不同饲养方式下藏猪盲肠与结肠细菌群落的差异分析

Differential Composition of Bacterial Communities in Cecum and Colon of Tibetan Pigs under Different Feeding Methods

为了探讨不同饲喂方式与不同肠段间藏猪细菌群落组成的差异性,部分阐明藏猪肠道微生物的特异性。选用两年龄的放牧与舍饲藏猪各3头,分别采集盲肠与结肠食糜样品,测定细菌16S rRNA基因的V3-V4区域,分析细菌群落的组成,探讨盲肠与结肠细菌群落的空间差异格局;采用Person相关性分析探索盲肠与结肠细菌群落的相关性。结果表明,不同饲养方式下,在门水平细菌群落分别有4个差异分类单元,在属水平盲肠中有19个差异分类单元、结肠中有9个差异分类单元。不同饲养方式下,藏猪细菌群落的Beta多样性表现出明显的差异性。在放牧养殖条件下,藏猪的盲肠食糜中拟杆菌门、变形菌门和TM7的相对丰度显著高于结肠(P<0.05),厚壁菌门、螺旋体门、放线菌门、软壁菌门与疣微菌门相对丰度两个肠段间无显著差异(P>0.05)。放牧藏猪盲肠中Unclassified_Ruminococcaceae(厚壁菌门、瘤胃球菌科)、Unclassified_Clostridiales(厚壁菌门、梭菌目)、Unclassified_Bacteroidales(拟杆菌门、拟杆菌目)、Turicibacter(厚壁菌门、苏黎世杆菌科)与梭菌属(厚壁菌门、梭菌科)相对丰度显著高于结肠(P<0.05),但链球菌属(厚壁菌门、链球菌科)相对丰度显著低于结肠(P<0.05)。舍饲藏猪盲肠与结肠间细菌群落无显著差异(P>0.05)。放牧藏猪盲肠与结肠中细菌群落关联网络中各节点联系较为紧密,彼此间呈现竞争或者协同作用,舍饲藏猪盲肠与结肠细菌群落关联网络中各节点联系较为松散。结果说明,饲养方式影响藏猪肠道中细菌群落的组成,放牧养殖条件下藏猪肠道细菌表现出更加多元的状态。

In the aim of exploring the differences in bacterial community composition between different feeding methods and different intestinal segments of Tibetan pigs,and partially elucidating the specificity of intestinal microorganisms in Tibetan pigs,this study employed three grazing and three housed Tibetan pigs of two different age groups to collect cecal and colonic surimi samples,and the V3-V4 regions of bacterial 16S rRNA genes were sequenced to analyze the bacterial community composition,and thereby to explore spatial differences in cecal and colonic bacterial communities.Person correlation analysis was used to investigate the correlation between cecal and colonic bacterial communities.The results showed that there were 4 different taxa at phylum level,19 different taxa at genus level in cecum and 9 different taxa in colon,respectively.The Beta diversity of bacterial community of Tibetan pigs exhibited significant variation under different feeding methods.Specifically,under grazing conditions,the relative abundance of Bacteroidetes,Proteobacteria and TM7 in cecal chyme of Tibetan pigs was significantly higher than that in colon(P<0.05),but there was no significant difference in the relative abundance of Firmicutes,Spirochetes,Actinobacteria,Tenericutes and Verrucobacteria between two intestinal segments(P>0.05).The relative abundance of Unclassified_Ruminococcaceae(Firmicutes,Ruminococcaceae),Unclassified_Clostridiales(Firmicutes,Clostridium),Unclassified_Bacteroidales(Bacteroidetes,Bacteroidales),Turicibacter(Firmicutes,Turicibacteraceae)and Clostridium(Firmicutes,Clostridiaceae)was significantly higher than that of colon(P<0.05),but the relative abundance of Streptococcus(Firmicutes,Streptococcaceae)was significantly lower than that of colon(P<0.05).There was no significant difference in bacterial community between cecum and colon of captive Tibetan pigs(P>0.05).Furthermore,the nodes in the association network of bacterial communities in cecum and colon of grazing Tibetan pigs were closely connected,indicating competition or synergism with each other.In contrast,the nodes in the association network of bacterial communities in cecum and colon of captive Tibetan pigs were loosely connected.The results indicated that feeding methods affectted the composition of bacterial communities in the intestinal tract of Tibetan pigs,and the intestinal bacteria of Tibetan pigs exhibited greater diversity under grazing farming conditions.