金华猪回肠菌群结构和脂肪酸结合蛋白发育性变化与脂肪沉积的相关性研究

本试验旨在研究金华猪回肠菌群结构和脂肪酸结合蛋白发育性变化及其与脂肪沉积的相关性。试验分别选取45（D45）、90（D90）、150（D150）和270（D270）日龄体重相近的健康金华猪各4头，测定其体重和背膘厚；并采集回肠黏膜及其内容物，通过荧光定量PCR测定回肠黏膜中脂肪酸结合蛋白基因的表达，采用基于16S rRNA基因的高通量测序分析金华猪回肠菌群结构。结果表明：1）随着日龄的增加，金华猪体重和背膘厚均显著增加（P<0.05）。2）回肠黏膜中脂肪酸结合蛋白（fatty acids binding protein，FABP）编码基因FABP1、FABP2和FABP4表达量随着日龄的增加均呈显著增加（P<0.05）。3）厚壁菌门（Firmicutes）和拟杆菌门（Bacteroidetes）为金华猪回肠的优势菌门；在属水平上，狭义梭菌属1（Clostridium sensu stricto 1）、乳酸菌属（Lactobacillus）、土孢杆菌属（Terrisporobacter）、Romboutsia和链球菌属（Streptococcus）为主要优势菌属；随着日龄的增加，狭义梭菌属1（Clostridium sensu stricto 1）和链球菌属（Streptococcus）相对丰度先增加后降低；乳酸菌属（Lactobacillus）、土孢杆菌属（Terrisporobacter）和Romboutsia相对丰度先降低后增加；PCoA分析表明，各日龄有显著不同的聚类。4） Spearman相关性分析表明，金华猪回肠黏膜中脂肪酸结合蛋白FABP1、FABP2和FABP4表达水平与背膘厚的相关性系数分别为0.480 1、0.597 9和0.795 3；金华猪回肠菌属Epulopiscium和Mycoplasma与脂肪酸结合蛋白FABP1、FABP2和FABP4和背膘厚的相关性系数范围分别为0.38~0.76、0.45~0.64。由此可见，金华猪回肠菌群结构和脂肪酸结合蛋白表达水平呈现发育性变化，且与脂肪沉积存在一定的相关性。

The Developmental Changes of Ileal Microbiota and Fatty Acid Binding Proteins and Its Correlation with Fat Deposition in Jinhua Pigs

The objective of this study was to investigate the developmental changes of ileal microbiota and fatty acid binding proteins and its correlation with fat deposition in Jinhua pigs.Four healthy Jinhua pigs at 45(D45),90(D90),150(D150)and 270(D270)days of age were selected,respectively to measure their body weight and backfat thickness.The ileal mucosa and contents were collected.The expression of fatty acid binding protein genes in the ileal mucosa was measured by fluorescent quantitative PCR,and ileal microbiota were analyzed using high-throughput sequencing based on 16S rRNA gene.The results showed:1)The weight and backfat thickness of Jinhua pigs increased significantly with age increasing(P<0.05);2)The expression of fatty acid binding protein genes FABP 1,FABP 2 and FABP 4 in the ileal mucosa showed significant increase with age increasing(P<0.05);3)Firmicutes and Bacteroidetes were the predominant phyla in the ileum of Jinhua pigs.At the genus level,Clostridium sensu stricto 1,Lactobacillus,Terrisporobacter,Romboutsia and Streptococcus were the dominant bacteria;With age increasing,the relative abunance of Clostridium sensu stricto 1 and Streptococcus increased at first and then decreased while Lactobacillus,Terrisporobacter and Romboutsia decreased at first and then increased.PCoA analysis showed that there were significantly different clusters at each age.4)Spearman correlation analysis showed that the correlation coefficients of the expression levels of fatty acid binding proteins FABP1,FABP2 and FABP4 with backfat thickness were 0.4801,0.5979 and 0.7953,respectively;The correlation coefficients of Epulopiscium and Mycoplasma with fatty acid binding proteins FABP1,FABP2 and FABP4 in the ileum and backfat thickness of Jinhua pigs were 0.38-0.76 and 0.45-0.64,respectively.It is concluded that the developmental changes were observed for the ileal microbiota and the expression of fatty acid binding protein,which were asscociated with fat deposition in Jinhua pigs.