Immunomodulating Effects of Fungal Beta-Glucans: From Traditional Use to Medicine

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.

Untapping the potential of algae for β-glucan production: A review of biological properties, strategies for enhanced production and future perspectives

β-Glucan, a naturally occurring polymer of glucose, is found in bacteria, algae, fungi, and higher plants (barley, oats, cereal seeds). Recently, β-glucan has gained attention due to its multiple biological roles, like anticancer, anti-inflammatory, and immunomodulatory effects. Globally, bacteria, mushrooms, yeast and cereals are used as conventional sources of β-glucan. However, obtaining it from these sources is challenging due to low quantity, complex branched structure, and costly extraction process. Algae have emerged as a potential sustainable alternative source of β-glucan to conventional sources due to several advantages including unique structural and functional advantages, higher yields, faster growth rates, and large-scale production in a controlled environment. Additionally, extracting β-glucan from microalgal sources is relatively easy and can be done without altering the structure of β-glucan. Some algal species, such as Euglena spp., are reported to contain higher β-glucan content than conventional β-glucan sources. This review highlights the current research and opportunities associated with algae-derived β-glucan and their biological roles. The challenges, research gaps and strategies to enhance algae-based β-glucan production and the need for further research in this promising area are also discussed. Future research can be extended to comprehend the cellular and molecular mechanisms via which β-glucan functions.

Sweeten the pill: Multi-faceted polysaccharide-based carriers for colorectal cancer treatment

Colorectal cancer (CRC) ranks as the second deadliest cancer globally and the third most common malignant tumor. While surgery remains the primary treatment for CRC, alternative therapies such as chemotherapy, molecular targeted therapy, and immunotherapy are also commonly used. The significant side effects and toxicity of conventional drugs drive the search for novel targeted therapies, including the design of advanced drug delivery systems. Polysaccharide-based biopolymers, with their low toxicity, non-immunogenic behavior, synergistic interactions with other biopolymers, and tissue and cell compatibility, emerge as excellent drug carriers for this application. This review aims to provide an in-depth overview of recent advancements in developing polysaccharide-based biopolymeric carriers for anticancer compounds in the treatment of CRC. We highlight the multifunctional nature of polysaccharides, showcasing their potential as standalone drug carriers or as integral components of intelligent robotic devices for biomedical therapeutic applications. In addition to exploring the opportunities for using carbohydrate polymers in CRC treatment, we address the challenges and failures that may limit their applicability in biomedical research, as well as summarize the recent preclinical and clinical trials, resulting in several commercialization attempts. This comprehensive overview critically summarizes the potential of polysaccharide-based biomaterials in CRC treatment.

The role of pattern recognition receptors in the innate immune system of Chinese mitten crab (Eriocheir sinensis)

Eriocheir sinensis (Chinese mitten crab) is one of the main economic species in China, which has evolved an extremely sophisticated innate immune system to fend off disease invasions. However, bacterial and viral infections have caused significant financial losses for the E. sinensis aquaculture in recent years. Making well-informed judgments for the control microbial infections would require a thorough understanding and clarification of the intricate innate immune system of E. sinensis. Innate immunity is essential for the host's defense against invasive pathogens. Pattern recognition receptors (PRRs) initially recognize pathogen-associated molecular patterns (PAMPs) and trigger an innate immune response, causing the generation of inflammatory cytokine and promoting the clearance and control of pathogens. In E. sinensis, Toll/Toll-like receptors, lipopolysaccharide and β-1,3-glucan binding proteins, C-type lectins, galactoside-binding lectins, L-type lectins, scavenger receptors, and down syndrome cell adhesion molecules have been identified to be PRRs that are involved in the recognition of bacteria, fungi, and viruses. In this review, we give a comprehensive overview of the literature regarding PRRs' roles in the immunological defenses of E. sinensis, with the aim of providing clues to the mechanisms of innate immunity.

Selenopolysaccharide Isolated from Lentinula edodes Mycelium Affects Human T-Cell Function

