Β-glucan Supplementation Research Articles

Mushroom and Silymarin Supplementation to Reduce Alzheimer’s Disease Progression: A Research Protocol

As life expectancy continues to rise, the incidence of diseases like Alzheimer’s disease (AD) increases. Curative fronts remain far from satisfactory. Interestingly, the gut microbiome may modulate brain functions. Shiitake mushroom β-(1,3)/(1,6)-glucans are dietary fibres that attenuate pro-inflammatory signalling, and silymarin is a neuroprotective agent, but their effect on AD progression remains elusive. This research protocol aims to examine the effects of shiitake mushroom β-glucan and silymarin supplementation in early-stage AD to reduce progression. A literature search was conducted to formulate this protocol. The potential of this nutraceutical supplementation against AD progression will be tested within mice models. Experimental groups will be fed with mushroom β-glucans and/or silymarin supplementation. Cognitive testing will involve novel object exploration time and Y-maze tests. Furthermore, brain and intestine tissues will be analyzed ex vivo to understand the nutraceutical supplement’s effects on the gut-brain axis in AD. It is anticipated that results demonstrate a synergistic effect of mushroom β-glucans and silymarin to reduce AD progression. This proposed nutraceutical supplement shows promise in reducing AD progression for individuals with early-stage AD. It also provides the foundation for future research on accessible interventions for cognitive impairment.

Yeast β-glucan supplementation lowers insulin resistance without altering microbiota composition compared to placebo in subjects with Type II diabetes: a phase I exploratory study.

The increased global prevalence of type II diabetes mellitus (T2DM) is associated with consumption of low fibre "Western diets". Characteristic metabolic parameters of these individuals include insulin resistance, high fasting and postprandial glucose, as well as low-grade systemic inflammation. Gut microbiota composition is altered significantly in these cohorts suggesting a causative link between diet, microbiota and disease. Dietary fibre consumption has been shown to alleviate these changes and improve glucose parameters in individuals with metabolic disease. We previously reported that yeast β-glucan (yeast beta-1,3/1,6-D-glucan; Wellmune) supplementation ameliorated hyperinsulinemia and insulin resistance in a murine model. Here we conducted a randomised, placebo-controlled, two-armed dietary fibre phase I exploratory intervention study in patients with T2DM. The primary outcome measure was alteration to microbiota composition while the secondary outcome measures included markers of glycaemic control, inflammation as well as metabolomics. Patients were supplemented with 2.5g/day of maltodextrin (placebo) or yeast β-1,3/1,6-D-glucan (treatment). Yeast β-glucan (Wellmune) lowered insulin resistance (HOMA-IR) compared to the placebo maltodextrin after 8 weeks of consumption. TNFα was significantly lower after 4 weeks of β-glucan supplementation. Significantly higher faecal concentrations of several bile acids were detected in the treatment group when compared to the placebo after 8 weeks. These included tauroursodeoxycholic acid (TUDCA) which was previously shown to improve glucose control and lower insulin resistance. Interestingly, the hypoglycaemic and anti-inflammatory effect of yeast β-glucan was independent of any changes in faecal microbiota composition or short-chain fatty acid (SCFA) levels. Our findings highlight the potential of yeast β-glucan to lower insulin resistance in patients with T2DM.

β-glucan regulates the intestinal immunity of pearl gentian grouper via the nuclear factor kappa B signaling pathway

