A Concise Review on the Molecular Structure and Function Relationship of β-Glucan

Synthesis and biological evaluation of mirror isomers of β-(1 → 3)-glucans as immune modulators

β-(1 → 3)-glucan is widely distributed in the cell walls of bacteria, fungi, yeasts and algae. A variety of pharmacological effects of β-(1 → 3)-glucan have been demonstrated, including immune modulation. The enzyme recognition pocket can recognize the chirality of the ligand and often give rise to disparate biological activities. The bioactivity of the mirror-image isomers of natural oligosaccharides is scarcely studied due to the difficulty of acquiring them. In this study, we have successfully completed the total synthesis of the naturally occurring β-ᴅ-(1 → 3)-glucans and their mirror image β-ʟ-(1 → 3)-glucans containing three, four, eight, and twelve monosaccharides for the first time. Subsequently, the immunomodulatory activities of ᴅ- and ʟ-type β-glucans were evaluated to explore their bioactivity and preliminary mechanism of action. The results indicated that mirror-image β-(1 → 3)-glucans exerted bidirectional regulatory effects on M0/M1-type macrophages. The ᴅ-type β-(1 → 3)-glucans have the potential to regulate macrophage polarization through the GPCR and CR3 signalling pathways. In contrast, the ʟ-type β-(1 → 3)-glucans achieved bidirectional regulation of macrophage polarization by influencing cellular metabolism. The findings presented herein provide new evidence for the further investigation of the biological activities of oligosaccharides and their mirror image isomers.

Extraction, purification, structural characterization, and anti-inflammatory activity of a polysaccharide from Lespedeza formosa

A new acidic polysaccharide was extracted from Lespedeza Formosa (LF) using microwave-assisted extraction. After a progressive purification, Lespedeza Formosa polysaccharide (LFP-1) with 96.14 % purity and moderate molecular weight was obtained. Subsequently, LFP-1's structural analysis and in vitro anti-inflammatory experiments were performed. LFP-1 is composed of nine monosaccharides, mainly including 39.7 % glucose, 29.1 % galactose, and 19.9 % arabinose, with three branched chains of its structure. The diverse monosaccharides and branched chains provided the essential conditions for the anti-inflammatory effects of LFP-1, which diminished the release of nitric oxide (NO) and reactive oxygen species (ROS). And they altered the release of internal inflammatory factors in lipopolysaccharide (LPS)-treated macrophages. LFP-1 exerted intracellularly anti-inflammatory effects through the nuclear factor kappa-B (NF-κB) signal pathway. The discovery of LFP-1 opens up a new possibility for natural anti-inflammatory medicine.

Prospects and applications of efficient physical field processing technologies for polysaccharide extraction and quality improvement in edible mushrooms: A systematic review

Edible mushroom-derived polysaccharides (EMPs) have been widely used in foods, medicine, and cosmetics due to theirs' diverse and versatile biological activities. Currently, many conventional extraction methods for extracting EMPs are struggling to meet the growing demand, and the produced EMPs with poor quality and low bioactivity. Novel physical field (e.g., acoustic, electromagnetic, electrical, and mechanical field) processing technologies not only overcome the shortcomings of conventional extraction methods, but also improve the structural feature, bioactivity, and solution behavior of EMPs. Moreover, physical field-assisted techniques can induce the degradation or modification of EMPs, thereby effectively altering the physicochemical properties and structural features of EMPs to improve their bioactivities or processing properties. Therefore, a comprehensive review of physical field processing technologies such as ultrasound, high pressure, pulsed electric field, and microwave for extracting and modifying EMPs in recent years, is presented. In addition, recent advances in physical field-assisted extraction/degradation techniques for EMPs, as well as their mechanisms of action and synergistic effects, are discussed and summarized. In summary, this review provides a theoretical basis and practical guidance for the physical field processing technology in improving the extraction yield and quality of EMPs, as well as large-scale industrial production.

Advanced insights into mushroom polysaccharides: Extraction methods, structure-activity, prebiotic properties, and health-promoting effects

Mushroom-derived polysaccharides, especially β-glucans, have attracted considerable attention because of their various biological regulatory functions. Advanced extraction technologies, including ultrasonic-assisted, microwave-assisted, enzyme-assisted, ultrasonic-microwave synergistic, subcritical water, and aqueous two-phase extractions, are extensively utilized to optimize the efficient recovery of biologically active compounds from mushrooms, progressively supplanting conventional methods. In addition, mushroom polysaccharides are acknowledged as "important biological response modifiers." Beyond their diverse bioactivities, including anticancer, immunomodulatory, anti-inflammatory, antimicrobial, antiviral, antidiabetic, hypocholesterolemia, anti-lipidemic, and antioxidant effects, increasing interest has been directed towards their prebiotic potential, especially regarding their ability to influence gut microbiota. This review presents a comprehensive summary of the extraction and purification methods, biological properties, structure-function relationships, and mechanisms of mushroom polysaccharides, highlighting the latest advancements in the field from 2019 to 2024. Additionally, this review discusses the key findings and limitations associated with the structure-function correlation. While most studies focus on β-glucans or their extracts, α-glucans and chitin have gained increasing attention. The prebiotic potential is associated with α-glucans and chitin, with chitin recognized for its substantial antimicrobial and wound-healing properties. This review systematically identifies current research gaps and proposes avenues for future investigation into the therapeutic potential of mushroom polysaccharides. However, further research is required to comprehensively understand their full therapeutic potential.

3D Printing of Hydrogel Polysaccharides for Biomedical Applications: A Review

Additive manufacturing, also known as 3D printing, is becoming more and more popular because of its wide range of materials and flexibility in design. Layer by layer, 3D complex structures can be generated by the revolutionary computer-aided process known as 3D bioprinting. It is particularly crucial for youngsters and elderly patients and is a useful tool for tailored pharmaceutical therapy. A lot of research has been carried out recently on the use of polysaccharides as matrices for tissue engineering and medication delivery. Still, there is a great need to create affordable, sustainable bioink materials with high-quality mechanical, viscoelastic, and thermal properties as well as biocompatibility and biodegradability. The primary biological substances (biopolymers) chosen for the bioink formulation are proteins and polysaccharides, among the several resources utilized for the creation of such structures. These naturally occurring biomaterials give macromolecular structure and mechanical qualities (biomimicry), are generally compatible with tissues and cells (biocompatibility), and are harmonious with biological digesting processes (biodegradability). However, the primary difficulty with the cell-laden printing technique (bioprinting) is the rheological characteristics of these natural-based bioinks. Polysaccharides are widely used because they are abundant and reasonably priced natural polymers. Additionally, they serve as excipients in formulations for pharmaceuticals, nutraceuticals, and cosmetics. The remarkable benefits of biological polysaccharides-biocompatibility, biodegradability, safety, non-immunogenicity, and absence of secondary pollution-make them ideal 3D printing substrates. The purpose of this publication is to examine recent developments and challenges related to the 3D printing of stimuli-responsive polysaccharides for site-specific medication administration and tissue engineering.

Lentinan suppresses the progression of neuroblastoma by inhibiting FOS-mediated transcription activation of VRK1 to stabilize p53 protein

Neuroblastoma (NB) is a common malignant and solid pediatric tumor with unfavorable prognosis. Although studies have shown the anti-tumor efficacy of lentinan (LNT), molecular mechanism that contribute to the anti-tumor effect on NB remains unclear. The aim of this study is to unmask the anti-tumor role of LNT in NB and the specific molecular mechanism. At first, the in vivo experiments were conducted and the results indicated that LNT could suppress tumor growth in NB. Subsequent cellular functional assays unveiled that LNT treatment could efficiently decrease NB cell viability, induce cell cycle stagnation at G0/G1 phase, increase the apoptosis rate, and weaken the migrating and invasive abilities. Furthermore, LNT resulted in a significant downregulation of FOS expression. FOS overexpression recovered the growth, migration and invasion of NB cells suppressed by LNT treatment. Mechanism investigations revealed that FOS interacted with JUND to transcriptionally activate VRK1. Moreover, VRK1 downregulated p53 protein via inducing the phosphorylation of p53 at site 291-393. In summary, this study reveals a novel molecular pathway by which LNT exerts tumor-suppressing functions in NB.