Lentinula edodes polysaccharides are natural immunomodulators. SeLe30, analyzed in this study, is a new mixture of selenium-enriched linear 1,4-α-glucans and 1,3-β- and 1,6-β-glucans isolated from L. edodes mycelium. In the present study, we evaluated its immunomodulatory properties in human T cells. Peripheral blood mononuclear cells (PBMCs) and T cells were isolated from healthy donors' buffy coats. The effects of SeLe30 on CD25, CD366, and CD279 expression, the subsets of CD8+ T cells, and IFN-γ, IL-6, and TNF-α production were analyzed. SeLe30 downregulated CD25, CD279, and CD366 expression on T cells stimulated by the anti-CD3 antibody (Ab) and upregulated in unstimulated and anti-CD3/CD28-Abs-stimulated T cells. It increased the percentage of central memory CD8+ T cells in unstimulated PBMCs and naïve and central memory T cells in anti-CD3-Ab-stimulated PBMCs. SeLe30 decreased the number of central memory and naïve CD8+ T cells in anti-CD3/CD28-stimulated T cells, whereas, in PBMCs, it reduced the percentage of effector memory CD8+ T cells. Moreover, SeLe30 upregulated cytokine production. SeLe30 exhibits context-dependent effects on T cells. It acts on unstimulated T cells, affecting their activation while increasing the expression of immune checkpoints, which sensitizes them to inhibitory signals that can silence this activation. In the case of a lack of costimulation, SeLe30 exhibits an inhibitory effect, reducing T-cell activation. In cells stimulated by dual signals, its effect is further enhanced, again increasing the "safety brake" of CD366 and CD279. However, the final SeLe30 effect is mediated by its indirect impacts by altering interactions with other immune cells.

Effects of Dietary Yeast β-1,3/1,6-D-Glucan on Immunomodulation in RAW 264.7 Cells and Methotrexate-Treated Rat Models

A new subclass of nutraceuticals, called immunoceuticals, is dedicated to immunological regulation. Although yeast-derived β-1,3/1,6-D-glucan shows promise as an immunoceutical candidate, further studies are needed to define its precise immune-enhancing processes and to standardize its use. Following methotrexate (MTX)-induced immunosuppression in rats, we evaluated the immunomodulatory efficacy of a highly pure and standardized β-1,3/1,6-D-glucan sample (YBG) in RAW 264.7 macrophages. In in vitro and in vivo models, YBG demonstrated remarkable immunomodulatory effects, such as repair of immune organ damage, elevation of blood cytokine levels, and enhanced phagocytosis and nitric oxide production in RAW 264.7 cells. These results are consistent with the established immunostimulatory properties of β-glucan. It is noteworthy that this research indicates the potential of YBG as an immunomodulatory nutraceutical, as it is among the first to demonstrate immunological augmentation in an immunosuppression setting produced by MTX. Based on these observations, further investigation of YBG is warranted, particularly given its potential to emerge as a combination immunoceutical to mitigate immunosuppression and reduce the risk of infection in rheumatoid arthritis (RA) patients receiving long-term MTX therapy.

Yeast β-glucan promotes antiviral type I interferon response via dectin-1

Pseudorabies virus (PRV), an alphaherpesvirus, is a neglected zoonotic pathogen. Dectin-1 sensing of β-glucan (BG) induces trained immunity, which can possibly form a new strategy for the prevention of viral infection. However, alphaherpesvirus including PRV have received little to no investigation in the context of trained immunity. Here, we found that BG pretreatment improved the survival rate, weight loss outcomes, alleviated histological injury and decreased PRV copy number of tissues in PRV-infected mice. Type I interferons (IFNs) including IFN-α/β levels in serum were significantly increased by BG. However, these effects were abrogated in the presence of Dectin-1 antagonist. Dectin-1-mediated effect of BG was also confirmed in porcine and murine macrophages. These results suggested that BG have effects on type I IFNs with antiviral property involved in Dectin-1. In piglets, oral or injected immunization with BG and PRV vaccine could significantly elevated the level of PRV-specific IgG and type I IFNs. And it also increased the antibody levels of porcine reproductive and respiratory syndrome virus vaccine and classical swine fever vaccine that were later immunized, indicating a broad-spectrum effect on improving vaccine immunity. On the premise that the cost was greatly reducing, the immunological effect of oral was better than injection administration. Our findings highlighted that BG induced type I IFNs related antiviral effect against PRV involved in Dectin-1 and potential application value as a feed additive to help control the spread of PRV and future emerging viruses.

β-glucan: a potent adjuvant in immunotherapy for digestive tract tumors

The immunotherapy for gastrointestinal tumors, as a significant research direction in the field of oncology treatment in recent years, has garnered extensive attention due to its potential therapeutic efficacy and promising clinical application prospects. Recent advances in immunotherapy notwithstanding, challenges persist, such as side effects, the complexity of the tumor immune microenvironment, variable patient responses, and drug resistance. Consequently, there is a pressing need to explore novel adjunctive therapeutic modalities. β-glucan, an immunomodulatory agent, has exhibited promising anti-tumor efficacy in preclinical studies involving colorectal cancer, pancreatic cancer, and gastric cancer, while also mitigating the adverse reactions associated with chemotherapy and enhancing patients' quality of life. However, further clinical and fundamental research is warranted to comprehensively evaluate its therapeutic potential and underlying biological mechanisms. In the future, β-glucan holds promise as an adjunctive treatment for gastrointestinal tumors, potentially bringing significant benefits to patients.

