Β-glucan Group Research Articles

Hypolipidemic effects of barley-β-glucan in experimentally induced hyperlipidemic rats

Hyperlipidemia is one of the major risk factors for heart disease. One way to reduce the risk of developing the disease is to lower serum cholesterol levels by making dietary changes. Beta-glucan are glucose polymers present in cereal grains as barley,consumption of the whole grain or concentrated β-glucan preparation has been shown to lower blood lipid profile and atherogenic ratios. Fifty male albino rats were assigned into five groups. The control groupreceived standard diet, the hyperlipidemic group fed 1% cholesterol and 20% coconut oil in the dietfor 8 weeks. The β-glucan treated group received high fat diet for 4 weeks then high fat diet plus barley β-glucan 10 mg/rats given orally for more 4 weeks. The β-glucan protected group received standard diet +10 mg/rat barley β-glucan for 2 weeks then high fat diet + barley β-glucan 10 mg/rat for another 8 weeks. The β-glucan group received standard diet + barley β-glucan 10 mg/rat for 8 weeks. The hyperlipidemicrats showed an increase in lipid profile, total lipid, phospholipids, atherogenic ratios, liver enzymes, kidney functions and glucose and a decrease in HDL-C and albumin compared with the control group. Moreover histological examination of liver tissue of hyperlipidemic rats showed fatty hepatocytes compared with the control. Administration of barley β-glucan 10 mg/rat in treated and protected groups ameliorated the levels of lipids, atherogenic ratios, liver functions, kidney functions and glucose. In addition, the liver tissues showed improved pathological alterations.

Pretreatment with β-glucan attenuates isoprenaline-induced myocardial injury in rats.

What is the central question of this study? The study was designed to assess whether pretreatment with β-glucan could exert any protective action against isoprenaline-induced myocardial injury in rats. What is the main finding and its importance? β-Glucan pretreatment could reduce myocardial injury by restoring cardiac biomarkers, antioxidant status, apoptosis and histopathological changes. Therefore, β-glucan might have the potential to be used in the prevention and/or treatment of myocardial infarction. This study was designed to investigate the cardioprotective effect of pretreatment with β-glucan, the glucose polymer derived from the yeast Saccharomyces cerevisiae, against isoprenaline (ISO)-induced myocardial injury in rats by studying biochemical cardiac markers, antioxidant parameters, apoptosis, ECG and histopathological changes. Male Sprague-Dawley rats were randomly divided into four treatment groups, namely control, β-glucan, isoprenaline and β-glucan+isoprenaline. The β-glucan treatment group received β-glucan (50mgkg-1 day-1 , p.o.) for 10 days. Myocardial injury was induced by ISO administration (100mgkg-1 , s.c.) twice, at an interval of 24h, on the 9th and 10th days. Isoprenaline administration resulted in a marked increase in heart rate, ST segment elevation, myocardial malondialdehyde content, cardiac marker levels (lactate dehydrogenase, creatine kinase-MB and high-sensitivity cardiac troponinT) and apoptotic index, and a significant decrease in R-wave amplitude and myocardial superoxide dismutase, catalase and glutathione peroxidase activities. In addition, apoptosis, congestion, necrosis, inflammatory cell infiltration and myofibrillar disorganization were observed histologically in myocardial tissue sections. The oral pretreatment with β-glucan prevented almost all the parameters of isoprenaline-induced myocardial injury in rats, and these findings were confirmed by the histopathological analysis. These findings provide evidence that β-glucan could protect rat myocardium against ISO-induced myocardial injury, and this was attributed to its antioxidant and anti-apoptotic properties.

Algae-derived β-glucan enhanced gut health and immune responses of weaned pigs experimentally infected with a pathogenic E. coli