Characterization of glucans from diverse sources and their influence on fat and carbohydrate absorption, digestion in vitro, and glucose tolerance in vivo

Glucan, a recognized prebiotic primarily derived from fungi, bacteria, and plants, possesses significant nutritional value and biological activity. It serves as a thickener and emulsifier stabilizer, enhancing the texture and sensory properties of food. This study aimed to compare the inhibitory effects of glucans from yeast, oats, and bacteria on energy intake by characterizing their physicochemical properties and evaluating their impact on fat and glucose adsorption, starch and fat digestion in vitro, and glucose tolerance in vivo. The findings revealed that despite sharing similar active groups, the glucans exhibited distinct structures, viscosities, water solubilities, thermal degradation behaviors, and micromorphologies. All three sources demonstrated effectiveness in adsorbing fat and glucose, inhibiting starch and fat digestion, and improving glucose tolerance in mice, albeit with notable differences. Among these, Salecan glucan, derived from bacterial sources, exhibited superior performance in fat absorption, inhibition of starch and fat digestion, and enhancement of glucose tolerance. This is likely attributable to its higher viscosity, greater water solubility, and linear molecular structure. These results highlight the functional significance of glucans from different sources and underscore their potential application in developing functional foods aimed at managing energy intake.

Molecular dynamics modeling of different conformations of beta-glucan, molecular docking with dectin-1, and the effects on macrophages

This study investigated β-glucan with diverse conformations by using molecular dynamics simulations to analyze their conformational transitions in water. Stable conformations were docked with the Dectin-1 protein to evaluate key metrics such as favorable conformations, root-mean-square deviation, hydrogen bond interactions, and their effects on macrophage activity. Results revealed that single-chain β-1,3-glucan with a degree of polymerization (DP) of 24 forms aggregates in water, while triple-chain β-1,3-glucan with a DP of 6 tends to form double helices. Other models exhibited single-helical or entangled-helical structures, with β-1,3/1,4-glucans favoring compact triple helices. The β-1,3 glycosidic bond promotes compact helical structures, while the β-1,4 bond hinders folding, increasing rigidity. Branching via β-1,6 glycosidic bonds introduces flexibility and enhances hydrogen bonding with water, although longer branches may cause localized aggregation. Molecular docking suggests that Dectin-1's recognition sites are predominantly hydrophobic. Lower polymerization models improve binding affinity through structural complexity, whereas higher polymerization models enhance binding via helical characteristics and larger contact areas. The study provides a comprehensive perspective on Dectin-1's differential recognition of β-glucans.

Structure and strain specificity for polysaccharides from king oyster mushroom (Pleurotus eryngii) fruiting bodies

King oyster mushroom Pleurotus eryngii is cultivated worldwide for culinary and to improve human health. However, the potential of some Mediterranean representatives of this species is still not evaluated. This work focuses on the study of polysaccharides from fruiting bodies of two Tunisian strains, P. eryngii var. elaeoselini and P. eryngii var. ferulae, and, for comparison, one deposited P. eryngii originated from Korea. Polysaccharides were successively extracted with hot water using microwave heating and 1 mol L-1 aqueous sodium hydroxide. The crude hot water extracts were purified by treating them with proteolytic enzymes, and the alkaline extracts were purified by re-dissolving with dimethyl sulphoxide. In both cases, a decrease or removal of proteins was detected. Glucans predominated in all these products; the insoluble parts also contained chitin. The purified hot water extracts contained glycogen, β-d-glucans and mannogalactan. Branching (1 → 3)(1 → 6)-β-d-glucan was the major polysaccharide in the alkali-soluble fractions, while (1 → 3)-α-d-glucan was only a minor component. The Tunisian strains demonstrated a higher proportion of water-soluble polysaccharides, compared to the alkaline soluble ones, and more β-d-glucan in the insoluble chitin-glucan complexes. Fruiting body proteins of these strains are more available for solubilisation and enzymatic or alkaline degradation and, thus, may have higher nutritional value than those of the reference strain. As a source of proteins or polysaccharides, the Tunisian endemic P. eryngii strains of this study are promising for the domestication and cultivation of fruiting bodies for gastronomic purposes in the North African region.

Interactions of non-starch polysaccharides with the gut microbiota and the effect of non-starch polysaccharides with different structures on the metabolism of the gut microbiota: A review

Humans consume large amounts of non-starch polysaccharides(NPs) daily. Some NPs, not absorbed by the body, proceed to the intestines. An increasing number of studies reveal a close relationship between NPs and gut microbiota(GM) that impact the human body. This review not only describes in detail the structures of several common NPs and their effects on GM, but also elucidates the degradation mechanisms of NPs in the intestine. The purpose of this review is to elucidate how NPs interact with GM in the intestine, which can provide valuable information for further studies of NPs.

Smart design in biopolymer-based hemostatic sponges: From hemostasis to multiple functions

Uncontrolled hemorrhage remains the leading cause of death in clinical and emergency care, posing a major threat to human life. To achieve effective bleeding control, many hemostatic materials have emerged. Among them, nature-derived biopolymers occupy an important position due to the excellent inherent biocompatibility, biodegradability and bioactivity. Additionally, sponges have been widely used in clinical and daily life because of their rapid blood absorption. Therefore, we provide the overview focusing on the latest advances and smart designs of biopolymer-based hemostatic sponge. Starting from the component, the applications of polysaccharide and polypeptide in hemostasis are systematically introduced, and the unique bioactivities such as antibacterial, antioxidant and immunomodulation are also concerned. From the perspective of sponge structure, different preparation processes can obtain unique physical properties and structures, which will affect the material properties such as hemostasis, antibacterial and tissue repair. Notably, as development frontier, the multi-functions of hemostatic materials is summarized, mainly including enhanced coagulation, antibacterial, avoiding tumor recurrence, promoting tissue repair, and hemorrhage monitoring. Finally, the challenges facing the development of biopolymer-based hemostatic sponges are emphasized, and future directions for in vivo biosafety, emerging materials, multiple application scenarios and translational research are proposed.

Unlocking the potential of beta-glucans: a comprehensive review from synthesis to drug delivery carrier potency

Modernization and lifestyle changes have resulted in a number of diseases, including cancer, that require complicated and thorough treatments. One of the most important therapies is the administration of antibiotics and medicines. This is known as chemotherapy for cancer, and it is a regularly utilised treatment plan in which the medications used have negative side effects. This has resulted in extensive research on materials capable of delivering pharmaceuticals to particular targets over an extended period of time. Biopolymers have often been preferred as effective drug delivery carriers. Of these, β-glucan, a natural polysaccharide, has not been extensively studied as a drug delivery carrier, despite its unique properties. This review discusses the sources, extraction techniques, structures, and characteristics of β-glucan to provide an overview. Furthermore, the different methods employed to encapsulate drugs into β-glucan and its role as an efficient drug, SiRNA and Plasmid DNA carrier have been elaborated in this article. The capacity of β-glucan-based to specifically target and alter tumour-associated macrophages, inducing an immune response ultimately resulting in tumour suppression has been elaborated. Finally, this study aims to stimulate further research on β-glucan by thoroughly describing its many characteristics and demonstrating its effectiveness as a drug delivery vehicle.

