β(1-3)(1-6)-D-glucans modulate immune status in pigs: potential importance for efficiency of commercial farming

Effects of β-glucan with vitamin E supplementation on the physiological response, litter performance, blood profiles, immune response, and milk composition of lactating sows

OBJECTIVE

This study was conducted to evaluate the effects of β-glucan with vitamin E supplementation on the physiological response, litter performance, blood profiles, immune response, and milk composition of lactating sows.

METHODS

A total of 50 multiparous F1 sows (Yorkshire×Landrace) with an average body weight (BW) of 233.6±4.30 kg and an average parity of 4.00±0.307 and their litters were used in this experiment. All sows were allotted to one of five treatments, taking into consideration BW, backfat thickness, and parity in a completely randomized design with 10 replicates. The experimental diets included a corn-soybean meal-based basal diet with or without 0.1% or 0.2% β-glucan and 110 IU vitamin E/kg diet.

RESULTS

All treatments added with β-glucan or vitamin E were statistically higher in the average daily feed intake (ADFI) of lactating sows compared to those of the control (Diet, p<0.01). Additionally, the ADFI of lactating sows was significantly higher in the groups supplemented with 0.1% β-glucan compared to 0.2% β-glucan (BG, p<0.01). There was an increasing trend in piglet weight at weaning (BG, p = 0.07), litter weight at the 21st day of lactation (BG, p = 0.07) and litter weight gain (BG, p = 0.08) in groups supplemented with 0.1% β-glucan. The addition of 110 IU vitamin E/kg diet increased vitamin E concentration significantly in lactating sows (VE, p<0.01) and exhibited a trend for higher concentrations of vitamin E (VE, p = 0.09) in piglets. Adding 0.1% β-glucan compared to 0.2% β-glucan induced a decrease in the concentration of tumor necrosis factor-α in lactating sows (BG, p = 0.06) and in piglets (BG, p = 0.09) on the 21st day of lactation. There were no significant differences in the milk composition of sows.

CONCLUSION

Adding 0.1% β-glucan and 110 IU vitamin E/kg to a lactating sow's diet was beneficial to the growth performance of piglets by leading to an increase in the feed intake of sows and efficiently supplying vitamin E to both the sows and piglets.

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

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

Inclusion of Oat and Yeast Culture in Sow Gestational and Lactational Diets Alters Immune and Antimicrobial Associated Proteins in Milk

Simple Summary

This study investigated the impact that supplementing sow’s gestation and lactation feed with oat alone or together with brewer’s yeast has on milk proteins and piglet growth and health. Oat and yeast supplements increased abundance of several milk proteins involved in immune protection. Piglets born from either the oat- or yeast-supplemented sows had decreased incidence of diarrhea after weaning. The average birth weights for piglets born of dams that consumed Oat were significantly greater than those that did not. However, piglets born to sows that consumed yeast in combination with oat weighed less at weaning and gained the least amount of weight post-weaning. These data suggest that oat, and to a lesser extent, yeast, added to maternal diets during gestation and lactation can positively impact milk, growth, and health of offspring but given in combination can potentially negatively affect piglet weight gain.

Abstract

Maternal diet supplementation with pro- and prebiotics is associated with decreased incidence of diarrhea and greater piglet performance. This study investigated the impact adding whole ground oat as a prebiotic, alone or in combination with a probiotic, yeast culture (YC) (Saccharomyces cerevisiae), to sow gestation and lactation rations had on milk protein composition, piglet growth, and incidence of post-weaning diarrhea (PWD). Diets: control (CON), CON + yeast culture (YC) [5 g/kg], CON + oat (15% inclusion rate) (Oat) or CON+ YC [5 g/kg] + Oat (15%) were fed the last 30 days of gestation and throughout lactation (18–21 days). Shotgun proteome analysis of day 4 and 7 postpartum milk found 36 differentially abundant proteins (P-adj < 0.1) in both Oat and YC supplemented sows relative to CON. Notable was the increased expression of antimicrobial proteins, lactoferrin and chitinase in milk of Oat and YC sows compared to CON. The levels of IgA, IgM (within colostrum and milk) and IgG (within milk) were similar across treatments. However, colostral IgG levels in Oat-supplemented sows were significantly lower (p < 0.05) than that of the control sows, IgG from Oat-supplemented sows displayed greater reactivity to E. coli-antigens compared with CON and YC. Piglets from sows that consumed Oat alone or in combination weighed significantly more (p < 0.05) at birth compared to CON and YC. However, piglets in the Oat + YC group weighed less at weaning and had the lowest weight gain (p < 0.05) postweaning, compared with CON. Taken together with the observation that piglets of either YC- or Oat-fed sows had less PWD compared to CON and YC+ Oat suggests that Oat or YC supplementation positively impacts piglets through expression of certain milk-associated immune and antimicrobial proteins.