Most of the commercially available β-glucans are derived from yeast, while there are limited research on algae-derived β-glucan in pigs. Therefore, the objective of this experiment was to investigate the influence of dietary supplementation of algae-derived β-glucan on diarrhea, gut permeability, and immune responses of weaned pigs experimentally infected with a pathogenic Escherichia coli (E. coli). Thirty-six weaned pigs (7.69 ± 0.77 kg BW) were individually housed in disease containment rooms and randomly allotted to one of three dietary treatments (n = 12): control diet and 2 additional diets containing either 54 or 108 mg/kg of β-glucan. The experiment lasted 17 d [5 d before and 12 d post inoculation (PI)]. The inoculum used in this experiment was F18 E. coli, containing heat-labile toxin, heat-stable toxin b, and shiga-lie toxin 2. The inoculation doses were 1010 cfu/3 mL oral dose daily for 3 days. Diarrhea score (1, normal, to 5, watery diarrhea) was recorded for each pig daily to calculate frequency of diarrhea. Blood samples were collected on d 0 before E. coli challenge, and on d 2, 5, 8, and 12 PI to measure total and differential blood cell count in whole blood and several inflammatory markers in serum. Fresh jejunal tissues were collected from 4 pigs in the control group and high dose β-glucan group to analyze gut permeability on d 5 and d 12 PI with Ussing Chamber. Jejunal and ileal mucosa were also collected to measure the mRNA expression of several genes related to gut barrier function and immune responses. Results of this experiment revealed that inclusion of high dose β-glucan reduced (P < 0.05) frequency of diarrhea (29.01% vs. 17.28%) for the entire experimental period. This was likely due to the reduced (P < 0.05) gut permeability and increased (P < 0.05) mRNA expression of gut barrier function genes (Claudin, Occludin, and MUC2) in jejunal mucosa of E. coli challenged pigs as β-glucan supplemented. Supplementation of β-glucan also reduced (P < 0.05) white blood cells, neutrophils, serum tumor necrosis factor (TNF)-α, cortisol, and haptoglobin, and down-regulated (P < 0.05) the mRNA expression of several immune genes (IL1B, IL6, and TNFA) in ileal mucosa of E. coli challenged pigs, compared with the control diet. In conclusion, in feed supplementation of algae-derived β-glucan alleviated diarrhea of F18 E. coli infected pigs by enhancing gut integrity. Feeding β-glucan also boosted host immune response against E. coli infection.

Influence of tallow replacement by oat β-glucan and canola oil on the fatty acid and volatile compound profiles of low-fat beef burgers

ABSTRACTIn view of the growing expectations of meat products consumers (quality and sensory properties), the meat industry must develop functional products to meet the consumer requirements. In the experiment, the influence of oat β-glucan, canola oil and both on the proximate composition, fatty acid profile, volatile compounds profile and sensory properties of beef burgers was analyzed. The beef tallow replacement by β-glucan, canola oil or both decreased the SFA and increased PUFA content. The consumption of one portion of product with canola oil and β-glucan can provide 57.6% of the daily amount of linolenic acid (C18:3n3). Volatile compounds analysis of grilled samples showed the presence of 1-penten-3-one and 2-methylpropanal only in case of groups with canola oil and butane-2-one in β-glucan group. This strategy improves not only the nutritional value but also the sensory properties and consumer acceptance. The obtained product may be labelled with health claims regarding oat β-glucan.

Feeding-regimen of β-glucan to enhance innate immunity and disease resistance of Nile tilapia, Oreochromis niloticus Linn., against Aeromonas hydrophila and Flavobacterium columnare

β-glucan is one of the most potent immunostimulants enhancing innate immune activity, disease resistance and growth performance of many aquatic organisms. Nevertheless, there are few studies on feeding regimens of β-glucan that correlate to immune response and disease resistance and are important considerations for practical β-glucan utilization. Thus, the effect of β-glucan and feeding duration on innate immunity and disease resistance was investigated to establish an optimal feeding regimen of β-glucan for Nile tilapia (Oreochromis niloticus Linn.). A variety of β-glucan feeding regimens were evaluated, including: i) feeding for 2 weeks, ii) feeding for 4 weeks, and iii) feeding every-other-week, with the objective of establishing the optimal feeding regimen that enhanced innate immunity and disease resistance. Innate immunity parameters were determined every week for eight weeks. Alternative complement activity of all β-glucan groups was significantly (P < 0.05) increased at the end of the first week, and then fluctuated but was not significantly (P > 0.05) different to the control until the end of the trial. Increased lysozyme activity was only detected at the end of the second week in all β-glucan-treated groups, and then decreased to the control level during most of the sampling periods. Phagocytosis percentage was increased and prolonged by β-glucan feeding, while the phagocytic index was not. Apart from innate immunity, β-glucan-fed fish demonstrated enhanced disease resistance against Aeromonas hydrophila and Flavobacterium columnare challenge at only the end of the fourth week of the trial. The growth performance of β-glucan-fed fish was not significantly (P > 0.05) different among the experimental groups and control. Taken together, the result indicated that all β-glucan-feeding regimens resulted in quite similar outcomes with respect to innate immunity stimulation, disease resistance and growth performance. This novel result suggests that an every-other-week regimen is the optimal choice for Nile tilapia cultivation as an economic cost saving benefit. This is the first study to determine the optimal feeding-regimen of β-glucan to enhance innate immunity and increase resistance to infection by pathogenic bacteria in Nile tilapia.

