Postbiotic GABA and Lactobacillus plantarum 1-2-3 alleviate stress-induced ovarian dysfunction and improve reproductive performance in laying hens through multi-mechanistic pathways.

Stress is a well-established disruptor of reproductive function in poultry. Gamma-aminobutyric acid (GABA), a notable postbiotic derived from Lactobacillus plantarum (L. plantarum), has attracted increasing attention as a dietary supplement. While existing research predominantly focuses on GABA applications in broilers and other species, its effects on laying hens remain underexplored. This study investigated whether GABA and L. plantarum 1-2-3 supplementation mitigated corticosterone (CORT)-induced chronic stress in laying hens. Results demonstrated that both GABA and L. plantarum 1-2-3 effectively mitigated CORT-induced declines in laying performance and ovarian damage. They reduced ovarian oxidative stress, inflammation, and atretic follicles by enhancing antioxidant capacity and normalizing expression of inflammatory factors (IL18, LITAF, IL6, IL1B), and apoptosis-related factors (BCL2, BAX, CASP9, CASP3). Furthermore, GABA and L. plantarum 1-2-3 markedly increased the serum reproductive hormone levels, as well as the transcription level of ovarian steroidogenic genes (LHCGR, FSHR, StAR, CYP11A1), while modulated ovarian cholesterol metabolism via PPARα-mediated pathways. These findings elucidate the mechanisms by which GABA and L. plantarum 1-2-3 alleviate stress in laying hens, providing a theoretical and practical basis for their use as functional feed additives in stress-exposed flocks.