Organoleptic properties and neuroimaging response on the perception of edible gels

The rapidly increasing number of elderly people in the world highlights the need for the development of innovative foods with modified textures that do not expose the elderly to the risks associated with food consumption (risk of aspiration, suffocation, and chocking). Providing specific food such as edible gel for the elderly population and the study of their properties is a challenge for the scientific community. There are some available gels in the supermarkets destined for the sports population, with specific texture and technological properties that could be used and extrapolated for senior people. To explore this potential, five types of sport commercial gels purchased from a local Slovak market were characterized in order to evaluate their technological properties and to know if these types of gels are suitable for the senior population. The energy gels were evaluated using acceptance testing, involving 75 seniors who evaluated important organoleptic attributes by a combination of hedonic and intensity scales. The same consumer panel then profiled the gels using the Temporal Dominance of Sensations (TDS) technique. The prevalence of food neophobia was measured with the Food Neophobia Scale (FNS) and also using neuroimaging and biometric methods. The results suggest that there are significant differences in the perception of edible gels, as confirmed by measurements via electroencephalography (EEG) and Facereading. We conclude by suggesting the potential of specific foods such as edible gels for the elderly population as our findings also confirm that the composition of these specific and sustainable foods may elicit different perceptions. This highlights the need to use biometric and neuroimaging methods in food research in order to create more optimal formulations for specific populations.

Reviewing the audacity of elixirs of inflammatory bowel disease from mushroom β-glucans: The solved and unresolved

BACKGROUND

Mushrooms are known as the elixirs of life, they are packed with various bioactive compounds that make them not only tasty but also healthy. Thus, they not just fall within the category of nutritional foods, but also functional foods. When medicinal bioactive components are sought after from every other available resource, these natural reservoirs are easily accessible therapeutic sources. Of the various bioactive that mushrooms have to offer, β-glucans are the most enriching.

METHODS

β-glucans are available in other sources as well, but their relative abundance is higher in mushrooms. Amidst the cascade of biological benefits from β-glucans, anti-inflammatory benefits are highly promising. In this present review, the anti-inflammatory properties of mushroom β-glucans have been discussed and its specific contributions against inflammatory bowel disease have been reviewed.

DISCUSSION

What is known regarding the modulus operandi of β-glucans against inflammatory bowel disease has been summarized and the gaps and lapses in the current understanding highlighted. This is the first state-of-the-art review that presents a comprehensive executive summary and discussion in this subject area.

The Effect of β-Glucan on the Release and Antiradical Activity of Phenolic Compounds from Apples in Simulated Digestion

Beneficial activities of phenolic compounds in the gastrointestinal tract, such as antiradical activity, are affected by the food matrix. The aim of this study was to investigate the influence of one constituent of the food matrix (dietary fiber β-glucan) on the release and antiradical activity of phenolic compounds from apples in gastrointestinal digestion. Simulated digestion in vitro was conducted on whole apples without or with added β-glucan. Antiradical activity was determined with the DPPH method. The total amount of released phenolic compounds in the stomach (563 mg kg-1 fresh weight (fw), 85%) decreased in the intestine (314 mg kg-1 fw, 47%) (p < 0.05). The presence of β-glucan decreased the release of phenolic compounds to 80 and 74% in the stomach and to 44 and 40% in the small intestine when there were lower and higher β-glucan amounts, respectively. A statistical analysis showed differences between release in digestion without or with β-glucan. B-glucan adsorbed up to 24 (stomach) and 32 mg g-1 (small intestine) of the phenolics. Phenolic compounds scavenged more free radicals in the small intestine than in the stomach, and β-glucan decreased this activity, but not significantly. The interaction between β-glucan and phenolic compounds should be considered when explaining the beneficial effects in the stomach and small intestine.

Exploring the structure-activity relationship of Safflower polysaccharides: From the structural characteristics to biological function and therapeutic applications

ETHNOPHARMACOLOGICAL RELEVANCE

Safflower, the florets of Carthamus tinctorius L., is a widely used traditional Chinese medicine for promoting circulation and improving dysmenorrhea. Polysaccharides is one of the principal water-soluble components in Safflower, which recently endowed with a variety of biological activities, thus making them have important research significance in the field of ethnopharmacology.

AIM OF THE STUDY

This review summarized the latest research progress on the preparation technology, structural characteristics, and pharmacological effects of Safflower polysaccharides. Moreover, by comparing the structural characteristic of Safflower polysaccharides, the potential structure-activity relationship of Safflower polysaccharides was also discussed.

MATERIALS AND METHODS

This article used keywords including Safflower polysaccharide, Carthamus tinctorius L polysaccharide, Safflower polysaccharide extraction and separation, Safflower polysaccharide structure, and Safflower polysaccharide anti-tumor effects to search for all relevant literature in PubMed, Web of Science, Google Scholar, ScienceDirect, CNKI and other databases from the establishment of the database to July 2024.

RESULTS

Summarizing current research findings, seventeen homogeneous Safflower polysaccharides have been obtained. Their structural characteristics, including molecular weights, monosaccharide composition, sugar residue types, glycosidic bond configuration, and the linkage sequence, were initially researched. In terms of pharmacological activity, Safflower polysaccharides exhibit a wide range of biological activities, including immune regulation, anti-tumor effects, and antioxidant properties. Furthermore, the structural characteristics of Safflower polysaccharides significantly influence its biological activities, encompassing factors such as molecular weight, monosaccharide composition, and degree of branching.

CONCLUSION

Safflower polysaccharides have seen significant advancements in recent years regarding preparation methods, structural characterization, and pharmacological studies. These achievements would provide a theoretical basis for the application of Safflower polysaccharide in the field of ethnopharmacology. While Safflower polysaccharides exhibit diverse biological activities and significant potential for development and utilization, further in-depth research is needed to enhance our understanding of their mechanisms of action and optimize their clinical applications.

The neurotoxicity of acrylamide in ultra-processed foods: interventions of polysaccharides through the microbiota-gut-brain axis

Ultra-processed foods (UPFs) have become popular in recent years, however, the detrimental effects of their excessive consumption have also become evident. Acrylamide (AA), a processing hazard present in UPFs, can further aggravate the harmful effects of UPFs. AA can cause significant damage to both the intestinal barrier and gut microbiota, thereby affecting the nervous system through the microbiota-gut-brain (MGB) axis. Natural polysaccharides have demonstrated the capacity to significantly alleviate the oxidative stress and inflammatory response associated with AA exposure. In addition, they exhibit neuroprotective properties that may be mediated through the MGB axis. This paper reviews literature on the presence of AA in certain UPFs and its potential to inflict serious harm on the human gut microbiota and brain. Moreover, the possibility of utilizing polysaccharides as a preventative measure against AA-induced neurotoxicity was also proposed. These findings provide new insights into the safety risks associated with the overconsumption of UPFs and highlight the potential of polysaccharides to counteract the neurodegeneration induced by AA.

The effect of β-Glucan induced intestinal trained immunity against Trichinella spiralis infection

Parasitic helminth Trichinella spiralis (Ts) induce mixed Th1/Th2 response with predominant type 2 immune responses, with protective immunity mediated by interleukin (IL)-4, IL-5, and IL-13. β-Glucan (BG) has been shown to have the ability to induce trained immunity, confers non-specific protection from secondary infections. However, whether BG-induced trained immunity played a role in protective type 2 immunity against Ts infection is unclear. In this study, BG was administered five days before Ts infection to induce trained immunity. Our findings demonstrate that BG pretreatment effectively reduced the number of T. spiralis adults and muscle larvae, whereas inhibition of trained immunity abolished the effect of BG. Additionally, we observed a significant increase in goblet cells and mucus production as evidenced by Alcian blue periodic acid-Schiff staining. Furthermore, quantitative real-time PCR analysis revealed a significant upregulation of IL-4, IL-5, and IL-13 expression in response to BG. Conversely, the inhibitor of trained immunity reversed these effects, suggesting that BG-induced trained immunity confers strong protection against Ts infection. In conclusion, these findings suggest that BG-induced trained immunity may play a role in protection against infections caused by other helminths.