Dietary Onion or Ginger Modulates the Stress Response and Susceptibility to Vibrio harveyi JML1 Infection in Brown-marbled Grouper Epinephelus fuscoguttatus Juveniles.

Onion Allium cepa and ginger Zingiber officinale have health-promoting properties that qualify them as functional foods. The effect of repeated acute stressors was examined in juvenile Brown-marbled Grouper Epinephelus fuscoguttatus that were fed four diets supplemented with onion at 1.8%, ginger at 1.8%, vitamin C at 0.86%, and β-glucan at 0.8% of the diet. The non-supplemented diet served as the control. After 12weeks of feeding, fish were exposed to stressors and were experimentally infected with a fish pathogen, the bacterium Vibrio harveyi JML1. After repeated exposure to hypoxia, cortisol levels rose significantly in the non-supplemented fish compared to those fed onion, ginger, β-glucan, or vitamin C. Within groups, postexposure cortisol levels in the onion-, ginger-, and vitamin C-fed fish did not change relative to pre-stress levels, whereas significant increases in poststress values were observed in the control and β-glucan groups. The net cortisol increase was also significantly greater in the non-supplemented group compared to the supplemented groups. The net cortisol increase did not vary among the supplemented groups except that the β-glucan-fed group exhibited a higher net increase than the onion-fed group. Similarly, repeated acute exposure to osmotic stress significantly increased the plasma cortisol level in the non-supplemented group compared to groups that received supplements; no differences were found in the supplemented groups except the β-glucan group. Within groups, significant increases in poststress values relative to pre-stress levels were found only in the control and β-glucan groups. Repeated acute exposure to hypoxia significantly increased cumulative mortality in the control group compared to the supplemented groups (except the β-glucan group), whereas repeated exposure to acute osmotic stress significantly increased cumulative mortality only in the control group 10d after infection with V. harveyi JML1. Based on our collective results, most of the supplemented groups performed better than the control, but the best supplements were onion and ginger in terms of enhancing stress tolerance and increasing survival of Brown-marbled Grouper upon infection with V. harveyi JML1.

Protective effect of β-glucan and glutamine on intestinal and immunological damage in mice induced by cytarabine (Ara-C)

ABSTRACT: Recently, glutamine and β-glucan have been demonstrated to play an important role in modulation of the immune system and in promoting intestinal health benefits. The aim of this study was to investigate the effect of this intervention on inflammatory responses and intestinal health in mice orally pretreated with soluble Saccharomyces cerevisiae derived 1,3/1,6-β-glucan (80mg/kg) with or without glutamine (150mg/kg) and then challenged with cytarabine (Ara-C) (15mg/kg). Improvements in villi and crypts were not observed in the β-glucan group. The intestinal morphometry in the glutamine group showed the best results. β-glucan in combination with glutamine presented the highest values of IL-1β and IL-10 and lowest values for leukocytes and INF-γ. Based on these results, combined β-glucan and glutamine pretreatment reduced intestinal inflammation and improved the immune response after Ara-C challenge.

