharides (ABP) are the main bioactive ingredient of the mushroom that confers health benefits. In this study, we prepared and characterized ABP, and the digestion, fermentation prosperities, and the effect of ABP on gut microbiota were detected via in vitro simulated digestion and gut microbiota fermentation. The results showed that during the simulated digestion process, the molecular weight of ABP was unchanged, and no free monosaccharide was produced, indicating that ABP could not be digested completely. However, after the fermentation, gut microbiota degraded and utilized ABP, which produced short-chain fatty acids and caused a decrease in pH value. Meanwhile, ABP modulated the gut microbiota composition by increasing the abundance of beneficial bacteria. The results suggested that ABP is a promising food component with prebiotic potential.

The Interaction between Mushroom Polysaccharides and Gut Microbiota and Their Effect on Human Health: A Review

Mushroom polysaccharides are a kind of biological macromolecule extracted from the fruiting body, mycelium or fermentation liquid of edible fungi. In recent years, the research on mushroom polysaccharides for alleviating metabolic diseases, inflammatory bowel diseases, cancers and other symptoms by changing the intestinal microenvironment has been increasing. Mushroom polysaccharides could promote human health by regulating gut microbiota, increasing the production of short-chain fatty acids, improving intestinal mucosal barrier, regulating lipid metabolism and activating specific signaling pathways. Notably, these biological activities are closely related to the molecular weight, monosaccharide composition and type of the glycosidic bond of mushroom polysaccharide. This review aims to summarize the latest studies: (1) Regulatory effects of mushroom polysaccharides on gut microbiota; (2) The effect of mushroom polysaccharide structure on gut microbiota; (3) Metabolism of mushroom polysaccharides by gut microbiota; and (4) Effects of mushroom polysaccharides on gut microbe-mediated diseases. It provides a theoretical basis for further exploring the mechanism of mushroom polysaccharides for regulating gut microbiota and gives a reference for developing and utilizing mushroom polysaccharides as promising prebiotics in the future.

Assessment of the Effects of Edible Microalgae in a Canine Gut Model

Microalgae are a source of bioactive compounds having recently been studied for their possible application as health-promoting ingredients. The aim of the study was to evaluate in an in vitro canine gut model the effects of four microalgae, Arthrospira platensis (AP), Haematococcus pluvialis (HP), Phaeodactylum tricornutum (PT) and Chlorella vulgaris (CV), on some fecal microbial populations and metabolites. The four microalgae were subjected to an in vitro digestion procedure, and subsequently, the digested biomass underwent colonic in vitro fermentation. After 6 h of incubation, PT increased propionate (+36%) and butyrate (+24%), and decreased total BCFA (−47%), isobutyrate (−52%) and isovalerate (−43%) and C. hiranonis (−0.46 log10 copies/75 ng DNA). After 24 h, PT increased propionate (+21%) and isovalerate (+10%), and decreased the abundance of Turicibacter spp. (7.18 vs. 6.69 and 6.56 log10 copies/75 ng DNA for CTRL vs. PT, respectively); moreover, after 24 h, CV decreased C. coccoides (−1.12 log10 copies/75 ng DNA) and Enterococcus spp. (−0.37 log10 copies/75 ng DNA). In conclusion, the microbial saccharolytic activities and the shift in fecal bacterial composition were less pronounced than expected, based on current literature. This study should be considered as a preliminary assessment, and future investigations are required to better understand the role of microalgae in canine nutrition.