The preceding study observed that yeast β-glucan supplementation enhanced intestinal health and augmented disease resistance in pearl gentian grouper (Epinephelus lanceolatus♂ × Epinephelus fuscoguttatus♀), which occurred concurrently with the activation of the nuclear factor kappa B (NFκB) signaling pathway. Thus, we hypothesized that β-glucan improves intestinal health in grouper by modulating the NFκB pathway. Accordingly, the present study examined the effects of NFκB pathway disruption using a specific inhibitor on the intestinal health of pearl gentian grouper that had been injected with β-glucan. The experimental groups were as follows, (1) CD group: PBS injected; (2) βG group: β-glucan injected at a dose of 80 mg/kg; (3) PDTC group: NFκB inhibitor PDTC injected at a dose of 30 mg/kg; (4) βG + PDTC group: a combination of β-glucan (80 mg/kg) and PDTC (30 mg/kg) injected together. The results demonstrated that β-glucan-induced increases in mRNA expression levels of NFκB inhibitor α (iκbα) and p65, the degradation and phosphorylation of IκBα, and the phosphorylation of NFκB p65 were significantly inhibited following NFκB inhibition using PDTC in the intestine of grouper. The PDTC injection resulted in a significant reduction in the β-glucan-induced increase in mucin levels. The β-glucan-induced elevation of alkaline phosphatase (AKP) activity, component 3 (C3) content, and inflammatory factors were significantly suppressed following NFκB inhibition. The βG + PDTC treatment resulted in a restoration of catalase (CAT) enzyme activity to the level observed in the CD treatment, while total antioxidant capacity (T-AOC) was decreased to the level of the βG treatment. The β-glucan-induced downregulation of caspase8 (casp8) was reversed following NFκB inhibition, as well as the mRNA levels of casp3 and casp9 being elevated to a greater extent. In conclusion, the β-glucan-regulated intestinal immunity in grouper may be mediated by the NFκB pathway. Furthermore, the inhibitory effect of β-glucan on apoptosis and oxidative stress may not be related to the NFκB signaling pathway.

Solubilized β-Glucan Supplementation in C57BL/6J Mice Dams Augments Neurodevelopment and Cognition in the Offspring Driven by Gut Microbiome Remodeling.

A maternal diet rich in dietary fiber, such as β-glucan, plays a crucial role in the offspring's acquisition of gut microbiota and the subsequent shaping of its microbiome profile and metabolome. This in turn has been shown to aid in neurodevelopmental processes, including early microglial maturation and immunomodulation via metabolites like short chain fatty acids (SCFAs). This study aimed to investigate the effects of oat β-glucan supplementation, solubilized by citric acid hydrolysis, from gestation to adulthood. Female C57BL/6J mice were orally supplemented with soluble oat β-glucan (ObG) or carboxymethyl cellulose (CMC) via drinking water at 200 mg/kg body weight during breeding while the control group received 50 mg/kg body weight of carboxymethyl cellulose. ObG supplementation increased butyrate production in the guts of both dams and 4-week-old pups, attributing to alterations in the gut microbiota profile. One-week-old pups from the ObG group showed increased neurodevelopmental markers similar to four-week-old pups that also exhibited alterations in serum markers of metabolism and anti-inflammatory cytokines. Notably, at 8 weeks, ObG-supplemented pups exhibited the highest levels of spatial memory and cognition compared to the control and CMC groups. These findings suggest a potential enhancement of neonatal neurodevelopment via shaping of early-life gut microbiome profile, and the subsequent increased later-life cognitive function.

Next-Generation Sequencing to Determine Changes in the Intestinal Microbiome of Juvenile Sturgeon Hybrid (Acipenser gueldenstaedtii♀ × Acipenser baerii♂) Resulting from Sodium Butyrate, Β-Glucan and Vitamin Supplementation

Background/Objectives: The effect of sodium butyrate (NaB), β-glucan (βG) and vitamins in the diet on gut microbiome, cortisol level, lysozyme activity and growth parameters of juvenile hybrid sturgeon (Acipenser gueldenstaedtii♀ × Acipenser baerii♂) was determined. Methods: Sturgeon hybrids (n = 144) were divided into three groups with enriched feeding (mg/kg of feed): FQV1 (50 NaB; 20 βG; const. vitamins), FQV2 (150 NaB; 20 βG; const. vitamins), FQV3 (50 NaB; 60 βG; const. vitamins) and control (not supplemented), each group in triplicate, 12 fish in each repetition. Rearing was carried out for 30 days in controlled conditions. Gut microbiome was characterized using Next Generation Sequencing (NGS) of DNA samples isolated from intestinal content. Cortisol level was determined using the ELISA test. Lysozyme activity was measured by turbidimetric test. Results: Based on data obtained from NGS, it was determined that the FQV1 group is characterized by the highest values of diversity indices (Shannon, Simpson and Chao-1) and the largest number of ASVs (Amplicon Sequence Variants). The highest abundance of probiotic bacteria (Lactobacillus, Lactococcus) was determined in the FQV1 group. The highest cortisol concentration was determined in the control (33.26 ng/mL), while the lowest was in FQV3 (27.75 ng/mL). The highest lysozyme activity was observed in FQV1 (154.64 U/mL), and the lowest in FQV2 (104.39 U/mL) and control (121.37 U/mL) (p < 0.05). FQV2 was characterized by significantly more favorable values of breeding indicators (p < 0.05). Conclusions: The obtained results prove that an appropriate composition of NaB, βG and vitamins can be used in the commercial breeding of juvenile hybrid sturgeons.

