Effects Of High-salt And High-fat Diet On Gut Microbiota And Expression Of HIF-1α And VEGF In Organs Of Broilers

Broiler breeding should reasonably use high-salt and high-fat diets(HSFD).In breeding,the improper ratios of broiler diets are often caused by wrong calculations or ratios,or blindly adding nutrients,which are harmful to the health of broilers and damaging to the economic returns of the breeding industry.In this study,we investigated the effects of high-salt and high-fat diets on broiler growth and immune organ development by comparing the live weight and immune organ index of broiler chickens;we investigated the effects of high-salt and high-fat diets on broiler cecum intestinal flora by sequencing the intestinal flora macrogenome;we analyzed the effects of high-salt and high-fat diets on broiler heart,liver,and lung by observing HE-stained broiler organ tissue sections;and we analyzed the effects of high-salt and high-fat diets on broiler heart,liver,and lung by using HE-stained broiler tissue sections.We also analyzed the effects of high-salt and high-fat diets on the heart,liver and lungs of broiler chickens by observing HE-stained broiler organ tissue sections,and analyzed the regulatory effects of HIF-1α and VEGF factors on the heart,liver and lungs of broiler chickens on high-salt and high-fat diets by using molecular biology techniques such as immunohistochemistry and real-time fluorescence quantitative PCR.This study was conducted to provide basic reference data for healthy broiler breeding and disease prevention.Comparison of body weight and immune organ indices showed that high-salt and high-fat diets reduce the growth rate of broilers and cause serious health hazards to broilers by inhibiting the growth and development of immune organs such as the spleen and bursa.Macrogenome sequencing of the intestinal flora showed that the addition of high salt and high fat to the diet reduced the abundance of the cecum flora and changed the structure of the intestinal flora in broiler chickens at certain levels.At the phylum level,high-salt and high-fat diets increased the abundance of the Firmicutes phylum and decreased the abundance of the Bacteroidetes phylum;at the genus level,high-salt and high-fat diets increased the abundance of the genus Lactobacillus and decreased the abundance of the Bacteroides genus,which affected the growth and development,morphological function and immune function of broilers.HE staining observed that the lungs of broiler chickens in the high-salt and high-fat diet group showed obvious remodeling phenomenon,the lumen became larger,the collagen fibers increased,and the inner membrane,middle membrane and outer membrane of the pulmonary artery were indistinguishable;the liver structure was loose,lost normal structure,and the arrangement of hepatocytes was disordered;the myocardial fibers were broken and the structure was loose and uneven,and the changes in the morphology of each organ were more serious and the phenomenon was more significant at the age of 56 days.The qRT-PCR results showed that the mRNA expression of HIF-1α and VEGF in three organs of broiler lung,heart and liver in ND14 group was not significantly different compared with broilers in HSFD group,and the mRNA expression of HIF-1α and VEGF in three organs of broiler lung,heart and liver in HSFD56 group was significantly different compared with broilers in ND56 group.After comparing the experimental data,among them,the mRNA expression of HIF-1α and VEGF in the liver of broiler chickens in HSFD group was the highest.Immunohistochemical results showed that broilers in the HSFD group had looser tissue structure in the heart,liver and lungs compared with broilers in the ND group;in the comparison between broilers in the HSFD56 group and broilers in the ND56 day-old group,the differences in the expression of HIF-1α and VEGF in the heart,liver and lungs of broilers in the HSFD56 group were significant compared with broilers in the ND56 day-old group,and the differences in the expression of HIF-1α and VEGF factor positive expression signals were more intense;both HIF-1α and VEGF factors had the strongest positive signals in the liver of the 56-day-old HSFD group;the positive expression rates of HIF-1α and VEGF factors in each organ were up-regulated with age.The results of this experiment showed that high salt and high fat diets would reduce the growth rate and immunity of broiler chickens;high salt and high fat diets would reduce the abundance of cecum flora of broiler chickens at a certain level,the phylum level,increases the abundance of the Firmicutes phylum and decreases the abundance of the Bacteroidetes phylumand,increase the abundance of the genus Lactobacillus and decrease the abundance of the genus Bacteroidetes at the genus level.The change of intestinal flora abundance was more severe and disordered with increasing age;HSFD caused different degrees of damage to the heart,liver and lungs of broilers,and the damage increased with time;mRNA expression of HIF-1α and VEGF in lungs,heart and liver were significantly different at 56 days of age compared with the basal diet group;broilers in the HSFD group at 56 days of age compared with the 56 The differences in expression of HIF-1α factor and VEGF factor in heart,liver and lung were significant in broilers of 56-day-old HSFD group compared with broilers of 56-day-old ND group.