Oat beta-glucan effects on neutrophil respiratory burst activity following exercise

Mechanisms underlying the beneficial effects of physical exercise on multiple sclerosis: focus on immune cells

Multiple sclerosis (MS) is a prevalent neuroimmunological illness that leads to neurological disability in young adults. Although the etiology of MS is heterogeneous, it is well established that aberrant activity of adaptive and innate immune cells plays a crucial role in its pathogenesis. Several immune cell abnormalities have been described in MS and its animal models, including T lymphocytes, B lymphocytes, dendritic cells, neutrophils, microglia/macrophages, and astrocytes, among others. Physical exercise offers a valuable alternative or adjunctive disease-modifying therapy for MS. A growing body of evidence indicates that exercise may reduce the autoimmune responses triggered by immune cells in MS. This is partially accomplished by restricting the infiltration of peripheral immune cells into the central nervous system (CNS) parenchyma, curbing hyperactivation of immune cells, and facilitating a transition in the balance of immune cells from a pro-inflammatory to an anti-inflammatory state. This review provides a succinct overview of the correlation between physical exercise, immune cells, and MS pathology, and highlights the potential benefits of exercise as a strategy for the prevention and treatment of MS.

Chemical characterization and biological effect of exopolysaccharides synthesized by Antarctic yeasts Cystobasidium ongulense AL101 and Leucosporidium yakuticum AL102 on murine innate immune cells

The current study aimed to investigate exopolysaccharides (EPSs) produced by two Antarctic yeasts isolated from soil and penguin feathers samples collected on Livingston Island (Antarctica). The strains were identified as belonging to the species Leucosporidium yakuticum (LY) and Cystobasidium ongulense (CO) based on molecular genetic analysis. The EPS production was investigated using submerged cultivation. Different chemical, chromatographic, and spectral analyses were employed to characterize EPSs. LY accumulated 5.5 g/L biomass and 4.0 g/L EPS after 120 h of cultivation, while CO synthesized 2.1 g/L EPS at the end of cultivation, and the biomass amount reached 5.5 g/L. LY-EPS was characterized by a higher total carbohydrate content (80%) and a lower protein content (18%) by comparison with CO-EPS (62%, 30%). The LY-EPS mainly consisted of mannose (90 mol%), whereas CO-EPS had also glucose, galactose, and small amounts of uronic acids (8-5 mol%). Spectral analyses (FT-IR and 1D, 2D NMR) revealed that LY-EPS comprised a typical β-(1 → 4)-mannan. Branched (hetero)mannan, together with β/α-glucans constituted the majority of CO-EPS. Unlike LY-EPS, which had a high percentage of high molecular weight populations, CO-EPS displayed a large quantity of lower molecular weight fractions and a higher degree of heterogeneity. LY-EPS (100 ng/mL) elevated significantly interferon gamma (IFN-γ) production in splenic murine macrophages and natural killer (NK) cells. The results indicated that newly identified EPSs might affect IFN-γ signaling and in turn, might enhance anti-infectious responses. The data obtained also revealed the potential of EPSs and yeasts for practical application in biochemical engineering and biotechnology.

Structure and function of non-digestible carbohydrates in the gut microbiome

Together with proteins and fats, carbohydrates are one of the macronutrients in the human diet. Digestible carbohydrates, such as starch, starch-based products, sucrose, lactose, glucose and some sugar alcohols and unusual (and fairly rare) α-linked glucans, directly provide us with energy while other carbohydrates including high molecular weight polysaccharides, mainly from plant cell walls, provide us with dietary fibre. Carbohydrates which are efficiently digested in the small intestine are not available in appreciable quantities to act as substrates for gut bacteria. Some oligo- and polysaccharides, many of which are also dietary fibres, are resistant to digestion in the small intestines and enter the colon where they provide substrates for the complex bacterial ecosystem that resides there. This review will focus on these non-digestible carbohydrates (NDC) and examine their impact on the gut microbiota and their physiological impact. Of particular focus will be the potential of non-digestible carbohydrates to act as prebiotics, but the review will also evaluate direct effects of NDC on human cells and systems.