Effects of dietary immunostimulants on the growth and non-specific immune responses of hybrid sturgeons (Huso huso♀ × Acipenser ruthenus♂)

Herein, we investigated the effects of immunostimulants on the growth, immune responses, and post-infection survival of hybrid sturgeons (Huso huso♀ × Acipenser ruthenus♂). Therefore, we examined the effects of dietary supplementation of β-glucan, vitamin C, and Radix Bupleuri (Chaihu) extract (RBE) at various concentrations (0.2, 0.4, and 0.6% incorporated through feed) on the growth rate and non-specific immune responses of hybrid sturgeon. When supplemented individually, these immunostimulants significantly reduced the feed conversion ratio while promoting weight gain, with the vitamin C-administered groups showing the most pronounced differences. Further, we observed that dietary β-glucan, vitamin C, and RBE, when fed at 0.4 and 0.6% concentrations, significantly enhanced the rates of superoxide anion production and phagocytosis by head kidney leukocytes. Moreover, vitamin C and RBE supplementation at 0.4 and 0.6% and β-glucan supplementation at 0.6% concentration significantly increased the serum lysozyme activity. Further, vitamin C and β-glucan supplementation at 0.6% and RBE supplementation at 0.4 and 0.6% concentrations showed the highest survival rates after Aeromonas hydrophila infection. In conclusion, our findings highlight that the dietary supplementation of β-glucan, vitamin C, or RBE in appropriate concentrations can significantly enhance superoxide anion production and phagocytic activity of leukocytes, serum lysozyme activity, and the survival of hybrid sturgeons after A. hydrophila infection. Our results suggest that incorporating immunostimulants such as Chinese medicinal herbs at optimal levels can effectively boost the growth, immunity, and disease resistance of hybrid sturgeons in aquaculture. These results provide valuable insights for future studies on the inclusion of immunostimulants in aquaculture feed.

Short-term dietary supplementation of β-glucan and chitosan modulates the immune response in freshwater prawn, Macrobrachium rosenbergii (De Man, 1879)

Aim: The present study evaluates the immunomodulatory potentials of β-glucan and chitosan administered orally for 15 days to the freshwater prawn, Macrobrachium rosenbergii juveniles. Methodology: Two diets were formulated supplementing 1.5 g kg-1 and 20 g kg-1 of β-glucan (diet G) and chitosan (diet C), respectively, with a control diet (diet B). The prawns were fed twice daily at 5% biomass. At the end of the feeding trials, mRNA expression profiles of immune-related genes lipopolysaccharide- and β-1,3-glucan binding protein (LGBP) and chitinase 3 were analyzed in qPCR. Corresponding LGBP protein and chitinases/CBP (chitinase 1, chitinase 1C and obstructor E, a chitin-binding protein) protein levels were also estimated by ELISA. Results: Supplementation of the immunostimulants (diets G and C) significantly enhanced the mRNA expression of both LGBP and chitinase 3 in the hepatopancreas. The protein expression of LGBP and chitinases/CBP was also significantly increased in the serum and hepatopancreas samples of both treatment groups. Interpretation: The short-term supplementation of β-glucan and chitosan in diets demonstrated beneficial effects in M. rosenbergii by enhancing the expression of important immune molecules like LGBP and chitinases, indicating their potential applications during the period of biotic stress. Key words: β-glucan, Chitinase, Hepatopancreas, Immunostimulants, LGBP, Macrobrachium rosenbergii

β-glucan improves intestinal health of pearl gentian grouper via activation of the p38 mitogen-activated protein kinase signaling pathway