Development of Fish Immunity and the Role of β-Glucan in Immune Responses

Administration of β-glucans through various routes, including immersion, dietary inclusion, or injection, have been found to stimulate various facets of immune responses, such as resistance to infections and resistance to environmental stress. β-Glucans used as an immunomodulatory food supplement have been found beneficial in eliciting immunity in commercial aquaculture. Despite extensive research involving more than 3000 published studies, knowledge of the receptors involved in recognition of β-glucans, their downstream signaling, and overall mechanisms of action is still lacking. The aim of this review is to summarize and discuss what is currently known about of the use of β-glucans in fish.

Impact of Yeast-Derived β-Glucans on the Porcine Gut Microbiota and Immune System in Early Life

Piglets are susceptible to infections in early life and around weaning due to rapid environmental and dietary changes. A compelling target to improve pig health in early life is diet, as it constitutes a pivotal determinant of gut microbial colonization and maturation of the host’s immune system. In the present study, we investigated how supplementation of yeast-derived β-glucans affects the gut microbiota and immune function pre- and post-weaning, and how these complex systems develop over time. From day two after birth until two weeks after weaning, piglets received yeast-derived β-glucans or a control treatment orally and were subsequently vaccinated against Salmonella Typhimurium. Faeces, digesta, blood, and tissue samples were collected to study gut microbiota composition and immune function. Overall, yeast-derived β-glucans did not affect the vaccination response, and only modest effects on faecal microbiota composition and immune parameters were observed, primarily before weaning. This study demonstrates that the pre-weaning period offers a ‘window of opportunity’ to alter the gut microbiota and immune system through diet. However, the observed changes were modest, and any long-lasting effects of yeast-derived β-glucans remain to be elucidated.

Effects of Dietary Inclusion of Seaweed, Heat Stress and Genetic Strain on Performance, Plasma Biochemical and Hematological Parameters in Laying Hens

Simple Summary

Prebiotics such as seaweeds have been proposed as positive influencers on hen health and productivity, including their response to stressors such as heat. The present study was undertaken to evaluate the effects of 3% red seaweed Chondrus crispus and 0.5% brown seaweed Ascophyllum nodosum supplements on the heat stress responses in two genetic strains of laying hens, Lohmann LSL-Lite (White) and Lohmann Brown-Lite (Brown). The short-term seaweed diet had little effect on blood characteristics, but long-term feeding affected several blood chemistry values. The seaweed supplement reduced the feed intake and improved the feed/egg efficiency in the short term, although did not consistently affect the long-term performance. Heat stress affected the leukocyte count and some plasma chemistry parameters, particularly in the Brown layer strain. Our results showed better production, feed efficiency and resistance to heat stress in the White layer strain, with significant liver enzyme changes in alkaline phosphatase (ALP), alanine aminotransferase (ALT) and gamma-glutamyl transferase (GGT). More research on the biological effects of seaweed supplementation is necessary to better understand its impacts on health and performance.

Abstract

This study was planned to investigate the effects of seaweed supplementation, genetic strain, heat stress and their interactions on laying hen performances, blood chemistry and hematology. In a short-term trial, laying hens of the two genetic lines Lohman LSL-Lite (White) and Lohman Brown-Lite (Brown) were supplemented with Chondrus crispus (CC) at 3% for 21 days, while a control group was not. In a long-term trial, the same two strains were assigned to control (0%), 3% red seaweed Chondrus crispus (CC) or 0.5% brown seaweed Ascophyllum nodosum (AN)-supplemented diets for 41 weeks, concluding with a four-week control or heat-stress period. The White hens displayed higher egg production and a lower feed/egg ratio. The short-term inclusion of CC significantly reduced the feed intake, weight gain and feed/egg ratio. The long-term seaweed intake affected the plasma albumin and gamma-glutamyl transferase (GGT) (p < 0.05), and there were significant strain-heat stress interactions; heat stress in the Brown birds was associated with reduced protein, globulin and glucose and increased cholesterol and GGT levels and higher heterophil-to-lymphocyte (H/L) ratios (p < 0.05) in response to heat stress (p < 0.05). In conclusion, a long-term seaweed supplementation affected the plasma protein and enzyme profiles, yet had little effect on hen leukocyte counts and the overall performance.

Innate Immunomodulation in Food Animals: Evidence for Trained Immunity?

Antimicrobial resistance (AMR) is a significant problem in health care, animal health, and food safety. To limit AMR, there is a need for alternatives to antibiotics to enhance disease resistance and support judicious antibiotic usage in animals and humans. Immunomodulation is a promising strategy to enhance disease resistance without antibiotics in food animals. One rapidly evolving field of immunomodulation is innate memory in which innate immune cells undergo epigenetic changes of chromatin remodeling and metabolic reprogramming upon a priming event that results in either enhanced or suppressed responsiveness to secondary stimuli (training or tolerance, respectively). Exposure to live agents such as bacille Calmette-Guerin (BCG) or microbe-derived products such as LPS or yeast cell wall ß-glucans can reprogram or "train" the innate immune system. Over the last decade, significant advancements increased our understanding of innate training in humans and rodent models, and strategies are being developed to specifically target or regulate innate memory. In veterinary species, the concept of enhancing the innate immune system is not new; however, there are few available studies which have purposefully investigated innate training as it has been defined in human literature. The development of targeted approaches to engage innate training in food animals, with the practical goal of enhancing the capacity to limit disease without the use of antibiotics, is an area which deserves attention. In this review, we provide an overview of innate immunomodulation and memory, and the mechanisms which regulate this long-term functional reprogramming in other animals (e.g., humans, rodents). We focus on studies describing innate training, or similar phenomenon (often referred to as heterologous or non-specific protection), in cattle, sheep, goats, swine, poultry, and fish species; and discuss the potential benefits and shortcomings of engaging innate training for enhancing disease resistance.