Effect of dietary β-glucan on growth, survival and regulation of immune processes in rainbow trout (Oncorhynchus mykiss) infected by Aeromonas salmonicida

The present study evaluated the effects of dietary β-glucan (0, 0.05%, 0.1%, and 0.2%) on growth performance after 42 days of feeding. Thereafter, rainbow trout (Oncorhynchus mykiss) were infected with Aeromonas salmonicida, and survival rates as well as the regulating processes of stress- and immune-related factors were analyzed. In general, higher dietary β-glucan levels obviously improved specific growth rate (SGR), weight gain (WG) and feed efficiency (FE) (P ≤ 0.05). Survival rates in β-glucan groups increased significantly compared with the control group after A. salmonicida infection (P ≤ 0.05). Serum total superoxide dimutase (T-SOD), peroxidase (POD) as well as catalase (CAT) activities, and their mRNA expressions in the head kidney of fish in the β-glucan groups generally increased to higher levels after infection, and more quickly, compared with in the control group. Serum lysozyme (LSZ) and its expression in the head kidney in β-glucan groups reached a higher peak earlier than in the control group.Serum glutamic oxalacetic transaminase (GOT) and glutamic pyruvic transaminase (GPT) levels in the β-glucan groups were significantly lower than in the control group (P ≤ 0.05). The peak of heat shock protein 70 (HSP70) expression in the 0.2% β-glucan group was higher and occurred earlier than in other groups (P ≤ 0.05). These results confirm that 0.1% and 0.2% dietary β-glucan are beneficial for promoting growth in rainbow trout and enhancing resistance against A. salmonicida. Furthermore, β-glucan could play an important role in regulating stress- and immune-related factors in rainbow trout to more quickly fight against bacterial infection.

Erratum: Agrobacterium sp.-derived β-1,3-glucan enhances natural killer cell activity in healthy adults: a randomized, double-blind, placebo-controlled, parallel-group study.

[This corrects the article on p. 43 in vol. 11, PMID: 28194264.].

Agrobacterium sp.-derived β-1,3-glucan enhances natural killer cell activity in healthy adults: a randomized, double-blind, placebo-controlled, parallel-group study.

BACKGROUND/OBJECTIVESThe present study investigated the hypothesis that a highly pure linear β-1,3-glucan produced by Agrobacterium sp. R259 enhances human natural killer (NK) cell activity and suppresses pro-inflammatory cytokines.SUBJECTS/METHODSIn an eight-week, double-blind, randomized, placebo-controlled clinical trial, 83 healthy adults with white blood cell counts of 4,000-8,000 cells/µL were participated and randomly assigned to take two capsules per day containing either 350 mg β-1,3-glucan or placebo. Six participants withdrew their study consent or were excluded due to NK cell activity levels outside the normal range. NK cell activity and serum levels of immunoglobulin G (IgG) and cytokines, such as interferon (IFN)-γ, interleukin (IL)-2, IL-4, IL-6, IL-10, IL-12 and tumor necrosis factor (TNF)-α were measured.RESULTSNK cell activity and the serum levels of IL-10 were significantly higher from baseline to week 8 in the β-glucan group compared with the placebo group (P = 0.048, P = 0.029). Consumption of β-1,3-glucan also significantly increased NK cell activity compared with placebo after adjusting for smoking and stress status (P = 0.009). In particular, the effect of β-1,3-glucan on NK cell activity was greater in participants with severe stress than in those experiencing mild stress. However, the administration β-1,3-glucan did not significantly modulate the levels of IFN-γ, IL-2, IL-4, IL-6, IL-12, TNF-α and IgG compared with the placebo.CONCLUSIONThe results showed that supplementation with bacterial β-1,3-glucan significantly increased NK cell activity without causing any adverse effects. Additionally, the beneficial effect of β-1,3-glucan on NK cell activity was greater in participants experiencing severe stress.

Effect of Immune-Enhancing Enteral Nutrition Enriched with or without Beta-Glucan on Immunomodulation in Critically Ill Patients.

We investigated whether high-protein enteral nutrition with immune-modulating nutrients (IMHP) enriched with β-glucan stimulates immune function in critically ill patients. In a randomized double-blind placebo-controlled study, 30 patients consumed one of three types of enteral nutrition: a control or IMHP with and without β-glucan. The IMHP with β-glucan group showed increases in natural killer (NK) cell activities relative to the baseline, and greater increases were observed in NK cell activities relative to the control group after adjusting for age and gender. The IMHP groups with and without β-glucan had greater increases in serum prealbumin and decreases in high-sensitivity C-reactive protein (hs-CRP) than the control group. The control group had a greater decrease in peripheral blood mononuclear cell (PBMC) interleukin (IL)-12 production than the IMHP with and without β-glucan groups. In all patients, the change (Δ) in hs-CRP was correlated with Δ prealbumin and Δ PBMC IL-12, which were correlated with ΔNK cell activity and Δ prealbumin. This study showed beneficial effects of a combination treatment of β-glucan and IMHP on NK cell activity. Additionally, strong correlations among changes in NK cell activity, PBMC IL-12, and hs-CRP suggested that β-glucan could be an attractive candidate for stimulating protective immunity without enhanced inflammation (ClinicalTrials.gov: NCT02569203).