Advances in understanding dietary fiber: Classification, structural characterization, modification, and gut microbiome interactions

Gut microbiota and their metabolites profoundly impact host physiology. Targeted modulation of gut microbiota has been a long-term interest in the scientific community. Numerous studies have investigated the feasibility of utilizing dietary fibers (DFs) to modulate gut microbiota and promote the production of health-beneficial bacterial metabolites. However, the complexity of fiber structures, microbiota composition, and their dynamic interactions have hindered the precise prediction of the impact of DF on the gut microbiome. We address this issue with a new perspective, focusing on the inherent chemical and structural complexity of DFs and their interaction with gut microbiota. The chemical and structural complexity of fibers was thoroughly elaborated, encompassing the fibers' molecular composition, polymorphism, mesoscopic structures, porosity, and particle size. Advanced characterization techniques to investigate fiber structural properties were discussed. Additionally, we examined the interactions between DFs and gut microbiota. Finally, we summarized processing techniques to modify fiber structures for improving the fermentability of DF by gut microbiota. The structure of fibers, such as their crystallinity, porosity, degree of branching, and pore wettability, significantly impacts their interactions with gut microbiota. These structural differences also substantially affect fiber's fermentability and capability to modulate the composition of gut microbiota. Conventional approaches are not capable of investigating complex fiber properties and their influences on the gut microbiome; therefore, it is of the essence to involve advanced material characterization techniques and artificial intelligence to unveil more comprehensive information on this topic.

Research Progress in the Extraction, Structural Characteristics, Bioactivity, and Commercial Applications of Oat β-Glucan: A Review

Oats (Avena sativa L.) are an important cereal crop with diverse applications in both food and forage. Oat β-glucan has gained attention for its beneficial biological activities, such as reducing cardiovascular risk, preventing diabetes, and enhancing intestinal health. Despite its potential, more comprehensive research is required to explore its preparation, modification, bioactivities, and applications. This review highlights recent advancements in the determination and preparation of oat β-glucan, explores its biological activities and mechanisms, and examines the impact of food processing techniques on its properties. This review is intended to provide a theoretical foundation and reference for the development and application of oat β-glucan in the functional food industry.

Release of Biopolymers from Saccharomyces cerevisiae Biomass Through Thermal and Non-Thermal Technologies

Components of yeast cell walls, such as β-glucans and mannoproteins, show promise for developing sustainable biopolymers for food packaging. Efficient extraction, however, is challenging due to the complexity of the yeast cell wall. This study explored high-pressure homogenisation (HPH) and pulsed electric fields (PEFs), alone and with heat treatment (TT), on bakery yeast (BY) and brewery spent yeast (BSY) biomasses. In the treated samples we assessed carbohydrates, proteins, β-glucans, and mannoproteins and evaluated cell wall disruption microscopically. HPH caused complete cell disintegration, enhancing intracellular release, while PEF primarily permeabilised the membranes. Combined HPH and PEF treatments significantly increased cell wall stress, leading to partial disintegration. Notably, the β-glucans released reached 3.90 g/100 g dry matter in BY and 10.44 g/100 g dry matter in BSY, demonstrating significant extraction improvements. These findings highlight the potential of HPH and PEF for enhancing β-glucan recovery from yeast biomass, offering a promising route for sustainable biopolymer production for food packaging.

Prebiotics: Comprehensive analysis of sources, structural characteristics and mechanistic roles in disease regulation

Prebiotics are nondigestible components that comprise short-chain carbohydrates, primarily oligosaccharides, which are converted into beneficial compounds by probiotics. Various plant substances with prebiotic properties provide substantial health benefits and are used to prevent different diseases and for medical and clinical applications. Consuming prebiotics gives impeccable benefits since it aids in gut microbial balance. Prebiotic research is primarily concerned with the influence of intestinal disorders. The proposed review will describe recent data on the sources, structures, implementation of prebiotics and potential mechanisms in preventing and treating various disorders, with an emphasis on the gut microbiome. Prebiotics have a distinctive impact on the gastro intestine by explicitly encouraging the growth of probiotic organisms like Bifidobacteria and Lactobacilli. This in turn augments the body's inherent ability to fend off harmful pathogens. Prebiotic carbohydrates may also provide other non-specific advantages due to their fermentation in the large intestine. Additional in vivo research is needed to fully comprehend the interactions between prebiotics and probiotics ingested by hosts to improve their nutritional and therapeutic benefits.

Oat β-(1 → 3, 1 → 4)-d-glucan alleviates food allergy-induced colonic injury in mice by increasing Lachnospiraceae abundance and butyrate production

Oat β-(1 → 3, 1 → 4)-d-glucan (OBG), a linear polysaccharide primarily found in oat bran, has been demonstrated to possess immunomodulatory properties and regulate gut microbiota. This study aimed to investigate the impact of low molecular weight (Mw) OBG (155.2 kDa) on colonic injury and allergic symptoms induced by food allergy (FA), and to explore its potential mechanism. In Experiment 1, results indicated that oral OBG improved colonic inflammation and epithelial barrier, and significantly relieved allergy symptoms. Importantly, the OBG supplement altered the gut microbiota composition, particularly increasing the abundance of Lachnospiraceae and its genera, and promoted the production of short-chain fatty acids, especially butyrate. However, in Experiment 2, the gut microbial depletion eliminated these protective effects of OBG on the colon in allergic mice. Further, in Experiment 3, fecal microbiota transplantation and sterile fecal filtrate transfer directly validated the role of OBG-mediated gut microbiota and its metabolites in relieving FA and its induced colonic injury. Our findings suggest that low Mw OBG can alleviate FA-induced colonic damage by increasing Lachnospiraceae abundance and butyrate production, and provide novel insights into the health benefits and mechanisms of dietary polysaccharide intervention for FA.

Family GH157 enzyme exhibits broad linkage tolerance and a dual endo/exo-β-glucanase activity on β-glucans

The structural and chemical diversity of β-glucans is reflected on the variety of essential biological roles tackled by these polysaccharides. This natural heterogeneity requires an elaborate assortment of enzymatic mechanisms to assemble, degrade or modify, as well as to extract their full biotechnological potential. Recent metagenomic efforts have provided an unprecedented growth in potential new biocatalysts, most of which remain unconfirmed or uncharacterized. Here we report the first biochemical and structural characterization of two bacterial β-glucanases from the recently created glycoside hydrolase family 157 (LaGH157 and BcGH157) and investigate their molecular basis for substrate hydrolysis. Structural analysis by X-ray crystallography revealed that GH157 enzymes belong to clan GH-A, possessing a (β/α)8-barrel fold catalytic domain, two β-sandwich accessory domains and two conserved catalytic glutamates residues, with relative positions compatible with a retaining mechanism of hydrolysis. Specificity screening and enzyme kinetics suggest that the enzymes prefer mixed-linkage glucans over β-1,3-glucans. Activity screening showed that both enzymes exhibit pH optimum at 6.5 and temperature optimum for LaGH157 and BcGH157 at 25 °C and 48 °C, respectively. Product analysis with HPAEC-PAD and LC-MS revealed that both enzymes are endo-1,3(4)-β-glucanases, capable of cleaving β-1,3 and β-1,4-linked glucoses, when preceded by a β-1,3 linkage. Moreover, BcGH157 needs a minimum of 4 subsites occupied for hydrolysis to occur, while LaGH157 only requires 3 subsites. Additionally, LaGH157 possesses exohydrolytic activity on β-1,3 and branching β-1,6 linkages. This unusual bifunctional endo-1,3(4)/exo-1,3-1,6 activity constitutes an expansion on our understanding of β-glucan deconstruction, with the potential to inspire future applications.

High barley intake in non-obese individuals is associated with high natto consumption and abundance of butyrate-producing bacteria in the gut: a cross-sectional study

Objective

Barley, abundant in β-glucan, a soluble dietary fiber, holds promise in obesity prevention. Given the microbial metabolism of dietary fiber in the gastrointestinal tract, we investigated the role of gut microbiota in non-obese individuals consuming high levels of barley.

Methods

Our study enrolled 185 participants from "The cohort study on barley and the intestinal environment (UMIN000033479)." Comprehensive physical examinations, including blood tests, were conducted, along with separate assessments of gut microbiome profiling and dietary intake. Participants were categorized into high and low barley consumption groups based on the median intake, with non-obese individuals in the high intake group identified as barley responders while participants with obesity were designated as non-responders. We compared the relative abundance of intestinal bacteria between these groups and used multivariate analysis to assess the association between intestinal bacteria and barley responders while controlling for confounding factors.