Short communication: Effect of yeast cell wall supplementation on peripheral leukocyte populations and mRNA expression of cytokines in lactating dairy cows

This study was designed to examine the effect of yeast cell wall (YCW) supplementation on peripheral leukocyte populations and mRNA expression of cytokines in lactating dairy cows. Fourteen Holstein lactating cows were assigned to 1 of 2 treatments; the control group (n = 7) were fed a total mixed ration without supplementation and cows in the YCW group (n = 7) were fed a total mixed ration supplemented with YCW (SafMannan; Phileo, Lesaffre Animal Care, Lille, France; 10 g/cow per day). Blood samples were collected 3 times during the experimental period [wk 0 (before any treatment), wk 4, and wk 8]. Peripheral leukocyte populations and cytokine mRNA expression of peripheral blood monocular cells were measured using flow cytometry and real-time PCR, respectively. Among the peripheral leukocyte populations, TcR1-N12 ⁺ and CD14⁺ T cells increased at wk 4, and CD4⁺ T cells and CD8⁺ T cells increased at wk 4 and wk 8 with YCW supplementation. The mRNA level of IL8 tended to be increased in the YCW group at wk 4. Expression of IL12A was lower in the YCW group than in the control group before the experiment (wk 0) but no differences were observed at later time points (wk 4 and wk 8). Expression of IL12A decreased in the control group and increased in the YCW group. Expression of CCR2 increased at wk 4, and CCL2 and CCL3 were increased at wk 8 in the YCW group. Thus, YCW supplementation increased the mRNA expression of cytokines in peripheral blood mononuclear cells of lactating dairy cows.

The Long-Term Consumption of Oats in Celiac Disease Patients Is Safe: A Large Cross-Sectional Study

A strict gluten-free diet (GFD) can be diversified by non-contaminated oats, but there is a shortage of long-term studies concerning its safety. We compared long-term treatment outcomes and factors associated with the introduction of oats between celiac patients on a GFD with or without oats. Eight hundred sixty-nine previously diagnosed celiac patients were interviewed. The validated Gastrointestinal Symptom Rating Scale (GSRS), Psychological General Well-Being (PGWB), and Short-Form 36 Health Survey (SF-36) questionnaires were used to assess symptoms and quality of life, serological tests were performed, and results of histology were confirmed from patient records. We found the median duration of GFD to be 10 years and 82% using oats. Factors predicting the consumption of oats were diagnosis after the year 2000, advice from a dietitian, detection by screening, and mild clinical presentation. Oat consumers and non-consumers did not differ in dietary adherence (96.5% vs. 97.4%, p = 0.746), the prevalence of symptoms (22.9% vs. 22.5%, p = 0.931), positivity for endomysial antibodies (8.8% vs. 6.0%, p = 0.237), histological recovery after one year (63.1% vs. 60.0%, p = 0.773), malignancy (4.8% vs. 3.3%, p = 0.420), osteoporosis/osteopenia (9.2% vs. 11.0%, p = 0.489), or fractures (26.9% vs. 27.9%, p = 0.791). The oat consumers had better SF-36 physical role limitations and general health scores. Based on our results, the long-term consumption of oats in celiac disease patients is safe and may improve quality of life.

Yeast cell wall supplementation alters aspects of the physiological and acute phase responses of crossbred heifers to an endotoxin challenge

A study was conducted to determine the effect of feeding yeast cell wall (YCW) products on the physiological and acute phase responses of crossbred, newly-received feedlot heifers to an endotoxin challenge. Heifers (n = 24; 219 ± 2.4 kg) were separated into treatment groups receiving either a control diet (n = 8), YCW-A (2.5 g/heifer/d; n = 8) or YCW-C (2.5 g/heifer/d; n = 8) and were fed for 52 d. On d 37 heifers were challenged i.v. with LPS (0.5 µg/kg body mass) and blood samples were collected from -2 h to 8 h and again at 24 h relative to LPS challenge. There was an increase in vaginal temperature in all heifers post-LPS, with YCW-C maintaining a lower vaginal temperature post-LPS than control and YCW-A heifers. Sickness behavior scores increased post-LPS in all heifers, but were not affected by treatment. Cortisol concentrations were greatest in control heifers post-LPS compared with YCW-A or YCW-C heifers. Concentrations of IFN-γ and TNF-α increased post-LPS, but were not affected by treatment. Serum IL-6 concentrations increased post-LPS and were greater in control heifers than YCW-A and YCW-C heifers. These data indicate that YCW supplementation can decrease the physiological and acute phase responses of newly-received heifers following an endotoxin challenge.

