β-Glucan supplementation, allergy symptoms, and quality of life in self-described ragweed allergy sufferers

β-Glucan-A promising immunocyte-targeting drug delivery vehicle: Superiority, applications and future prospects

Drug delivery technologies that could convert promising therapeutics into successful therapies have been under broad research for many years. Recently, β-glucans, natural-occurring polysaccharides extracted from many organism species such as yeast, fungi and bacteria, have attracted increasing attention to serve as drug delivery carriers. With their unique structure and innate immunocompetence, β-glucans are considered as promising carriers for targeting delivery especially when applied in the vaccine construction and oral administration of therapeutic agents. In this review, we focus on three types of β-glucans applied in the drug delivery system including yeast β-glucan, Schizophyllan and curdlan, highlighting the benefits of β-glucan based delivery system. We summarize how β-glucans as delivery vehicles have aided various therapeutics ranging from macromolecules including proteins, peptides and nucleic acids to small molecular drugs to reach desired cells or organs in terms of loading strategies. We also outline the challenges and future directions for developing the next generation of β-glucan based delivery systems.

Managing children with frequent respiratory infections and associated wheezing: a preliminary randomized study with a new multicomponent nasal spray

BACKGROUND

Preschoolers frequently have respiratory infections (RIs), which may cause wheezing in some subjects. Type 2 polarization may favor increased susceptibility to RIs and associated wheezing. Non-pharmacological remedies are garnering increasing interest as possible add-on therapies. The present preliminary study investigated the efficacy and safety of a new multi-component nasal spray in preschoolers with frequent RIs and associated wheezing.

METHODS

Some preschoolers with these characteristics randomly took this product, containing lactoferrin, dipotassium glycyrrhizinate, carboxymethyl-beta-glucan, and vitamins C and D3 (Saflovir), two sprays per nostril twice daily for 3 months. Other children were randomly treated only with standard therapy. Outcomes included the number of RIs and wheezing episodes, use of medications, and severity of clinical manifestations.

RESULTS

Preschoolers treated add-on with this multicomponent product experienced fewer RIs and used fewer beta-2 agonists than untreated children (P = 0.01 and 0.029, respectively).

CONCLUSIONS

This preliminary study demonstrated that a multicomponent product, administered add-on as a nasal spray, could reduce the incidence of RIs and use of symptomatic drugs for relieving wheezing in children.

Dietary yeast beta 1,3/1,6 glucan supplemented to adult Labrador Retrievers alters peripheral blood immune cell responses to vaccination challenge without affecting protective immunity

Yeast-derived 1,3/1,6 β-glucans may alter host immunity to produce robust and quickly resolved responses that align with companion animal health goals. In adult dogs, immunomodulation by yeast 1,3/1,6 β-glucans in extruded kibble diet have not been well documented. The study objective was to evaluate systemic immune responses in dogs fed kibble diets with two yeast 1,3/1,6 β-glucans doses before and after vaccine challenge. Twenty-four adult Labrador Retrievers were assigned to three dietary treatments consisting of a basal diet (control) supplemented with 0.012% or 0.023% (0.5 or 1×, respectively) yeast 1,3/1,6 β-glucan with equal sex representation within each treatment (8 dogs/diet). Animals were fed experimental diets for a 29-d acclimation period, after which baseline blood samples were collected before administration of a combination canine distemper virus, parvovirus, and adenovirus-2 vaccine. Blood samples were collected weekly for 21 d following vaccination with whole blood for CBC analysis, serum for titer and cytokine assays, and peripheral blood mononuclear cells (PBMC) isolated for flow cytometric immune cell profiling. Data were analyzed using the MIXED procedure with diet and timepoint fixed effects. Serum titer was analyzed by Kruskal-Wallis test (SAS 9.4; P ≤ 0.05). Prior to vaccination, β-glucan diets did not affect serum cytokines, antibody titer, or immune cell populations. In the first 7 d post-vaccination (dpv), PBMC CD21low B cells increased 36.5% to 58.1% in all groups but the magnitude of change was lesser in the 0.5× β-glucan diet resulting in 25.6% lower CD21low populations compared to control-fed dogs (P = 0.007). By 21 dpv, B-cell populations recovered to baseline levels in dogs fed 1× β-glucan, but CD21high cells remained elevated 50.5% in dogs fed 0.5× β-glucan diets compared with baseline (P < 0.0001). While no differences in serum titer or cytokines were observed, feeding both β-glucan diets maintained stable blood monocytes, whereas a 53.0% decrease between baseline and 14 dpv was observed in control-fed dogs (P = 0.01). Collectively, these outcomes suggest that a 1× dose of 1,3/1,6 yeast β-glucan in extruded kibble diets altered monocytes associated with trained immunity, did not reduce PBMC CD21low B-cell responsiveness, and simultaneously contributed to B-cell population resolution by 21 dpv in adult dogs. Additional research to assess the functionality of these changes is needed.