Results and discussion

Among the fermented food choices, responders exhibited notably higher consumption of natto (fermented soybeans) than non-responders. Moreover, after adjusting for confounders, Butyricicoccus and Subdoligranulum were found to be significantly more prevalent in the intestines of responders. Given natto's inclusion of Bacillus subtilis, a glycolytic bacterium, and the butyrate-producing capabilities of Butyricicoccus and Subdoligranulum, it is hypothesized that fiber degradation and butyrate production are likely to be enhanced within the digestive tract of barley responders.

Effect of Complexation with Different Molecular Weights of Oat β-Glucan and Sea Buckthorn Flavonoid on the Digestion of Rice Flour

The complex of oat β-glucan (OBG) and flavonoids hampered the digestion of starch-based food and retarded the blood glucose response; however, its effect on gastric emptying and its relative mechanism have not been thoroughly investigated. By using Fourier transform infrared (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM), antioxidant ability, and enzymic inhibitory tests for the characterization and in vitro semi-dynamic digestion of complexes of OBG (high and low molecular weights) and sea buckthorn flavonoids, we found that the higher molecular weight complex (FU) exhibited stronger ABTS and DPPH radical scavenging abilities and higher α-glucosidase and α-amylase inhibition rates. Mice fed with rice flour with FU addition exhibited the slowest gastric emptying and intestinal propulsion rates and blood glucose rise and had the lowest activity of digestive enzymes and levels of insulin, ghrelin, motilin (MTL), and relevant gene (ghrelin and GHSR mRNA) expression than those in the control and low-molecular-weight groups. This study provided scientific data for the development of foods with delayed gastric rate and hypoglycemic index for specific populations.

Characterization of the Immune-Modulating Properties of Different β-Glucans on Myeloid Dendritic Cells

In allergen-specific immunotherapy, adjuvants are explored for modulating allergen-specific Th2 immune responses to re-establish clinical tolerance. One promising class of adjuvants are β-glucans, which are naturally derived sugar structures and components of dietary fibers that activate C-type lectin (CLR)-, "Toll"-like receptors (TLRs), and complement receptors (CRs). We characterized the immune-modulating properties of six commercially available β-glucans, using immunological (receptor activation, cytokine secretion, and T cell modulating potential) as well as metabolic parameters (metabolic state) in mouse bone marrow-derived myeloid dendritic cells (mDCs). All tested β-glucans activated the CLR Dectin-1a, whereas TLR2 was predominantly activated by Zymosan. Further, the tested β-glucans differentially induced mDC-derived cytokine secretion and activation of mDC metabolism. Subsequent analyses focusing on Zymosan, Zymosan depleted, β-1,3 glucan, and β-1,3 1,6 glucan revealed robust mDC activation with the upregulation of the cluster of differentiation 40 (CD40), CD80, CD86, and MHCII to different extents. β-glucan-induced cytokine secretion was shown to be, in part, dependent on the activation of the intracellular Dectin-1 adapter molecule Syk. In co-cultures of mDCs with Th2-biased CD4+ T cells isolated from birch allergen Bet v 1 plus aluminum hydroxide (Alum)-sensitized mice, these four β-glucans suppressed allergen-induced IL-5 secretion, while only Zymosan and β-1,3 glucan significantly suppressed allergen-induced interferon gamma (IFNγ) secretion, suggesting the tested β-glucans to have distinct effects on mDC T cell priming capacity. Our experiments indicate that β-glucans have distinct immune-modulating properties, making them interesting adjuvants for future allergy treatment.

Proanthocyanidins and β-Glucan Synergistically Regulate Intestinal Inflammation in Dextran Sulfate Sodium-Induced Colitis Mice

Proanthocyanidins (PA) have been proven to have an anti-inflammation effect in multiple models by regulating oxidative stress. β-glucan (BG) could alleviate colitis from the perspectives of intestinal permeability and gut microbiota. In the present study, the synergistic anti-inflammatory function of PA and BG was explored from multiple aspects including immune response, intestinal barrier, gut microbiota, and differential metabolites. The results showed that the supplementation of PA and BG improved the colitis symptoms including atrophy of the colon, body weight loss, and organ index increase. Additionally, inflammatory cytokine levels and oxidative stress status were significantly regulated with the intake of PA and BG. Moreover, PA and BG intervention improved intestinal permeability and promoted the expression of barrier proteins. The microbiome and metabolic profile of cecal contents showed that PA and BG supplementation increased the abundance of anti-inflammatory bacteria and decreased the abundance of pro-inflammatory bacteria. Furthermore, some beneficial metabolites involved in amino acid metabolism, carbohydrate metabolism, and biosynthesis of other secondary metabolite pathways were increased. Overall, these findings have demonstrated the regulation of the inflammatory response and remodel of metabolite profiles by PA and BG complexes, indicating that it may serve as a new strategy for inflammatory bowel disease treatment in the future.

Effect of β-glucans on rainbow trout (Oncorhynchus mykiss) IgM+ B cells

β-glucans are carbohydrates present in the cell wall of many fungi, which are often used as immunostimulants in feeds for farmed species. Their capacity to activate innate immune responses directly acting on innate cell populations has been widely documented in fish. However, whether they can affect the functionality of adaptive immune cells has been scarcely explored. In this context, in the current work, we have determined the effects of β-glucans on rainbow trout blood IgM+ B cells in the presence or absence of 2,4,6-trinitrophenyl hapten conjugated to lipopolysaccharide (TNP-LPS), a model antigen. For this, rainbow trout peripheral blood leukocytes were incubated with different doses of β-glucans or media alone in the presence or absence of TNP-LPS for 48 h. The size, levels of expression of surface MHC II, antigen processing and phagocytic capacities and proliferation of IgM+ B cells were then studied by flow cytometry. The number of IgM-secreting cells in the cultures was also estimated by ELISpot. β-glucans significantly decreased the levels of surface MHC II expression and the antigen processing capacities of these cells, especially in the presence of TNP-LPS, while they increased their phagocytic activity. On their own, β-glucans slightly activated the proliferation of IgM+ B cells but reduced that induced by TNP-LPS. In contrast, β-glucans significantly increased the number of cells secreting IgM in the cultures. This effect of β-glucans on the IgM-secreting capacity of B cells was also confirmed through a feeding experiment, in which the IgM-secreting capacity of blood leukocytes obtained from fish fed a β-glucan-supplemented diet for one month was compared to that of leukocytes obtained from fish fed a control diet. Altogether, these findings contribute to increase our knowledge regarding the effects of β-glucans on fish adaptive responses.

Isolation and purification of carbohydrate components in functional food: a review

Medicinal plants, increasingly utilized in functional foods, possess potent therapeutic properties and health-promoting functions, with carbohydrates playing a crucial role and exhibiting a range of effects, such as antioxidant, antitumor, immune-enhancing, antibacterial, anticoagulant, and hypoglycemic activities. However, comprehensively, accurately, rapidly, and economically assessing the quality of carbohydrate components is challenging due to their diverse and complex nature. Additionally, the purification and identification of carbohydrates also guarantee related efficacy research. This paper offers a thorough review of research progress carried out by both domestic and international scholars in the last decade on extracting, purifying, separating, identifying, and determining the content of carbohydrate components from functional foods, which are mainly composed of medicinal plants, and also explores the potential for achieving comprehensive quantitative analysis and evaluating structure-activity relationships of carbohydrate components. These findings aim to serve as a valuable reference for the future development and application of natural carbohydrate components in functional food and medicine.

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.

A structure-functionality insight into the bioactivity of microbial polysaccharides toward biomedical applications: A review

Microbial polysaccharides (MPs) are biopolymers secreted by microorganisms such as bacteria and fungi during their metabolic processes. Compared to polysaccharides derived from plants and animals, MPs have advantages such as wide sources, high production efficiency, and less susceptibility to natural environmental influences. The most attractive feature of MPs lies in their diverse biological activities, such as antioxidative, anti-tumor, antibacterial, and immunomodulatory activities, which have demonstrated immense potential for applications in functional foods, cosmetics, and biomedicine. These bioactivities are precisely regulated by their sophisticated molecular structure. However, the mechanisms underlying this precise regulation are not yet fully understood and continue to evolve. This article presents a comprehensive review of the most representative species of MPs, including their fermentation and purification processes and their biomedical applications in recent years. In particular, this work presents an in-depth analysis into the structure-activity relationships of MPs across multiple molecular levels. Additionally, this review discusses the challenges and prospects of investigating the structure-activity relationships, providing valuable insights into the broad and high-value utilization of MPs.

