Lactiplantibacillus plantarum FRT4 attenuates high-energy low-protein dietinduced fatty liver hemorrhage syndrome in laying hens through regulating gut-liver axis

Background Fatty liver hemorrhage syndrome(FLHS)becomes one of the most major factors resulting in the laying hen death for caged egg production.This study aimed to investigate the therapeutic effects of Lactiplantibacillus plan-tarum(Lp.plantarum)FRT4 on FLHS model in laying hen with a focus on liver lipid metabolism,and gut microbiota.Results The FLHS model of laying hens was established by feeding a high-energy low-protein(HELP)diet,and the treatment groups were fed a HELP diet supplemented with differential proportions of Lp.plantarum FRT4.The results indicated that Lp.plantarum FRT4 increased laying rate,and reduced the liver lipid accumulation by regulating lipid metabolism(lipid synthesis and transport)and improving the gut microbiota composition.Moreover,Lp.plan-tarum FRT4 regulated the liver glycerophospholipid metabolism.Meanwhile,“gut-liver”axis analysis showed that there was a correlation between gut microbiota and lipid metabolites.Conclusions The results indicated that Lp.plantarum FRT4 improved the laying performance and alleviated FLHS in HELP diet-induced laying hens through regulating“gut-liver”axis.Our findings reveal that glycerophospholipid metabolism could be the underlying mechanism for the anti-FLHS effect of Lp.plantarum FRT4 and for future use of Lp.plantarum FRT4 as an excellent additive for the prevention and mitigation of FLHS in laying hens.

Ammonia-induced oxidative stress triggered proinflammatory response and apoptosis in pig lungs

Ammonia,a common toxic gas,is not only one of the main causes of haze,but also can enter respiratory tract and directly affect the health of humans and animals.Pig was used as an animal model for exploring the molecular mechanism and dose effect of ammonia toxicity to lung.In this study,the apoptosis of type II alveolar epithelial cells was observed in high ammonia exposure group using transmission electron microscopy.Gene and protein expression analysis using transcriptome sequencing and western blot showed that low ammonia exposure induced T-cell-involved proinflammatory response,but high ammonia exposure repressed the expression of DNA repair-related genes and affected ion transport.Moreover,high ammonia exposure significantly increased 8-hydroxy-2-deoxyguanosine (8-OHdG) level,meaning DNA oxidative damage occurred.In addition,both low and high ammonia exposure caused oxidative stress in pig lungs.Integrated analysis of transcriptome and metabolome revealed that the up-regulation of LDHB and ND2 took part in high ammonia exposure-affected pyruvate metabolism and oxidative phosphorylation progress,respectively.Inclusion,oxidative stress mediated ammonia-induced proinflammatory response and apoptosis of porcine lungs.These findings may provide new insights for understanding the ammonia toxicity to workers in livestock farms and chemical fertilizer plants.