Nutritional intervention with perennial ryegrass alleviates hepatic dysfunction by modulating lipid metabolism: insights from gut-liver axis

Liver is a central organ regulating energy metabolism in poultry, yet concentrate diets predispose geese to hepatic steatosis and fatty liver disease. Derived dietary fiber is known to improve gut health, modulate lipid metabolism, and protect liver against oxidative and inflammatory damage. Current study investigated the hepatoprotective role of perennial ryegrass as a natural fiber source in geese. Goslings were allocated into three dietary groups: a concentrate diet (CD), and diets with 50 % (PRD1) and 30 % (PRD2) inclusion of perennial ryegrass. Perennial ryegrass significantly increased microbial diversity, enriched short chain fatty acid producing taxa (Faecalibacterium, Lactobacillus, Romboutsia and Akkermansia), reduced fibrosis associated bacteria (Turicibacter, Megamonas), thereby enhancing microbe-metabolite interaction. These changes suppressed the lipogenic genes (SREBP-1c/FAS/ACC1/SCD1), enhanced PPAR-α mediated fatty acid oxidation, and reduced hepatic lipid accumulation. Histopathological analysis further confirmed attenuation of steatosis, hepatocellular ballooning, and inflammation, consistent with lower nonalcoholic fatty liver disease activity scores (NAS) in the PRD groups. Additionally, there was significant reduction in hepatic inflammation due to enhanced antioxidant potential. Furthermore, metabolomics profiling revealed a significant reduction in lipotoxic metabolites and saturated fatty acids (behenic acid), alongside an increase in omega-3 polyunsaturated fatty acids (EPA and DHA), as well as increased levels of phytometabolites (caffeic acid) in PRD group. Collectively, these findings demonstrate that proportional inclusion of perennial ryegrass as a natural fiber source confers multi-level hepatoprotection by modulating gut-liver crosstalk, enhancing redox balance, and restoring lipid homeostasis, highlighting its potential as a cost-effective nutritional strategy to prevent fatty liver disease.