Exercise-induced immunodepression in endurance athletes and nutritional intervention with carbohydrate, protein and fat-what is possible, what is not?

Heavily exercising endurance athletes experience extreme physiologic stress, which is associated with temporary immunodepression and higher risk of infection, particularly upper respiratory tract infections (URTI). The aim of this review is to provide a critical up-to-date review of existing evidence on the immunomodulatory potential of selected macronutrients and to evaluate their efficacy. The results of 66 placebo-controlled and/or crossover trials were compared and analysed. Among macronutrients, the most effective approach to maintain immune function in athletes is to consume ≥6% carbohydrate during prolonged exercise. Because inadequate nutrition affects almost all aspects of the immune system, a well-balanced diet is also important. Evidence of beneficial effects from other macronutrients is scarce and results are often inconsistent. Using a single nutrient may not be as effective as a mixture of several nutritional supplements. Due to limited research evidence, with the exception of carbohydrate, no explicit recommendations to reduce post-exercise URTI symptoms with single macronutrients can be derived.

Nutritional evaluation of distillery sludge and its effect as a substitute of canola meal on performance of broiler chickens

The study was conducted to investigate the chemical composition of distillery yeast sludge and its inclusion in broiler diets to replace canola meal. Raw distillery yeast sludge was washed with water using water and sludge in the ratio 6:1, respectively. Proximate analysis of raw distillery yeast sludge and washed distillery sludge was carried out for crude protein (CP), true protein (TP), ether extract (EE), ash, acid insoluble ash and nitrogen free extract (NFE) determination. Mineral contents and amino acid profile of raw distillery yeast sludge and washed distillery sludge were also determined. After chemical evaluation, four iso-caloric and iso-nitrogenous broiler starter and finisher diets were prepared in mash form using 0 (control), 4, 8 and 12% levels of washed distillery sludge replacing canola meal. One hundred and twenty day-old broiler chicks were randomly distributed into 12 experimental units in such a way that each diet was offered to three experimental units, each comprising of 10 chicks. It was observed that washing affected the nutrients either by decreasing or increasing their concentration. It decreased the total mineral contents whereas CP, TP, EE and NFE contents increased. Washing also increased amino acid profile. Average feed intake and weight gain were higher in birds fed diet containing 8% washed distillery sludge and lower in birds fed diet containing 0% washed distillery sludge. Feed cost per kg live weight gain decreased significantly as the level of washed distillery sludge was increased in the diet. Average heart, liver and pancreas weights decreased with increased level of washed distillery sludge in the diet. The study revealed that after washing, distillery yeast sludge can be used successfully in broiler diets up to the level of 8% without any adverse effect on broiler’s performance.

Effects of dietary yeast extract on turkey stress response and heterophil oxidative burst activity

1. Effective nutritional approaches to counteract the negative effects of stress may provide food animal producers with useful alternatives to antibiotics. In this study, turkeys were fed on a standard diet, or the same diet supplemented with yeast extract (YE), to determine if YE would improve disease resistance in a stress model. 2. At 16 weeks of age, half of the birds were exposed to a bacterial challenge using a coarse spray of the pen environment. A subset of control and challenged birds was also treated with dexamethasone (Dex) prior to challenge (Dex/challenge). At 18 weeks, another subset was subjected to a 12?h transport stress protocol (Challenge/transport). All birds were bled and necropsied the morning after transport. The numbers and proportions of blood cells and the heterophil oxidative burst activity (OBA) were determined. Serum corticosterone (Cort) levels of male birds were measured using a commercial ELISA kit. Body weight and gain were increased by YE during week 1. 3. YE decreased mortality and bacterial isolation following Dex/challenge only in females. Cort levels in male turkeys were decreased by YE and Dex treatment. OBA was higher in males and in birds given YE and was reduced by challenge and transport. 4. These results suggest there may be gender differences in the turkey stress response and that dietary YE has potential for modulating the impact of stress on innate immunity of turkeys.

