摘要
The increased concentrate amounts in cow diets may initiate changes in both particle-associated (PaM) and epimural microbiota (EpM) with the potential for promoting the establishment of pathogens. Clay minerals have shown promising potentials in binding harmful microorganisms and metabolites due to their high adsorption capacity. This study evaluated the effects of a clay-mineral based product (CM) on PaM, EpM, fermentation parameters, and epithelial gene expression in cows fed a high-concentrate diet. Eight rumen-cannulated non-lactating Holstein cows received a concentrate mix supplemented with CM or not (CON) in a change-over design with an initial 100% roughage diet phase (RD, 1 week), followed by intermittent 65%-high-concentrate-diet phases (HC1, HC2; 1 and 2 week duration, respectively), interrupted by 1 week roughage only. Rumen samples for short-chain fatty acids, ammonia, and lactate quantification, as well as PaM, and epithelial biopsies for EpM examination and epithelial gene expression were collected via the cannula once during each feeding phase. Phylogenetic distance analysis of Illumina MiSeq sequencing of the 16S rRNA gene region V345 showed a clear clustering of RD microbiota compared to HC in PaM, showing the impact of the high-concentrate diet on the bacterial community. In the EpM this effect was less pronounced, due to higher variability in RD. In the PaM, a decrease (P < 0.01) of community diversity occurred with the onset of HC feeding, while in the EpM there was an increase in diversity (P < 0.05). In the PaM, CM increased the relative abundance of genus Butyrivibrio (P < 0.01), a commensal bacterium of the rumen, which was, with 6.4%, the second most abundant genus. There, the CM supplementation decreased the genera Lactobacillus, Fusobacterium, and Treponema (P = 0.05), which are potentially either lactate producing or opportunistic pathogens. In the EpM, CM decreased the relative abundance of Succiniclasticum genus (P < 0.01), a possible endotoxin producer, and increased bacteria that are associated with a normobiotic rumen, such as Campylobacter (P = 0.06). Barrier function genes were upregulated in HC2 and nutrient transport genes downregulated in HC1 (P < 0.05); however, there was little effect on pro-inflammatory genes at the epithelium. The CM showed a significant decreasing effect on the cellular metabolism genes HMGCS1 (P = 0.04). Our results suggest that CM supplementation can increase the relative abundance of commensal microbiota and decrease bacteria that could negatively impact the rumen milieu and health during high-concentrate feeding.
摘要译文
奶牛日粮中浓缩物含量的增加可能会引发颗粒相关（PaM）和硬膜外微生物群（EpM）的变化，并可能促进病原体的建立。粘土矿物质因其高吸附能力而在结合有害微生物和代谢物方面显示出令人鼓舞的潜力。这项研究评估了粘土矿物质产品（CM）对高浓度日粮奶牛的PaM，EpM，发酵参数和上皮基因表达的影响。八头瘤胃插管的非哺乳期荷斯坦奶牛，在设计初期以100％粗饲料阶段（RD，1周）为基础，进行了混合添加或不添加CM（CON）的浓缩混合饲料，随后间歇性地添加了65％（高）饲料。集中饮食阶段（HC1，HC2；分别为1周和2周），仅被1周粗加工中断。在每个进食阶段，通过套管收集一次用于短链脂肪酸，氨和乳酸盐定量的瘤胃样品，以及PaM，以及用于EpM检查和上皮基因表达的上皮活检样品。对16S rRNA基因区域V345进行Illumina MiSeq测序的系统发生距离分析显示，与PaM中的HC相比，RD微生物群明显聚集，表明高浓度饮食对细菌群落的影响。在EpM中，由于RD的可变性较高，因此这种影响不太明显。在PaM中，随着HC摄入的开始，群落多样性降低（P <0.01），而在EpM中，多样性增加（P <0.05）。在PaM中，CM增加了瘤胃的常见细菌Butyrivibrio属的相对丰度（P <0.01），其含量为6.4％，是第二丰富的属。在那里，添加CM可以减少乳酸杆菌属，梭菌属和螺旋体属（P = 0.05），它们可能是产生乳酸或机会性病原体。在EPM中，CM降低了可能产生内毒素的琥珀色菌属的相对丰度（P <0.01），并增加了与正常瘤胃相关的细菌，例如弯曲杆菌（Py = 0.06）。 HC2中的屏障功能基因被上调，而HC1中的营养转运基因被下调（P <0.05）；然而，对上皮的促炎基因影响不大。 CM对细胞代谢基因HMGCS1有显着降低作用（P = 0.04）。我们的结果表明，在高浓度喂养期间，补充CM可以增加共生微生物的相对丰度，并减少可能对瘤胃环境和健康产生负面影响的细菌。
ViktoriaNeubauer[a][b][c];ElkeHumer[a];EvelyneMann[b];IrisKröger[a];NicoleReisinger[d];MartinWagner[b][c];QendrimZebeli[a];Renee M.Petri[a]. Effects of clay mineral supplementation on particle-associated and epimural microbiota, and gene expression in the rumen of cows fed high-concentrate diet[J]. Anaerobe, 2019,59: 38-48