Laboratory Animal Research Center/ Institute of Comparative Medicine, Zhejiang Chinese Medical University, Hangzhou 310053, China
Objective To observe changes in the intestinal flora in a Wuzhishan minipig model of atherosclerosis (AS) induced by a high-fat / high-sugar diet. Methods Twelve male Wuzhishan minipigs were divided into normal control (NC) and AS model groups according to body weight (n= 6 per group). The NC group was fed a normal diet and the AS model group was fed a high-fat / high-sugar diet. After 24 weeks of continuous diet, blood samples were taken from the anterior vena cava to determine biochemical indexes, including glucolipid metabolism, and a glucose to tolerance test was also performed. At the end of the experiment, the minipigs were euthanized and body fat deposition was observed. The aortic vessels were stained with Sudan IV and the abdominal aortic vessels were stained with hematoxylin and eosin to observe lipid deposition and histopathological changes, respectively. The cecal contents were used for 16S rDNA sequencing to analyze changes in the intestinal flora. Results Serum total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, blood glucose, and fructosamine levels were all significantly higher in the AS model group compared with the NC group (P< 0.05, P< 0.01). Body weight and body fat deposition were also significantly higher in the AS model group ( P< 0.01). The aortic vessels showed increased lipid deposition and AS lesions. DNA sequencing analysis showed significantly lower intestinal flora α-diversity in the AS model group compared with the NC group ( P< 0.05, P< 0.01). At the phylum level, the phyla Bacteroidetes and Actinomycetes were significantly reduced in the AS model group (P< 0.05, P< 0.01), while the phylum Proteobacteria and the Firmicutes/ Bacteroidetes ratio were significantly increased (P< 0.05). At the genus level, the relative abundances of 17 genera, including Hespellia, Ruminococcus, Lachnospiracea_incertae_sedis, Pseudobutyrivibrio, and Barnesiella, were significantly decreased (P< 0.05, P< 0.01), and the relative abundances of 11 genera, including Ramlibacter, Sphingorhabdus, Cloacibacillus, Oxalobacter, Sphingomonas, and Novosphingobium, were significantly increased (P< 0.05). Functional prediction analysis showed that multiple pathways such as lipopolysaccharide biosynthesis, lipopolysaccharide biosynthesis proteins, primary bile acid biosynthesis, and arachidonic acid metabolism may participate in the formation of AS. Correlation analysis showed that total cholesterol, intima media thickness, lipid deposition, and fructosamine were associated with 14 genera, including Oxalobacter, Sphingomonas, Cloacibacillus, Clostridialse _ unclassified, and Ruminococcus. Conclusions High-fat / high sugar diet-induced AS in Wuzhishan minipigs is characterized by obesity, disturbed glucolipid metabolism, and obvious AS lesions, possibly related to dysbiosis of the intestinal flora.