From Cancer Therapy to Winemaking: The Molecular Structure and Applications of β-Glucans and β-1, 3-Glucanases

β-glucans are a diverse group of polysaccharides composed of β-1,3 or β-(1,3-1,4) linked glucose monomers. They are mainly synthesized by fungi, plants, seaweed and bacteria, where they carry out structural, protective and energy storage roles. Because of their unique physicochemical properties, they have important applications in several industrial, biomedical and biotechnological processes. β-glucans are also major bioactive molecules with marked immunomodulatory and metabolic properties. As such, they have been the focus of many studies attesting to their ability to, among other roles, fight cancer, reduce the risk of cardiovascular diseases and control diabetes. The physicochemical and functional profiles of β-glucans are deeply influenced by their molecular structure. This structure governs β-glucan interaction with multiple β-glucan binding proteins, triggering myriad biological responses. It is then imperative to understand the structural properties of β-glucans to fully reveal their biological roles and potential applications. The deconstruction of β-glucans is a result of β-glucanase activity. In addition to being invaluable tools for the study of β-glucans, these enzymes have applications in numerous biotechnological and industrial processes, both alone and in conjunction with their natural substrates. Here, we review potential applications for β-glucans and β-glucanases, and explore how their functionalities are dictated by their structure.

Therapeutic and Industrial Applications of Curdlan With Overview on Its Recent Patents

Curdlan is an exopolysaccharide, which is composed of glucose linked with β-(1,3)-glycosidic bond and is produced by bacteria, such as Alcaligenes spp., Agrobacterium spp., Paenibacillus spp., Rhizobium spp., Saccharomyces cerevisiae, Candida spp., and fungal sources like Aureobasidium pullulan, Poria cocos, etc. Curdlan has been utilized in the food and pharmaceutical industries for its prebiotic, viscosifying, and water-holding properties for decades. Recently, the usefulness of curdlan has been further explored by the pharmaceutical industry for its potential therapeutic applications. Curdlan has exhibited immunoregulatory and antitumor activity in preclinical settings. It was observed that curdlan can prevent the proliferation of malarial merozoites in vivo; therefore, it may be considered as a promising therapy for the treatment of end-stage malaria. In addition, curdlan has demonstrated potent antiviral effects against human immunodeficiency virus (HIV) and Aedes aegypti virus. It has been suggested that the virucidal properties of curdlans should be extended further for other deadly viruses, such as severe acute respiratory syndrome (SARS), Middle East respiratory syndrome (MERS), and the current severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2/COVID-19). The prebiotic property of curdlan would confer beneficial effects on the host by promoting the growth of healthy microbiota in the gut and consequently help to reduce gastrointestinal disorders. Therefore, curdlan can be employed in the manufacture of prebiotics for the management of various gastrointestinal dysbiosis problems. Studies on the mechanism of action of curdlan-induced suppression in microbial and tumor cells at the cellular and molecular levels would not only enhance our understanding regarding the therapeutic effectiveness of curdlan but also help in the discovery of new drugs and dietary supplements. The primary focus of this review is to highlight the therapeutic interventions of curdlan as an anticancer, anti-malaria, antiviral, and antibacterial agent in humans. In addition, our review provides the latest information about the chemistry and biosynthesis of curdlan and its applications for making novel dairy products, functional foods, and nutraceuticals and also details about the recent patents of curdlan and its derivatives.

