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

摘要： 目的　探讨高胆固醇饮食3个月对巴马小型猪口腔微生物群的影响。方法　将8月龄普通级雄性巴马小型 猪12头随机分为对照组(OS1组,n=6)和实验组(OS3组,n=6),OS1组小型猪普通饲料喂养,OS3组给予高胆固 醇饮食。小型猪实验满3个月收集全血分离血清用于检测血脂,无菌采集两组小型猪口腔拭子12份进行16S rRNA基因V3-V4区测序,分析小型猪口腔微生物群的Alpha多样性、Beta多样性、优势菌属及相关的功能通路。 结果　实验满3个月时,OS3组小型猪体质量较OS1组显著增加(P<0.05),OS3组小型猪血清总胆固醇(total cholesterol,TC)、甘油三酯(triglyceride,TG)、高密度脂蛋白胆固醇(high-density lipoprotein cholesterol,HDL-C)和低 密度脂蛋白胆固醇(low-density lipoprotein cholesterol,LDL-C)的浓度较OS1组显著增加(均P<0.05)。OS1组与 OS3组小型猪口腔微生物群的Alpha多样性和丰富度无差异。OS1组与OS3组小型猪口腔微生物群的Beta多样 性有显著差异(均P<0.05)。OS1组小型猪口腔的优势菌属为Moraxella、Actinobacillus、Streptococcus和Bergeyella; OS3组小型猪口腔的优势菌属为Moraxella、Actinobacillus、Streptococcus、Porphyromonas和Fusobacterium;两组优势菌 属的种类和比例有所差异。OS3组小型猪的口腔厚壁菌门与拟杆菌门的比率显著降低(P<0.05)。口腔微生物群 功能预测显示,OS3组小型猪的代谢通路发生显著改变,其中其他聚糖降解、脂蛋白生物合成、氨基酸代谢、碳水化 合物代谢、次级胆汁酸生物合成和核苷酸代谢显著上调,辅助因子和维生素代谢、胆汁分泌显著下调(均P<0.05)。 结论　高胆固醇饮食满3个月时小型猪血脂发生紊乱,并对其口腔微生物群产生影响,改变了小型猪口腔优势微 生物群的组成和比例。

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