Baker's yeast beta glucan supplementation increases salivary IgA and decreases cold/flu symptomatic days after intense exercise

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.

Effects of Chronic Barley Consumption on Upper Respiratory Tract Symptoms in Japanese Healthy Adults: A Randomized, Parallel-Group, Controlled Trial

β-(1,3/1,4)-glucan is a major component of cereal grains, such as oats and barley. In this study, we investigated the effects of cooked waxy barley, which contains β-(1,3/1,4)-glucan, on upper respiratory tract physical symptoms and mood status by performing a randomized, parallel-group, comparative trial. The primary outcome was assessed using the Wisconsin Upper Respiratory Symptom Survey-21 and Profile of Mood States second edition. Twenty-seven healthy Japanese adult participants were supplemented with 100 g of cooked waxy barley (containing 1.8 g of β-glucan) or 100 g of cooked white rice daily for 8 weeks. Participants receiving cooked waxy barley reported a reduction in cumulative days of sneezing (p < 0.05) and feeling tired (p < 0.0001) compared with the control group. After the intervention period, there were significantly less severe nasal symptoms, such as runny nose, plugged nose, and sneezing (p < 0.05), and a significantly greater reduction of the Tension-Anguish score (p < 0.05) in the barley group than in the control group. This study suggests that supplementation of cooked waxy barley containing β-(1,3/1,4)-glucan prevents or alleviates nasal upper respiratory tract symptoms and improves mood status. The findings of this study should be confirmed by double-blind trials with a larger number of participants.

Dry blood spot samples to monitor immune-associated mRNA expression in intervention studies: Impact of Baker's yeast beta glucan

Monitoring immunological response to physical stressors in a field setting is challenging because existing methods require a laboratory visit and traditional blood collection via venipuncture. The purpose of this study was to determine if our optimized dry blood spot (DBS) methodology yields sufficient total RNA to quantify the effect of Baker's Yeast Beta Glucan supplementation (BYBG; Wellmune; 250 mg/d) on post-exercise mRNA expression. Participants had venous DBS samples collected prior to (PRE), and immediately (POST), 2 (2H), and 4 (4H) hrs after completion of a 90 min run/walk trial in a hot, humid environment. Total RNA extracted from DBS was analyzed using a 574-plex Human Immunology mRNA panel (Nanostring). BYBG supplementation was associated with the increased expression of 12 mRNAs (LTB4R, PML, PRFM1, TNFRSF14, LCK, MYD88, STAT3, CCR1, TNFSF10, LILRB3, MME, and STAT6) and decreased expression of 4 mRNAs (MAP4K1, IKBKG, CD5, and IL4R) across all post-exercise time points. In addition to individually changed mRNA targets, we found eleven immune-response pathways that were significantly enriched by BYBG following exercise (TNF Family signaling, immunometabolism, oxidative stress, toll-like receptor (TLR) signaling, Treg differentiation, autophagy, chemokine signaling, complement system, Th2 differentiation, cytokine signaling, and innate immune). The present approach showed that DBS samples can be used to yield useful information about mRNA biomarkers in an intervention study. We have found that BYBG supplementation induces changes at the mRNA level that support the immune system and reduce susceptibility to opportunistic infection (i.e., upper respiratory tract infection) and facilitate improved physical recovery from exercise. Future studies may look to use DBS sampling for testing other nutritional, health, or medical interventions.

The microbial food revolution

Our current food system relies on unsustainable practices, which often fail to provide healthy diets to a growing population. Therefore, there is an urgent demand for new sustainable nutrition sources and processes. Microorganisms have gained attention as a new food source solution, due to their low carbon footprint, low reliance on land, water and seasonal variations coupled with a favourable nutritional profile. Furthermore, with the emergence and use of new tools, specifically in synthetic biology, the uses of microorganisms have expanded showing great potential to fulfil many of our dietary needs. In this review, we look at the different applications of microorganisms in food, and examine the history, state-of-the-art and potential to disrupt current foods systems. We cover both the use of microbes to produce whole foods out of their biomass and as cell factories to make highly functional and nutritional ingredients. The technical, economical, and societal limitations are also discussed together with the current and future perspectives.

Comparison of the Effects of Prebiotics and Synbiotics Supplementation on the Immune Function of Male University Football Players

This study was conducted to compare the effects of long-term prebiotic and synbiotic supplementations on the immunosuppression of male football players after daily high-intensity training and a one-time strenuous exercise. A total of 30 male university student-athletes were recruited and randomly assigned to the prebiotic (PG, n = 15) or synbiotic group (SG, n = 15), receiving a prebiotic or synbiotic once per day for six weeks. Physiological assessments were conducted by a maximal oxygen uptake (VO2max) test and an exhaustive constant load exercise (75% VO2max test). Inflammatory cytokine and secretory immunoglobulin A (SIgA) were measured. VO2max, maximal heart rate (HRmax), and lactic acid elimination rate (ER) were used to evaluate aerobic capacity. Upper respiratory tract infection (URTI) complaints were evaluated using a questionnaire. URTI incidence and duration were significantly lower in the SG group than that in the PG group (p < 0.05). At baseline, SIgA and interleukin-1β (IL-1β) levels in the SG group (p < 0.01) as well as IL-1β and IL-6 in the PG group (p < 0.05) were significantly increased, and IL-4 concentration was markedly reduced in the PG group (p < 0.01). The concentrations of IL-4, IL-10 and transforming growth factor-β1 (TGF-β1) were significantly reduced in the PG and SG group immediately after the constant load exercise. Significantly decreased HRmax and enhanced ER (increased by 193.78%) were detected in the SG group, not in the PG group, during the constant load experiment (p < 0.05) and the recovery period (p < 0.01), respectively. However, VO2max value was not changed. These data suggest that synbiotic supplementation for six weeks has a more positive effect than prebiotics on the immune function and athletic performance of male university football players.

Evaluation of Immune Modulation by β-1,3; 1,6 D-Glucan Derived from Ganoderma lucidum in Healthy Adult Volunteers, A Randomized Controlled Trial

Fungi-derived β-glucan, a type of glucopolysaccharide, has been shown to possess immune-modulatory properties in clinical settings. Studies have indicated that β-glucan derived from Ganoderma lucidum (commonly known as Reishi) holds particular promise in this regard, both in laboratory and in vivo settings. To further investigate the efficacy and safety of Reishi β-glucan in human subjects, a randomized, double-blinded, placebo-controlled clinical trial was conducted among healthy adult volunteers aged 18 to 55. Participants were instructed to self-administer the interventions or placebos on a daily basis for 84 days, with bloodwork assessments conducted at the beginning and end of the study. The results of the trial showed that subjects in the intervention group, who received Reishi β-glucan, exhibited a significant enhancement in various immune cell populations, including CD3⁺, CD4⁺, CD8⁺ T-lymphocytes, as well as an improvement in the CD4/CD8 ratio and natural killer cell counts when compared to the placebo group. Additionally, a statistically significant difference was observed in serum immunoglobulin A levels and natural killer cell cytotoxicity between the intervention and placebo groups. Notably, the intervention was found to be safe and well tolerated, with no statistically significant changes observed in markers of kidney or liver function in either group. Overall, the study provides evidence for the ability of Reishi β-glucan to modulate immune responses in healthy adults, thereby potentially bolstering their defense against opportunistic infections.

β-Glucan "Trained Immunity" Immunomodulatory Properties Potentiate Tissue Wound Management and Accelerate Fitness Recover

Introduction

It is well established that moderate physical activity can improve the immune status, rather excess or high-intensity physical exercise can cause damage to the immune system. In addition, muscle injuries resulting from increased frequency and intensity of exercises compromise innate immune activity and may decrease tissue regeneration. Thus, β-glucans, a natural compound, may represent an important substance with strong immunomodulatory properties acting as an immunostimulant therapy known as "trained immunity". This immune stimulating therapeutic is an immunological memory phenomenon linked to the innate immune system, triggering cellular changes at epigenetic, transcriptional, and functional levels, to regulate the immune system and recover its homeostasis with clinical benefits.

Conclusion

This narrative review works with the current evidence regarding β-glucans as a possible alternative therapy for wound healing and its safety and efficacy in the treatment of muscle injuries and physical recovery including other chronic conditions and diseases.