Effects of fungal beta-glucans on health - a systematic review of randomized controlled trials

INTRODUCTION

Beta-glucans are polysaccharides that exhibit a wide range of biological properties as a result of their varying chemical composition. Like all dietary fibers, they avoid catabolism in the upper gastrointestinal tract, and they reach the large intestine undigested. There, they undergo fermentation by the gut microbiota, a process that has potential beneficial effects for the host. The aim of this systematic review is to assess the effects of consumption of beta-(1 → 3,1 → 6)-d-glucans, naturally found in the cell walls of fungi, on health outcomes.

METHODS

A comprehensive literature search was performed on PubMed, Cochrane Library and Web of Science to retrieve studies that applied randomized controlled trials (RCTs) to investigate the impact of exclusive oral administration of fungal beta-glucans in any form and at any dosage to healthy subjects or patients.

RESULTS

Thirty-four RCTs, of the 917 records retrieved in total, met the eligibility criteria and are included in the present review. The sources of fungal beta-glucans were Saccharomyces cerevisiae, Aureobasidium pullulans, Pleurotus ostreatus, Lentinula edodes and Ganoderma lucidum, and the dosage of supplementation ranged from 2.5 to 1000 mg daily for up to 6.5 months. The primary physiological outcome of the majority of the interventions was immunomodulation, which resulted in (a) strengthened immune defense that reduces the incidence and symptoms of cold, flu and other respiratory infections and (b) improvement of allergic symptoms. However, the findings on the induction of immune response alterations were inconsistent at the cellular and molecular levels. Another aspect is psychological wellbeing, as the cohorts that received the polysaccharides of interest reported improvement in their mood states as well as amelioration of overall wellbeing. At the same time, it might also be useful as a complementary agent to patients undergoing cancer therapies. Furthermore, supplements containing beta-(1 → 3,1 → 6)-d-glucan administered to overweight/obese adults might have the potential to decrease comorbid conditions associated with obesity. Notably, no adverse event causally related to glucans was recorded.

CONCLUSIONS

Supplementation with beta-(1 → 3,1 → 6)-d-glucans is well-tolerated, and health-promoting properties are manifested primarily through the potentiation of the immune system. More studies are required to confirm their additional beneficial effects, to establish the optimal dose, and to reveal the underlying molecular mechanisms.

Derivation of an occupational exposure limit for β-glucans

β-Glucans are abundant bacterial, yeast, and fungal cell wall polysaccharides that have been shown to activate the immune system. Establishment of an occupational exposure limit (OEL) for β-glucan exposure is critical to the protection of worker health, as these exposures have been linked to immunosuppressive and inflammatory reactions and possibly the development of respiratory diseases. Detectable concentrations of β-glucans have been identified in common occupational inhalation exposure scenarios, such as in the agricultural and waste management sectors. However, no published exposure benchmarks for inhalation of β-glucans are available for workers or the general population. Thus, a health-based OEL for inhalation exposure of workers to β-glucans was derived based on consideration of human and non-human effect data for this class of compounds and contemporary risk assessment methods. The weight of the evidence indicated that the available data in humans showed significant methodological limitations, such as lack of a representative study size, appropriate control population, and clear dose-response relationship. Thus, an OEL of 150 ng/m³ was derived for β-glucans based on the most relevant nonclinical study. This OEL provides an input to the occupational risk assessment process, allows for comparisons to worker exposure, and can guide risk management and exposure control decisions.

β-1,3/1,6-Glucans and Immunity: State of the Art and Future Directions

The innate immune system responds in a rapid and non-specific manner against immunologic threats; inflammation is part of this response. This is followed by a slower but targeted and specific response termed the adaptive or acquired immune response. There is emerging evidence that dietary components, including yeast-derived β-glucans, can aid host defense against pathogens by modulating inflammatory and antimicrobial activity of neutrophils and macrophages. Innate immune training refers to a newly recognized phenomenon wherein compounds may "train" innate immune cells, such that monocyte and macrophage precursor biology is altered to mount a more effective immunological response. Although various human studies have been carried out, much uncertainty still exists and further studies are required to fully elucidate the relationship between β-glucan supplementation and human immune function. This review offers an up-to-date report on yeast-derived β-glucans as immunomodulators, including a brief overview of the current paradigm regarding the interaction of β-glucans with the immune system. The recent pre-clinical work that has partly decrypted mode of action and the newest evidence from human trials are also reviewed. According to pre-clinical studies, β-1,3/1,6-glucan derived from baker's yeast may offer increased immuno-surveillance, although the human evidence is weaker than that gained from pre-clinical studies.