Effect of Pleuran (β-glucan from Pleurotus ostreatus) supplementation on cellular immune response after intensive exercise in elite athletes

Excessive and exhausting physical loads depress the immune system. Carbohydrate consumption may minimize the postexercise suppression of the innate immune system. β-Glucan is a well-known immunomodulator, with positive effects on the functioning of immunocompetent cells. The goal of this study was to determine whether β-glucan dietary supplementation from the mushroom Pleurotus ostreatus decreases the suppressed immune system responses induced by short-term high-intensity exercise in humans. In this double-blind pilot study, 20 elite athletes were randomized to β-glucan (n = 9) or placebo (n = 11) groups; these groups consumed 100 mg of β-glucan (Imunoglukan) or placebo supplements, respectively, once a day for 2 months. Venous whole blood was collected before and after 2 months of supplementation (baseline), both immediately and 1 h after (recovery period) a 20-min intensive exercise bout at the end of the supplementation period. The blood samples were used to measure the cell counts of leukocytes, erythrocyte, and lymphocytes; subpopulations of lymphocytes, granulocytes, and monocytes; and natural killer (NK) cell activity (NKCA). A 28% reduction in NKCA (p < 0.01) below the baseline value was observed in the placebo group during the recovery period, whereas no significant reduction in NKCA was found in the β-glucan group. In addition, no significant decrease in NK cell count was measured in the β-glucan group during the recovery period. Immune cell counts did not differ significantly between the groups. These results indicate that insoluble β-glucan supplementation from P. ostreatus may play a role in modulating exercise-induced changes in NKCA in intensively training athletes.

Pleuran (β-glucan from Pleurotus ostreatus) supplementation, cellular immune response and respiratory tract infections in athletes

Prolonged and exhausting physical activity causes numerous changes in immunity and sometimes transient increases the risk of upper respiratory tract infections (URTIs). Nutritional supplements as countermeasures to exercise-induced changes have increasingly been studied in the last decade. One of the most promising nutritional supplements is β-glucan, a well-known immunomodulator with positive effects on the function of immunocompetent cells. In this double blind, placebo-controlled study, we investigated the effect of pleuran, an insoluble β-(1,3/1,6) glucan from mushroom Pleurotus ostreatus, on selected cellular immune responses and incidence of URTI symptoms in athletes. Fifty athletes were randomized to pleuran or placebo group, taking pleuran (commercial name Imunoglukan(®)) or placebo supplements during 3 months. Venous whole blood was collected before and after 3 months of supplementation and additionally 3 months after supplementation period was completed. Incidence of URTI symptoms together with characterization of changes in phagocytosis and natural killer (NK) cell count was monitored during the study. We found that pleuran significantly reduced the incidence of URTI symptoms and increased the number of circulating NK cells. In addition, the phagocytosis process remained stable in pleuran group during the study in contrast to placebo group where significant reduction of phagocytosis was observed. These findings indicate that pleuran may serve as an effective nutritional supplement for athletes under heavy physical training. Additional research is needed to determine the mechanisms of pleuran function.

Immunomodulatory dietary polysaccharides: a systematic review of the literature

BACKGROUND

A large body of literature suggests that certain polysaccharides affect immune system function. Much of this literature, however, consists of in vitro studies or studies in which polysaccharides were injected. Their immunologic effects following oral administration is less clear. The purpose of this systematic review was to consolidate and evaluate the available data regarding the specific immunologic effects of dietary polysaccharides.

METHODS

Studies were identified by conducting PubMed and Google Scholar electronic searches and through reviews of polysaccharide article bibliographies. Only articles published in English were included in this review. Two researchers reviewed data on study design, control, sample size, results, and nature of outcome measures. Subsequent searches were conducted to gather information about polysaccharide safety, structure and composition, and disposition.

RESULTS

We found 62 publications reporting statistically significant effects of orally ingested glucans, pectins, heteroglycans, glucomannans, fucoidans, galactomannans, arabinogalactans and mixed polysaccharide products in rodents. Fifteen controlled human studies reported that oral glucans, arabinogalactans, heteroglycans, and fucoidans exerted significant effects. Although some studies investigated anti-inflammatory effects, most studies investigated the ability of oral polysaccharides to stimulate the immune system. These studies, as well as safety and toxicity studies, suggest that these polysaccharide products appear to be largely well-tolerated.