Effects of oat soluble and insoluble β-glucan on 1,2-dimethylhydrazine-induced early colon carcinogenesis in mice

ABSTRACTThe study is aimed at studying the effects of soluble and insoluble oat β-glucan on colon carcinogenesis in mice. One hundred and twenty male Kunming mice were divided into normal control (NC), model control (MC), high doses (100 mg/kg body weight) of soluble (H-SOG) and insoluble β-glucan (H-IOG), and low doses (50 mg/kg body weight) of soluble (L-SOG) and insoluble β-glucan (L-IOG) groups. The mice except those in the NC group were given subcutaneous injections of DMH to induce colon cancer. The bile acid content was significantly reduced but the colonic short-chain fatty acid content was enhanced (p < .05) in mice administered β-glucan, moreover, the tumor cells apoptosis was significantly promoted (p < .05), compared to the MC group. The effect of high doses β-glucan was better than the low doses, but there is little difference between the SOG and IOG. Results suggested that both SOG and IOG exert favorable effects in preventing colon cancer in a doses-dependent manner while the specific mechanism maybe different.

Effects of beta-glucan on protection of young and aged rats from renal ischemia and reperfusion injury.

Ischemia-reperfusion injury is one of the leading causes of acute renal failure which is a common clinical event leading to development of chronic kidney disease and a high mortality; especially in elderly people. β-glucans are glucose polymer groups with free-radical scavenger, macrophage activator, and immune defense inducer functions. We designed this study to determine the possible protective effects of β-glucan against renal ischemia-reperfusion injury comparatively in young and aged rats. Rats were assigned to the following groups: Young and aged sham, young and aged ischemia-reperfusion, young and aged β-glucan, young and aged ischemia-reperfusion+β-glucan. At the end of the experiment, following collection of blood samples, rats were sacrificed and kidneys were removed for histopathological and biochemical examination. Mean tissue histopathological damage scores of young β-glucan group was lower than that of young ischemia-reperfusion group, and of aged β-glucan group was lower than that of aged ischemia-reperfusion group. Urea and creatinine levels of young and aged of sham group and β-glucan administered groups were all lower than those of ischemia-reperfusion and β-glucan+ischemia-reperfusion groups. Oxidative stress indexes of ischemia-reperfusion groups were increased however ; oxidative stress indexes of β-glucan administered to young and aged rats were lower than those of ischemia-reperfusion groups. We conclude that β-glucan is effective to protect kidneys from ischemia-reperfusion-induced oxidative damage, especially in young rats (Fig. 6, Ref. 45).

Effect of β-glucan Originated from Aureobasidium on Dermal Wound Healing in Normal Nude Mouse Model

The purpose of this study was to examine the directive wound healing effects of β-glucan on the full-thickness skin wounding in nude mouse models. Full-thickness dermatotomies were performed on the dorsal wall of the mice, and β-glucan was topically applied at dosages of 10, 50 and 100 mg/kg and madecassol was topically applied at 100 mg/kg. No significant changes in body weight were observed. A significant decrease of wound sizes and increases of angiogenesis, re-epithelialization and reconstruction of dermis in all β-glucan groups and madecassol group were demonstrated compared to that of control (p<0.05). Dosedependent and significant decreases of inflammatory cells like PMNs, macrophages and lymphocytes were observed in all β- glucan groups compared to that of control (p<0.05). There were significant increase of micro-vessels, fibroblast and re-epithelialization (p<0.05). Therefore, these data suggest that β-glucan has properties which may be beneficial in the treatment of wound healing, and that β-glucan may have a potential to develop as therapeutic agents or as an adjuvant for the treatment of skin wounds.