Agaricus blazei-Based Mushroom Extract Supplementation to Birch Allergic Blood Donors: A Randomized Clinical Trial

Since Agaricus blazei Murill (AbM) extract reduced specific IgE and ameliorated a skewed Th1/Th2 balance in a mouse allergy model, it was tested in blood donors with self-reported, IgE-positive, birch pollen allergy and/or asthma. Sixty recruited donors were randomized in a placebo-controlled, double-blinded study with pre-seasonal, 7-week, oral supplementation with the AbM-based extract Andosan^TM. Before and after the pollen season, questionnaires were answered for allergic rhino-conjunctivitis, asthma, and medication; serum IgE was measured, and Bet v 1-induced basophil activation was determined by CD63 expression. The reported general allergy and asthma symptoms and medication were significantly reduced in the AbM compared to the placebo group during pollen season. During the season, there was significant reduction in specific IgE anti-Bet v 1 and anti-t3 (birch pollen extract) levels in the AbM compared with the placebo group. While the maximal allergen concentrations needed for eliciting basophil activation before the season, changed significantly in the placebo group to lower concentrations (i.e., enhanced sensitization) after the season, these concentrations remained similar in the Andosan^TM AbM extract group. Hence, the prophylactic effect of oral supplementation before the season with the AbM-based Andosan^TM extract on aeroallergen-induced allergy was associated with reduced specific IgE levels during the season and basophils becoming less sensitive to allergen activation.

Use of Dietary Supplements among Spanish Pediatricians in Daily Practice: A Cross-Sectional Survey Study

A cross-sectional survey study was designed to gather information on the use of dietary supplements by Spanish pediatricians. The study questionnaire was completed by 433 pediatricians (62% men, mean age 52.5 years) throughout the country. They also provided data on 10 of their patients (n = 4304) in which synbiotics, immune stimulants, and omega-3 polyunsaturated fatty acids (PUFAs) had been prescribed. Synbiotics were used by 92% of pediatricians, immune stimulants by 80.4%, and omega-3 PUFAs by 75.1%. Synbiotics were mainly used combined with antibiotics (92.6%) and for gastrointestinal disorders (91.2%), immune stimulants to enhance defenses and cold prevention (87.1%), and omega-3 PUFAs to improve symptoms of attention-deficit hyperactivity disorder (ADHD) (84.8%) and concentration (80.1%). Confidence and previous experience with the product (51.6%), composition and indications of the product (43.1%), and tolerability (39.9%) were main factors involved in decision-making. Children treated with omega-3 supplements were significantly older (mean age 7.6 (3.0) years) than those treated with synbiotics (3.9 (3.9) years) or immune stimulants (3.4 (2.8) years) (P<0.001). Short duration of treatment (<1 month) was significantly more common in the synbiotics group (90.5%), whereas longer duration of treatment (>3 months) was more frequent in the omega-3 group (79.1%). In the immune stimulants group, 60.4% of patients were treated for a period between 1 and 3 months. Clinical improvement was rated by participants as “a lot” in 39% of cases and as “quite” improvement in 50.6%. The overall level of satisfaction was rated as “very satisfied” by 52.1% of participants and as “quite satisfied” by 40.9%. The results show that the use of dietary supplements to improve different conditions, particularly minor disorders, is a widespread clinical practice among Spanish pediatricians. Administration regimens for the three types of supplements, synbiotics, immune stimulants, and omega-3 PUFAs, were consistent with guideline recommendations.