Bioactive polysaccharides and oligosaccharides from garlic (Allium sativum L.): Production, physicochemical and biological properties, and structure-function relationships

Garlic is a common food, and many of its biological functions are attributed to its components including functional carbohydrates. Garlic polysaccharides and oligosaccharides as main components are understudied but have future value due to the growing demand for bioactive polysaccharides/oligosaccharides from natural sources. Garlic polysaccharides have molecular weights of 1 × 10³ to 2 × 10⁶  Da, containing small amounts of pectins and fructooligosaccharides and large amounts of inulin-type fructans ((2→1)-linked β-d-Fruf backbones alone or with attached (2→6)-linked β-d-Fruf branched chains). This article provides a detailed review of research progress and identifies knowledge gaps in extraction, production, composition, molecular characteristics, structural features, physicochemical properties, bioactivities, and structure-function relationships of garlic polysaccharides/oligosaccharides. Whether the extraction processes, synthesis approaches, and modification methods established for other non-garlic polysaccharides are also effective for garlic polysaccharides/oligosaccharides (to preserve their desired molecular structures and bioactivities) requires verification. The metabolic processes of ingested garlic polysaccharides/oligosaccharides (as food ingredients/dietary supplements), their modes of action in healthy humans or populations with chronic conditions, and molecular/chain organization-bioactivity relationships remain unclear. Future research directions related to garlic polysaccharides/oligosaccharides are discussed.

Effect of Polysaccharide Extracted From Gynostemma Pentaphyllum on the Body Weight and Gut Microbiota of Mice

Researchers have investigated the role of polysaccharides in disease treatment via gut microbiota regulation but ignore their function in disease prevention and physique enhancement. In this work, a Gynostemma pentaphyllum polysaccharide (GPP) was tested by methyl thiazolyl tetrazolium (MTT) assay and proved to be safe to Caco-2 cells. Animal experiments showed that the administration of GPP for 3 weeks decreased the body weight gain of mice from 15.4 ± 1.7 to 12.2 ± 1.8 g in a concentration-dependent manner. Analysis of short-chain fatty acids (SCFAs) indicated that GPP increased the levels of acetate, propionate, butyrate, and total SCFAs in the cecum contents of normal mice. Furthermore, GPP improved the species richness and abundance in the gut microbiota but reduced the Firmicutes/Bacteroidetes ratio from 0.8021 to 0.3873. This work provides a basis for incorporating GPP into diet to prevent or mitigate the occurrence of obesity via gut microbiota regulation.

Anti-hyperlipidemic and ameliorative effects of chickpea starch and resistant starch in mice with high fat diet induced obesity are associated with their multi-scale structural characteristics

Chickpea starches were isolated from both untreated (UC-S) and conventionally cooked seeds (CC-S), and their multi-scale structural characteristics and in vivo physiological effects on controlling hyperlipidemia in high fat diet induced obese mice were compared with their corresponding resistant starch (RS) fractions obtained by an in vitro enzymatic isolation method (UC-RS and CC-RS). The degree of order/degree of double helix in Fourier transform infrared spectroscopy was in the following order: CC-RS > UC-RS > CC-S > UC-S, which was consistent with the trend observed for relative crystallinity and double helix contents monitored by X-ray diffractometer and solid-state ¹³C cross-polarization and magic angle spinning NMR analyses. The influence of different types of chickpea starch and their corresponding resistant starch fractions on regulating the serum lipid profile, antioxidant status, and histopathological changes in liver, colon and cecal tissues, and gene expressions associated with lipid metabolism, gut microbiota, as well as short-chain fatty acid metabolites in mice with high fat diet induced obesity was investigated. The results showed that the chickpea RS diet group exhibited overall better anti-hyperlipidemic and ameliorative effects than those of the starch group, and such effects were most pronounced in the CC-RS intervention group. After a six-week period of administration with chickpea starch and RS diets, mice in the UC-RS and CC-RS groups tended to have relatively significantly higher levels (P < 0.05) of butyric acid in their fecal contents. The 16S rRNA sequencing results revealed that mice fed with CC-RS showed the greatest abundance of Akkermansia and Lactobacillus compared with the other groups.