Sick building syndrome (SBS) among office workers in a Malaysian university — Associations with atopy, fractional exhaled nitric oxide (FeNO) and the office environment

There are few studies on sick building syndrome (SBS) including clinical measurements for atopy and fractional exhaled nitric oxide (FeNO). Our aim was to study associations between SBS symptoms, selected personal factors, office characteristics and indoor office exposures among office workers from a university in Malaysia. Health data were collected by a questionnaire (n=695), skin prick test (SPT) (n=463) and FeNO test (n=460). Office settled dust was vacuumed and analyzed for endotoxin, (1,3)-β-glucan and house dust mites (HDM) allergens group 1 namely Dermatophagoides pteronyssinus (Der p 1) and Dermatophagoides farinae (Der f 1). Office indoor temperature, relative air humidity (RH), carbon monoxide (CO) and carbon dioxide (CO2) were measured by a direct reading instrument. Associations were studied by two-levels multiple logistic regression with mutual adjustment and stratified analysis. The prevalence of weekly dermal, mucosal and general symptoms was 11.9%, 16.0% and 23.0% respectively. A combination of SPT positivity (allergy to HDM or cat) and high FeNO level (≥25ppb) was associated with dermal (p=0.002), mucosal (p<0.001) and general symptoms (p=0.05). Der f1 level in dust was associated with dermal (p<0.001), mucosal (p<0.001) and general (p=0.02) symptoms. Among those with allergy to D. farinae, associations were found between Der f 1 levels in dust and dermal (p=0.003), mucosal (p=0.001) and general symptoms (p=0.007). Office-related symptoms were associated with Der f 1 levels in dust (p=0.02), low relative air humidity (p=0.04) and high office temperature (p=0.05). In conclusion, a combination of allergy to cat or HDM and high FeNO is a risk factor for SBS symptoms. Der f 1 allergen in dust can be a risk factor for SBS in the office environment, particularly among those sensitized to Der f 1 allergen.

The Effect of β-glucan on Blood and Mucus of Catfish Clarias gariepinus Infected with Pseudomonas florescence

The present study was planned to investigate the immunological changes in blood and mucus of catfish Clarias gariepinus infected with Pseudomonas florescence along with trial for control using (β-glucan). A total number of 240 catfish were collected from Ismailia channel and subdivided to 4 equal groups: the control group, infected group with virulent strain of P. florescence, β-glucan group and β-glucan infected group fed on diet supplemented with β-glucan. The blood and mucus samples were taken at 2 days, 3 and 5 weeks for immunological examinations. There were significant decreases in total protein and albumin of the infected group, while β-glucan and β-glucan infected groups revealed significant increases in total protein and globulin compared to the control group. The serum and mucus immunological studies revealed enhanced immune parameters (lysozyme activity and IgM) in all groups with non-significant change in protease level in serum but increased in mucus only compared to the control group. These results concluded that dietary supplementation of β-glucan enhanced skin mucosal and serum humoral defence responses and resistance of catfish againstinfection with P. florescence. The results could be useful for better understanding the role of skin mucus as a key component of the innate immune system, which could be beneficial in control of fish health.

Clinicopathological Studies on Blood of African catfish (Clarias gariepinus) Infected with Pseudomonas florescence

The present study was planned to investigate the clinicoplathological and histopathological changes on the blood of catfish (Clarias gariepinus) infected with Pseudomonas florescence. A total number of 240 catfish were collected from Ismailia channel and subdivided to 4 groups 60 for each: the control group, infected group, β-glucan group and β-glucan infected group. The blood samples were taken at 1, 3 and 5 weeks for hematological and biochemical examinations. Tissue samples from spleen, liver, kidney and gills were taken for histopathological techniques. The hematological results revealed significant decrease of RBCs count, Hb concentration and PCV% with significant increase of T.L.C, heterophils and lymphocytes of the infected group compared to the control group. The β-glucan groups showed significant increase of RBCs count, Hb and PCV% with significant increase of T.L.C, heterophils, lymphocytes and monocytes. Serum biochemical results showed marked elevation in ALT, AST, urea, creatinine, uric acid and glucose of the infected group. While, β-glucan improved the liver function, kidney function tests and glucose before and after the infection compared to the control group. The challenge test revealed a significant lower mortality percentage in the group received β-glucan supplemented diets. Histopathologically, marked degenerative changes and necrosis were evident in the infected group. While, β-glucan groups showed hyperactivity of melenomacrophage centers of haemopiotic organs. It could be concluded that β-glucan acts as a dietary supplement.