β-glucans from Euglena gracilis or Saccharomyces cerevisiae effects on immunity and inflammatory parameters in dogs

Considering the differences in molecular structure and function, the effects of β-1,3-glucans from Euglena gracilis and β-1,3/1,6-glucans from Saccharomyces cerevisiae on immune and inflammatory activities in dogs were compared. Four diets were compared: control without β-glucans (CON), 0.15 mg/kg BW/day of β-1,3/1,6-glucans (Β-Y15), 0.15 mg/kg BW/day of β-1,3-glucans (Β-S15), and 0.30 mg/kg BW/day of β-1,3-glucans (Β-S30). Thirty-two healthy dogs (eight per diet) were organized in a block design. All animals were fed CON for a 42-day washout period and then sorted into one of four diets for 42 days. Blood and faeces were collected at the beginning and end of the food intake period and analysed for serum and faecal cytokines, ex vivo production of hydrogen peroxide (H2O2) and nitric oxide (NO), phagocytic activity of neutrophils and monocytes, C-reactive protein (CRP), ex vivo production of IgG, and faecal concentrations of IgA and calprotectin. Data were evaluated using analysis of covariance and compared using Tukey's test (P<0.05). Dogs fed Β-Y15 showed higher serum IL-2 than dogs fed Β-S30 (P<0.05). A higher phagocytic index of monocytes was observed in dogs fed the B-S15 diet than in those fed the other diets, and a higher neutrophil phagocytic index was observed for B-S15 and B-Y15 than in dogs fed the CON diet (P<0.05). Monocytes from dogs fed B-S15 and B-S30 produced more NO and less H2O2 than those from the CON and B-Y15 groups (P<0.05). Despite in the reference value, CRP levels were higher in dogs fed B-S15 and B-S30 diets (P<0.05). β-1,3/1,6-glucan showed cell-mediated activation of the immune system, with increased serum IL-2 and neutrophil phagocytic index, whereas β-1,3-glucan acted on the immune system by increasing the ex vivo production of NO by monocytes, neutrophil phagocytic index, and serum CRP. Calprotectin and CRP levels did not support inflammation or other health issues related to β-glucan intake. In conclusion, both β-glucan sources modulated some immune and inflammatory parameters in dogs, however, different pathways have been suggested for the recognition and action of these molecules, reinforcing the necessity for further mechanistic studies, especially for E. gracilis β-1,3-glucan.

Dietary Intake of Yeast-Derived β-Glucan and Rice-Derived Arabinoxylan Induces Dose-Dependent Innate Immune Priming in Mice

Beta-glucans and arabinoxylans are known for their immunostimulatory properties. However, in vivo these have been documented almost exclusively following parenteral administration, underemphasizing oral intake. C57BL/6 mice are fed either a control diet or a diet supplemented with yeast-derived whole β-glucan particle (yWGP) or with rice-derived arabinoxylan (rice bran-1) at a concentration of 1%, 2.5%, or 5% weight/weight (w/w) for 2 weeks. Thereafter, cells from blood, bone marrow, and spleen are collected for ex vivo stimulation with various microbial stimuli. Dietary intake of yWGP for 2 weeks at concentrations of 1% and 2.5% w/w increases ex vivo cytokine production in mouse blood and bone marrow, whereas 5% w/w yWGP shows no effect. In the spleen, cytokine production remains unaffected by yWGP. At a concentration of 1% w/w, rice bran-1 increases ex vivo cytokine production by whole blood, but 2.5% and 5% w/w cause inhibitory effects in bone marrow and spleen. This study demonstrates that dietary yWGP and rice bran-1 induce immune priming in mouse blood and bone marrow, with the strongest effects observed at 1% w/w. Future human trials should substantiate the efficacy of dietary β-glucans and arabinoxylans to bolster host immunity, focusing on dose optimization.

Ripe papaya pectins inhibit the proliferation of colon cancer spheroids and the formation of chemically induced aberrant crypts in rats colons

Pectins are a class of soluble polysaccharides that can have anticancer properties through several mechanisms. This study aimed to characterize the molecular structure of water-soluble fractions (WSF) derived from ripe and unripe papayas and assess their biological effects in two models: the 3D colon cancer spheroids to measure cell viability and cytotoxicity, and the in vivo model to investigate the inhibition of preneoplastic lesions in rats. WSF yield was slightly higher in ripe papaya, and both samples mainly consisted of pectin. Both pectins inhibited the growth of colon cancer HT29 and HCT116 spheroids. Unripe pectin disturbed HT29/NIH3T3 spheroid formation, decreased HCT116 spheroid viability, and increased spheroid cytotoxicity. Ripe pectin had a more substantial effect on the reduction of spheroid viability for HT29 spheroids. Furthermore, in vivo experiments on a rat model revealed a decrease in aberrant crypt foci (ACF) formation for both pectins and increased apoptosis in colonocytes for ripe papaya pectins. The results suggest potential anticancer properties of papaya pectin, with ripe pectin showing a higher potency.