Comparison on chemical features and antioxidant activity of polysaccharides from Auricularia auricula by three different enzymes

To investigate and compare the chemical features and antioxidant activities of Auricularia auricula polysaccharides (AAPs), three different AAPs (AAP-M, AAP-D, and AAP-C) were prepared by mannanase, β-dextranase, and cellulase. Their chemical features were determined using high-performance liquid chromatography and infrared spectroscopy. The antioxidant properties were performed both in vitro and in vivo. Results showed that the surface morphology of the A. auricula cell wall treated with three enzymes was slightly different under scanning electron microscopy. The extraction yields of AAP-M, AAP-D, and AAP-C were 18.33% ± 1.93%, 26.42% ± 0.87%, and 17.17% ± 0.08% under optimal conditions, respectively. The monosaccharide composition, molecular weight (AAP-M, AAP-D, and AAP-C were 1.03E+03 kDa, 1.76E+03 kDa, and 1.15E+03 kDa, respectively), and antioxidant activities of the three AAPs were different. AAP-C composed of mannose, glucuronic acid, glucose, and galactose, exhibiting the remarkable ability of scavenging ABTS⁺ , DPPH, and H₂ O₂ (IC₅₀ was 0.065, 0.081, and 0.293 mg/ml, respectively). Moreover, AAP-C could significantly prolonged the lifespan of Caenorhabditis elegans under oxidative stress (p < .05). The results showed that cellulase could be served as an efficient enzyme to prepare AAPs with higher antioxidant capacity. PRACTICAL APPLICATIONS: According to the statistics of China Edible Fungi Association in 2019, the output of Auricularia auricula was accounting for 17.54% of the total output of edible fungi. AAPs account for more than 60% of the fruiting bodies and have various biological activities. Cell wall breaking is an important process of extracting AAPs which has always been the bottleneck restricting the production of AAPs. The traditional chemical acid-base method will pollute the environment, and the yield of hot water extraction is low. In contrast, the bioenzyme method widely used because of its mild conditions and environmental friendly. In this paper, three common bioenzymes which have been widely used in food industry were used to extract AAPs, and Box-Behnken design to improve the yield of AAPs. The results show that AAP-C had high yield and strong antioxidant activity. This study could provide a reference for the industrial production of AAPs.

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.

Differences of gut microbiota composition in mice supplied with polysaccharides from γ-irradiated and non-irradiated Schizophyllum commune

In this study, polysaccharides from normal (N-SFP) and γ-irradiated (I-SFP) Schizophyllum commune were supplied to Kunming mice for 30 days. The results showed that N-SFP and I-SFP supplementation prevent body weight gain, enhance kidney uric acid metabolism and increase the concentration of SCFAs to a certain extent. Moreover, N-SFP and I-SFP promote the growth of beneficial gut microbiota and inhibit the growth of harmful bacteria. Compared to N-SFP, I-SFP decreased the relative abundance of Muribaculaceae and Lactobacillaceae, and increased the beneficial gut microbiota, especially the family of Akkermansiaceae, Lachnospiraceae and Bacteroidaceae. In total, I-SFP showed better effects than N-SFP in preventing weight gain, and modulating the mice gut microbiota, which suggests that I-SFP could act as a potential health supplement in the prevention of obesity.

Cereus sinensis Polysaccharide Alleviates Antibiotic-Associated Diarrhea Based on Modulating the Gut Microbiota in C57BL/6 Mice

The present study investigated whether the purified polysaccharide from Cereus sinensis (CSP-1) had beneficial effects on mice with antibiotic-associated diarrhea (AAD). The effects of CSP-1 on gut microbiota were evaluated by 16S rRNA high-throughput sequencing. Results showed that CSP-1 increased the diversity and richness of gut microbiota. CSP-1 enriched Phasecolarctobacterium, Bifidobacterium and reduced the abundance of Parabacteroides, Sutterella, Coprobacillus to near normal levels, modifying the gut microbial community. Microbial metabolites were further analyzed by gas chromatography-mass spectrometry (GC-MS). Results indicated CSP-1 promoted the production of various short-chain fatty acids (SCFAs) and significantly improved intestinal microflora dysfunction in AAD mice. In addition, enzyme linked immunosorbent assay and hematoxylin-eosin staining were used to assess the effects of CSP-1 on cytokine levels and intestinal tissue in AAD mice. Results demonstrated that CSP-1 inhibited the secretion of interleukin-2 (IL-2), interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) and improved the intestinal barrier. Correspondingly, the daily records also showed that CSP-1 promoted recovery of diarrhea status score, water intake and body weight in mice with AAD. In short, CSP-1 helped alleviate AAD by regulating the inflammatory cytokines, altering the composition and richness of intestinal flora, promoting the production of SCFAs, improving the intestinal barrier as well as reversing the dysregulated microbiota function.