A Diagnostic Stewardship Intervention to Improve Utilization of 1,3 β-D-Glucan Testing at a Single Academic Center: Five-Year Experience

Background

(1,3)- β-D-glucan (BDG) testing is one of the noninvasive tests to aid diagnosis of invasive fungal infections (IFIs). The study results have been heterogenous, and diagnostic performance varies depending on the risks for IFI. Thus, it is important to select appropriate patients for BDG testing to prevent false-positive results. An algorithmic diagnostic stewardship intervention was instituted at a single academic medical center to improve BDG test utilization.

Methods

The BDG test order in the electronic health record was replaced with the BDG test request order, which required approval to process the actual test order. The approval criteria were (1) immunocompromised or intensive care unit patient and (2) on empiric antifungal therapy, or inability to undergo invasive diagnostic procedures. A retrospective observational study was conducted to evaluate the efficacy of the intervention by comparing the number of BDG tests performed between 1 year pre- and post-intervention. Safety was assessed by chart review of the patients for whom BDG test requests were deemed inappropriate and rejected.

Results

The number of BDG tests performed per year decreased by 85% from 156 in the pre-intervention period to 24 in the post-intervention period. The average monthly number of BDG tests performed was significantly lower between those periods (P = .002). There was no delay in IFI diagnosis or IFI-related deaths in the patients whose BDG test requests were rejected. The sustained effectiveness of the intervention was observed for 5 years.

Conclusions

Institution of the diagnostic stewardship intervention successfully and safely improved BDG test utilization.

Malassezia restricta as an unexpected cause of infectious osteomyelitis diagnosed by metagenomic sequencing: a case report and literature review

BACKGROUND

Malassezia restricta, a lipophilic and lipodependent yeast belonging to the basidiomycetes group, is an opportunistic fungal pathogen associated with various skin diseases, including seborrheic dermatitis and dandruff. Typically, Malassezia infection in neonates manifests as fungemia or hematogenous dissemination to the bone or lungs. However, vertebral osteomyelitis caused by these fungi is rarely reported owing to non-specific clinical presentations and laboratory/imaging findings. The Pathogen Metagenomics Sequencing (PMseq) technique enables direct high-throughput sequencing of infected specimens, facilitating the rapid and accurate detection of all microorganisms in clinical samples through comprehensive reports.

CASE PRESENTATION

A 52-year-old male was admitted to our hospital on July 20, 2022 with a 3-month history of ambulatory difficulties and localized low back pain. Magnetic Resonance Imaging (MRI) examination of the spinal column revealed irregular bone destruction affecting the L2, L3, and L5 vertebral bodies. Additionally, low T1 and high T2 intensity lesions were observed at the intervertebral discs between L3 and L5. The presumptive diagnosis of tuberculous spondylitis was made based on the imaging findings, despite negative results in all mycobacterium tests. However, the patient exhibited no improvement after receiving regular anti-tuberculosis treatment for 3 months. Subsequent MRI revealed an expansive abnormal signal within the vertebral body, leading to progressive bone destruction. The absence of spinal tuberculosis or other infective microorganisms was confirmed through culture from blood and pathological tissue from the L4 vertebral body. Subsequently, PMseq was performed on the specimens, revealing M. restricta as the predominant pathogen with the highest relative abundance value. The pathological examination revealed the presence of fungal mycelium in the L4 vertebral body, with positive findings on periodic Schiff-methenamine and periodic acid-Schiff staining. The anti-tuberculosis treatment was discontinued, and an antifungal combination of fluconazole and voriconazole was administered. All symptoms were resolved after 7 consecutive months of treatment, and the patient was able to ambulate autonomously. Vertebral lesions were reduced on MRI during the 13-month follow-up.

CONCLUSIONS

M. restricta is not a commonly recognized pathogen associated with infectious vertebral osteomyelitis. However, PMseq can aid in diagnosis, timely treatment, and decision making for some non-specific infectious diseases.

The effects of cereal β-glucans on cardiovascular risk factors and the role of the gut microbiome

The human gut microbiome has emerged as a key influencer of human health and disease, particularly through interactions with dietary fiber. However, national dietary guidelines worldwide are only beginning to capitalize on the potential of microbiome research, which has established the vital role of host-microbe interactions in mediating the physiological effects of diet on overall health and disease. β-glucans have been demonstrated to modulate the composition of the gut microbiota, leading to improved outcomes in cardiovascular disease (CVD). Raised serum cholesterol and blood pressure are important modifiable risk factors in the development of CVD and emerging evidence highlights the role of the gut microbiota in ameliorating such biomarkers and clinical characteristics of the disease. The proposed mechanism of action of β-glucans on the pathophysiological mechanisms of disease have yet to be elucidated. Validating gaps in the literature may substantiate β-glucans as a potential novel dietary therapy against modifiable risk factors for CVD and would further support the public health significance of including a habitual fiber-rich diet.

An Overview on Mushroom Polysaccharides: Health-promoting Properties, Prebiotic and Gut Microbiota Modulation Effects and Structure-function Correlation

Mushroom polysaccharides are recognized as "biological response modifiers". Besides several bioactivities, a growing interest in their prebiotic potential has been raised due to the gut microbiota modulation potential. This review comprehensively summarizes mushroom polysaccharides' biological properties, structure-function relationship, and underlying mechanisms. It provides a recent overview of the key findings in the field (2018-2024). Key findings and limitations on structure-function correlation are discussed. Although most studies focus on β-glucans or extracts, α-glucans and chitin have gained interest. Prebiotic capacity has been associated with α-glucans and chitin, while antimicrobial and wound healing potential is attributed to chitin. However, further research is of utmost importance. Human fecal fermentation is the most reported approach to assess prebiotic potential, indicating impacts on intestinal biological, mechanical, chemical and immunological barriers. Gut microbiota dysbiosis has been directly connected with intestinal, cardiovascular, metabolic, and neurological diseases. Concerning gut microbiota modulation, animal experiments have suggested proinflammatory cytokines reduction and redox balance re-establishment. Most literature focused on the anticancer and immunomodulatory potential. However, anti-inflammatory, antimicrobial, antiviral, antidiabetic, hypocholesterolemic, antilipidemic, antioxidant, and neuroprotective properties are discussed. A significant overview of the gaps and research directions in synergistic effects, underlying mechanisms, structure-function correlation, clinical trials and scientific data is also given.

Ganoderma lucidum spores-derived particulate β-glucan treatment improves antitumor response by regulating myeloid-derived suppressor cells in triple-negative breast cancer

Granular β-1,3-glucan extracted from the wall of Ganoderma lucidum spores, named GPG, is a bioregulator. In this study, we investigated the structural, thermal, and other physical properties of GPG. We determined whether GPG ameliorated immunosuppression caused by Gemcitabine (GEM) chemotherapy. Triple-negative breast cancer mice with GPG combined with GEM treatment had reduced tumor burdens. In addition, GEM treatment alone altered the tumor microenvironment(TME), including a reduction in antitumor T cells and a rise in myeloid-derived suppressor cells (MDSC) and regulatory T cells (Tregs). However, combined GPG treatment reversed the tumor immunosuppressive microenvironment induced by GEM. GPG inhibited bone marrow (BM)-derived MDSC differentiation and reversed MDSC expansion induced by conditioned medium (CM) in GEM-treated E0771 cells through a Dectin-1 pathway. In addition, GPG downgraded PD-L1 and IDO1 expression on MDSC while boosting MHC-II, CD86, TNF-α, and IL-6 expression. In conclusion, this study demonstrated that GPG could alleviate the adverse effects induced by GEM chemotherapy by regulating TME.

