关键词: 小型猪, 高胆固醇饮食, 口腔微生物群, 多样性, 16S rRNA基因测序

Abstract: Objective　To explore the effects of a high cholesterol diet on the oral microbiota of Bama minipigs over a period of 3 months.Methods　Twelve 8-month-old male Bama minipigs were randomly divided into control group (OS1 group, n=6) and experimental group (OS3 group, n=6). The minipigs in the OS1 group were fed with ordinary feed, while the OS3 group was given high cholesterol diet. Whole blood was collected and serum was separated for blood lipid detection. Twelve oral swabs were aseptically collected from two groups of minipigs for 16S rRNA gene V3-V4 region sequencing to analyze the Alpha diversity, Beta diversity, dominant genera and related functional pathways of the oral microbiota of minipigs.Results　At 3 months of the experiment, the body weight of minipigs in group OS3 significantly increased (P<0.05), and the levels of serum TC, TG, HDL-C and LDL-C in minipigs in group OS3 also significantly increased compared with OS1 (all P<0.05). There was no significant difference in the Alpha diversity and richness of the oral microbiota of the minipigs between the OS1 group and the OS3 group. The Beta diversity of oral microbiota in minipigs from the OS1 group and the OS3 group showed significantly differences (all P<0.05).The dominant genus of minipigs in the OS1 group were Moraxella, Actinobacillus, Streptococcus and Bergeyella; the dominant genus of minipigs in the OS3 group were Moraxella, Actinobacillus, Streptococcus, Porphyromonas and Fusobacterium; the proportion of the same dominant bacterial genus was different between the two groups. The ratio of Firmicutes to Bacteroidetes in the oral cavity of OS3 group minipigs was significantly reduced (P<0.05). Functional prediction of oral microbiota revealed significant alterations in metabolic pathways in the OS3 group of minipigs. Specifically, other glycan degradation, lipid biosynthesis proteins, amino acid metabolism, carbohydrate metabolism, secondary bile acid biosynthesis, and nucleotide metabolism were significantly upregulated, while the metabolism of cofactors and vitamins and bile secretion were significantly downregulated (all P<0.05).Conclusion　High-cholesterol diet over a period of 3 months causes disorder of blood lipid in minipigs and has an impact on their oral microbiota, changing the composition and proportion of the dominant oral microbiota in minipigs.

Key words: minipig, high cholesterol diet, oral microbiome, diversity, 16S rRNA gene sequencing