Our previous study has demonstrated that supplementation of yeast β-glucan improves intestinal health in pearl gentian grouper (Epinephelus lanceolatus♂ × Epinephelus fuscoguttatus♀), accompanied by the activation of the mitogen-activated protein kinase (MAPK) signaling pathway. In this study, we investigated the effects of perturbing p38 MAPK activity using an inhibitor on the intestinal health of β-glucan-injected pearl gentian grouper to elucidate the potential molecular mechanism underlying the protective effects of β-glucan on the fish gut. The pearl gentian grouper was categorized into four groups: PBS injected (CD group), β-glucan injected at a dose of 80 mg/kg (βG group), p38 MAPK inhibitor SB203580 injected at a dose of 1 mg/kg (SB203580 group), and a combination of β-glucan (80 mg/kg) and SB203580 (1 mg/kg) injected together (βG + SB203580 group). The results revealed that the introduction of SB203580 significantly suppressed the β-glucan-induced increase in p38α and p38β mRNA expression, as well as the phosphorylation of p38 MAPK. Both the βG group and SB203580 group exhibited reduced plica height and muscularis thickness. The βG + SB203580 group displayed a significant reduction in mucin cell level; interleukin 1β (il1β) mRNA expression; induced nitric oxide synthase, tumor necrosis factor α, and IL1β concentration; catalase and total antioxidant capacity activities. Additionally, there was a significant increase in the levels of intestinal malondialdehyde in the βG + SB203580 group compared to the βG group. The inhibition of the p38 MAPK signaling halted the trend of apoptosis-related caspase molecular expression induced by β-glucan. In conclusion, β-glucan injection resulted in elevated levels of mucous cells, nonspecific immunity, antioxidant capacity, and anti-apoptosis in grouper by modulating the p38 MAPK pathway. This study offers insights into the potential molecular mechanism underlying the protective effects of β-glucan on intestinal health in pearl gentian grouper.

Enhancement of systemic virus-specific T lymphocyte responses in pigs supplemented with algae-derived β-glucan

Algae-derived β-glucan has been widely used as a feed additive in the swine industry. The supplementation of β-glucan aims to improve growth performance and modulate the immunity of pigs. However, the potential effects of supplementing β-glucan from algae on immune responses in pigs—specifically antigen-specific immunity—must be determined. In this study, the effects of algae-derived β-glucan supplementation on growth performance, virus neutralising antibody and virus-specific T lymphocytes responses were investigated in pigs. Piglets (n=112 per treatment) were assigned to three treatments including non-supplemented group (control), β-glucan 100 g/ton supplemented group (BG100), and β-glucan 200 g/ton supplemented group (BG200).In this study, production performance of pigs was not found to be different between the experimental groups. Pigs supplemented with β-glucan exhibited high levels of classical swine fever virus (CSFV)-specific producing T lymphocytes and neutralising antibody titer, compared to the control group. Interestingly, supplementation of β-glucan significantly enhanced porcine reproductive and respiratory syndrome virus (PRRSV)-specific interferon-gamma (IFN-γ) producing T lymphocytes, including CD4+, CD8+, and CD4+CD8+ T lymphocyte subpopulations. Moreover, PRRS modified live vaccine (MLV) viremia was reduced in earlier for β-glucan-supplemented pigs compared to the control group. The findings indicate that the algae-derived β-glucan possesses biological potential as an immunomodulatory substance to enhance antiviral immunity, which may contribute to disease resistance in pigs.

Enhancing farmed striped catfish (Pangasianodon hypophthalmus) robustness through dietary β-glucan.

β-glucan is a well-documented feed additive for its potent immunostimulatory properties in many farmed fish species. This study examined how it can also be a promising growth promoter, modulate antioxidant enzyme activities, and act as an anti-stress agent in striped catfish (Pangasianodon hypophthalmus). A 12-week feeding experiment was untaken to determine the effects of dietary β-glucan supplementation at graded levels (0, 0.5, 1.0, and 1.5 g kg-1). Measured indicators suggest that a dietary inclusion level of 1.5 g kg-1 β-glucan gave the highest positive responses: weight gain (120.10 g fish-1), survival (98.30%), and lower FCR (1.70) (P<0.05). Whole body proximate analysis had only revealed that crude protein was significantly affected by the dietary inclusion of β-glucan (P<0.05), with the highest protein content (19.70%) being in fish that were fed with 1.5 g kg-1 β-glucan. Although other inclusion levels (i.e., 0.5 and 1 g kg-1) of β-glucan did not enhance body protein content (P>0.05). The assessment of fatty acid composition in muscle, liver, and adipose tissues showed modifications with the inclusion of β-glucan. Antioxidative-related enzyme activities (inc. catalase, glutathione peroxidase, and superoxide dismutase) that were measured in the liver had higher levels when fed with β-glucan inclusion diets (P<0.05). Following the feed trial, fish were subjected to crowding stress treatment. It was subsequently found that catfish fed with β-glucan-based diet groups had lower levels of blood stress-related indicators compared to the control group with no dietary β-glucan. The use of 1.5 g kg-1 of dietary β-glucan resulted in the lowest measured levels of cortisol (43.13 ng mL-1) and glucose (50.16 mg dL-1). This study has demonstrated that the dietary inclusion of β-glucan can have functional benefits beyond the immunological enhancements in striped catfish. Furthermore, its use can increase production levels and mitigate the stress associated with intensive farming practices.