Revisiting gas-chromatography/mass-spectrometry molar response factors for quantitative analysis (FID or TIC) of glycosidic linkages in polysaccharides produced by oral bacterial biofilms

Methylation analysis was performed on methylated alditol acetate standards and Streptococcus mutans extracellular polymeric substances (EPS) produced from wild-type and Gtf knockout strains (∆GtfB, ∆GtfB, and ∆GtfD). The methylated alditol acetate standards were representative of glycosidic linkages found in S. mutans EPS and were used to calibrate the GC-MS system for an FID detector and MS (TIC) and produce molar response factor, a necessary step in quantitative analysis. FID response factors were consistent with literature values (Sweet et al., 1975) and found to be the superior option for quantitative results, although the TIC response factors now give researchers without access to an FID detector a needed option for molar response factor correction. The GC-MS analysis is then used to deliver the ratio of the linkage types within a biofilm.

Lipid metabolism regulation by dietary polysaccharides with different structural properties

Lipid metabolism plays an important role in energy homeostasis maintenance in response to stress. Nowadays, hyperlipidemia-related chronic diseases such as obesity, diabetes, atherosclerosis, and fatty liver pose significant health challenges. Dietary polysaccharides (DPs) have gained attention for their effective lipid-lowering properties. This review examines the multifaceted mechanisms that DPs employ to lower lipid levels in subjects with hyperlipidemia. DPs could directly inhibit lipid intake and absorption, promote lipid excretion, and regulate key enzymes involved in lipid metabolism pathways, including triglyceride and cholesterol anabolism and catabolism, fatty acid oxidation, and bile acid synthesis. Additionally, DPs indirectly improve lipid homeostasis by modulating gut microbiota composition and alleviating oxidative stress. Moreover, the lipid-lowering mechanisms of particular structural DPs (including β-glucan, pectin, glucomannan, inulin, arabinoxylan, and fucoidan) are summarized. The relationship between the structure and lipid-lowering activity of DPs is also discussed based on current researches. Finally, potential breakthroughs and future directions in the development of DPs in lipid-lowering activity are discussed. The paper could provide a reference for further exploring the mechanism of DPs for lipid regulations and utilizing DPs as lipid-lowering dietary ingredients.

In vitro batch fermentation demonstrates variations in the regulation of gut microbiota and metabolic functions by β-glucans of differing structures

The gut microbiota is widely acknowledged as a crucial factor in regulating host health. The structure of dietary fibers determines changes in the gut microbiota and metabolic differences resulting from their fermentation, which in turn affect gut microbe-related health effects. β-Glucan (BG) is a widely accessible dietary fiber to humans, and its structural characteristics vary depending on the source. However, the interactions between different structural BGs and gut microbiota remain unclear. This study used an in vitro fermentation model to investigate the effects of BG on gut microbiota, and microbiomics and metabolomics techniques to explore the relationship between the structure of BG, bacterial communities, and metabolic profiles. The four sources of BG (barley, yeast, algae, and microbial fermentation) contained different types and proportions of glycosidic bonds, which differentially altered the bacterial community. The BG from algal sources, which contained only β(1 → 4) glycosidic bonds, was the least metabolized by the gut microbiota and caused limited metabolic changes. The other three BGs contain more diverse glycosidic bonds and can be degraded by bacteria from multiple genera, causing a wider range of metabolic changes. This work also suggested potential synergistic degradation relationships between gut bacteria based on BG. Overall, this study deepens the structural characterization-microbial-functional understanding of BGs and provides theoretical support for the development of gut microbiota-targeted foods.

Glucans: A Therapeutic Alternative for Sepsis Treatment

Sepsis treatment is a challenging condition due to its complexity, which involves host inflammatory responses to a severe and potentially fatal infection, associated with organ dysfunction. The aim of this study was to analyze the scientific literature on the immunomodulatory effects of glucans in a murine model of systemic infection induced by cecal ligation and puncture. This study comprises an integrative literature review based on systematic steps, with searches carried out in the PubMed, ScienceDirect, Scopus, Web of Science, and Embase databases. In most studies, the main type of glucan investigated was β-glucan, at 50 mg/kg, and a reduction of inflammatory responses was identified, minimizing the occurrence of tissue damage leading to increased animal survival. Based on the data obtained and discussed in this review, glucans represent a promising biotechnological alternative to modulate the immune response and could potentially be used in the clinical management of septic individuals.

Translating Human and Animal Model Studies to Dogs' and Cats' Veterinary Care: Beta-Glucans Application for Skin Disease, Osteoarthritis, and Inflammatory Bowel Disease Management

The inclusion of beta-glucans in dog and cat food is associated with numerous beneficial effects on the health of these animals. In this regard, there is an effort to elucidate the potential of this nutraceutical in chronic patients. Since there is a lack of a review on the topic, this review article aims to compile and discuss the evidence found to date. Atopic dermatitis, inflammatory bowel disease, and osteoarthritis are diseases of significant clinical relevance in dogs and cats. In general, the pathophysiology of these chronic conditions is related to immune-mediated and inflammatory mechanisms. Therefore, the immunomodulation and anti-inflammatory effects of beta-glucans are highlighted throughout this review. The available information seems to indicate that the studies on beta-glucans' impact on allergic processes in dogs indicate a reduction in clinical signs in atopic dermatitis cases. Additionally, while beta-glucans show promise as a safe supplement, particularly for osteoarthritis, further clinical trials are imperative, especially in uncontrolled environments. Beta-glucans emerge as a potential nutraceutical offering immune benefits for inflammatory bowel disease patients, although extensive research is required to define its optimal origin, molecular weight, dosage, and specific applications across animals suffering from this disease.

Natural polysaccharides and their derivatives targeting the tumor microenvironment: A review

Polysaccharides have gained attention as valuable supplements and natural medicinal resources, particularly for their anti-tumor properties. Their low toxicity and potent anti-tumor effects make them promising candidates for cancer prevention and treatment. The tumor microenvironment is crucial in tumor development and offers potential avenues for novel cancer therapies. Research indicates that polysaccharides can positively influence the tumor microenvironment. However, the structural complexity of most anti-tumor polysaccharides, often heteropolysaccharides, poses challenges for structural analysis. To enhance their pharmacological activity, researchers have modified the structure and properties of natural polysaccharides based on structure-activity relationships, and they have discovered that many polysaccharides exhibit significantly enhanced anti-tumor activity after chemical modification. This article reviews recent strategies for targeting the tumor microenvironment with polysaccharides and briefly discusses the structure-activity relationships of anti-tumor polysaccharides. It also summarises the main chemical modification methods of polysaccharides and discusses the impact of chemical modifications on the anti-tumor activity of polysaccharides. The review aims to lay a theoretical foundation for the development of anti-tumor polysaccharides and their derivatives.

Chitin-induced disease resistance in plants: A review

Chitin is composed of N-acetylglucosamine units. Chitin a polysaccharide found in the cell walls of fungi and exoskeletons of insects and crustaceans, can elicit a potent defense response in plants. Through the activation of defense genes, stimulation of defensive compound production, and reinforcement of physical barriers, chitin enhances the plant's ability to defend against pathogens. Chitin-based treatments have shown efficacy against various plant diseases caused by fungal, bacterial, viral, and nematode pathogens, and have been integrated into sustainable agricultural practices. Furthermore, chitin treatments have demonstrated additional benefits, such as promoting plant growth and improving tolerance to abiotic stresses. Further research is necessary to optimize treatment parameters, explore chitin derivatives, and conduct long-term field studies. Continued efforts in these areas will contribute to the development of innovative and sustainable strategies for disease management in agriculture, ultimately leading to improved crop productivity and reduced reliance on chemical pesticides.

