Dietary Lactic Acid Bacteria Modulate Yolk Components and Cholesterol Metabolism by Hmgr Pathway in Laying Hens

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 × 10 5 (low), 3 × 10 7 (medium), or 3 × 10 9 (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.

Effect of Dietary Tetramethylpyrazine on Egg Production, Nutrient Retention and Cecal Bacterial Diversity in Aged Laying Hens

“…A total of 288 commercial Hy-Line brown hens at 74 wks of age with similar egg production and body weights were randomly assigned to four dietary groups. Each treatment contained 6 replicates of 12 hens each in four continuous cages of three-layers and all replicates were uniformly distributed in a chicken house to minimize the environmental effect (Deng et al, 2020a). All hens were supplied with feed at 108 g/hen/day and ad libitum water according to the management manual of Hy-Line brown strain in the house with auto-ventilation, lighting system at 16L/8D and the temperature at approximately 22°C.…”

“…At the last day of 78, 82 and 86 wks, feces per replicate were collected for the analysis of nutrient retention (Shi et al, 2022). At the 86 th wk, 8 hens (2 hens/cage) per replicate were randomly selected and suffocated by carbon dioxide, the cecal content was collected, pooled by replicate and stored (Deng et al, 2020a) for the analysis of microbiota diversity.…”

The effects of L-carnitine-loaded solid lipid nanoparticles on performance, antioxidant parameters, and expression of genes associated with cholesterol metabolism in laying hens

“…The use of inhibitors of 3-hydroxy-3-methylglutaryl coenzyme A reductase ( HMGR ) has been demonstrated to be one of the most successful strategies for lowering egg cholesterol content ( Puertas and Vázquez, 2019 ). HMGR regulates cholesterol production in the liver ( Deng et al, 2020 ) and some studies showed that LC inhibits HMGR activity ( Wu et al, 2015 ; Bagherzadeh et al, 2019 ). It appears that LC either inhibits HMGR in the liver of laying hens or induces excessive cholesterol excretion through bile by raising the activity of the cholesterol 7 alpha-hydroxylase ( CYP7A1 ) enzyme.…”