Immune stress impairs broiler performance by affecting hypothalamic methylation modification and intestinal 5-HT
Bingjian Huang1, Yan Wan1, Guang Li1
1State Key Laboratory of Animal Nutrition and Feeding, College of Animal Science and Technology, China Agricultural University, No. 2, Yuanmingyuan West Road, Haidian District, Beijing 100193, China.
Poultry Science
|June 26, 2025
Summary
Lipopolysaccharide (LPS) induced immune stress in broiler chickens significantly reduced performance and impaired intestinal barrier function. This stress impacts molecular pathways, including mTOR signaling and 5-hydroxytryptamine (5-HT) synthesis, affecting overall broiler health.
Area of Science:
- Animal Science
- Immunology
- Molecular Biology
Background:
- Chronic immune stress, often induced by lipopolysaccharide (LPS), significantly impacts livestock health and productivity.
- Understanding the molecular and neuroendocrine mechanisms underlying immune stress responses is crucial for improving broiler chicken welfare and performance.
Purpose of the Study:
- To investigate the effects of LPS-induced immune stress on the performance and intestinal mucosal barrier function of broiler chickens.
- To identify key molecular and neuroendocrine pathways, including m6A methylation, involved in the response to immune stress in broilers.
Main Methods:
- Establishment of a chronic immune stress model in broiler chickens using daily LPS injections for 10 days.
- Analysis of broiler performance, immune organ indices, serum corticosterone, and gene/protein expression in the hypothalamus and ileum.
- Measurement of serum 5-hydroxytryptamine (5-HT) levels and m6A methylation in affected tissues.
Main Results:
- LPS injection significantly reduced broiler performance, increased immune organ indices, and elevated serum corticosterone levels.
- Immune stress led to altered gene expression in the spleen and ileum (e.g., increased IL-1β, TNF-α; decreased mTOR, PCNA) and hypothalamus (e.g., increased MCH, PREPRO; decreased NPY).
- Significant reductions in serum 5-HT and ileal 5-HT receptor expression, alongside increased m6A methylation in the hypothalamus and ileum, were observed.
Conclusions:
- LPS-induced immune stress inhibits the mTOR/P70S6K pathway in the ileum and suppresses intestinal 5-HT synthesis, impairing the intestinal mucosal barrier.
- Immune stress affects hypothalamic appetite-related gene expression and m6A RNA methylation, contributing to reduced broiler performance.
- These findings highlight critical molecular targets for mitigating the negative impacts of immune stress in poultry production.
