Yeast β-glucan ameliorated Salmonella-induced gut impairment in broiler chickens by modulating gut microbiome.

Yeast β-glucan (YG) was reported to control Salmonella infection in poultry. Gut microbiota plays an important role in regulating immune functions and intestinal health. However, it is still unclear whether YG protects chickens from Salmonella infection by regulating gut microbiota. The impacts of YG on gut health of chickens infected with Salmonella enteritidis (SE) was investigated through histochemical and immunological methods, along with microbiomics. The role of gut microbiome induced by YG treatment in combating Salmonella infection was explored through fecal microbiota transplantation (FMT). Our findings showed that YG administration significantly ameliorated SE-induced gut impairment by decreasing gut permeability, enhancing intestinal barrier function, inhibiting intestinal inflammation, reducing Salmonella colonization and invasion, lowering g_Streptococcus and g_Ligilactobacillus but increasing g_Blautia, g_Bacillus5555555555555555555555 and g_Faecalibacterium relative abundance. Transplantation fecal microbiota from YG-treated healthy donor chickens to antibiotic-treated recipient chicks significantly attenuated gut injury caused by SE infection through decreasing Salmonella colonization and invasion along with intestinal permeability, improving gut morphology, upregulating intestinal tight junction genes and proteins expression, downregulating pro-inflammatory cytokines expression. Additionally, FMT remarkably increased g_Bacteroides and g_Faecalibacterium relative abundances and butyric acid level, decreased g_Ruminococcus-torque-group relative abundance in the cecum. Collectively, we assume that yeast β-glucan alleviated Salmonella-induced gut impairment, a mechanism that is dependent on the gut commensal g_Bacteroides and g_Faecalibacterium.