Effects of single or combination of dietary vitamin C and β-glucan supplementation on golden trevally, \(\textit{Gnathanodon speciosus}\) (Carangidae)

This study aims to test the single and combination effects of dietary vitamin C and β-glucan on golden trevally, Gnathanodon speciosus. The basal diet (D0) was added with vitamin C at 200 mg kg-1 diet (D1), β-glucan at 1.0 g kg-1 diet (D2), and a combination of vitamin C and β-glucan (200 mg vitamin C and 1 g β-glucan per kilogram diet) (D3). The diets were fed the fish for eight weeks. After eight weeks of diet feeding, the growth rate of the fish enhanced significantly with the presence of vitamin C, β-glucan, and the combination of Vitamin C and β-glucan (p &lt; 0.05). The growth rate was significantly higher in a fish-fed diet combined with vitamin C and β-glucan. Survival rates were not significantly different among diet treatments. Muscle protein of fish ranged from 18.36–21.50% among diet treatments. Fish protein content in fish was not influenced by vitamin C, but the protein was higher in fish fed with the β-glucan-added diet and combination the β-glucan and vitamin C-added diet. The current results suggest that a supplemented combination of vitamin C and β-glucan could boost this golden trevally’s growth and body composition at the juvenile stage.

Effects of β-Glucan Supplementation on LPS-Induced Endotoxemia in Horses

β-glucan is part of the cell wall of fungi and yeasts and has been known for decades to have immunomodulating effects on boosting immunity against various infections as a pathogen-associated molecular pattern that is able to modify biological responses. β-glucan has been used in rat models and in vitro studies involving sepsis and SIRS with good results, but this supplement has not been evaluated in the treatment of endotoxemia in horses. This study aims to evaluate the effects of preventive supplementation with β-glucan in horses submitted to endotoxemia by means of inflammatory response modulation. Eight healthy horses, both male and female, aged 18 ± 3 months, weighing 300 ± 100 kg of mixed breed, were randomly assigned to two groups of four animals, both of which were subjected to the induction of endotoxemia via the intravenous administration of E. coli lipopolysaccharides (0.1 µg/kg). For 30 days before the induction of endotoxemia, horses in the β-glucan group (GB) received 10 mg/kg/day of β-glucan orally, and horses in the control group (GC) received 10 mg/kg/day of 0.9% sodium chloride orally. The horses were submitted to physical exams, including a hematological, serum biochemistry, and peritoneal fluid evaluation, and the serum quantification of cytokines TNF-α, IL-6, IL-8, and IL-10. For statistical analysis, the normality of residues and homogeneity of variances were verified; then, the variables were analyzed as repeated measures over time, checking the effect of treatment, time, and the interaction between time and treatment. Finally, the averages were compared using Tukey’s test at a significance level of 5%. Horses from both experimental groups presented clinical signs and hematological changes in endotoxemia, including an increase in heart rate and body temperature, neutrophilic leukopenia, an increase in serum bilirubin, glucose, lactate, and an increase in TNF-α, IL-6, and IL-10. Hepatic and renal function were not compromised by β-glucan supplementation. GB presented higher mean values of the serum total protein, globulins, and IL-8 compared to that observed in GC. In the peritoneal fluid, horses from GB presented a lower mean concentration of neutrophils and a higher mean concentration of macrophages compared to the GC. It was concluded that preventive supplementation of β-glucan for thirty days modulated the immune response, as evidenced by increasing serum total proteins, globulins, IL-8, and changes in the type of peritoneal inflammatory cells, without effectively attenuating clinical signs of endotoxemia in horses. Considering the safety of β-glucan in this study, the results suggest the potential clinical implication of β-glucan for prophylactic use in horse endotoxemia.