Edible fungal polysaccharides, the gut microbiota, and host health

The plasticity of the gut microbiota (GM) creates an opportunity to reshape the biological output of gut microbes by manipulating external factors. It is well known that edible fungal polysaccharides (EFPs) can reach the distal intestine and be assimilated to reshape the GM. The GM has unique devices that utilize various EFPs and produce oligosaccharides, which can selectively promote the growth of beneficial bacteria and are fermented into short-chain fatty acids that interact closely with intestinal cells. Here we review EFPs-based interventions for the GM, particularly the key microorganisms, functions, and metabolites. In addition, we discuss the bi-directional causality between GM imbalance and diseases, and the beneficial effects of EFPs on host health via GM. This review can offer a valuable reference for the design of edible fungal polysaccharide- or oligosaccharide-based nutrition interventions or drug development for maintaining human health by targeted regulation of the GM.

Auricularia auricula-judae (Bull.) polysaccharides improve type 2 diabetes in HFD/STZ-induced mice by regulating the AKT/AMPK signaling pathways and the gut microbiota

Auricularia auricula-judae is an edible fungus with high nutritional value due to abundant polysaccharides, and is acknowledged as traditional food and medicine in Asia. Polysaccharides from A. auricula (AAPs) are typically fungal polysaccharides and have a wide range of biological activities. It has been shown the potential of AAPs to improve diabetes as an effective adjuvant, but the underlying mechanism remains unclear. In this study, we explored the effects and potential mechanism of AAPs on type 2 diabetes (T2D) using a high-fat diet and streptozotocin (STZ) induced C57BL/6J mice. The results indicated that 50 and 100 mg/kg AAPs significantly decreased inflammation, liver injury, and insulin resistance. In addition, AAPs improved glycolipid metabolism disorders by activating the AKT and adenosine 5`monophosphate-activated protein kinase (AMPK) signaling pathways in T2D mice. Furthermore, we investigated the association between changes of gut microbiota and AAPs effects using high-throughput sequencing of 16S rDNA for fecal samples. In our study, AAPs elevated gut microbiota diversity and optimized microbial composition and function in T2D mice, characterized by increased Lactobacillus and Bacteroides abundance and decreased Clostridium and Allobaculum abundance. Particularly, AAPs intervention mainly affected the amino acid metabolism and glycolipid metabolism pathways. Overall, this study confirms that AAPs can improve type 2 diabetes by regulating the AKT and AMPK pathways and modulating intestinal microbiota. PRACTICAL APPLICATION: The article systematically verified the positive effects of AAPs on insulin resistance, glycolipid metabolism disorder, inflammation, and liver injury, key factors closely related to T2D. Furthermore, our study firstly determined the specific underlying mechanism that AAPs ameliorates T2D through regulating AKT/AMPK pathways and modifying the gut microbiota. These results could offer a full explanation and a potential option for the adjuvant therapy of diabetes with AAPs.