Intestinal microbiota and immune related genes in sea cucumber (Apostichopus japonicus) response to dietary β-glucan supplementation

β-glucan is a prebiotic well known for its beneficial outcomes on sea cucumber health through modifying the host intestinal microbiota. High-throughput sequencing techniques provide an opportunity for the identification and characterization of microbes. In this study, we investigated the intestinal microbial community composition, interaction among species, and intestinal immune genes in sea cucumber fed with diet supplemented with or without β-glucan supplementation. The results show that the intestinal dominant classes in the control group are Flavobacteriia, Gammaproteobacteria, and Alphaproteobacteria, whereas Alphaproteobacteria, Flavobacteriia, and Verrucomicrobiae are enriched in the β-glucan group. Dietary β-glucan supplementation promoted the proliferation of the family Rhodobacteraceae of the Alphaproteobacteria class and the family Verrucomicrobiaceae of the Verrucomicrobiae class and reduced the relative abundance of the family Flavobacteriaceae of Flavobacteria class. The ecological network analysis suggests that dietary β-glucan supplementation can alter the network interactions among different microbial functional groups by changing the microbial community composition and topological roles of the OTUs in the ecological network. Dietary β-glucan supplementation has a positive impact on immune responses of the intestine of sea cucumber by activating NF-κB signaling pathway, probably through modulating the balance of intestinal microbiota.

The contribution to studies of the effect of β-glucan on plasma viscosity in a rat sepsis model

Objective: Sepsis is a complex pathophysiological process that involves both alterations in the microcirculation and changes in the biochemical and physiological characteristics of the blood constituents and hyperdynamic syndrome characterized by maldistribution of blood flow. Plasma viscosity is a major determinant of capillary blood flow through the microcirculation. β-glucan is accepted to be one of the most powerful immune response modifiers. The aim of this study was to investigate the possible protective effect of β-glucan on the levels of plasma viscosity and malondialdehyde (MDA), after rats was exposed to sepsis. Methods: Sepsis was induced by cecal ligation and perforation (CLP) in 14 male Wistar albino rat. To evaluate this, rats were divided into four groups as sham operated, β-glucan treated sham operated, CLP and β-glucan treated CLP. Sixteen hours after operation, rats were decapitated and MDA, plasma viscosity levels were measured. Results: Plasma viscosity represented, 1.30±0.12 mPa.s in CLP group and 1.35±0.09 mPa.s in CLP+β-glucan group. In the CLP group, MDA levels were found to be higher than in control group. When CLP group compared with CLP+β-glucan group, no significant statistical differences were observed in the levels of plasma viscosity and MDA. Conclusion: Our results seem that the given dose of β-glucan was probably insufficient to prevent sepsis induced plasma viscosity.

Protective effect of β-glucan on acute lung injury induced by lipopolysaccharide in rats.

Lipopolysaccharide (LPS)-induced endotoxemia can cause serious organ damage such as acute lung injury and death by triggering the secretion of proinflammatory cytokines and acute-phase reactants. The goal of this study was to evaluate the effects of β-glucan on inflammatory mediator levels and histopathological changes in LPS-induced endotoxemia. Forty-seven male Wistar albino rats were randomly allocated into four groups as follows: control group, LPS group (10 mg/kg LPS), LPS + β-glucan group (100 mg/kg β-glucan before LPS administration), and β-glucan group. Twelve hours after LPS administration, lung and serum samples were collected. Concentrations of IL-6, IL-8, C-reactive protein (CRP), and procalcitonin were measured in the serum at hours 0 (basal) and 12. The severity of lung damage was assessed by an appropriate histopathological scoring system. Serum levels of CRP in the LPS group at 12 h were significantly higher than in the other groups, whereas serum IL-6 levels in the LPS and LPS + β-glucan groups at 12 h were significantly decreased. The mean histopathological damage score of the LPS group was slightly higher than that of the LPS + β-glucan group. Moreover, mortality rate was significantly decreased in the LPS + β-glucan group versus the LPS group. β-glucan reduces endotoxemia-induced mortality and might be protective against endotoxemia-induced lung damage.