Highland barley β-glucan supplementation attenuated hepatic lipid accumulation in Western diet-induced non-alcoholic fatty liver disease mice by modulating gut microbiota.

Non-alcoholic fatty liver disease (NAFLD) has become one of the most common chronic liver diseases worldwide. NAFLD is caused by numerous factors, including the genetic susceptibility, oxidative stress, unhealthy diet, and gut microbiota dysbiosis. Among these, gut microbiota is a key factor and plays an important role in the development of NAFLD. Therefore, modulating the composition and structure of gut microbiota might provide a new intervention strategy for NAFLD. Highland barley β-glucan (HBG) is a polysaccharide that can interact with gut microbiota after entering the lower gastrointestinal tract and subsequently improves NAFLD. Therefore, a Western diet was used to induce NAFLD in mouse models and the intervention effects and underlying molecular mechanisms of HBG on NAFLD mice based on gut microbiota were explored. The results indicated that HBG could regulate the composition of gut microbiota in NAFLD mice. In particular, HBG increased the abundance of short-chain fatty acids (SCFA)-producing bacteria (Prevotella-9, Bacteroides, and Roseburia) as well as SCFA contents. The increase in SCFA contents might activate the adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK) signaling pathway, thereby improving the liver lipid metabolism disorder and reducing liver lipid deposition.

Effect of xylo-oligosaccharides and β-glucan on gut microbiota and short chain fatty acid in diabetic rats

Obesity and type 2 diabetes mellitus (T2DM) have an impact on an imbalance in the number of microbiota (dysbiosis) which can cause disruption of glucose metabolism by inhibiting short chain fatty acid (SCFA). SCFA is produced by intestinal microbial fermentation of indigestible dietary fibre and it has beneficial role in T2DM. Xylo-oligosaccharides (XOS) and β-glucans can improve the gut the composition of microbiota with prebiotic capabilities. The objective of the study was to investigate the effect of XOS and β-glucan on the Lactobacillus, Roseburia, and SCFA in diabetic rats. A total of 28 Wistar rats were divided into 4 groups including control (C), diabetic (D), diabetic+XOS (DX), and diabetic+β-glucan (DBG). D, DX, and DBG groups were provided with a high-fat diet (HFD) for 14 days before receiving an injection of streptozotocin (STZ) (45 mg/kg BW) and nicotinamide (110 mg/kg BW). DX received XOS (450 mg/200 g BW), and DBG received β-glucan (450 mg/200 g BW) for 28 days. The blood glucose levels at DX and DBG showed a significant difference compared with the D gro diabetic rats. XOS did not change the number, while β-glucan increased the number of Lactobacillus and Roseburia. The XOS and β-glucan supplementation significantly increased SCFA levels compared to diabetic rats. These results suggest that XOS can improve blood glucose although it does not change the number of Lactobacillus and Roseburia. Meanwhile, β-glucan increases blood glucose, Lactobacillus, Roseburia, and total SCFA in diabetic rats.

Dietary β-Glucan Alleviates Antibiotic-Associated Side Effects by Increasing the Levels of Antioxidant Enzyme Activities and Modifying Intestinal Microbiota in Pacific White Shrimp (Litopenaeus vannamei).