Effects of Euglena gracilis EOD-1 Ingestion on Salivary IgA Reactivity and Health-Related Quality of Life in Humans

Euglena gracilis EOD-1, a microalgal strain known for high yields of the β-1, 3-glucan paramylon, is suggested to function as a dietary fiber and enhance immunity. Here, we aimed to investigate the effects of E. gracilis EOD-1 biomass (EOD1BM) ingestion on immunoglobulin A (IgA) antibody titers in saliva, its reactivity, and the health-related quality of life (QOL) in humans. Reacting human immunoglobulin preparations and saliva with paramylon granules revealed the presence of anti-paramylon antibodies in the blood and saliva. We conducted a placebo-controlled, double-blind, crossover study involving 13 healthy subjects who ingested the placebo or EOD1BM for 4 weeks. Saliva was collected from each subject before and after ingestion, and IgA titers and E. gracilis EOD-1 paramylon (EOD1PM) reactivity were compared. In the EOD1BM Ingestion group, the anti-EOD1PM IgA content and titer increased after EOD1BM ingestion. No such change was observed in the Placebo group. Furthermore, the health-related QOL, especially mental health, increased in the EOD1BM Ingestion group. Thus, EOD1BM ingestion led to the production of paramylon (PM)-specific IgA antibody and increased salivary IgA antibody titers. We demonstrate that EOD1BM ingestion enhanced the immunity in the mucosal surface, evoked an antigen-specific response, and increased the health-related QOL, thereby contributing to health improvement.

Beta Glucan: Supplement or Drug? From Laboratory to Clinical Trials

Glucans are part of a group of biologically active natural molecules and are steadily gaining strong attention not only as an important food supplement, but also as an immunostimulant and potential drug. This paper represents an up-to-date review of glucans (β-1,3-glucans) and their role in various immune reactions and the treatment of cancer. With more than 80 clinical trials evaluating their biological effects, the question is not if glucans will move from food supplement to widely accepted drug, but how soon.

A β-Glucan-Based Dietary Fiber Reduces Mast Cell-Induced Hyperpermeability in Ileum From Patients With Crohn's Disease and Control Subjects

BACKGROUND

Administration of β-glucan has shown immune-enhancing effects. Our aim was to investigate whether β-glucan could attenuate mast cell (MC)-induced hyperpermeability in follicle-associated epithelium (FAE) and villus epithelium (VE) of patients with Crohn's disease (CD) and in noninflammatory bowel disease (IBD)-controls. Further, we studied mechanisms of β-glucan uptake and effects on MCs in vitro.

METHODS

Segments of FAE and VE from 8 CD patients and 9 controls were mounted in Ussing chambers. Effects of the MC-degranulator compound 48/80 (C48/80) and yeast-derived β-1,3/1,6 glucan on hyperpermeability were investigated. Translocation of β-glucan and colocalization with immune cells were studied by immunofluorescence. Caco-2-cl1- and FAE-cultures were used to investigate β-glucan-uptake using endocytosis inhibitors and HMC-1.1 to study effects on MCs.

RESULTS

β-glucan significantly attenuated MC-induced paracellular hyperpermeability in CD and controls. Transcellular hyperpermeability was only significantly attenuated in VE. Baseline paracellular permeability was higher in FAE than VE in both groups, P<0.05, and exhibited a more pronounced effect by C48/80 and β-glucan P<0.05. No difference was observed between CD and controls. In vitro studies showed increased passage, P<0.05, of β-glucan through FAE-culture compared to Caco-2-cl1. Passage was mildly attenuated by the inhibitor methyl-β-cyclodextrin. HMC-1.1 experiments showed a trend to decreasing MC-degranulation and levels of TNF-α but not IL-6 by β-glucan. Immunofluorescence revealed more β-glucan-uptake and higher percentage of macrophages and dendritic cells close to β-glucan in VE of CD compared to controls.

CONCLUSIONS

We demonstrated beneficial effects of β-glucan on intestinal barrier function and increased β-glucan-passage through FAE model. Our results provide important and novel knowledge on possible applications of β-glucan in health disorders and diseases characterized by intestinal barrier dysfunction.