β-Glucan as a Techno-Functional Ingredient in Dairy and Milk-Based Products—A review

The article systematizes information about the sources of β-glucan, its technological functions and practical aspects of its use in dairy and milk-based products. According to the analysis of scientific information, the main characteristics of β-glucan classifications were considered: the source of origin, chemical structure, and methods of obtention. It has been established that the most popular in the food technology of dairy products are β-glucans from oat and barley cereal, which exhibit pronounced technological functions in the composition of dairy products (gel formation, high moisture-binding capacity, increased yield of finished products, formation of texture, and original sensory indicators). The expediency of using β-glucan from yeast and mushrooms as a source of biologically active substances that ensure the functional orientation of the finished product has been revealed. For the first time, information on the use of β-glucan of various origins in the most common groups of dairy and milk-based products has been systematized. The analytical review has scientific and practical significance for scientists and specialists in the field of food production, in particular dairy products of increased nutritional value.

Counteracting Health Risks by Modulating Homeostatic Signaling

Homeostasis was initially conceptualized by Bernard and Cannon around a century ago as a steady state of physiological parameters that vary within a certain range, such as blood pH, body temperature, and heart rate^1,2. The underlying mechanisms that maintain homeostasis are explained by negative feedbacks that are executed by the neuronal, endocrine, and immune systems. At the cellular level, homeostasis, such as that of redox and energy steady state, also exists and is regulated by various cell signaling pathways. The induction of homeostatic mechanism is critical for human to adapt to various disruptive insults (stressors); while on the other hand, adaptation occurs at the expense of other physiological processes and thus runs the risk of collateral damages, particularly under conditions of chronic stress. Conceivably, anti-stress protection can be achieved by stressor-mimicking medicinals that elicit adaptive responses prior to an insult and thereby serve as health risk countermeasures; and in situations where maladaptation may occur, downregulating medicinals could be used to suppress the responses and prevent subsequent pathogenesis. Both strategies are preemptive interventions particularly suited for individuals who carry certain lifestyle, environmental, or genetic risk factors. In this article, we will define and characterize a new modality of prophylactic intervention that forestalls diseases via modulating homeostatic signaling. Moreover, we will provide evidence from the literature that support this concept and distinguish it from other homeostasis-related interventions such as adaptogen, hormesis, and xenohormesis.

β-Glucans from Yeast—Immunomodulators from Novel Waste Resources

β-glucans are a large class of complex polysaccharides with bioactive properties, including immune modulation. Natural sources of these compounds include yeast, oats, barley, mushrooms, and algae. Yeast is abundant in various processes, including fermentation, and they are often discarded as waste products. The production of biomolecules from waste resources is a growing trend worldwide with novel waste resources being constantly identified. Yeast-derived β-glucans may assist the host’s defence against infections by influencing neutrophil and macrophage inflammatory and antibacterial activities. β-glucans were long regarded as an essential anti-cancer therapy and were licensed in Japan as immune-adjuvant therapy for cancer in 1980 and new mechanisms of action of these molecules are constantly emerging. This paper outlines yeast β-glucans’ immune-modulatory and anti-cancer effects, production and extraction, and their availability in waste streams.

A Review on Measures to Rejuvenate Immune System: Natural Mode of Protection Against Coronavirus Infection

SARS-CoV-2, a novel Corona virus strain, was first detected in Wuhan, China, in December 2019. As of December 16, 2021, almost 4,822,472 people had died and over 236,132,082 were infected with this lethal viral infection. It is believed that the human immune system is thought to play a critical role in the initial phase of infection when the viruses invade the host cells. Although some effective vaccines have already been on the market, researchers and many bio-pharmaceuticals are still working hard to develop a fully functional vaccine or more effective therapeutic agent against the COVID-19. Other efforts, in addition to functional vaccines, can help strengthen the immune system to defeat the corona virus infection. Herein, we have reviewed some of those proven measures, following which a more efficient immune system can be better prepared to fight viral infection. Among these, dietary supplements like- fresh vegetables and fruits offer a plentiful of vitamins and antioxidants, enabling to build of a healthy immune system. While the pharmacologically active components of medicinal plants directly aid in fighting against viral infection, supplementary supplements combined with a healthy diet will assist to regulate the immune system and will prevent viral infection. In addition, some personal habits, like- regular physical exercise, intermittent fasting, and adequate sleep, had also been proven to aid the immune system in becoming an efficient one. Maintaining each of these will strengthen the immune system, allowing innate immunity to become a more defensive and active antagonistic mechanism against corona-virus infection. However, because dietary treatments take longer to produce beneficial effects in adaptive maturation, personalized nutrition cannot be expected to have an immediate impact on the global outbreak.

Yeast β-Glucan Altered Intestinal Microbiome and Metabolome in Older Hens

The prebiotics- and probiotics-mediated positive modulation of the gut microbiota composition is considered a useful approach to improve gut health and food safety in chickens. This study explored the effects of yeast β-glucan (YG) supplementation on intestinal microbiome and metabolites profiles as well as mucosal immunity in older hens. A total of 256 43-week-old hens were randomly assigned to two treatments, with 0 and 200 mg/kg of YG. Results revealed YG-induced downregulation of toll-like receptors (TLRs) and cytokine gene expression in the ileum without any effect on the intestinal barrier. 16S rRNA analysis claimed that YG altered α- and β-diversity and enriched the relative abundance of class Bacilli, orders Lactobacillales and Enterobacteriales, families Lactobacillaceae and Enterobacteriaceae, genera Lactobacillus and Escherichia–Shigella, and species uncultured bacterium-Lactobacillus. Significant downregulation of cutin and suberin, wax biosynthesis, atrazine degradation, vitamin B6 metabolism, phosphotransferase system (PTS), steroid degradation, biosynthesis of unsaturated fatty acids, aminobenzoate degradation and quorum sensing and upregulation of ascorbate and aldarate metabolism, C5-branched dibasic acid metabolism, glyoxylate and dicarboxylate metabolism, pentose and glucuronate interconversions, steroid biosynthesis, carotenoid biosynthesis, porphyrin and chlorophyll metabolism, sesquiterpenoid and triterpenoid biosynthesis, lysine degradation, and ubiquinone and other terpenoid-quinone biosyntheses were observed in YG-treated hens, as substantiated by the findings of untargeted metabolomics analysis. Overall, YG manifests prebiotic properties by altering gut microbiome and metabolite profiles and can downregulate the intestinal mucosal immune response of breeder hens.

Acute respiratory illness and return to sport: a systematic review and meta-analysis by a subgroup of the IOC consensus on 'acute respiratory illness in the athlete'

OBJECTIVE

To determine the days until return to sport (RTS) after acute respiratory illness (ARill), frequency of time loss after ARill resulting in >1 day lost from training/competition, and symptom duration (days) of ARill in athletes.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

PubMed, EBSCOhost, Web of Science, January 1990-July 2020.

ELIGIBILITY CRITERIA

Original research articles published in English on athletes/military recruits (15-65 years) with symptoms/diagnosis of an ARill and reporting any of the following: days until RTS after ARill, frequency (%) of time loss >1 day after ARill or symptom duration (days) of ARill.

RESULTS

767 articles were identified; 54 were included (n=31 065 athletes). 4 studies reported days until RTS (range: 0-8.5 days). Frequency (%) of time loss >1 day after ARill was 20.4% (95% CI 15.3% to 25.4%). The mean symptom duration for all ARill was 7.1 days (95% CI 6.2 to 8.0). Results were similar between subgroups: pathological classification (acute respiratory infection (ARinf) vs undiagnosed ARill), anatomical classification (upper vs general ARill) or diagnostic method of ARinf (symptoms, physical examination, special investigations identifying pathogens).

CONCLUSIONS

In 80% of ARill in athletes, no days were lost from training/competition. The mean duration of ARill symptoms in athletes was 7 days. Outcomes were not influenced by pathological or anatomical classification of ARill, or in ARinf diagnosed by various methods. Current data are limited, and future studies with standardised approaches to definitions, diagnostic methods and classifications of ARill are needed to obtain detailed clinical, laboratory and specific pathogen data to inform RTS.

PROSPERO REGISTRATION NUMBER

CRD42020160479.