Antibiotics and their secondary metabolites are commonly found in aquatic ecosystems, leading to the passive exposure of many aquatic animals to low doses of antibiotics, which can affect their health. However, there is limited information available on how to mitigate the side effects of antibiotics on normal aquatic animals. This study aimed to investigate the potential of dietary β-glucan to alleviate the side effects induced by antibiotics in Pacific white shrimp (Litopenaeus vannamei) (0.37 ± 0.02 g). A six-week feeding trial was conducted with four dietary treatments including a control, 1 g/kg β-glucan (β-glucan), 50 mg/kg oxytetracycline (OTC), and a combination of 50 mg/kg OTC and 1 g/kg β-glucan (Mix) groups. At the end of the trial, the growth performance, intestinal microbial composition, antioxidant capacity, and immune response of the shrimp were assessed. There were no significant differences in growth performance among the groups, but the condition factor of the shrimp in the Mix group was significantly decreased when compared to the control and β-glucan groups. The activities of hepatopancreas catalase (CAT) and serum phenol oxidase in the OTC group were significantly lower than those in the control group. On the other hand, the activities of hepatopancreas superoxide dismutase and CAT enzymes in the β-glucan group were significantly higher than those in the OTC group. The supplementation of β-glucan in combination with antibiotics significantly increased the CAT activity and bacteriolytic activity compared to the OTC and control groups, respectively. Moreover, an analysis of the intestinal microbiota revealed that the Observed_species estimator in the Mix group was significantly higher than that in the control group. Dietary antibiotics significantly increased the abundance of Actinobacteria at the phylum level, but the Mix group showed no significant difference. The supplementation of β-glucan in combination with antibiotics also significantly increased the relative abundance of Meridianimaribacter compared to the control group. Additionally, the synergistic influence of β-glucan with antibiotics increased the beta diversity of intestinal microbiotas. These findings suggest that the supplementation of β-glucan in combination with antibiotics on Pacific white shrimp can alleviate the low antioxidant capacity and immune response caused by antibiotics while enhancing the intestinal microbial composition. This provides a potential solution to mitigate the negative impacts of antibiotics in aquaculture.

Effects of dietary chito-oligosaccharide and β-glucan on the water quality and gut microbiota, intestinal morphology, immune response, and meat quality of Chinese soft-shell turtle (Pelodiscus sinensis).

Chito-oligosaccharides (COS) and β-glucan are gradually being applied in aquaculture as antioxidants and immunomodulators. However, this study examined the effects of dietary supplementation of COS and β-glucan on the water quality, gut microbiota, intestinal morphology, non-specific immunity, and meat quality of Chinese soft-shell turtle. To investigate the possible mechanisms, 3-year-old turtles were fed basal diet (CK group) and 0.1%, 0.5%, and 1% COS or β-glucan supplemented diet for 4 weeks. Colon, liver, blood and muscle tissues, colon contents, water and sediment of paddy field samples were collected and analyzed after feeding 2 and 4 weeks. The results indicated that COS and β-glucan altered microbial community composition and diversity in Chinese soft-shell turtles. The relative abundance of Cellulosilyticum, Helicobacter and Solibacillus were increased after feeding COS, while Romboutsia, Akkermansia and Paraclostridium were increased after feeding β-glucan, whereas Cetobacterium, Vibrio and Edwardsiella were enriched in the control group. Furthermore, colon morphology analysis revealed that COS and β-glucan improved the length and number of intestinal villi, and the effect of 0.5% β-glucan was more obvious. Both β-glucan and COS significantly improved liver and serum lysozyme activity and antibacterial capacity. COS significantly increased the total antioxidant capacity in the liver. Further, 0.1% β-glucan significantly increased the activity of hepatic alkaline phosphatase, which closely related to the bacteria involved in lipid metabolism. Moreover, dietary supplementation with 1% COS and 1% β-glucan significantly enhanced the content of total amino acids, especially umami amino acids, in muscle tissue, with β-glucan exerting a stronger effect than COS. Additionally, these two prebiotics promoted the quality of culture water in paddy fields and reshaped the bacterial community composition of aquaculture environment. All these phenotypic changes were closely associated with the gut microbes regulated by these two prebiotics. In summary, the findings suggest that dietary supplementation with COS and β-glucan in Pelodiscus sinensis could modulate the gut microbiota, improve intestinal morphology, enhance non-specific immunity and antioxidant capacity of liver and serum, increase meat quality, and improve the culture water environment. This study provides new insights and a comprehensive understanding of the positive effects of COS and β-glucan on Pelodiscus sinensis.