Oral microbe-host interactions: influence of β-glucans on gene expression of inflammatory cytokines and metabolome profile

Background

The aim of this study was to evaluate the effects of β-glucan on the expression of inflammatory mediators and metabolomic profile of oral cells [keratinocytes (OBA-9) and fibroblasts (HGF-1) in a dual-chamber model] infected by Aggregatibacter actinomycetemcomitans. The periodontopathogen was applied and allowed to cross the top layer of cells (OBA-9) to reach the bottom layer of cells (HGF-1) and induce the synthesis of immune factors and cytokines in the host cells. β-glucan (10 μg/mL or 20 μg/mL) were added, and the transcriptional factors and metabolites produced were quantified in the remaining cell layers and supernatant.

Results

The relative expression of interleukin (IL)-1-α and IL-18 genes in HGF-1 decreased with 10 μg/mL or 20 μg/mL of β-glucan, where as the expression of PTGS-2 decreased only with 10 μg/mL. The expression of IL-1-α increased with 20 μg/mL and that of IL-18 increased with 10 μg/mL in OBA-9; the expression of BCL 2, EP 300, and PTGS-2 decreased with the higher dose of β-glucan. The production of the metabolite 4-aminobutyric acid presented lower concentrations under 20 μg/mL, whereas the concentrations of 2-deoxytetronic acid NIST and oxalic acid decreased at both concentrations used. Acetophenone, benzoic acid, and pinitol presented reduced concentrations only when treated with 10 μg/mL of β-glucan.

Conclusions

Treatment with β-glucans positively modulated the immune response and production of metabolites.

Orally administered β-glucan attenuates the Th2 response in a model of airway hypersensitivity

β-Glucan is a polysaccharide that can be extracted from fungal cell walls. Wellmune WGP^®, a preparation of β-1,3/1,6-glucans, is a dietary supplement that has immunomodulating properties. Here we investigated the effect WGP had on a mouse model of asthma. OVA-induced asthma in mice is characterized by infiltration of eosinophils into the lung, production of Th2 cytokines and IgE. Daily oral administration of WGP (400 µg) significantly reduced the influx of eosinophils into the lungs of OVA-challenged mice compared to control mice. In addition, WGP inhibited pulmonary production of Th2 cytokines (IL-4, IL-5, IL-13), however serum IgE levels were unaffected by WGP treatment. These data indicate that WGP could potentially be useful as an oral supplement for some asthma patients, however, it would need to be combined with therapies that target other aspects of the disease such as IgE levels. As such, further studies that examine the potential of WGP in combination with other therapies should be explored.

Cow's milk-based beverage consumption in 1- to 4-year-olds and allergic manifestations: an RCT

Background

Nutrients such as docosahexaenoic acid (DHA), prebiotics and β-glucan have been associated with reduced incidence of respiratory illnesses and allergic manifestations (AM). Our objective was to assess if consumption of a cow’s milk-based beverage with these and other nutrients supports respiratory, gastrointestinal, and skin health in otherwise well-nourished, healthy children.

Methods

In this double-blind, randomized, controlled trial, healthy children (1–4 years of age) from two daycare centers in Brazil were fed three servings/day of a cow’s milk-based beverage (CMBB; n = 125) containing DHA, the prebiotics polydextrose (PDX) and galactooligosaccharides (GOS), β-glucan, and other key nutrients, or a control cow’s milk-based beverage (control; n = 131) for up to 28 weeks. Occurrence of respiratory infections, diarrheal disease and AM was assessed by study pediatricians and the number of episodes were analyzed with the Cochran-Mantel-Haenszel test and the Andersen-Gill model.

Results

The CMBB group had fewer episodes of AM, which included allergic rhinitis or conjunctivitis, wheezing, allergic cough, eczema and urticaria, compared to the control group (p = 0.021). The hazard ratio for increased number of episodes of AM was lower in the CMBB group compared to control (HR, 0.64; 95 % CI 0.47–0.89; p = 0.007). There was no difference in the incidence of respiratory infections and diarrheal disease between groups.

Conclusion

A cow’s milk-based beverage containing DHA, PDX/GOS, and yeast β-glucan, and supplemented with micronutrients, including zinc, vitamin A and iron, when consumed 3 times/day for 28 weeks by healthy 1- to 4-year-old children was associated with fewer episodes of allergic manifestations in the skin and the respiratory tract.

Trial registration

registration number: NCT01431469