Dietary Polyphenol and Methylsulfonylmethane Supplementation Improves Immune, DAMP Signaling, and Inflammatory Responses During Recovery From All-Out Running Efforts

Nutritional ingredients with defined mechanisms of action can be useful in the recovery of the body from the physical demands of a habitual training plan. The purpose of this study was to determine the effect of dietary supplementation with optimized curcumin, pomegranate ellagitannins, and MSM (R + MSM) on immune-associated mRNA during early recovery (i.e., up to 8 h post-exercise) following all-out running efforts (5-km, 10-km, and 21.1-km). Subjects (N = 14) were randomized to either a supplement (R + MSM) or a control group using an open label design. The study was completed over a period of 31-day prior to a scheduled half-marathon race. Venous blood samples were collected into PAXgene tubes at baseline, subsequent samples were collected at 2, 4, and 8 h after each running effort. A 574-plex mRNA Immunology Array (NanoString) was measured for each sample and ROSALIND^® Advanced Analysis Software was used to examined changes in 31 annotated immune response pathways and specific mRNA changes. The greatest change in immune pathways occurred at 2 h (GSS > 3) followed by 4 h (GSS 2–3) and 8 h (GSS 1–2). R + MSM was associated with an increase in innate immunity (CAMP, LTF, TIRAP, CR1, IL1R1, CXCR1, PDCDILG2, and GNLY) and a blunted/smaller increase in damage-associated molecular pattern (DAMP) signaling/inflammation (TLR4, TLR5, S100A8, S100A9, and IFP35). We also found changes in immune-associated mRNA that have not been previously linked to exercise recovery (SOCS1, SOCS2, MME, CECAM6, MX1, IL-1R2, KLRD1, KLRK1, and LAMP3). Collectively these results demonstrate that supplementation with a combination of optimized curcumin, pomegranate ellagitannins, and methylsulfonylmethane resulted in changes that may improve biological recovery from all-out running efforts.

Adjuvant Effect of Orally Applied Preparations Containing Non-Digestible Polysaccharides on Influenza Vaccination in Healthy Seniors: A Double-Blind, Randomised, Controlled Pilot Trial

Senior individuals can suffer from immunosenescence and novel strategies to bolster the immune response could contribute to healthy ageing. In this double-blind, randomised, controlled pilot trial, we investigated the ability of non-digestible polysaccharide (NPS) preparations to enhance the immune response in a human vaccination model. In total, 239 subjects (aged 50-79 years) were randomised to consume one of five different NPS (yeast β-glucan (YBG), shiitake β-glucan (SBG), oat β-glucan (OBG), arabinoxylan (AX), bacterial exopolysaccharide (EPS)) or control (CTRL) product daily for five weeks. After two weeks of intervention, subjects were vaccinated with seasonal influenza vaccine. The post-vaccination increases in haemagglutination inhibition antibody titres and seroprotection rate against the influenza strains were non-significantly enhanced in the NPS intervention groups compared to CTRL. Specifically, a trend towards a higher mean log2 fold increase was observed in the AX group (uncorrected p = 0.074) combined with a trend for an increased seroprotection rate, AX group (48.7%) compared to CTRL (25.6%) (uncorrected p = 0.057), for the influenza A H1N1 strain. Subjects consuming AX also had a reduced incidence of common colds compared to CTRL (1 vs. 8; p = 0.029 in Fisher exact test). No adverse effects of NPS consumption were reported. The findings of this pilot study warrant further research to study AX as an oral adjuvant to support vaccine efficacy.

Metabolic Disturbance and Th17/Treg Imbalance Are Associated With Progression of Gingivitis

Objective

This study sought to explore the role of metabolic disturbance in immunoregulation of gingivitis targeting T helper 17 cells (Th17)/regulatory T cell (Treg).

Materials and Methods

A total of 20 gingivitis patients and 19 healthy volunteers were recruited. Quantitative real time polymerase chain reaction (qRT-PCR) was used to evaluate expression patterns of Forkhead box protein P3 (Foxp3), transforming growth factor-β (TGF-β), retinoid-related orphan receptor-gammat (RORγt) and interleukin 17A (IL-17A) in the peripheral blood lymphocytes of subjects across the two groups. Moreover, the enzyme-linked immunosorbent assay (ELISA) technique was used to detect levels of TGF-β, IL-4, IL-6,TL-10 and L-17A secreted in the plasma as well as the SIgA secreted in saliva. Flow cytometry was used to detect the percentage of CD4⁺CD25⁺ Foxp3⁺Treg cells and the percentage of CD4⁺IL-17A⁺ Th17 cells in whole blood of subjects in both groups. Gas chromatography-mass spectrometry (GC-MS) was employed to analyze the plasma metabolites in the gingivitis patient group. Statistical analysis was applied to determine whether the plasma metabolites and related metabolic pathways significantly differed between gingivitis patients and healthy controls. Ingenuity pathway analysis (IPA) was employed to identify the potential relation between the metabolites and the Th17 and Treg related pathway.

Results

The percentages of CD4⁺IL17A⁺Th17 cells and IL-17 significantly increased in the peripheral blood in the gingivitis group. Moreover, the upregulation of IL-17A mRNA and RORγt mRNA were also found in the gingivitis group. However, the percentage of CD4⁺CD25⁺ Foxp3⁺Treg cells and Foxp3 mRNA in the whole blood did not significantly change. However, TGF-β mRNA as well as TGF-β, IL-4, IL-6, IL-10 in the periperial blood and SIgA in the saliva were higher in the gingivitis group. Notably, that the ratio of Th17/Treg cells was significantly increased during peripheral circulation. Furthermore, we identified 18 different metabolites which were differentially expressed in plasma between the gingivitis and healthy control groups. Notably, the levels of cholesterol, glycerol 1-octadecanoate, d-glucose, uric acid, cyclohexaneacetic acid, 3-pyridine, tryptophan, and undecane 2,4-dimethyl were significantly up-regulated. whereas the levels of lactic acid, glycine, linoleic acid, monopalmitic acid, glycerol, palmitic acid, pyruvate, 1-(3-methylbutyl)-2,3,4,6-tetramethylbenzene, 1 5-anhydro d-altrol, and boric acid were down-regulated in the gingivitis group, relative to healthy controls. IPA showed that these metabolites are connected to IL17 signaling, TGF-B signaling, and IL10 signaling, which are related closely to Th17 and Treg pathway.

Conclusion

Overall, these results showed that disturbance to glycolysis as well as amino and fatty acid metabolism are associated with Th17/Treg balance in gingivitis. Impaired immunometabolism may influence some periodontally involved systemic diseases, hence it is a promising strategy in targeted development of treatment therapies.

Continuous Exposure to Non-Soluble β-Glucans Induces Trained Immunity in M-CSF-Differentiated Macrophages

Beta-glucans enable functional reprogramming of innate immune cells, a process defined as "trained immunity", which results in enhanced host responsiveness against primary (training) and/or secondary infections (resilience). Trained immunity holds great promise for promoting immune responses in groups that are at risk (e.g. elderly and patients). In this study, we modified an existing in vitro model for trained immunity by actively inducing monocyte-to-macrophage differentiation using M-CSF and applying continuous exposure. This model reflects mucosal exposure to β-glucans and was used to study the training effects of a variety of soluble or non-soluble β-glucans derived from different sources including oat, mushrooms and yeast. In addition, trained immunity effects were related to pattern recognition receptor usage, to which end, we analyzed β-glucan-mediated Dectin-1 activation. We demonstrated that β-glucans, with different sources and solubilities, induced training and/or resilience effects. Notably, trained immunity significantly correlated with Dectin-1 receptor activation, yet Dectin-1 receptor activation did not perform as a sole predictor for β-glucan-mediated trained immunity. The model, as validated in this study, adds on to the existing in vitro model by specifically investigating macrophage responses and can be applied to select non-digestible dietary polysaccharides and other components for their potential to induce trained immunity.

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.

β -Glucan Improves Protective Qi Status in Adults with Protective Qi Deficiency-A Randomized, Placebo-Controlled, and Double-Blinded Trial

OBJECTIVE

To test the hypothesis that β -glucan enhances protective qi (PQi), an important Chinese medicine (CM) concept which stipulates that a protective force circulates throughout the body surface and works as the first line of defense against "external pernicious influences".