(1 → 3),(1 → 6) and (1 → 3)-β-D-glucan physico-chemical features drive their fermentation profile by the human gut microbiota

Mushroom polysaccharides consist of a unique set of polymers that arrive intact in the human large intestine becoming available for fermentation by resident gut bacteria with potential benefits to the host. Here we have obtained four glucans from two mushrooms (Pholiota nameko and Pleurotus pulmonarius) under different extraction conditions and their fermentation profile by human gut bacteria in vitro was evaluated. These glucans were isolated and characterized as (1 → 3),(1 → 6)-β-D-glucans varying in branching pattern and water-solubility. An aliquot of each (1 → 3),(1 → 6)-β-D-glucan was subjected to controlled smith degradation process in order to obtain a linear (1 → 3)-β-D-glucan from each fraction. The four β-D-glucans demonstrated different water solubilities and molar mass ranging from 2.2 × 105 g.mol-1 to 1.9 × 106 g.mol-1. In vitro fermentation of the glucans by human gut microbiota showed they induced different short chain fatty acid production (52.0-97.0 mM/50 mg carbohydrates), but an overall consistent high propionate amount (28.5-30.3 % of total short chain fatty acids produced). All glucans promoted Bacteroides uniformis, whereas Anaerostipes sp. and Bacteroides ovatus promotion was strongly driven by the β-D-glucans solubility and/or branching pattern, highlighting the importance of β-D-glucan discrete structures to their fermentation by the human gut microbiota.

An Update on Drug-Nutrient Interactions and Dental Decay in Older Adults

In recent decades, the global demographic landscape has undergone a discernible shift that has been characterised by a progressive increase in the proportion of elderly individuals, indicative of an enduring global inclination toward extended lifespans. The aging process, accompanied by physiological changes and dietary patterns, contributes to detrimental deviations in micronutrient consumption. This vulnerable aging population faces heightened risks, including dental caries, due to structural and functional modifications resulting from insufficient nutritional sustenance. Factors such as physiological changes, inadequate nutrition, and the prevalence of multiple chronic pathologies leading to polypharmacy contribute to the challenge of maintaining an optimal nutritional status. This scenario increases the likelihood of drug interactions, both between medications and with nutrients and the microbiome, triggering complications such as dental decay and other pathologies. Since the drug industry is evolving and new types of food, supplements, and nutrients are being designed, there is a need for further research on the mechanisms by which drugs interfere with certain nutrients that affect homeostasis, exemplified by the prevalence of caries in the mouths of older adults. Infectious diseases, among them dental caries, exert serious impacts on the health and overall quality of life of the elderly demographic. This comprehensive review endeavours to elucidate the intricate interplay among drugs, nutrients, the microbiome, and the oral cavity environment, with the overarching objective of mitigating the potential hazards posed to both the general health and dental well-being of older adults. By scrutinising and optimising these multifaceted interactions, this examination aims to proactively minimise the susceptibility of the elderly population to a spectrum of health-related issues and the consequences associated with dental decay.

Effect of the β-glucan from Lentinus edodes on colitis-associated colorectal cancer and gut microbiota

Colorectal cancer is the third most common cancer in the world, and therapies with safety are in great need. In this study, the β-glucan isolated from Lentinus edodes was successfully fractionated into three fractions with different weight-average molecular weight (M_w) by ultrasonic degradation and used for the treatment of colorectal cancer. In our findings, the β-glucan was successfully degraded with the M_w decreased from 2.56 × 10⁶ Da to 1.41 × 10⁶ Da, exhibiting the triple helix structure without conformation disruption. The in vitro results indicate that β-glucan fractions inhibited colon cancer cell proliferation, induced colon cancer cell apoptosis, and reduced inflammation. The in vivo results based on Azoxymethane (AOM)/dextran sulfate sodium (DSS) mouse model demonstrate that the lower-molecular weight β-glucan fraction showed stronger anti-inflammatory and anti-colon cancer activities by reconstructing intestinal mucosal barrier, increasing short chain fatty acids (SCFAs) content, regulating metabolism of gut microbiota, and rebuilding the gut microbiota structure with the increased Bacteroides and the decreased Proteobacteria at the phylum level, as well as with the decreased Helicobacter and the increased Muribaculum at the genus level. These findings provide scientific basis for using the β-glucan to regulate gut microbiota as an alternative strategy in the clinical treatment of colon cancer.