Regulation of wheat germ polysaccharides in the immune response of mice from newborn to adulthood associated with intestinal microbiota

The aim of this study was to determine the effects of wheat germ polysaccharides (WGPs), which are indigestible carbohydrate fibers, on mice in early life, and the changes leading to long-lasting consequences. We determined the influences of early life ceftriaxone and WGP treatment on intestinal microbiota and immunity both in newborn and adulthood mice. The results showed that ceftriaxone significantly altered the intestinal microbiota, short-chain fatty acids' (SCFAs) metabolism, organ index, and serum OVA-specific IgE levels in newborn mice. Comparing adulthood mice to ceftriaxone-treated mice, the diversity and composition of intestinal microbiota were significantly improved after WGP treatment. In addition, the levels of OVA-specific IgE in the WGP-treated mice were significantly decreased, and the expression of cytokines (IL-2, IL-4, IL-6, IFN-γ, and TNF-α) were obviously increased. Therefore, we speculate that the mechanism of action of the indigestible carbohydrate fibers of WGPs is through maintaining immune homeostasis in newborns, which may partly last into adulthood. More importantly, this may be closely related to alterations in the intestinal microbiota.

Health benefits of edible mushroom polysaccharides and associated gut microbiota regulation

Edible mushrooms have been an important part of the human diet for thousands of years, and over 100 varieties have been cultivated for their potential human health benefits. In recent years, edible mushroom polysaccharides (EMPs) have been studied for their activities against obesity, inflammatory bowel disease (IBD), and cancer. Particularly, accumulating evidence on the exact causality between these health risks and specific gut microbiota species has been revealed and characterized, and most of the beneficial health effects of EMPs have been associated with its reversal impacts on gut microbiota dysbiosis. This demonstrates the key role of EMPs in decreasing health risks through gut microbiota modulation effects. This review article compiles and summarizes the latest studies that focus on the health benefits and underlying functional mechanisms of gut microbiota regulation via EMPs. We conclude that EMPs can be considered a dietary source for the improvement and prevention of several health risks, and this review provides the theoretical basis and technical guidance for the development of novel functional foods with the utilization of edible mushrooms.

Value added immunoregulatory polysaccharides of Hericium erinaceus and their effect on the gut microbiota

Hericium erinaceus polysaccharides (HEPs) were isolated from the fruiting bodies of H. erinaceus with 53.36 % total carbohydrates and 32.56 % uronic acid. To examine whether HEPs can alter the diversity and the abundance of gut microbiota, adult mice and middle-aged and old mice were fed with HEPs for 28 days. Based on the result of 16S sequencing of gut microbiota it was found that the relative abundances of Lachnospiraceae and Akkermansiaceae significantly increased, while the relative abundance of Rikenellaceae and Bacteroidaceae appeared to decrease. Bacterial solutions from different murine intestinal segments and feces were collected to ferment HEPs in vitro. It was found that HEPs remarkably promoted the production of NO, IL-6, IL-10, INF-γ and TNF-α. Moreover, HEPs significantly increased phosphorylation of signaling molecules, indicating that the immunomodulatory activity was completed via NF-кB, MAPK and PI3K/Akt pathways. Collectively, HEPs have potential to be developed as functional ingredients or foods to promote health.

Wheat germ glycoprotein regionally modulates immunosuppressed mouse intestinal immunity function from early life to adulthood

Wheat germ glycoprotein (WGP) is widely used due to its nutritional benefits and biological activity. This study evaluated the effects of WGP on intestinal-immunosuppressed mice from early life to adulthood and detected the underlying mechanism. The results revealed that WGP demonstrated no clinical side effects on the body index, serum total IgA level, protein expression and the morphology of intestine in newborn mice. In the phase of life, compared with the cyclophosphamide-treated group (CG), WGP clearly promoted the secretion of sIgA and effectively regulated the cytokine gene (IL-2, IFN-γ, TNF-α, IL-4, IL-6, IL-5, IL-17, and TGF-β1) expression in the intestine. Furthermore, WGP promoted the expression of CD40L and CD40, phosphorylation of IKKα/β and transcription of NF-κB-p65. The data as reported in this present analysis suggest that WGP can improve the intestinal immunity of newborn mice to adulthood via the CD40L-CD40-IKKα/β-NF-κB p65 signaling pathway.

