ABSTRACT This study aimed to investigate the effect of Lactobacillus plantarum DPP8 and Lactobacillus acidophilus C7282 in feed supplementation on growth performance, Salmonella invasion, inflammation, and mediating signaling in broilers infected with Salmonella Typhimurium (S. Typhimurium). A total of 240 broilers at day old were randomly allocated into four groups, orally infected with S. Typhimurium and supplemented with individual or combined Lactobacilli DPP8 and C7282 at doses of 0 (control), 1010 (individual), or 2.0 × 1010 (combination) cfu/kg of diet for 21 d. The results showed that supplementing Lactobacilli improved (p<0.05) feed intake and body weight gain and decreased (p<0.05) S. Typhimurium load in the caecum, harder gland, spleen and bursa of Fabricius. Also, the supplements decreased (p<0.05) interleukin (1β/2/4), tumor necrosis factor α and interferon γ in the serum, enhanced (p<0.05) interleukin 10, and downregulated gene expressions of inflammatory mediators including Janus kinase (Jak2/3), signal transducer and activator of transcription protein (STAT3/4/5/6) in the intestinal mucosa. In contrast, diets containing DPP8 exhibited greater effects on the inhibition of the pathogen and inflammatory response than C7282. The obtained data suggest that Lactobacilli C7282 and DPP8 can be used as feed additives to inhibit colonization and translocation of S. Typhimurium and inflammatory responses via downregulating Jak/STAT signaling in broilers.

ABSTRACT This study aimed to investigate the effect of dietary lactic acid bacteria (LAB) on egg production, yolk components, cholesterol metabolism, and enterohepatic circulation of bile acids in hens. Four treatment diets included a control and LAB added at 3 × 105 (low), 3 × 107 (medium), or 3 × 109 (high) cfu/kg. The treatment LAB contained equal amounts of Lactobacillus acidophilus, Lactobacillus plantarum, and Enterococcus faecium. Results showed that high LAB increased (p<0.05) laying rate, egg mass, and yolk phospholipid, but decreased (p<0.05) yolk triglyceride and phosvitin. Diets with LAB decreased (p<0.05) yolk and serum cholesterol content, and serum bile acid by 9.3 to 39.9%. In liver, high LAB downregulated (p<0.05) mRNA expression of serine/threonine kinase 11 (STK11), 3-hydroxy-3-methylglutaryl-CoA reductase (HMGR), AMP-activated protein kinase catalytic subunit (PRKAA1, 2), and protein phosphatase catalytic subunits (PPP2CA, PPP2CB and PPP3CA) by 49.5 to 175.4%. In mucosa, high LAB downregulated (p<0.05) PRKAA1 and HMGR by 68.2 and 69.6%, respectively; but upregulated (p<0.05) PPP2CA and PPP2CB by 51.2 and 45%, respectively. Linear decreasing (p≤0.035) responses to LAB doses were found on cholesterol, phosvitin, bile acid, and hepatic gene expressions, and quadratic (p≤0.006) effects on yolk cholesterol and hepatic STK11. It is concluded that probiotic LAB can improve yolk components and decrease hepatic cholesterol synthesis by regulating HMGR pathway in hens.