Polysaccharide-Based Coatings as Drug Delivery Systems

Therapeutic polysaccharide-based coatings have recently emerged as versatile strategies to transform a conventional medical implant into a drug delivery system. However, the translation of these polysaccharide-based coatings into the clinic as drug delivery systems still requires a deeper understanding of their drug degradation/release profiles. This claim is supported by little or no data. In this review paper, a comprehensive description of the benefits and challenges generated by the polysaccharide-based coatings is provided. Moreover, the latest advances made towards the application of the most important representative coatings based on polysaccharide types for drug delivery are debated. Furthermore, suggestions/recommendations for future research to speed up the transition of polysaccharide-based drug delivery systems from the laboratory testing to clinical applications are given.

Nutraceuticals as Modulators of Immune Function: A Review of Potential Therapeutic Effects

Dietary supplementation with nutraceuticals can promote optimal immune system activation, modulating different pathways that enhance immune defenses. Therefore, the immunity-boosting effects of nutraceuticals encompass not only immunomodulatory but also antioxidant, antitumor, antiviral, antibacterial, and antifungal properties, with therapeutic effects against diverse pathological conditions. However, the complexity of the pathways that regulate the immune system, numerous mechanisms of action, and heterogeneity of the immunodeficiencies, and subjects treated make their application in the clinical field difficult. Some nutraceuticals appear to safely improve immune system function, particularly by preventing viral and bacterial infections in specific groups, such as children, the elderly, and athletes, as well as in frail patients, such as those affected by autoimmune diseases, chronic diseases, or cancer. Several nutraceuticals, such as vitamins, mineral salts, polyunsaturated omega-3 fatty acids, many types of phytocompounds, and probiotic strains, have the most consolidated evidence in humans. In most cases, further large and long-term randomized clinical trials are needed to confirm the available preliminary positive data.

Food By-Products and Agro-Industrial Wastes as a Source of β-Glucans for the Formulation of Novel Nutraceuticals

Food and agro-industrial by-products provoke a great environmental and economic impact that must be minimized by adding value to these wastes within the framework of circular economy. The relevance of β-glucans obtained from natural sources (cereals, mushrooms, yeasts, algae, etc.), in terms of their interesting biological activities (hypocholesterolemic, hypoglycemic, immune-modulatory, antioxidant, etc.), has been validated by many scientific publications. Since most of these by-products contain high levels of these polysaccharides or can serve as a substrate of β-glucan-producing species, this work reviewed the scientific literature, searching for studies that utilized food and agro-industrial wastes to obtain β-glucan fractions, attending to the applied procedures for extraction and/or purification, the characterization of the glucans and the tested biological activities. Although the results related to β-glucan production or extraction using wastes are promising, it can be concluded that further research on the glucans' characterization, and particularly on the biological activities in vitro and in vivo (apart from antioxidant capacity), is required to reach the final goal of formulating novel nutraceuticals based on these molecules and these raw materials.

Anti-inflammatory and anti-apoptotic potential of beta-glucan on chemotherapy-induced nephrotoxicity in rats

Background/Aim: Cyclophosphamide (CP) is an anti-cancer agent that mediates nephrotoxicity. Beta (β)-glucan has restorative effects on kidney toxicities through its antioxidant potential; however, the effects of β-glucan on CP-induced renal injury remain unknown. In an experimental nephrotoxicity model using rats, we sought to examine the potential protective action of β-glucan on kidney histomorphology, apoptosis, and TNF-α expression. Methods: Male albino Wistar rats were divided equally into four groups: control, CP, β-glucan, and CP+β-glucan. The kidney tissues of the rats were examined for TNF-α and caspase-3 immunostaining to evaluate inflammation and apoptosis, respectively. Hematoxylin and eosin (H&E) and periodic acid–Schiff (PAS) staining were used for histopathological analyses. Results: The CP group showed severe histopathological damage in the renal tissues of rats. In the renal tissue of the CP group, immunoreactivities for TNF-α (1.25 [0.079] and caspase-3 (1.506 [0.143] were also higher than the control group (0.117 [0.006] and 0.116 [0.002], respectively; P<0.001). In the CP+β-glucan group, the histopathological changes significantly improved. Conclusion: Beta-glucan has therapeutic potential against CP-induced nephrotoxicity in rat kidney.