METHODS

A total of 138 participants with PQi deficiency (PQD) were randomized to receive β -glucan (200 mg daily) or placebo for 12 weeks. Participants' PQi status was assessed every 2 weeks via conventional diagnosis and a standardized protocol from which a PQD severity and risk score was derived. Indices of participants' immune and general health status were also monitored, including upper respiratory tract infection (URTI), saliva secretory IgA (sIgA), and self-reported measures of physical and mental health (PROMIS).

RESULTS

PQi status was not significantly different between the β -glucan and placebo treatment groups at baseline but improved significantly in the β -glucan (vs. placebo) group in a time-dependent manner. The intergroup differences [95% confidence interval (CI)] in severity score (scale: 1-5), risk score (scale: 0-1), and proportion of PQD participants (%) at finish line was 0.49 (0.35-0.62), 0.48 (0.35-0.61), and 0.36 (0.25-0.47), respectively. Additionally, β -glucan improved URTI symptom (scale: 1-9) and PROMIS physical (scale: 16.2-67.7) and mental (scale: 21.2-67.6) scores by a magnitude (95% CI) of 1.0 (0.21-1.86), 5.7 (2.33-9.07), and 3.0 (20.37-6.37), respectively, over placebo.

CONCLUSIONS

β -glucan ameliorates PQi in PQD individuals. By using stringent evidence-based methodologies, our study demonstrated that Western medicine-derived remedies, such as β -glucan, can be employed to advance CM therapeutics. (ClinicalTrial.Gov registry: NCT03782974).

Effects of yeast β-glucans for the prevention and treatment of upper respiratory tract infection in healthy subjects: a systematic review and meta-analysis

PURPOSE

Yeast β-glucans are known for their immune-modulating effects; however, their effects on human upper respiratory tract infections (URTIs) remain unclear. The aim of the present study was to use a systematic review and meta-analysis approach to investigate the effects of yeast β-glucans for the prevention and treatment of URTIs in healthy subjects.

METHODS

Databases including Pubmed, Web of Science, EMBASE and the Cochrane Library were searched and 13 RCTs investigating the effects of yeast β-glucans on the incidence, duration, and severity of URTIs in healthy subjects were included.

RESULTS

The results showed that compared to the placebo group, yeast β-glucan could significantly reduce the incidence of URTIs (OR = 0.345, 95% CI = 0.192 to 0.620, p < 0.001), decrease the average number of URTI episodes (SMD =  - 0.315, 95% CI =  - 0.500 to  - 0.130, p < 0.05), and decrease the duration of URTIs (SMD =  - 0.312, 95% CI =  - 0.561 to  - 0.064, p < 0.001). Improved severity of symptoms was found in yeast β-glucan group compared to the placebo group in the majority of included studies. In addition, yeast β-glucan was well tolerated and safe in general.

CONCLUSION

These findings suggest a positive effect of yeast β-glucans on human URTIs. However, due to the high heterogeneity and small number of included studies, more high-quality research and clinical trials are warranted.

Effects of select dietary supplements on the prevention and treatment of viral respiratory tract infections: a systematic review of randomized controlled trials

Introduction: Viral respiratory tract infections (RTIs) have been recognized as a global public health burden. Despite current theories about their effectiveness, the true benefits of dietary supplements on the prevention and treatment of viral RTIs remain elusive, due to contradictory reports. Hence, we aimed to evaluate the effectiveness of dietary supplements on the prevention and treatment of viral RTIs.Areas covered: We systematically searched databases of PubMed, Web of Science, Scopus, and Google Scholar through 4 March 2020, to identify randomized controlled trials that evaluated the effects of consuming selected dietary supplements on the prevention or treatment of viral RTIs.Expert opinion: Thirty-nine randomized controlled trials (n = 16,797 participants) were eligible and included. Namely, vitamin D supplementation appeared to improve viral RTIs across cohorts particulate in those with vitamin D deficiency. Among the evaluated dietary supplements, specific lactobacillus strains were used most commonly with selected prebiotics that showed potentially positive effects on the prevention and treatment of viral RTIs. Further, ginseng extract supplementation may effectively prevent viral RTIs as adjuvant therapy. However, longitudinal research is required to confirm these observations and address the optimal dose, duration, and safety of dietary supplements being publicly recommended.

Effect of High Fat and Fructo-Oligosaccharide Consumption on Immunoglobulin A in Saliva and Salivary Glands in Rats

Consumption of indigestible dietary fiber increases immunoglobulin A (IgA) levels in saliva. The purpose of this study is to clarify the synergistic effect of the intake of a high amount of fats and indigestible dietary fiber on IgA levels in saliva and submandibular glands (SMG). Seven-week-old Wistar rats were fed a low-fat (60 g/kg) fiberless diet, low-fat fructo-oligosaccharide (FOS, 30 g/kg) diet, high-fat (220 g/kg) fiberless diet, or high-fat FOS diet for 70 days. The IgA flow rate of saliva (IgA FR-saliva) was higher in the low-fat FOS group than in the other groups (p < 0.05). Furthermore, the concentration of tyrosine hydroxylase (a marker of sympathetic nerve activation) in the SMG was higher in the low-fat FOS group (p < 0.05) and positively correlated with the IgA FR-saliva (rs = 0.68. p < 0.0001. n = 32) in comparison to that in the other groups. These findings suggest that during low-fat FOS intake, salivary IgA levels may increase through sympathetic nerve activation.

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.

Investigation of the natural supplement IQP-AS-119 for the prevention of upper respiratory tract infections in marathon race participants: A randomized, double-blind, placebo-controlled pilot study

Intense and prolonged exercise leads to immune suppression, causing upper respiratory tract infections (URTI). A proprietary standardized dietary supplement, IQP-AS-119 has been previously developed to aid immune responses under such conditions. The current randomized, double-blind, placebo-controlled pilot study aimed to investigate the effects of IQP-AS-119 on marathon runners. A total of 80 participants were randomized equally into groups receiving either placebo (P group) or IQP-AS-119 (V group) treatment, starting 3 weeks before and for 14 days after the marathon. Benefit assessment was performed using different questionnaires. Post-marathon, the V and P groups reported 1±2.38 and 2.11±3.25 days with upper respiratory tract symptoms (URTS), respectively (P=0.038). During the 14 days post-marathon, 20.0% of the participants in the V group compared with 44.4% in the P group reported URTS (P=0.042). The V group reported significantly milder URTS compared with the P group on Days 9, 12, 13 and 14 post-marathon (P<0.05). The total Perceived Stress Questionnaire-20 score on days 2-14 were significantly lower for the V group compared with the P group (P=0.035). In the Short Form 12 Health Survey, the V group exhibited significant improvement in mental composite score on days -5 to 14 compared with the P group (P=0.038). In the overall treatment effect assessment, there were no statistically significant differences between the groups. The IQP-AS-119 was rated ‘very good’ or ‘good’ by investigators and participants, respectively, for 71 and 65% of the participants. The tolerability of IQP-AS-119 was rated as ‘very good’ or ‘good’ by both investigators and 95% of participants. No clinically relevant differences were observed between groups regarding adverse events or other safety parameters. Therefore, IQP-AS-119 was demonstrated to reduce the incidence and severity of URTI in marathon runners. Given its good tolerability profile, IQP-AS-119 may be a good nutritional supplement for the reduction of URTS in susceptible individuals.

How to boost the immune defence prior to respiratory virus infections with the special focus on coronavirus infections

The emergence of the novel coronavirus SARS-CoV-2, which causes severe respiratory tract infections in humans (COVID-19), has become a global health concern. One of the most worrying features of COVID-19 is a phenomenon known as the "cytokine storm", which is a rapid overreaction of the immune system. Additionally, coagulation abnormalities, thrombocytopenia and digestive symptoms, including anorexia, vomiting, and diarrhea, are often observed in critically ill patients with COVID-19. Baker's yeast β-glucan, a natural immunomodulatory component derived from Saccharomyces cerevisiae, primes the immune system to respond better to any microbial infection. Our previous studies have shown that oral administration of yeast β-glucans decreased the diarrhoea, modulated cytokine expression, and reduced the intestinal inflammation. Additionally, we showed that β-glucan fractions decreased coagulation in plasma and reduced the activation of platelets. During the period of home confinement facing individuals during the COVID-19 pandemic, our immune defence could be weakened by different factors, including stress, anxiety and poor nutrition, while a healthy diet rich in vitamins C and D can reinforce the immune defence and reduce the risk of microbial infections. Additionally, β-glucan can be used to strengthen the immune defence in healthy individuals prior to any possible viral infections. This short review focuses on the role of baker's yeast β-glucan, with a healthy diet rich in natural vitamins C and D, in addition to a healthy gut microbiota can provide synergistic immune system support, helping the body to naturally defend prior to respiratory virus infections, until stronger options such as vaccines are available.

