Gao Jiang, Ren Hongrui, Wu Xuanfu, Zou Cunzhi, He Bin, Ma Wenqiang
Key Laboratory of Animal Physiology and Biochemistry, Ministry of Agriculture and Rural Affairs, College of Veterinary Medicine, Nanjing Agricultural University, NO.1 Weigang Road, Nanjing, Jiangsu, 210095, China.
MOE Joint International Research Laboratory of Animal Health & Food Safety, Nanjing Agricultural University, Nanjing, Jiangsu, 210095, China.
Stress Biol. 2025 Aug 12;5(1):49. doi: 10.1007/s44154-025-00243-8.
Heat stress (HS) disrupts intestinal homeostasis and hepatic lipid metabolism in poultry, yet effective interventions remain limited. We investigate the protective effects of dietary glycerol monolaurate (GML) supplementation in laying hens under HS conditions. In a 10-week trial, 504 Hy-Line Brown hens were assigned to four groups (control and GML at 65, 195, and 325 mg/kg) with six replicates per group. Hens receiving 325 mg/kg GML exhibited significantly higher egg production and egg weight (P < 0.05), alongside improved egg quality metrics, including increased shell strength and Haugh units by week 8 (P < 0.05). Histological analysis revealed that GML (325 mg/kg) improved duodenal and ileal villus height and duodenal villus-to-crypt ratios while reducing duodenal crypt depth (P < 0.05), thereby restoring gut barrier integrity. These findings were supported by reduced plasma D-lactate (D-LA) levels and upregulated expression of tight-junction proteins ZO-1 and Occludin in the ileum and jejunum (P < 0.05). In the liver, GML supplementation alleviated HS-induced steatosis, reducing lipid droplet accumulation (P < 0.05), plasma low-density lipoprotein cholesterol (LDL-C), aspartate aminotransferase (AST), and alanine aminotransferase (ALT) levels, and hepatic triglyceride content, while elevating high density lipoprotein cholesterol (HDL-C). Integrated plasma metabolomics and hepatic transcriptomics identified 36 differential metabolites (enriched in sphingolipid metabolism) and 1,176 differentially expressed genes (enriched in PPAR signaling and Fatty acid degradation), with ACSL1 as a central regulatory gene. Key genes (ACSL1, CPT1 A) and metabolites correlated positively with production performance and gut-liver health, while SCD and Probucol showed negative associations. These findings indicate that GML supplementation enhances intestinal barrier function, promotes hepatic fatty acid β-oxidation, and reinforces sphingolipid metabolism, thereby mitigating HS-induced oxidative stress and lipid dysregulation. Our results identify 325 mg/kg GML as the optimal dosage, proposing a practical strategy to enhance poultry resilience during heat stress.
热应激（HS）会破坏家禽的肠道稳态和肝脏脂质代谢，但有效的干预措施仍然有限。我们研究了在热应激条件下，日粮中添加甘油单月桂酸酯（GML）对蛋鸡的保护作用。在一项为期10周的试验中，将504只海兰褐蛋鸡分为四组（对照组以及添加65、195和325 mg/kg GML的组），每组六个重复。接受325 mg/kg GML的蛋鸡产蛋量和蛋重显著更高（P < 0.05），同时蛋品质指标也有所改善，包括到第8周时蛋壳强度和哈氏单位增加（P < 0.05）。组织学分析表明，GML（325 mg/kg）提高了十二指肠和回肠绒毛高度以及十二指肠绒毛与隐窝的比例，同时降低了十二指肠隐窝深度（P < 0.05），从而恢复了肠道屏障完整性。血浆D - 乳酸（D - LA）水平降低以及回肠和空肠中紧密连接蛋白ZO - 1和闭合蛋白的表达上调（P < 0.05）支持了这些发现。在肝脏中，添加GML减轻了热应激诱导的脂肪变性，减少了脂滴积累（P < 0.05）、血浆低密度脂蛋白胆固醇（LDL - C）、天冬氨酸转氨酶（AST）和丙氨酸转氨酶（ALT）水平以及肝脏甘油三酯含量，同时提高了高密度脂蛋白胆固醇（HDL - C）。综合血浆代谢组学和肝脏转录组学鉴定出36种差异代谢物（富集于鞘脂代谢）和1176个差异表达基因（富集于PPAR信号通路和脂肪酸降解），其中ACSL1为核心调控基因。关键基因（ACSL1、CPT1 A）和代谢物与生产性能以及肠道 - 肝脏健康呈正相关，而SCD和普罗布考呈负相关。这些发现表明，添加GML可增强肠道屏障功能，促进肝脏脂肪酸β - 氧化，并加强鞘脂代谢，从而减轻热应激诱导的氧化应激和脂质失调。我们的结果确定325 mg/kg GML为最佳剂量，提出了一种提高家禽在热应激期间恢复力的实用策略。