Dietary intake of mixture coarse cereals prevents obesity by altering the gut microbiota in high-fat diet fed mice

Functional components including β-glucan, dietary fiber, resistant starch and polyphenols extracted from various coarse cereals have been reported to prevent high-fat diet (HFD) induced obesity via modulating gut microbiota. In this study, millet, maize, oat, soybean, and purple potato were ultrafine comminuted, mixed, and then extruded for the preparation of puffed mixture coarse cereals. HFD was used to investigate the effects of mixture coarse cereals on obesity and gut microbiota in mice. The results showed that dietary intake of mixture coarse cereals could decrease body weight gain and fat accumulation, improve the blood glucose tolerance and serum lipids levels, reduce the systemic inflammation, and down-regulate the expression of hepatic lipogenic genes. In addition, the levels of SCFAs and the composition of gut microbiota were investigated. The results indicated that mixture coarse cereals could promote the release of SCFAs, enhance the diversity of gut microbiota, and increase the relative abundance of Lactobacillus and Bifidobacterium, which might contribute to the anti-obesity activity. Present work suggested that the mixture coarse cereals could be developed as a nutraceutical for the prevention of HFD-induced obesity.

Effects of Polysaccharides From Auricularia auricula on the Immuno-Stimulatory Activity and Gut Microbiota in Immunosuppressed Mice Induced by Cyclophosphamide

Recently, the immuno-enhancing potential of polysaccharide from Auricularia auricula (AAP) has been an area of research interest. However, the immune-stimulatory activity and mechanisms of AAP in immunosuppressive mice treated with cyclophosphamide (CTX) are still poorly understood. This study aimed to evaluate the immuno-enhancing effects of AAP and mine its possible mechanisms. Firstly, polysaccharides were isolated from A. auricula and purified. Secondly, the immune-stimulatory activities of the first AAP fraction (AAP1) were evaluated in the CTX-treated mice. Results showed that AAP1 significantly enhanced immune organ indexes, remarkably stimulated IFN-γ, IL-2, IL-4, IL-10, and TNF-α levels in the serum, and dramatically up-regulated the mRNA levels of Claudin-1, Occludin and ZO-1. Compared to the CTX group, AAP1 administration restored the gut microbiota composition similar to that of the control group by decreasing the ratio of Firmicutes/Bacteroidetes and increasing the relative abundances of short-chain fatty acid-producing microbiota. This study provides useful information for its further application as an immune-stimulator in foods and drugs.

Marine polysaccharides from Gelidium pacificum Okamura and Cereus sinensis reveal prebiotic functions

Many marine polysaccharides as prebiotics can promote host health by modulating gut microbiota. This study investigated the beneficial effects of purified marine plant-derived Gelidium pacificum Okamura polysaccharide (GPOP-1) and marine animal-derived Cereus sinensis polysaccharide (CSP-1) on normal mice by modulating gut microbiota. The composition and diversity of gut microbiota were evaluated using 16S rRNA high-throughput sequencing. The results showed that GPOP-1 and CSP-1 altered the composition of the gut microbiota and promoted the growth of beneficial bacteria. At the genus level, GPOP-1 increased the relative abundance of Bacteroides, Phascolarctobacterium, and decreased the relative abundance of Ruminococcus, Helicobacter, Allobaculum, Dorea and AF12. While CSP-1 increased the relative abundance of Coprococcus, Adlercreutzia, Roseburia, Phascolarctobacterium, and decreased the relative abundance of Bacteroides, Ruminococcus and Oscillospira. The changes in the gut microbiota may affect the body weight, immune organ index and the production of short-chain fatty acids in normal mice. Compared to the normal control group, GPOP-1 decreased average weight gain while CSP-1 increased average weight gain. Furthermore, both GPOP-1 and CSP-1 significantly increased thymus and spleen indexes and total short chain fatty acids production in mice. In summary, GPOP-1 and CSP-1 exerted prebiotic effects on normal mice.