Alterations in Systemic Inflammatory Response Following a Half-Marathon Race with a Combined Curcumin and Pomegranate Supplement: A Feasibility Study

Endurance running training can lead to gradual accumulation of inflammation and soreness ultimately resulting in overuse injuries. Management of soreness and inflammation with pharmaceuticals (i.e. non-prescription pain relievers) during long-term training is not a suitable solution due to known side effects (e.g. gastrointestinal complications, etc.). Dietary polyphenols (i.e. curcumin, pomegranate, etc.) have been purported to reduce inflammation and muscle soreness, without these negative side effects making them ideal for use in an exercise model. The purpose of the present feasibility study was to explore the combined effect of optimized curcumin and pomegranate extract supplementation prior to (PRE) and after (4H and 24H) an organized half-marathon race on blood inflammatory proteins and inflammation-associated RNA. Daily supplementation (1000 mg/d) started 26 days before a half-marathon which doubled on days 27-31. Data were analyzed with R software and Welch t-test, significance set at p < 0.05. At both 4H and 24H, supplementation was associated with alterations in protein (IL-10, IL-13, IL-4, ITAC, MIP-1alpha, MIP-3alpha, BDNF, sIL-2Ralpha, and TNF-alpha; p < 0.05) and RNA (CCL22, GUSB, IL-6, LINC00305, NKILA, PTGES, THRIL, TRAF6, ARG2, CD1A, CD55, CFI, CSF2, CXC3CL1, CX3CR1, EDNRB, GATA3, LILRB5, THY1, CD3D, MRC1, GPR183, HAMP, MBL2, CASP3, B2M, KLRF2, PDCD1LG2, IL-10, PTGS2, TLR2, IL-6R, IL-8, IL-7R, MASP1, MYD88, TNFRSF1B, TNFRSF1A, and TIRAP; p < 0.05) biomarkers compared to control. Pathway classification of these biomarkers indicated supplementation may be associated with a more favorable muscle recovery profile. Our findings support the notion that combined curcumin and pomegranate supplementation may represent a useful addition to a comprehensive exercise training plan.

Nutrition and Athlete Immune Health: New Perspectives on an Old Paradigm

Respiratory and gastrointestinal infections limit an athlete's availability to train and compete. To better understand how sick an athlete will become when they have an infection, a paradigm recently adopted from ecological immunology is presented that includes the concepts of immune resistance (the ability to destroy microbes) and immune tolerance (the ability to dampen defence yet control infection at a non-damaging level). This affords a new theoretical perspective on how nutrition may influence athlete immune health; paving the way for focused research efforts on tolerogenic nutritional supplements to reduce the infection burden in athletes. Looking through this new lens clarifies why nutritional supplements targeted at improving immune resistance in athletes show limited benefits: evidence supporting the old paradigm of immune suppression in athletes is lacking. Indeed, there is limited evidence that the dietary practices of athletes suppress immunity, e.g. low-energy availability and train- or sleep-low carbohydrate. It goes without saying, irrespective of the dietary preference (omnivorous, vegetarian), that athletes are recommended to follow a balanced diet to avoid a frank deficiency of a nutrient required for proper immune function. The new theoretical perspective provided sharpens the focus on tolerogenic nutritional supplements shown to reduce the infection burden in athletes, e.g. probiotics, vitamin C and vitamin D. Further research should demonstrate the benefits of candidate tolerogenic supplements to reduce infection in athletes; without blunting training adaptations and without side effects.

Faster Short-Chain Fatty Acid Absorption from the Cecum Following Polydextrose Ingestion Increases the Salivary Immunoglobulin A Flow Rate in Rats

Salivary immunoglobulin A (IgA) plays a vital role in preventing upper respiratory tract infections (URTI). In our previous study, we showed that the intake of carbohydrates increases the intestinal levels of short-chain fatty acids (SCFAs), which in turn increase salivary IgA levels. However, the mechanism underlying this phenomenon has not been fully elucidated. In this study, we investigated in rats the effect of polydextrose (PDX) ingestion on salivary IgA level and SCFA concentration in cecal digesta and the portal vein. Five-week-old rats were fed with a fiber-free diet (control) or with 40 g/kg of PDX for 28 days. Compared to the control, ingestion of PDX led to a higher salivary IgA flow rate (p = 0.0013) and a higher concentration of SCFAs in the portal vein (p = 0.004). These two data were positively correlated (r_s = 0.88, p = 0.0002, n = 12). In contrast, the concentration of SCFAs in cecal digesta and cecal digesta viscosity were significantly lower following PDX ingestion, compared to the control (p = 0.008 and 0.05, respectively). These findings suggest that the ingestion of PDX increases the absorption rate of SCFAs in the intestine through PDX-induced fermentation, which is accompanied by an increase in SCFA levels in the blood, and ultimately leads to increased salivary IgA levels.

Pretreatment with Yeast-Derived Complex Dietary Polysaccharides Suppresses Gut Inflammation, Alters the Microbiota Composition, and Increases Immune Regulatory Short-Chain Fatty Acid Production in C57BL/6 Mice

BACKGROUND

β-Glucans (BGs), a group of complex dietary polysaccharides (CDPs), are available as dietary supplements. However, the effects of orally administered highly purified BGs on gut inflammation are largely unknown.

OBJECTIVES

The aim of this study was to investigate the impact of orally administering highly purified, yeast-derived BG (YBG; β-1,3/1,6-d-glucan) on susceptibility to colitis.

METHODS

Eight-week-old C57BL/6 (B6) mice were used in a series of experiments. Experiment (Expt) 1: male and female mice were treated every day, for 40 d, with saline (control) or 250 μg YBG, followed by 2.5% (wt:vol) dextran sulfate sodium (DSS) in drinking water during days 30-35; and colitis severity and intestinal immune phenotype were determined. Expt 2: female B6 mice were treated with saline or YBG for 30 d and intestinal immune phenotype, gut microbiota composition, and fecal SCFA concentrations were determined. Expt 3: female B6 mice were treated as in Expt 2, given drinking water with or without antibiotics [Abx; ampicillin (1 g/L), vancomycin (0.5 g/L), neomycin (1 g/L), and metronidazole (1 g/L)] during days 16-30, and gut immune phenotype and fecal SCFA concentrations were determined. Expt 4: female B6 Foxp3-green fluorescent protein (-GFP) reporter mice were treated as in Expt 3, and intestinal T-regulatory cell (Treg) frequencies and immune phenotypes were determined. Expt 5: female mice were treated as in Expt 1, given drinking water with or without antibiotics during days 16-40, and colitis severity and intestinal cytokine production were determined.

RESULTS

Compared with controls, the YBG group in Expt 1 exhibited suppressive effects on features of colitis, such as loss of body weight (by 47%; P < 0.001), shortening of colon (by 24%; P = 0.016), and histopathology severity score (by 45%; P = 0.01). The YBG group of Expt 2 showed a shift in the abundance of gut microbiota towards Bacteroides (by 16%; P = 0.049) and Verrucomicrobia (mean ± SD: control = 7.8 ± 0.44 vs. YBG = 21.0 ± 9.6%) and a reduction in Firmicutes (by 66%; P < 0.001). The YBG group also showed significantly higher concentrations of fecal SCFAs such as acetic (by 37%; P = 0.016), propionic (by 47%; P = 0.026), and butyric (by 57%; P = 0.013) acids. Compared with controls, the YBG group of Expt 2 showed higher frequencies of Tregs (by 32%; P = 0.043) in the gut mucosa. Depletion of gut microbiota in the YBG group of mice caused diminished fecal SCFA concentrations (Expt 3) and intestinal Treg frequencies (Expt 4). Compared with the YBG group, the YBG-(Abx) group of Expt 5 showed aggravated colitis features including loss of body weight (by >100%; P < 0.01) and colonic inflammation score (by 42%; P = 0.04).