CONCLUSIONS

Taken as a whole, the oral polysaccharide literature is highly heterogenous and is not sufficient to support broad product structure/function generalizations. Numerous dietary polysaccharides, particularly glucans, appear to elicit diverse immunomodulatory effects in numerous animal tissues, including the blood, GI tract and spleen. Glucan extracts from the Trametes versicolor mushroom improved survival and immune function in human RCTs of cancer patients; glucans, arabinogalactans and fucoidans elicited immunomodulatory effects in controlled studies of healthy adults and patients with canker sores and seasonal allergies. This review provides a foundation that can serve to guide future research on immune modulation by well-characterized polysaccharide compounds.

Immune modulating effects of β-glucan

PURPOSE OF REVIEW

To examine the recent scientific literature on the immune modulating effects of β-glucans and subsequent benefits on infection and cancer.

RECENT FINDINGS

β-Glucans have been investigated for their ability to protect against infection and cancer and more recently for their therapeutic potential when combined with cancer therapy. Their immune modulating effects are attributed to the ability to bind to pattern recognition receptors including complement receptor 3, scavenger receptors, lactosylceramide, and dectin-1 that results in activation of different aspects of the immune response depending on the cell types and species involved although there is some controversy about the relative importance of each of these receptors. Most of the available evidence comes from preclinical data and human studies are just now beginning to appear in the literature, therefore firm conclusions on its clinical importance cannot yet be made. Perhaps the most promising evidence to date in human trials has come from recent studies on a benefit of β-glucan on quality of life and survival when given in combination with cancer treatment. We identify the need for future studies that compare purified forms of β-glucans from different sources to further the understanding of the mechanisms of action and aid in the development of clinical studies.

SUMMARY

β-Glucans appear to be effective at enhancing immune function and reducing susceptibility to infection and cancer. A better understanding of the mechanisms of β-glucan recognition and subsequent immune activation is necessary for the design of effective treatment approaches in future clinical trials.

Bacterial clearance, heterophil function, and hematological parameters of transport-stressed turkey poults supplemented with dietary yeast extract

Yeast extracts (YE) contain biological response modifiers that may be useful as alternatives to antibiotics for controlling pathogens in poultry production and mitigating the deleterious effects of production stressors. The objective of the present study was to determine the ability of a commercial dietary YE (Alphamune) to modulate the immune response in male turkey poults challenged with Escherichia coli and subjected to transport stress. Alphamune was added to turkey poult diets at 0, 500, or 1,000 g/ton. Poults were challenged by air sac injection with 60 cfu of E. coli at 1 wk of age. At 3 wk of age, these challenged birds were subjected to transport stress and birds were bled and necropsied the following morning. Blood cell numbers and percentages, hematological parameters, and clinical chemistry values were determined. Oxidative burst activity of isolated heterophils was measured using stimulation with phorbol myristate acetate and a 2',7'-dichlorofluorescein diacetate assay. Data were analyzed using GLM and least squares means procedures of the SAS program. The numbers and percentages of heterophils in peripheral blood were increased and their oxidative burst activity was stimulated by YE. The stress challenge dramatically increased oxidative burst and this increase was significantly modulated by YE treatment. Serum levels of calcium, phosphorus, and triglycerides were decreased and uric acid levels, erythrocyte numbers, hemoglobin, and hematocrit were increased by YE supplementation. Bacteria were isolated from the air sac and liver of a lower percentage of birds provided with YE. These results suggest that dietary YE has potential as a nonantibiotic alternative for decreasing bacterial pathogens in turkey production.

Production of interleukin-10 in asthmatic children after Beta-1-3-glucan

BACKGROUND

Beta-1-3 Glucan is a polysaccharide extracted from Saccharomyces cerevisiae with a possible immunomodulating action that may have a favourable action on asthma symptoms and other allergic diseases. An experimental study carried out using a murine respiratory model detected a decrease in pulmonary tissue eosinophilia, as well as an increase in Interleukin-10 (IL-10) after glucan use.