Oral supplementation with yeast β-glucans improves the resolution of Escherichia coli-associated inflammatory responses independently of monocyte/macrophage immune training

Introduction

Confronted with the emerging threat of antimicrobial resistance, the development of alternative strategies to limit the use of antibiotics or potentiate their effect through synergy with the immune system is urgently needed. Many natural or synthetic biological response modifiers have been investigated in this context. Among them, β-glucans, a type of soluble or insoluble polysaccharide composed of a linear or branched string of glucose molecules produced by various cereals, bacteria, algae, and inferior (yeast) and superior fungi (mushrooms) have garnered interest in the scientific community, with not less than 10,000 publications over the last two decades. Various biological activities of β-glucans have been reported, such as anticancer, antidiabetic and immune-modulating effects. In vitro, yeast β-glucans are known to markedly increase cytokine secretion of monocytes/macrophages during a secondary challenge, a phenomenon called immune training.

Methods

Here, we orally delivered β-glucans derived from the yeast S. cerevisiae to mice that were further challenged with Escherichia coli.

Results

β-glucan supplementation protected the mice from E. coli intraperitoneal and intra-mammary infections, as shown by a lower bacterial burden and greatly diminished tissue damage. Surprisingly, this was not associated with an increased local immune response. In addition, granulocyte recruitment was transient and limited, as well as local cytokine secretion, arguing for faster resolution of the inflammatory response. Furthermore, ex-vivo evaluation of monocytes/macrophages isolated or differentiated from β-glucan-supplemented mice showed these cells to lack a trained response versus those from control mice.

Conclusion

In conclusion, dietary β-glucans can improve the outcome of Escherichia coli infections and dampen tissue damages associated to excessive inflammatory response. The mechanisms associated with such protection are not necessarily linked to immune system hyper-activation or immune training.

Role of ascomycete and basidiomycete fungi in meeting established and emerging sustainability opportunities: a review

Fungal biomass is the future's feedstock. Non-septate Ascomycetes and septate Basidiomycetes, famously known as mushrooms, are sources of fungal biomass. Fungal biomass, which on averagely comprises about 34% protein and 45% carbohydrate, can be cultivated in bioreactors to produce affordable, safe, nontoxic, and consistent biomass quality. Fungal-based technologies are seen as attractive, safer alternatives, either substituting or complementing the existing standard technology. Water and wastewater treatment, food and feed, green technology, innovative designs in buildings, enzyme technology, potential health benefits, and wealth production are the key sectors that successfully reported high-efficiency performances of fungal applications. This paper reviews the latest technical know-how, methods, and performance of fungal adaptation in those sectors. Excellent performance was reported indicating high potential for fungi utilization, particularly in the sectors, yet to be utilized and improved on the existing fungal-based applications. The expansion of fungal biomass in the industrial-scale application for the sustainability of earth and human well-being is in line with the United Nations' Sustainable Development Goals.

Analysis of Biochemical and Genetic Variability of Pleurotus ostreatus Based on the β-Glucans and CDDP Markers

Oyster mushroom (Pleurotus ostreatus) is still one of the most cultivated edible and medicinal mushrooms. Despite its frequent cultivation around the world, there is currently just a little information available on the variability of strains in terms of the content of β-glucans in them. This work presents an extensive study of 60 strains in terms of the content of α-glucans and β-glucans in their caps and stipes. The authenticity of the production strains based on an analysis of the variability of their genome by CDDP (Conserved DNA-derived polymorphism) markers was confirmed, whereas identical CDDP profiles were identified between samples 45, 89, 95, and 96. Genetic variability of the analyzed production strains showed a high polymorphism and effective discriminative power of the used marking technique. Medium positive correlations were found among the CDDP profiles and β-glucan content in the group of strains that generated the same CDDP profiles, and low negative correlation was found among these profiles in the group of low β-glucan content strains. For the determination of glucans content, Mushroom and Yeast analytical enzymatic kit (Megazyme, Bray, Co. Wicklow, Ireland) were used. The results clearly showed that the stipe contains on average 33% more β-glucans than the cap. The minimum detected β-glucan content in the stipe was in strain no. 72, specifically 22%, and the maximum in strain no. 43, specifically 56%, which after the conversion represents a difference of 155%. From the point of view of β-glucan content, the stated strain no. 43 appears to be very suitable for the commercial production of β-glucans under certain conditions.

Ingestion, Immunity, and Infection: Nutrition and Viral Respiratory Tract Infections