CONCLUSIONS

Studies using B6 mice show that dietary BGs are beneficial for promoting intestinal health when the gut microbiota is intact. However, these CDPs may produce adverse effects if gut microbiota is compromised.

Yeast Beta-Glucan Supplementation Downregulates Markers of Systemic Inflammation after Heated Treadmill Exercise

Aerobic exercise and thermal stress instigate robust challenges to the immune system. Various attempts to modify or supplement the diet have been proposed to bolster the immune system responses. The purpose of this study was to identify the impact of yeast beta-glucan (Saccharomyces cerevisiae) supplementation on exercise-induced muscle damage and inflammation. Healthy, active men (29.6 ± 6.7 years, 178.1 ± 7.2 cm, 83.2 ± 11.2 kg, 49.6 ± 5.1 mL/kg/min, n = 16) and women (30.1 ± 8.9 years, 165.6 ± 4.1 cm, 66.7 ± 10.0 kg, 38.7 ± 5.8 mL/kg/min, n = 15) were randomly assigned in a double-blind and cross-over fashion to supplement for 13 days with either 250 mg/day of yeast beta-glucan (YBG) or a maltodextrin placebo (PLA). Participants arrived fasted and completed a bout of treadmill exercise at 55% peak aerobic capacity (VO_2Peak) in a hot (37.2 ± 1.8 °C) and humid (45.2 ± 8.8%) environment. Prior to and 0, 2, and 72 h after completing exercise, changes in white blood cell counts, pro- and anti-inflammatory cytokines, markers of muscle damage, markers of muscle function, soreness, and profile of mood states (POMS) were assessed. In response to exercise and heat, both groups experienced significant increases in white blood cell counts, plasma creatine kinase and myoglobin, and soreness along with reductions in peak torque and total work with no between-group differences. Concentrations of serum pro-inflammatory cytokines in YBG were lower than PLA for macrophage inflammatory protein 1β (MIP-1β) (p = 0.044) and tended to be lower for interleukin 8 (IL-8) (p = 0.079), monocyte chemoattractment protein 1 (MCP-1) (p = 0.095), and tumor necrosis factor α (TNF-α) (p = 0.085). Paired samples t-tests using delta values between baseline and 72 h post-exercise revealed significant differences between groups for IL-8 (p = 0.044, 95% Confidence Interval (CI): (0.013, 0.938, d = −0.34), MCP-1 (p = 0.038, 95% CI: 0.087, 2.942, d = −0.33), and MIP-1β (p = 0.010, 95% CI: 0.13, 0.85, d = −0.33). POMS outcomes changed across time with anger scores in PLA exhibiting a sharper decline than YBG (p = 0.04). Vigor scores (p = 0.04) in YBG remained stable while scores in PLA were significantly reduced 72 h after exercise. In conclusion, a 13-day prophylactic period of supplementation with 250 mg of yeast-derived beta-glucans invoked favorable changes in cytokine markers of inflammation after completing a prolonged bout of heated treadmill exercise.

Effect of a Euglena gracilis Fermentate on Immune Function in Healthy, Active Adults: A Randomized, Double-Blind, Placebo-Controlled Trial

Euglena gracilis produce high amounts of algal β-1,3-glucan, which evoke an immune response when consumed. This study investigated the effect of supplementation with a proprietary Euglena gracilis fermentate (BG), containing greater than 50% β-1,3-glucan, on immune function as measured by self-reported changes in upper respiratory tract infection (URTI) symptoms. Thirty-four healthy, endurance-trained participants were randomized and received either 367 mg of BG or placebo (PLA) for 90 days. Symptoms were assessed by the 24-item Wisconsin Upper Respiratory Symptom Survey and safety via clinical chemistry, hematology, vitals, and adverse event reporting. Participants supplemented with BG over 90 days reported fewer sick days (BG: 1.46 ± 1.01; PLA: 4.79 ± 1.47 days; p = 0.041), fewer URTI symptoms (BG: 12.62 ± 5.92; PLA: 42.29 ± 13.17; p = 0.029), fewer symptom days (BG: 5.46 ± 1.89; PLA: 15.43 ± 4.59 days; p = 0.019), fewer episodes (BG: 2.62 ± 0.67; PLA: 4.79 ± 0.67; p = 0.032), and lower global severity measured as area under curve for URTI symptoms (BG: 17.50 ± 8.41; PLA: 89.79 ± 38.92; p = 0.0499) per person compared to placebo. Sick days, symptoms, and global severity were significantly (p < 0.05) fewer over 30 days in the BG group compared to PLA. All safety outcomes were within clinically normal ranges. The study provides evidence that supplementation with a proprietary Euglena gracilis fermentate containing greater than 50% β-1,3-glucan may reduce and prevent URTI symptoms, providing immune support and protecting overall health.

Soluble and Insoluble Yeast β-Glucan Differentially Affect Upper Respiratory Tract Infection in Marathon Runners: A Double-Blind, Randomized Placebo-Controlled Trial

In a previous study, consumption of a dairy beverage incorporating insoluble β-glucan decreased upper respiratory tract infection (URTI) symptomatic days and severity in marathon runners. In this report, we extended our previous findings by presenting data on a dairy beverage containing soluble β-glucan and URTI in marathon runners. Healthy adults running in the 2017 Austin Marathon consumed dairy beverages (250 mL/day) containing 250 mg of insoluble (n = 69) or soluble (n = 76) baker's yeast β-glucan (Wellmune^®) or placebo (n = 133) for the 45 days before, day of, and 45 days after the marathon (91 days total). Participants completed a daily online survey assessing compliance and URTI symptoms, which were evaluated using the Jackson Index and confirmed by the study physician. Total severity of URTI was significantly lower in the insoluble yeast β-glucan group compared to the placebo group, but was not different between the soluble yeast β-glucan group and placebo group. Severity ratings for nasal discharge were significantly lower in both the insoluble and soluble yeast β-glucan groups compared to the placebo group. Additionally, severity rating for sore throat was lower in the insoluble, but not the soluble yeast β-glucan group compared to the placebo group. The insoluble yeast β-glucan group, but not the soluble yeast β-glucan group also reported fewer URTI symptomatic days compared to the placebo group. The results suggest that soluble and insoluble yeast β-glucan, incorporated into a food matrix, differentially affected exercise-induced URTI in marathon runners.

Effect of ingesting yogurt fermented with Lactobacillus delbrueckii ssp. bulgaricus OLL1073R-1 on influenza virus-bound salivary IgA in elderly residents of nursing homes: a randomized controlled trial

Objective: The purpose of this study was to clarify the influence of consuming yogurt fermented with Lactobacillus delbrueckii ssp. bulgaricus OLL1073R-1 (1073R-1-yogurt) on influenza virus-bound salivary immunoglobulin A (IgA) levels, in the elderly residents of nursing homes. Methods: A double-blind, parallel-group, randomized controlled trial was conducted with 96 elderly volunteers residing in 2 nursing homes. During the trial, participants consumed 100 g of 1073R-1-yogurt every morning for 12 weeks, whereas the control participants consumed yogurt fermented with a different Lactobacillus strain (control yogurt). Saliva was collected before the trial and after 4, 8 and 12 weeks of yogurt ingestion. Results: Our data indicated that consumption of 1073R-1-yogurt affected influenza A virus subtype H3N2-bound IgA levels in saliva (p = .001). In addition, saliva flow rate and total IgA levels increased in response to the yogurt intake period in both the 1073R-1 and control yogurt groups (p = .04). Conclusions: Our study suggests that continuous daily ingestion of 1073R-1-yogurt may help prevent infection with influenza A virus subtype H3N2 in elderly subjects with weakened immunity, by increasing the production of influenza A virus subtype of H3N2-bound salivary IgA.

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.

Consumption of β-glucans to spice up T cell treatment of tumors: a review

INTRODUCTION

Adoptive T-cell treatments of solid cancers have evolved into a robust therapy with objective response rates surpassing those of standardized treatments. Unfortunately, only a limited fraction of patients shows durable responses, which is considered to be due to a T cell-suppressive tumor microenvironment (TME). Here we argue that naturally occurring β-glucans can enable reversion of such T cell suppression by engaging innate immune cells and enhancing numbers and function of lymphocyte effectors.

