基于肠道菌群探讨雄性WHBE兔与日本大耳白兔胆固醇代谢的差异性

Analysis of differences in cholesterol metabolism between male WHBE rabbits and Japanese white rabbits based on intestinal microbiota

目的从肠道菌群途径分析雄性日本大耳白兔黑眼系(white hair and black eyes rabbit,WHBE兔)和日本大耳白兔胆固醇代谢的差异性。方法各取4~5月龄雄性WHBE兔和日本大耳白(JW)兔6只,取血检测血脂水平,并取结肠内容物提取DNA后进行16S rRNA微生物测序,观察肠道菌群结构与功能的变化。结果雄性WHBE兔血清总胆固醇(TC)和低密度脂蛋白-胆固醇水平(LDL-C)均明显低于JW兔(P<0.05)。多样性分析显示,两品系兔的肠道微生物群分离明显,WHBE兔Chao1指数显著低于JW兔(P<0.05)。在门水平,WHBE兔梭杆菌门、软壁菌门和蓝藻菌门的丰度低于JW兔(P<0.05,P<0.01),且厚壁菌门/拟杆菌门比值亦低于JW兔(P>0.05)。在属水平,WHBE兔中有24个菌属的相对丰度与JW兔存在显著性差异(P<0.05,P<0.01)。LEFSe分析显示,WHBE兔中发现了5个关键菌属,以理研菌科RC9群(Rikenellaceae_RC9_gut_group)最多;JW兔中发现了10个关键菌属,以瘤胃球菌科UCG-014(Ruminococcaceae_UCG_014)最多。PICRUSt功能预测显示,两品系兔肠道菌群中的花生四烯酸代谢和醚脂代谢途径存在显著差异(P<0.05,P<0.01)。相关性分析显示,TC和LDL-C水平与短波单胞菌属(Brevundimonas)、回肠杆菌属(Ileibacterium)、梭杆菌属(Fusobacterium)、罗尔斯顿菌属(Ralstonia)、Mollicutes_RF39_unclassified呈正相关,与Coriobacteriaceae_unclassified、厌氧菌属(Anaerovorax)、梭菌属(Clostridium)、DTU014_unclassified、Barnesiellaceae_unclassified、瘤胃球菌科UCG-009(Ruminococcaceae_UCG_009)、Clostridiales_vadinBB60_group_unclassified呈负相关。结论雄性WHBE兔和JW兔胆固醇代谢的差异性与宿主的肠道菌群结构与功能差异有关,其中肠道菌群中的花生四烯酸代谢和醚脂代谢途径尤为关键。

Objective To analyze the differences in cholesterol metabolism between male white hair and black eye(WHBE)rabbits and Japanese white rabbits by gut microbiota.Methods Six male WHBE rabbits and six male Japanese white(JW)rabbits aged 4 to 5 months were used and blood samples were collected for blood lipid detection.DNA was extracted from colon samples and 16S rRNA microbial sequencing was performed to observe changes in the structure and function of gut microbiota.Results Serum total cholesterol(TC)and low-density lipoprotein cholesterol(LDL-C)levels of male WHBE rabbits were significantly lower than those of JW rabbits(P<0.05).Diversity analysis showed that the gut microbiota of these two strains of rabbits were significantly isolated,and the Chao1 index of WHBE rabbits was significantly lower than that of JW rabbits(P<0.05).At the phylum level,the abundances of Fusobacteria,Tenericutes,and Cyanobacteria of WHBE rabbits were also lower than those of JW rabbits(P<0.05,P<0.01),and the Firmicutes/Bacteroidetes ratio was lower than that of JW rabbits(P>0.05).At the genus level,the relative abundance of 24 genera in WHBE rabbits was significantly different from that of JW rabbits(P<0.05,P<0.01).Linear discriminant analysis effect size analysis showed that five key genera were found in WHBE rabbits,and Rikenelaceae_RC9_gut_group was the most abundant,whereas ten key genera were found in JW rabbits,and Ruminococcaceae_UCG_014 was the most abundant.PICRUSt functional prediction analysis showed that there were significant differences in arachidonic acid metabolism and ether lipid metabolism between gut microbiota in the two strains of rabbit(P<0.05,P<0.01).Correlation analysis showed that TC and LDL-C levels were positively correlated with Brevundimonas,Ileibacterium,Fusobacterium,Ralstonia and Mollicutes_RF39_unclassified,and negatively correlated with Coriobacteriaeae_unclassified,Anaerovorax,Clostridium,DTU014_unclassified,Barnesiellaceae_unclassified,Ruminococcaceae_UCG_009,and Clostridiales_vadinBB60_group_unclassified.Conclusions The differences in cholesterol metabolism between male WHBE rabbits and JW rabbits may be related to differences in the structure and function of host gut microbiota,in which arachidonic acid metabolism and ether lipid metabolism pathways are particularly critical.