Respiratory infections place a heavy burden on the health care system, particularly in the winter months. Individuals with a vulnerable immune system, such as very young children and the elderly, and those with an immune deficiency, are at increased risk of contracting a respiratory infection. Most respiratory infections are relatively mild and affect the upper respiratory tract only, but other infections can be more serious. These can lead to pneumonia and be life-threatening in vulnerable groups. Rather than focus entirely on treating the symptoms of infectious disease, optimizing immune responsiveness to the pathogens causing these infections may help steer towards a more favorable outcome. Nutrition may have a role in such prevention through different immune supporting mechanisms. Nutrition contributes to the normal functioning of the immune system, with various nutrients acting as energy sources and building blocks during the immune response. Many micronutrients (vitamins and minerals) act as regulators of molecular responses of immune cells to infection. It is well described that chronic undernutrition as well as specific micronutrient deficiencies impair many aspects of the immune response and make individuals more susceptible to infectious diseases, especially in the respiratory and gastrointestinal tracts. In addition, other dietary components such as proteins, pre-, pro- and synbiotics, and also animal- and plant-derived bioactive components can further support the immune system. Both the innate and adaptive defense systems contribute to active antiviral respiratory tract immunity. The initial response to viral airway infections is through recognition by the innate immune system of viral components leading to activation of adaptive immune cells in the form of cytotoxic T cells, the production of neutralizing antibodies and the induction of memory T and B cell responses. The aim of this review is to describe the effects of a range different dietary components on anti-infective innate as well as adaptive immune responses and to propose mechanisms by which they may interact with the immune system in the respiratory tract.

Immunomodulatory activity of β-glucan polysaccharides isolated from different species of mushroom - A potential treatment for inflammatory lung conditions

Acute respiratory distress syndrome (ARDS) is the most common form of acute severe hypoxemic respiratory failure in the critically ill with a hospital mortality of 40%. Alveolar inflammation is one of the hallmarks for this disease. β-Glucans are polysaccharides isolated from a variety of natural sources including mushrooms, with documented immune modulating properties. To investigate the immunomodulatory activity of β-glucans and their potential as a treatment for ARDS, we isolated and measured glucan-rich polysaccharides from seven species of mushrooms. We used three models of in-vitro injury in THP-1 macrophages, Peripheral blood mononuclear cells (CD14+) (PMBCs) isolated from healthy volunteers and lung epithelial cell lines. We observed variance between β-glucan content in extracts isolated from seven mushroom species. The extracts with the highest β-glucan content found was Lentinus edodes which contained 70% w/w and Hypsizygus tessellatus which contained 80% w/w with low levels of α-glucan. The extracts had the ability to induce secretion of up to 4000 pg/mL of the inflammatory cytokine IL-6, and up to 5000 pg/mL and 500 pg/mL of the anti-inflammatory cytokines IL-22 and IL-10, respectively, at a concentration of 1 mg/mL in THP-1 macrophages. In the presence of cytokine injury, IL-8 was reduced from 15,000 pg/mL to as low as 10,000 pg/mL in THP-1 macrophages. After insult with LPS, phagocytosis dropped from 70-90% to as low 10% in CD14+ PBMCs. After LPS insult CCL8 relative gene expression was reduced, and IL-10 relative gene expression increased from 50 to 250-fold in THP-1 macrophages. In lung epithelial cells, both A549 and BEAS-2B after IL-1β insult, IL-8 levels dropped from 10,000 pg/mL to as low as 6000 pg/mL. TNF-α levels dropped 10-fold from 100 pg/mL to just below 10 pg/mL. These results demonstrate the therapeutic potential of β-glucans in inflammatory lung conditions. Findings also advance bio-based research that connects green innovation with One Health applications for the betterment of society.

Bioactive Components in Traditional Foods Aimed at Health Promotion: A Route to Novel Mechanistic Insights and Lead Molecules?

Traditional foods and diets can provide health benefits beyond their nutrient composition because of the presence of bioactive compounds. In various traditional healthcare systems, diet-based approaches have always played an important role, which has often survived until today. Therefore, investigating traditional foods aimed at health promotion could render not only novel bioactive substances but also mechanistic insights. However, compared to pharmacologically focused research on natural products, investigating such nutrition-based interventions is even more complicated owing to interacting compounds, less potent and relatively subtle effects, the food matrix, and variations in composition and intake. At the same time, technical advances in 'omics' technologies, cheminformatics, and big data analysis create new opportunities, further strengthened by increasing insights into the biology of health and homeostatic resilience. These are to be combined with state-of-the-art ethnobotanical research, which is key to obtaining reliable and reproducible data. Unfortunately, socioeconomic developments and climate change threaten traditional use and knowledge as well as biodiversity. Expected final online publication date for the Annual Review of Food Science and Technology, Volume 13 is March 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

In vivo toxicity of bioreactor-grown biomass and exopolysaccharides from Malaysian tiger milk mushroom mycelium for potential future health applications

