Isolation and identification of tropical source Lactobacillus plantarum CK3 and its effects on fatty liver in laying hens.

Fatty liver syndrome (FLS)，a prevalent metabolic disorder, severely compromises egg production and increases mortality in laying hens, leading to substantial economic losses. It has been reported that probiotic has efficacy effects in ameliorating fatty liver disease. However, the effects of chick-derived probiotics on FLS remain uncertain. This study aimed to extract and characterize probiotics from Hainan Wenchang Chicken and investigate their effects on fatty liver in laying hens. Lactobacillus plantarum CK3 was isolated from the intestine, showing better tolerance of 55 °C, pH 2.0, 0.3% bile salts and 1.4% trypsin than the published strains. Subsequently, a fatty liver model was successfully created using a HFHCD diet, which was validated by the increasing body weight and liver index, higher serum and liver TG and TC levels, higher serum ALT and AST activities, and hepatic steatosis. Lactobacillus plantarum CK3 supplementation reversed the above parameters, reduced mRNA levels of IL-1β and IL-18 and increased IL-10 mRNA levels in the liver of laying hens. Additionally, Lactobacillus plantarum CK3 significantly alleviated intestinal pathological changes, reversed the down-regulating mRNA levels of ZO-1 and Occludin, and reversed the increasing mRNA levels of IL-1β, IL-18 and TNF-α. Lactobacillus plantarum CK3 reversed the increasing MDA contents and decreasing T-AOC contents of the liver and ileum. In addition, Lactobacillus plantarum CK3 slightly modified gut microbiota. These results showed that Lactobacillus plantarum CK3 ameliorated fatty liver and intestinal damage and increased antioxidant capacity. This work suggests Lactobacillus plantarum CK3 as a promising probiotic candidate for feed additive in poultry.