Modulations of growth performance, gut microbiota, and inflammatory cytokines by trehalose on Salmonella Typhimurium-challenged broilers

Salmonellosis in broilers is not merely a significant disease with high economic costs in the poultry industry but also the foodborne disease with the impact on public health by cross-contamination. This study was to investigate the prebiotic ability of trehalose supplementing in diets (0, 1, 3, and 5%, w/w) against Salmonella by using S. Typhimurium (ST)-inoculated broilers. The improvements (P < 0.05) of feed conversion ratio (FCR) were observed with 5% trehalose supplementation in ST-inoculated broilers' diets. An addition of 3 or 5% trehalose in diets increased (P < 0.05) the abundance of lactobacilli in the duodenum and jejunum but decreased (P < 0.05) the growth of ST in the cecum. The adverse effects on serum levels of aspartate aminotransferase, triglyceride, and albumin and globulin ratio in ST-inoculated broilers were noticed and counteracted by supplementing 3 or 5% trehalose in diets (P < 0.05). Besides, the inclusion of trehalose in diets alleviated the intestinal damages and maintained the integrity of cecal epithelial cells after ST challenge under an haematoxylin and eosin-staining observation. Supplementing trehalose further showed the inhibitions of toll-like receptor 4-mediated nuclear factor-kappa-B pathway, including the downregulation (P < 0.05) of proinflammatory cytokine genes, such as interleukin 1 beta and lipopolysaccharide-induced tumor necrosis factor-alpha factor and the upregulation (P < 0.05) of interleukin 10 and interferon-alpha in ST-inoculated broilers. Overall, supplementing trehalose alleviated the adverse effects from ST challenge on FCR, serum biochemistry, the damage, and inflammation in the liver and cecum. Those improvements on ST challenged broilers also contributed to the overgrowth of lactobacilli, the decrement of ST, and anti-inflammatory effects in affected broilers. Trehalose, therefore, could be a promising prebiotic against salmonellosis to benefit broiler production and promote food safety in the poultry industry.