METHODS

This open, exploratory study with blind outcome evaluation included asthmatic children between 6 and 12 years of age with mild to moderate persistent asthma and inadequate disease control (rescue medication needed more than twice a week) in spite of inhaled budesonide 400 microg/day. After a four week run-in period, subcutaneous Beta-1-3-glucan injections were given weekly for the first four weeks and then every two weeks for the last four weeks. IL-10 levels, measured by the immunoenzymatic method (ELISA), were compared before and after glucan administration.

RESULTS

Twenty patients (14 male and 6 female) were included. Mean IL-10 levels were 6.4 pg/ml and 11.3 pg/ml before and after glucan, respectively (p = 0.02). There was also a reduction of asthmatic symptoms score at the end of study.

CONCLUSIONS

This is the first study which shows that subcutaneous particulate Beta-1-3-glucan increases serum IL-10 levels in asthmatics. The possibility of glucan being able to modulate allergic sensitisation and having a beneficial action in restoring Th2 function should be assessed by means of properly planned controlled clinical trials, as it may represent a new therapeutic strategy.

The interaction of a high-fat diet and regular moderate intensity exercise on intestinal polyp development in Apc Min/+ mice

Diet and exercise are two environmental factors that can alter colon cancer risk. The purpose of this study was to determine if regular moderate-intensity treadmill exercise training could attenuate polyp formation in Apc(Min/+) mice fed the Western-style diet. Four-week-old male Apc(Min/+) mice (n = 12 per group) were assigned to AIN-76A Control, AIN-76A Exercise, Western Control, or Western Exercise treatment groups. Mice were weaned to these diets and either subjected to regular moderate-intensity treadmill exercise (18 m/min, 60 min/d, 6 d/wk) or remained sedentary for 6 weeks. Mice fed the Western-style diet consumed approximately 14% more calories and had 42% more epididymal fat compared with mice fed the AIN-76A diet. Exercise had no effect on fat pad mass with either diet treatment. Exercise reduced total intestinal polyp number by 50% and the number of large polyps (>1 mm diameter) by 67% in AIN-76A-fed mice. The Western-style diet increased polyp number by 75% when compared with AIN-76A-fed mice, but exercise did not decrease polyp number or alter polyp size in mice fed the Western-style diet. Markers of systemic inflammation and immune system function were improved with exercise in mice fed the AIN-76A diet. Mice fed the Western-style diet showed more inflammation and immunosuppression, which were not completely ameliorated by exercise. These data suggest that the induction of adiposity, inflammation, and immunosuppression by the Western-style diet may compromise the beneficial effect of moderate-intensity exercise on the intestinal polyp burden in Apc(Min/+) mice.

Beta-glucan, immune function, and upper respiratory tract infections in athletes

PURPOSE

This study investigated the effects of oat beta-glucan (BG) supplementation on chronic resting immunity, exercise-induced changes in immune function, and self-reported upper respiratory tract infection (URTI) incidence in human endurance athletes.

METHODS

Trained male cyclists were randomized to BG (N = 19) or placebo (P; N = 17) groups and under double-blind procedures received BG (5.6 g x d(-1)) or P beverage supplements for 2 wk before, during, and 1 d after a 3-d period in which subjects cycled for 3 h x d(-1) at approximately 57% maximal watts. URTI symptoms were monitored during BG supplementation and for 2 wk afterward. Blood samples were collected before and after 2 wk of supplementation (both samples, 8:00 a.m.), immediately after the 3-h exercise bout on day 3 (6:00 p.m.), and 14 h after exercise (8:00 a.m.) and were assayed for natural killer cell activity (NKCA), polymorphonuclear respiratory burst activity (PMN-RBA), phytohemagglutinin-stimulated lymphocyte proliferation (PHA-LP), plasma interleukin 6 (IL-6), IL-10, IL-1 receptor agonist (IL-1ra), and IL-8, and blood leukocyte IL-10, IL-8, and IL-1ra mRNA expression.

RESULTS

Chronic resting levels and exercise-induced changes in NKCA, PMN-RBA, PHA-LP, plasma cytokines, and blood leukocyte cytokine mRNA did not differ significantly between BG and P groups. URTI incidence during the 2-wk postexercise period did not differ significantly between groups.

CONCLUSIONS

An 18-d period of BG versus P ingestion did not alter chronic resting or exercise-induced changes in immune function or URTI incidence in cyclists during the 2-wk period after an intensified exercise.