Gut-DerivedGG Alleviates Intestinal Inflammation in Laying Hens via Microbiota Remodeling and Tryptophan Metabolic Reprogramming.

Abstract

Intestinal inflammation compromises nutrient absorption, health, and productivity in laying hens. Here, we isolated a gut-residentGG (LGG) strain from indigenous chickens and evaluated its prophylactic effects against dextran sulfate sodium (DSS)-induced intestinal inflammation. Oral LGG administration improved growth performance and antioxidant capacity, restored the villus structure, and reinforced epithelial barrier integrity by upregulating tight junction genes. LGG markedly reduced pro-inflammatory cytokines (-1β,-γ) and increased-β. 16S rRNA sequencing showed that LGG normalized microbial diversity, corrected the Firmicutes/Bacteroidetes ratio, enriched beneficial taxa (,), and reduced inflammation-associated genera (,). Untargeted metabolomics revealed a significant modulation of tryptophan metabolism, including elevated levels of kynurenic acid, xanthurenic acid, and indoleglyoxylic acid. The microbiota-metabolite correlations indicate a coordinated regulatory axis underlying LGG-mediated protection. These findings demonstrate that native LGG mitigates intestinal inflammation through microbiota remodeling and metabolic reprogramming, supporting its potential as an antibiotic-free strategy for improving gut health in poultry.