Impact of β-glucan dietary supplementation on productive, reproductive performance and physiological response of laying hens under heat stress conditions

The exploration for effective in-feed additives is growing owing to the global climatic change trend to alleviate the negative effects of heat stress in laying hens. This research assessed the potential of using B-glucan (G) as an antiheat stress agent in Matrouh laying hens subjected to early heat shock programs during the growing period. Factorial design (3 × 3) was used, including 3 levels of heat stress (control, heat shock at 3 d and at 3 d and 8 wk of age) and 3 levels of β-glucan (0, 100, and 200 mg β-glucan /kg diet). During the first 12 wk of egg production (EP), treatments were exposed to heat challenge. The results revealed that heat shock program applications at 3 d and 8 wk of age significantly decreased body weight at 36 wk of age (P < 0.05) and reduced (P < 0.05) feed intake (FI). While significantly (P < 0.05) improved feed conversion ratio (FCR), hemoglobin, RBCs, WBCs, immunoglobulin M (IgM), immunoglobulin G (IgG), and Heat shock protein (HSP70) of the Liver (P < 0.01) as compared with the control group. At the same time, there was a decrease in lymphocyte%, H/L ratio, cortisol, and T3 compared to the thermo-neutral control. When compared to the control group, hens fed a diet containing 200 mg of βG significantly (P < 0.05) improved body weight at 16 wk and final weight at 36 wk, feed conversion (FCR) (g. feed/g. egg mass), hen-day egg production, and egg mass, as well as the digestibility coefficients of crude protein (CP), dry matter (DM), metabolizable energy (ME), and cortisol. The interactions between heat chock programs and βG levels were nonsignificant for the most studied traits except daily feed intake. Therefore, the early heat shock exposure 2 times and supplementation of Β-glucan (βG) at 200 mg/kg diet during the growth period for laying hens that are exposed to heat stress during the reproductive period could improve productive, reproductive performance, HSP70 level and enhance immunity responses.

Assessment of dietary mannaoligosaccharides and β-glucan on the growth, somatic indices and haematological parameters of African catfish (&lt;i&gt;Clarias gariepinus&lt;/i&gt;)

The effects of dietary mannaoligosaccharides (MOS) and β-glucan on the production performance of African catfish, Clarias gariepinus, was examined in this study. Three (3) trial diets were produced viz-a-vis., Control (basal diet, BD), MOS (BD + 0.2% MOS) and β-glucan (BD +0.02% β-glucan) and fed to catfish (11.77±0.05 g fish-1) for 63 days. Nine circular tanks were distinctly assigned into 3 dietary groups in triplicate, stocked with 100 fish per tank (85 L), and fed twice daily (8:00 - 9:00h and 17:00 - 18:00h). The results indicated that there was no significant difference (p&gt;0.05) in the mean final body weight, specific growth rates, feed conversion and protein efficiency ratios, and survivals among the various treatments groups. Similarly, somatic indices (condition factors, hepatosomatic indices, and viscerosomatic indices) measured were not significantly different (p&gt;0.05) across the experimental groups. However, the haematological parameters such as packed cell volume, haemoglobin as well as the erythrocyte and leucocyte counts were significantly (p&lt;0.05) lower in the catfish fed MOS diet. It could be concluded herewith that dietary supplementation of MOS and β-glucan do not have a deleterious effect on African catfish production. Further study is however warranted to establish dose-response effect of MOS and β-glucan on innate immunity of African catfish (C. gariepinus).

P27-021-23 Fetal Cognitive Neurodevelopment by the Maternal Gut Microbiome Remodeling by β-Glucan Supplementation in Mice

P27-021-23 Fetal Cognitive Neurodevelopment by the Maternal Gut Microbiome Remodeling by β-Glucan Supplementation in Mice

Deciphering the Immunostimulatory Effects of β-Glucan on a Rainbow Trout (Oncorhynchus mykiss) Macrophage-like Cell Line (RTS11) by Whole Transcriptome Analysis.

β-glucans are a commonly used immunostimulant/prebiotic in many aquaculture applications for boosting the immune status in fish. However, the method of action as an immunostimulant has not been fully deciphered. To determine the immunomodulatory effects of β-glucans on the innate immune response, we stimulated the rainbow trout spleen macrophage-like cell line (RTS11) with β-1,3/1,6-glucans for 4 h. This study uses a whole transcriptomic approach to analyse the immunomodulatory properties of β-glucans. Several proinflammatory pathways were found to be enriched after stimulation, demonstrating the immunomodulatory effects of β-glucan supplementation. Several pathways relating to responses to bacteria were also found to be enriched. This study clearly demonstrates the immunomodulatory effects of the supplementation of β-glucans within an aquaculture setting and further validates the use of cell lines as predictive models to interpret the responses caused by dietary intervention.