Diagnostic Challenge for Positive 1,3-β-D-Glucan in an Immunocompromised Patient Receiving Intravenous Immunoglobulin Presenting With Respiratory Failure

Diagnosing Pneumocystis jirovecii pneumonia (PJP) can be complex, particularly in cases of significant respiratory failure. The 1,3-β-D-glucan (BDG) serum assay has emerged as a promising non-invasive diagnostic tool for detecting fungal infections, including PJP. However, factors that can confound the interpretation of BDG levels by causing elevation in serum levels have been documented. Here, we present the case of 51-year-old woman with underlying autoimmune disorder, hematologic malignancy, and chronic steroid use, who was admitted for acute hypoxemic respiratory failure. Obtaining the BDG assay after the administration of intravenous immunoglobulin (IVIG) posed a diagnostic challenge, as the patient was unable to undergo bronchoscopy. This circumstance led to a debate regarding the possibility of a false-positive BDG due to IVIG use or the presence of PJP. Ultimately, the patient was empirically treated for PJP. This case underscores the importance of comprehending factors that may contaminate BDG results, particularly in immunocompromised individuals.

Caffeic acid combined with arabinoxylan or β-glucan attenuates diet-induced obesity in mice via modulation of gut microbiota and metabolites

Polyphenols and dietary fibers in whole grains are important bioactive compounds to reduce risks for obesity. However, whether the combination of the two components exhibits a stronger anti-obesity effect remains unclear. Caffeic acid is a major phenolic acid in cereals, and arabinoxylan and β-glucan are biological macromolecules with numerous health benefits. Here, we investigated the effect of caffeic acid combined with arabinoxylan or β-glucan on glucose and lipid metabolism, gut microbiota, and metabolites in mice fed a high-fat diet (HFD). Caffeic acid combined with arabinoxylan or β-glucan significantly reduced the body weight, blood glucose, and serum free fatty acid concentrations. Caffeic acid combined with β-glucan effectively decreased serum total cholesterol levels and hepatic lipid accumulation, modulated oxidative and inflammatory stress, and improved gut barrier function. Compared with arabinoxylan, β-glucan, and caffeic acid alone, caffeic acid combined with arabinoxylan or β-glucan exhibited a better capacity to modulate gut microbiota, including increased microbial diversity, reduced Firmicutes/Bacteroidetes ratio, and increased abundance of beneficial bacteria such as Bifidobacterium. Furthermore, caffeic acid combined with β-glucan reversed HFD-induced changes in microbiota-derived metabolites involving tryptophan, purine, and bile acid metabolism. Thus, caffeic acid and β-glucan had a synergistic anti-obesity effect by regulating specific gut microbiota and metabolites.

Potential inhibitory effect of Auricularia auricula polysaccharide on advanced glycation end-products (AGEs)

In this study, a novel polysaccharide, AAP-2S, was extracted from Auricularia auricula, and the anti-glycosylation effect of AAP-2S and its underlying mechanisms were investigated using an in vitro BSA-fructose model and a cellular model. The results demonstrated the inhibiting formation of advanced glycation end products (AGEs) in vitro by AAP-2S. Concurrently, it attenuated oxidative damage to proteins in the model, preserved protein sulfhydryl groups from oxidation, reduced protein carbonylation, prevented structural alterations in proteins, and decreased the formation of β-crosslinked structures. Furthermore, AAP-2S demonstrated metal-chelating capabilities. GC-MS/MS-based metabolomics were employed to analyze changes in metabolic profiles induced by AAP-2S in a CML-induced HK-2 cell model. Mechanistic investigations revealed that AAP-2S could mitigate glycosylation and ameliorate cell fibrosis by modulating the RAGE/TGF-β/NOX4 pathway. This study provides a foundational framework for further exploration of Auricularia auricular polysaccharide as a natural anti-AGEs agent, paving the way for its potential development and application as a food additive.

Prebiotic potential of pectin and cello-oligosaccharides from apple bagasse and orange peel produced by high-pressure homogenization and enzymatic hydrolysis

Apple bagasse and orange peel were subjected to high-pressure homogenization (HPH), enzymatic hydrolysis (EH) and their combination (HPHE) to study their effect on oligosaccharide production and in vitro fermentability. The application of a cellulase-pectinase mixture on the by-products generated significant quantities of cellobiose (COS-2) and pectin derived oligosaccharides (POS) which were identified as mainly methylated and acetylated oligogalacturonides with DP 2-5 (POS 2-5). When pre-treating the substrates with HPH, the release in orange peel was enhanced significantly leading to a POS content of 44.51 g/100 g peel, whereas oligosaccharide solubilization in apple bagasse was not affected. In vitro fermentation of the hydrolysates containing COS-2 and POS showed faster fermentation rates, between 6 and 10 h, and enhanced gas production, compared to those samples not subjected to enzymatic hydrolysis. Short chain fatty acid (SCFA) production was not impacted by the presence of POS and COS-2 in the induced quantities.

Microbiota modulation by dietary oat beta-glucan prevents steatotic liver disease progression

Background & Aims

Changes in gut microbiota in metabolic dysfunction-associated steatotic liver disease (MASLD) are important drivers of disease progression towards fibrosis. Therefore, reversing microbial alterations could ameliorate MASLD progression. Oat beta-glucan, a non-digestible polysaccharide, has shown promising therapeutic effects on hyperlipidemia associated with MASLD, but its impact on gut microbiota and most importantly MASLD-related fibrosis remains unknown.

Methods

We performed detailed metabolic phenotyping, including assessments of body composition, glucose tolerance, and lipid metabolism, as well as comprehensive characterization of the gut-liver axis in a western-style diet (WSD)-induced model of MASLD and assessed the effect of a beta-glucan intervention on early and advanced liver disease. Gut microbiota were modulated using broad-spectrum antibiotic treatment.

Results

Oat beta-glucan supplementation did not affect WSD-induced body weight gain or glucose intolerance and the metabolic phenotype remained largely unaffected. Interestingly, oat beta-glucan dampened MASLD-related inflammation, which was associated with significantly reduced monocyte-derived macrophage infiltration and fibroinflammatory gene expression, as well as strongly reduced fibrosis development. Mechanistically, this protective effect was not mediated by changes in bile acid composition or signaling, but was dependent on gut microbiota and was lost upon broad-spectrum antibiotic treatment. Specifically, oat beta-glucan partially reversed unfavorable changes in gut microbiota, resulting in an expansion of protective taxa, including Ruminococcus, and Lactobacillus followed by reduced translocation of Toll-like receptor ligands.

Conclusions

Our findings identify oat beta-glucan as a highly efficacious food supplement that dampens inflammation and fibrosis development in diet-induced MASLD. These results, along with its favorable dietary profile, suggest that it may be a cost-effective and well-tolerated approach to preventing MASLD progression and should be assessed in clinical studies.

Impact and Implications

Herein, we investigated the effect of oat beta-glucan on the gut-liver axis and fibrosis development in a mouse model of metabolic dysfunction-associated steatotic liver disease (MASLD). Beta-glucan significantly reduced inflammation and fibrosis in the liver, which was associated with favorable shifts in gut microbiota that protected against bacterial translocation and activation of fibroinflammatory pathways. Together, oat beta-glucan may be a cost-effective and well-tolerated approach to prevent MASLD progression and should be assessed in clinical studies.

β-Glucans obtained from fungus for wound healing: A review

The cell surface of fungus contains a large number of β-glucans, which exhibit various biological activities such as immunomodulatory, anti-inflammatory, and antioxidation. Fungal β-glucans with highly branched structure show great potential as wound healing reagents, because they can stimulate the expression of many immune- and inflammatory-related factors beneficial to wound healing. Recently, the wound healing ability of many fungal β-glucans have been investigated in animals and clinical trials. Studies have proved that fungal β-glucans can promote fibroblasts proliferation, collagen deposition, angiogenesis, and macrophage infiltration during the wound healing process. However, the development of fungal β-glucans as wound healing reagents is not systematically reviewed till now. This review discusses the wound healing studies of β-glucans obtained from different fungal species. The structure characteristics, extraction methods, and biological functions of fungal β-glucans with wound healing ability are summarized. Researches about fungal β-glucan-containing biomaterials and structurally modified β-glucans for wound healing are also involved.