Yeast ß-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 ß-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 ß-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.

Dietary yeast ß-glucan supplementation improves eggshell color and fertile eggs hatchability as well as enhances immune functions in breeder laying hens.

The study was conducted to evaluate the effects of dietary yeast ß-glucan (YG) on performance and immune functions in breeder hens in a non-challenged setting. A total of 512 43-week-old Hy-Line Brown breeder hens were assigned into four treatments, and fed a basal diet with YG at 0, 50, 100 and 200 mg /kg for 8 weeks, respectively. Results showed that supplementation of YG did not affect production performance, but linearly increased hatchability (P < 0.05). Compared with the control, hens fed with 200 mg/kg YG had improved eggshell color and reduced mortality. Moreover, feeding 200 mg/kg YG significantly (P < 0.05) enhanced lymphocyte proliferation response to LPS, increased the percentage of peripheral blood CD3+ T cells and phytohemagglutinin (PHA) skin response; remarkably down-regulated splenic TLR4, IL-6 and TGF-ß mRNA levels while upregulated TLR6 and IFN-γ mRNA levels (P < 0.05). In addition, inclusion of YG at 200 mg/kg considerably promoted the production of serum cytokines, total IgA, and specific antibody titers against BSA, AIV and NDV vaccine (P < 0.05). These results suggested that dietary inclusion of 200 mg/kg YG could improve eggshell color and fertile eggs hatchability and enhance cellular and humoral immune function of breeder hens in a nonchallenged setting without disturbing immune homeostasis.