AREAS COVERED

This review summarizes timely reports with respect to absorption, trafficking and immune stimulatory effects of β-glucans, particularly in relation to innate immune cells. Furthermore, we list effects toward well-being and immune functions in healthy subjects as well as cancer patients treated with orally administered β-glucans, extended with effects of β-glucan treatments in mouse cancer models.

EXPERT OPINION

Beta-glucans, when present in food and following uptake in the proximal gut, stimulate immune cells present in gut-associated lymphoid tissue and initiate highly conserved pro-inflammatory pathways. When tested in mouse cancer models, β-glucans result in better control of tumor growth and shift the TME toward a T cell-sensitive environment. Along these lines, we advocate that intake of β-glucans provides an accessible and immune-potentiating adjuvant when combined with adoptive T-cell treatments of cancer.

Complex dietary polysaccharide modulates gut immune function and microbiota, and promotes protection from autoimmune diabetes

The dietary supplement and prebiotic values of β-glucan-rich products have been widely recognized and dietary approaches for modulating autoimmunity have been increasingly explored, we assess the impact of oral administration of high-purity yeast β-glucan (YBG) on gut immune function, microbiota and type 1 diabetes (T1D) using mouse models. Oral administration of this non-digestible complex polysaccharide caused a dectin-1-dependent immune response involving increased expression of interleukin-10 (IL-10), retinaldehyde dehydrogenase (Raldh) and pro-inflammatory cytokines in the gut mucosa. YBG-exposed intestinal dendritic cells induced/expanded primarily Foxp3⁺ , IL-10⁺ and IL-17⁺ T cells, ex vivo. Importantly, prolonged oral administration of low-dose YBG at pre-diabetic stage suppressed insulitis and significantly delayed the appearance of T1D in non-obese diabetic (NOD) mice. Further, prolonged treatment with YBG showed increased Foxp3⁺ T-cell frequencies, and a significant change in the gut microbiota, particularly an increase in the abundance of Bacteroidetes and a decrease in the Firmicute members. Oral administration of YBG, together with Raldh-substrate and β-cell antigen, resulted in better protection of NOD mice from T1D. These observations suggest that YBG not only has a prebiotic property, but also an oral tolerogenic-adjuvant-like effect, and these features could be exploited for modulating autoimmunity in T1D.

Combined bead-based multiplex detection of RNA and protein biomarkers: Implications for understanding the time course of skeletal muscle injury and repair

Biological response to skeletal muscle injury time course is generally classified as initial (elevated within first 4-h), delayed (elevated at 24-h), and/or prolonged (elevated at 4-h and sustained to 24-h). Accurate description of this process requires the ability to measure a robust set of RNA and protein biomarkers, yet such an approach is not common and not always feasible. This method proposes a novel experimental approach that focuses on the use of bead-based multiplex detection to measure mRNA, lncRNA, cytokines, soluble cytokine receptors, and myokines at 4-h and 24-h post muscle injury. We used an extreme aerobic exercise session (half-marathon race) to create a consistent muscle injury stimulus via oxidative stress and eccentric contractions. Venous blood samples were analyzed to determine the change in 90 targets. Specifically, we identified 14 mRNA, 2 lncRNA, 4 cytokines, and 5 myokines that had only an initial response (change at 4-h). We identified 2 mRNA, 2 cytokines, 13 soluble cytokine receptors, and 1 myokine that had only a delayed response (change at 24-h). Finally, we identified 18 mRNA, 4 lncRNA, 6 myokines and 15 cytokines that had a prolonged response (change at 4-h and sustained at 24-h). We found 4 targets to be undetectable or having no response relative to muscle injury recovery. These findings demonstrate the interplay between RNA and protein biomarkers in response to skeletal muscle injury. This novel experimental application of bead-based multiplexing is applicable to a variety of clinical models that involve muscle injury and/or wasting.

Upper Respiratory Symptoms, Gut Health and Mucosal Immunity in Athletes

Upper respiratory symptoms remain the most common illness in athletes. Upper respiratory symptoms during heavy training and competition may impair performance. Preventing illness is the primary reason for the use of supplements, such as probiotics and prebiotics, for maintaining or promoting gut health and immune function. While exercise-induced perturbations in the immune system may increase susceptibility to illness and infection, growing evidence indicates that upper respiratory symptoms are related to a breakdown in the homeostatic regulation of the mucosal immune system of the airways. Balancing protection of the respiratory tract with normal physiological functioning requires dynamic orchestration between a wide array of immune parameters. The intestinal microbiota regulates extra-intestinal immunity via the common mucosal immune system and new evidence implicates the microbiota of the nose, mouth and respiratory tract in upper respiratory symptoms. Omics’ approaches now facilitate comprehensive profiling at the molecular and proteomic levels to reveal new pathways and molecules of immune regulation. New targets may provide for personalised nutritional and training interventions to maintain athlete health.

Effects of Yeast (1,3)-(1,6)-Beta-Glucan on Severity of Upper Respiratory Tract Infections: A Double-Blind, Randomized, Placebo-Controlled Study in Healthy Subjects

OBJECTIVES

Each year, adults suffer about two to four upper respiratory tract infections (URTIs), mostly in winter. The aim of the study was to evaluate the effects of brewers' yeast (1,3)-(1,6)-beta-glucan on incidence and severity of upper respiratory tract infections (URTIs).

METHODS

Generally healthy men and women (n = 299) reporting at least three URTIs during the previous year were randomized to receive either a placebo or 900 mg of yeast beta-glucan daily for 16 weeks during winter. In cases of acute URTI, the severity of URTI symptoms was assessed via the WURSS-21 questionnaire and the Jackson scale, and a clinical confirmation was implemented by the investigator.

RESULTS

Overall, 70 subjects under placebo and 71 subjects under yeast beta-glucan experienced at least one clinically confirmed URTI episode. The global severity using WURSS-21 had been quite similar between the study groups (p = 0.5267), whereas during the first days of URTIs the severity was less pronounced in the yeast beta-glucan group. On the episode level, the severity of physical symptoms was significantly lower for all investigated time intervals up to 7 days under yeast beta-glucan (WURSS (Q2-11) (days 1-2: p = 0.0465, days 1-3: p = 0.0323, days 1-4: p = 0.0248, days 1-7: p = 0.0278), also confirmed for the Jackson scale). The reduction of severity was accompanied by a significant increase in the joy subscore of the Perceived Stress Questionnaire (PSQ20) (p = 0.0148). In addition, there was a reduction of systolic (p = 0.0458) and diastolic (p = 0.1439) blood pressure.

CONCLUSION

Subjects supplementing with yeast beta-glucan benefit by a reduced severity of physical URTI symptoms during the first week of an episode, even though the incidence and global severity of common colds could not be altered in comparison to placebo. Furthermore, accompanying benefits in terms of blood pressure and mood were identified. Altogether, yeast beta-glucan supports the immune function.

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 Supplementation with Baker's Yeast Beta Glucan Is Associated with Altered Monocytes, T Cells and Cytokines following a Bout of Strenuous Exercise

Exercise and physical labor in extreme environmental conditions causes transient decreases in immune cell and cytokine concentrations, likely increasing the susceptibility to opportunistic infection. Baker's yeast beta glucan (BYBG) has been previously demonstrated to be an effective countermeasure in athletes, but its effectiveness in individuals of average fitness under similar physical stress is unknown. The purpose of this study was to determine if 10 days of oral supplementation with BYBG could modify previously observed suppression of monocytes, T cells, circulating and whole blood LPS-stimulated cytokines due to strenuous exercise. Venous blood samples were collected from 109 healthy volunteers prior to, immediately after, 2 and 4 h post-exercise. Monocyte and T cell concentration, cell-surface receptor expression and serum and LPS-stimulated cytokines were assessed. BYBG significantly (P < 0.05) altered total and classic monocyte concentration and expression of CD38, CD80, CD86, TLR2, and TLR4 on monocyte subsets. BYBG also significantly increased CD4+ and CD8+ T cell concentration and the exercise response of CCR7+/CD45RA- central memory (T_CM) cells. Likewise, BYBG significantly (P < 0.05) altered serum IFN-γ and IL-2, and LPS-stimulated IFN-γ, IL-2, IL-4, and IL-7. Taken together these data support the hypothesis that oral BYBG supplementation modulates the expected exercise response for individuals of average fitness. This may result in a decrease in susceptibility to opportunistic infections after strenuous exercise.