Major cereal carbohydrates in relation to intestinal health of monogastric animals: A review

Type, quality, and origin of cereals in diets of poultry and pigs could influence gut microbes and affect their diversity and function, thereby impacting the intestinal function of the monogastric animal. In this review, we focus on the major carbohydrates in cereals that interact directly with gut microbes and lead to the production of key metabolites such as short-chain fatty acids (SCFA), and discuss how cereal fiber impact intestinal health of poultry and pigs. An overview of how the cereals and cereals-derived carbohydrates such as beta-glucans, resistant starch, cellulose, and arabinoxylans could promote intestinal health and reduce the use of in-feed antibiotics in animal production are presented. The metabolic pathway utilized by microbes and the mechanism of action underlying the produced SCFA on intestinal health of monogastric animals is also discussed.

β-Glucan and Parasites

Immunosuppression caused by parasitic infections represents the foremost way by which the parasites overcome or escape the host’s immune response. Glucan is a well-established natural immunomodulator with the ability to significantly improve immune system, from innate immunity to both branches of specific immunity. Our review is focused on the possible role of glucan’s action in antiparasite therapies and vaccine strategies. We concluded that the established action of glucan opens a new window in treatment and protection against parasitic infections.

Administration of Bacillus Amyloliquefaciens and Saccharomyces Cerevisiae as Direct-Fed Microbials Improves Intestinal Microflora and Morphology in Broiler Chickens

This study was conducted to investigate the effects of Bacillus amyloliquefaciens (BA) and Saccharomyces cerevisiae (SC) as directed-fed microbials on performance, intestinal microflora, and intestinal morphology in broiler chickens. A total of four hundred one-day-old broiler chickens were randomly divided into 16 pens of 25 chickens each, and every treatment had 4 replicated pens with two pens of males and females respectively. A formulated corn-soybean meal based control diets and experimental diets, including 0.1% BA (1×10⁷ colony-forming units (CFU)/kg), the mixture of 0.05% BA (5×10⁶ CFU/kg) and 0.05% SC (5×10⁶ CFU/kg), and 10 ppm antibiotic (avilamycin), were fed for 5 weeks. The results showed no significant difference in the growth performance among all treatments. Supplementation of the mixture of BA and SC increased acetate and propionate and decreased the E. coli in ceca compared to control and antibiotic treatment. The treatments with antibiotic, BA, and the mixture of BA and SC compared to control treatment increased villus height / crypt depth ratio and decreased ammonia in excreta. In addition, supplementation of BA and the mixture of BA and SC compared to antibiotic treatment increased serum high-density lipoprotein, and decreased serum glutamic-oxaloacetic transaminase, respectively. In conclusion, supplementation of the mixture of BA and SC was better than added BA only, and the mixed probiotics product could potentially alter the use of avilamycin in broiler diets.

Dietary Supplementation of Phoenix dactylifera Seeds Enhances Performance, Immune Response, and Antioxidant Status in Broilers

The date palm (Phoenix dactylifera) seeds were utilized in some traditional medical remedies and have been investigated for their possible health benefits. This proposed study wanted to assess the effect of date palm seeds (DPS) dietary supplementation in comparison to mannan-oligosaccharides (Bio-Mos®) and β-glucan over antioxidant and immunity events that have effect on growth and carcass performances of broilers. An aggregate of 180, one-day-old, chicks were raised in the wire-floored cages and allotted into control, Bio-Mos (0.1%  Bio-Mos), β-glucan (0.1%  β-glucan), DPS2 (2% date crushed seeds), DPS4 (4% date crushed seeds), and DPS6 (6% date crushed seeds) groups. Broilers in DPS2 and DPS4 groups showed significant variations (P < 0.05) in relative growth rate (RGR), feed conversion ratio (FCR), and efficiency of energy utilization in comparison to control group. Moreover, all DPS fed groups showed significant increases (P < 0.05) in serum reduced glutathione (GSH) values. Meanwhile, both serum interferon-gamma (IFN-γ) and interleukin-2 (IL-2) levels were significantly increased (P < 0.05) in DPS2. Consequently, obtained data revealed a substantial enhancement of performance, immunity, and antioxidant status by DPS supplementation in broiler that might be related to the antioxidant and immune-stimulant constituents of P. dactylifera seeds.

The Effects of β-Glucan on Pig Growth and Immunity

With increasing amounts of data showing significant immunostimulating effects of glucan, it is not surprising that attention is also focused on commercially farmed animals. Despite marked progress, development of more efficient uses of glucan in pig farming still needs substantial additional research.