Natural mycelial biomass (MB) and exopolysaccharides (EPS) of Malaysian tiger milk mushroom Lignosus rhinocerus are considered high-end components due to their high commercial potential value in drug discovery. This study aims to evaluate the toxicity of the mushroom extracts' generated in a bioreactor using the zebrafish embryo toxicity (ZFET) model assay as a new therapy for treating asthma. Both MB and EPS extracts, at concentrations 0.16-10 mg/mL, were tested for ZFET and early development effects on Zebrafish Embryos (ZE) during 24-120 h post-fertilisation (HPF). Findings revealed that MB was deemed safe with an LC₅₀ of 0.77 mg/mL; the EPS were non-toxic (LC₅₀ of 0.41 mg/mL). Neither MB nor EPS delayed hatching nor teratogenic defects in the treated ZE at a 2.5 mg/mL dose. There were no significant changes in the ZE heart rate after treatments with MB (130 beats/min) and EPS (140 beats/min), compared to that of normal ZE (120-180 beats/min). Mixing both natural compounds MB and EPS did not affect toxicity using ZFET testing; thus, intimating their safe future use as therapeutic interventions. This represents the first study to have used the ZFET assay on MB and EPS extracts of L. rhinocerus for future health applications.

Pleurotus eryngii improves postprandial glycaemia, hunger and fullness perception, and enhances ghrelin suppression in people with metabolically unhealthy obesity

The aim of this study was to examine potential postprandial benefits of Pleurotus eryngii in nineteen volunteers with metabolically unhealthy obesity. An acute, randomized, crossover-designed trial comparing a meal with Pleurotus eryngii and a control meal was performed. The two meals matched in macronutrient and caloric content. Participants consumed both meals in random order after an overnight fast. Blood samples were drawn before and 30, 60, 90, 120, 150 and 180 min after meal consumption (in total 266 samples) to determine glucose, insulin, ghrelin, peptide YY, glucagon-like peptide-1 and glicentin. Visual analog scales measuring the subjective perception of hunger and fullness were completed at the same time points. The test meal resulted in lower glucose incremental area under the curve (iAUC). Additionally, the iAUC of the ghrelin response over time was substantially lower after the test meal (p = 0.033). Lower desire to eat and higher fullness was reflected by significantly lower hunger iAUC (p = 0.046) and higher fullness iAUC (p = 0.042) after the test meal. No differences in insulin, PYY, GLP-1 and glicentin were observed. Pleurotus eryngii can ameliorate postprandial glycaemia, appetite and regulate ghrelin levels at the postprandial state. This effect is attributed to the bioactive polysaccharides that inhibit the activity of enzymes catalysing carbohydrate hydrolysis, cause a delayed gastric emptying and glucose absorption.

Beta-Glucans from Fungi: Biological and Health-Promoting Potential in the COVID-19 Pandemic Era

Beta-glucans comprise a group of polysaccharides of natural origin found in bacteria, algae, and plants, e.g., cereal seeds, as well as microfungi and macrofungi (mushrooms), which are characterized by diverse structures and functions. They are known for their metabolic and immunomodulatory properties, including anticancer, antibacterial, and antiviral. Recent reports suggest a potential of beta-glucans in the prevention and treatment of COVID-19. In contrast to β-glucans from other sources, β-glucans from mushrooms are characterized by β-1,3-glucans with short β-1,6-side chains. This structure is recognized by receptors located on the surface of immune cells; thus, mushroom β-glucans have specific immunomodulatory properties and gained BRM (biological response modifier) status. Moreover, mushroom beta-glucans also owe their properties to the formation of triple helix conformation, which is one of the key factors influencing the bioactivity of mushroom beta-glucans. This review summarizes the latest findings on biological and health-promoting potential of mushroom beta-glucans for the treatment of civilization and viral diseases, with particular emphasis on COVID-19.

Synthesis and Study of Antifungal Properties of New Cationic Beta-Glucan Derivatives

The interaction of positively charged polymers (polycations) with a biological membrane is considered to be the cause of the frequently observed toxicity of these macromolecules. If it is possible to obtain polymers with a predominantly negative effect on bacterial and fungal cells, such systems would have great potential in the treatment of infectious diseases, especially now when reports indicate the growing risk of fungal co-infections in COVID-19 patients. We describe in this article cationic derivatives of natural beta-glucan polymers obtained by reacting the polysaccharide isolated from Saccharomyces boulardii (SB) and Cetraria islandica (CI) with glycidyl trimethyl ammonium chloride (GTMAC). Two synthesis strategies were applied to optimize the product yield. Fungal diseases particularly affect low-income countries, hence the emphasis on the simplicity of the synthesis of such drugs so they can be produced without outside help. The three structures obtained showed selective anti-mycotic properties (against, i.e., Scopulariopsis brevicaulis, Aspergillus brasiliensis, and Fusarium solani), and their toxicity established using fibroblast 3T3-L1 cell line was negligible in a wide range of concentrations. For one of the polymers (SB derivative), using in vivo model of Aspergillus brasiliensis infection in Galleria mellonella insect model, we confirmed the promising results obtained in the preliminary study.