Gut-Derived Lipid Mediators Orchestrate Ovarian Metabolic Homeostasis and Clutch Persistence in Aging Laying Hens via the PLA2G6-ALOX15B-AGPAT3 Axis.

Clutch persistence, defined as the ability to sustain consecutive egg-laying cycles, is a pivotal determinant of profitability in the poultry industry, particularly for aging laying hens (≥65 weeks). However, the molecular mechanisms governing this trait remain elusive, largely due to the traditional "ovary-centric" paradigm that overlooks systemic regulation by the gut microbiota. To address this knowledge gap, the present study aimed to dissect the comprehensive regulatory network governing clutch persistence using integrated multi-omics analyses. A total of 20 sixty-five-week-old Rhode Island Red (RIR) laying hens with cumulative egg production exceeding 300 eggs but distinct clutch persistence were stratified into a high-clutch persistence group (HCP, ≥25 clutches, n = 10) and a low-clutch persistence group (LCPLCP, ≤15 clutches, n = 10). Multi-omics profiling, including ovarian transcriptomics, proteomics, and metabolomics; serum metabolomics; and cecal microbiota 16S rRNA sequencing was performed. Data integration and association mining were conducted via Spearman correlation analysis with stringent thresholds (r > 0.6, p < 0.01). Integrated analyses revealed a "gut-ovary axis" regulatory model mediated by a lipid mediator network, operating through a three-tiered mechanism: (1) Gut Initiation: The HCP group exhibited enriched cecal γ-Proteobacteria, which promoted biosynthesis of lipid precursors. (2) Serum Transport: Key serum lipid mediators, most notably LysoPC (22:6) (VIP = 4.5) and cholesterol ester CE (20:4), served as critical carriers transducing gut-derived signals to the ovary. (3) Ovarian Execution: These lipid signals activated a core ovarian metabolic pathway centered on the PLA2G6-ALOX15B-AGPAT3 axis, which coordinated follicular development and ovulation by supplying steroid hormone synthesis substrates, exerting anti-inflammatory effects, and stabilizing membrane structures. Collectively, this study demonstrates that gut microbiota modulates clutch persistence in aging laying hens via lipid mediators, orchestrating a systemic "gut-serum-ovary" regulatory cascade. These findings provide a novel molecular framework for extending the economic egg-laying cycle through the targeted manipulation of intestinal microbiota or serum lipid metabolism.