Assessment of Granulocyte Subset Activation: New Information from Image-Based Flow Cytometry

Analysis of granulocyte function can provide important information about the state of the body's innate immune system. Existing flow cytometry methods that lack image-based analysis capabilities fail to fully evaluate granulocyte function. In the present method, we combine simultaneous detection of phagocytosis and oxidative burst in granulocytes to identify unique subsets of activated granulocytes. This analysis method provides novel information about granulocytes that allows our lab and others to evaluate the effectiveness of nutritional and lifestyle countermeasures, designed to improve immunity.

Respiratory Tract Infections and the Role of Biologically Active Polysaccharides in Their Management and Prevention

Respiratory tract infections (RTIs) are the most common form of infections in every age category. Recurrent respiratory tract infections (RRTIs), a specific form of RTIs, represent a typical and common problem associated with early childhood, causing high indirect and direct costs on the healthcare system. They are usually the consequence of immature immunity in children and high exposure to various respiratory pathogens. Their rational management should aim at excluding other severe chronic diseases associated with increased morbidity (e.g., primary immunodeficiency syndromes, cystic fibrosis, and ciliary dyskinesia) and at supporting maturity of the mucosal immune system. However, RRTIs can also be observed in adults (e.g., during exhausting and stressful periods, chronic inflammatory diseases, secondary immunodeficiencies, or in elite athletes) and require greater attention. Biologically active polysaccharides (e.g., β-glucans) are one of the most studied natural immunomodulators with a pluripotent mode of action and biological activity. According to many studies, they possess immunomodulatory, anti-inflammatory, and anti-infectious activities and therefore could be suggested as an effective part of treating and preventing RTIs. Based on published studies, the application of β-glucans was proven as a possible therapeutic and preventive approach in managing and preventing recurrent respiratory tract infections in children (especially β-glucans from Pleurotus ostreatus), adults (mostly the studies with yeast-derived β-glucans), and in elite athletes (studies with β-glucans from Pleurotus ostreatus or yeast).

Potential Impact of Nutrition on Immune System Recovery from Heavy Exertion: A Metabolomics Perspective

This review describes effective and ineffective immunonutrition support strategies for the athlete, with a focus on the benefits of carbohydrates and polyphenols as determined from metabolomics-based procedures. Athletes experience regular cycles of physiological stress accompanied by transient inflammation, oxidative stress, and immune perturbations, and there are increasing data indicating that these are sensitive to nutritional influences. The most effective nutritional countermeasures, especially when considered from a metabolomics perspective, include acute and chronic increases in dietary carbohydrate and polyphenols. Carbohydrate supplementation reduces post-exercise stress hormone levels, inflammation, and fatty acid mobilization and oxidation. Ingestion of fruits high in carbohydrates, polyphenols, and metabolites effectively supports performance, with added benefits including enhancement of oxidative and anti-viral capacity through fruit metabolites, and increased plasma levels of gut-derived phenolics. Metabolomics and lipidomics data indicate that intensive and prolonged exercise is associated with extensive lipid mobilization and oxidation, including many components of the linoleic acid conversion pathway and related oxidized derivatives called oxylipins. Many of the oxylipins are elevated with increased adiposity, and although low in resting athletes, rise to high levels during recovery. Future targeted lipidomics-based studies will help discover whether n-3-polyunsaturated fatty acid (n-3-PUFA) supplementation enhances inflammation resolution in athletes post-exercise.

Measurement of T-Cell Telomere Length Using Amplified-Signal FISH Staining and Flow Cytometry

Exposure to pathogen-associated molecular patterns (PAMPS), damage-associated molecular patterns (DAMPS), and physiologically challenging stimuli either positively or negatively affect leukocyte maturity. Cellular maturity has implications for the effectiveness of host response to bacterial or viral infection and/or tissue injury. Thus, the ability to accurately assess cellular maturity and health is important to fully understand immune status and function. The most common technique for measuring cellular maturity is to measure telomere length; however, existing techniques are not optimized for single-cell measurements using flow cytometry. Specifically, existing methods used to measure telomere length are PCR-based, making it difficult for a researcher to measure maturity within specific leukocyte subsets (e.g., T cells). In this report, we describe a new approach for the measurement of telomere length within individual T cells using an amplified fluorescence in situ hybridization (FISH) technique (PrimeFlow RNA Assay). The unique aspect of this technique is that it amplifies the fluorescent signal rather than the target up to 3000-fold, resulting in the detection of as few as 1 copy of the target nucleic acid. While the current technique focuses on human T cells, this method can be broadly applied to a variety of cell types and disease models. © 2017 by John Wiley & Sons, Inc.

Flow cytometry what you see matters: Enhanced clinical detection using image-based flow cytometry

Image-based flow cytometry combines the throughput of traditional flow cytometry with the ability to visually confirm findings and collect novel data that would not be possible otherwise. Since image-based flow cytometry borrows measurement parameters and analysis techniques from microscopy, it is possible to collect unique measures (i.e. nuclear translocation, co-localization, cellular synapse, cellular endocytosis, etc.) that would not be possible with traditional flow cytometry. The ability to collect unique outcomes has led many researchers to develop novel assays for the monitoring and detection of a variety of clinical conditions and diseases. In many cases, investigators have innovated and expanded classical assays to provide new insight regarding clinical conditions and chronic disease. Beyond human clinical applications, image-based flow cytometry has been used to monitor marine biology changes, nano-particles for solar cell production, and particle quality in pharmaceuticals. This review article summarizes work from the major scientists working in the field of image-based flow cytometry.

Cellular and molecular effects of yeast probiotics on cancer

The cancer is one of the main causes of human deaths worldwide. The exact mechanisms of initiation and progression of malignancies are not clear yet, but there is a common agreement about the role of colonic microbiota in the etiology of different cancers. Probiotics have been examined for their anti-cancer effects, and different mechanisms have been suggested about their antitumor functions. Nonpathogenic yeasts, as members of probiotics family, can be effective on gut microbiota dysbiosis. Generally safe yeasts have shown so many beneficial effects on human health. Probiotic yeasts influence physiology, metabolism, and immune homeostasis in the colon and contribute to cancer treatment due to possessing anti-inflammatory, anti-proliferative and anti-cancer properties. This study reviews some of the health-beneficial effects of probiotic yeasts and their biological substances like folic acid and β-glucan on cancer and focuses on the possible cellular and molecular mechanisms of probiotic yeasts such as influencing pathogenic bacteria, inactivation of carcinogenic compounds, especially those derived from food, improvement of intestinal barrier function, modulation of immune responses, antitoxic function, apoptosis, and anti-proliferative effects.

Natural Immunoreactivity of Secretory IgA to Indigenous Strains of Streptococcus mutans From Chinese Spousal Pairs

Background

Dental caries is a well-known biofilm-mediated disease initiated by Streptococcus mutans, which should infect and colonize in a milieu perfused with components of the mucosal immune system. Little is known, however, regarding the relationship between the natural secretory IgA activity and S. mutans of a variety of diverse genotypes.

Objectives

The current study aimed to use spousal pairs to investigate the natural immunoreactivity of salivary secretory IgA to different genotype strains of S. mutans.

Patients and Methods

Indigenous strains were characterized from nine spousal pairs using polymerase reaction chain (PCR) and arbitrarily primed polymerase chain reaction (AP-PCR) by genotype monitoring. Unstimulated submandibular/sublingual secretions were collected and the concentrations of secretory IgA were determined by the enzyme-linked immunosorbent assay (ELISA). Each saliva sample was examined by Western blot to analyze the immunoreactivity of naturally occurring salivary secretory IgA antibodies for his/her own indigenous strain, spouse’s strain and reference strains including S. mutans GS-5 and Ingbritt (C).

Results

The results showed that naturally induced salivary IgA antibodies against S. mutans were present in all subjects. Almost all subjects had the similar individual immunoblotting profiles to different genotype strains.

Conclusions

The current study indicated that the immunoreactivity of secretory IgA might have no direct correlation with the colonization of indigenous flora and rejection of exogenous strains in adults. The relationship of microbes, host and dental caries should be in the light of coevolved microecosystem as a whole, but not caused by one factor alone.