Pinna Carlo, Vecchiato Carla Giuditta, Delsante Costanza, Grandi Monica, Biagi Giacomo
Department of Veterinary Medical Sciences, University of Bologna, via Tolara di Sopra 50, 40064 Ozzano Emilia (BO), Italy.
Animals (Basel). 2021 Jan 18;11(1):225. doi: 10.3390/ani11010225.
Canine faecal microbial populations and metabolome are being increasingly studied to understand the interplay between host and gut microbiome. However, the distribution of bacterial taxa and microbial metabolites throughout the canine stool is understudied and currently no guidelines for the collection, storage and preparation of canine faecal samples have been proposed. Here, we assessed the effects that different sampling points have on the abundance of selected microbial populations and bacterial metabolites within the canine stool. Whole fresh faecal samples were obtained from five healthy adult dogs. Stool subsamples were collected from the surface to the inner part and from three equally sized areas (cranial, central, caudal) along the length axis of the stool log. All samples were finally homogenised and compared before and after homogenisation. Firmicutes, Bacteroidetes, cluster I, spp., spp. and spp. populations were analysed, as well as pH, ammonia and short-chain fatty acids (SCFA) concentrations. Compared to the surface of the stool, inner subsamples resulted in greater concentrations of SCFA and ammonia, and lower pH values. qPCR assay of microbial taxa did not show any differences between subsamples. Homogenisation of faeces does not affect the variability of microbial and metabolome data. Although the distribution patterns of bacterial populations and metabolites are still unclear, we found that stool subsampling yielded contradictory result and biases that can affect the final outcome when investigating the canine microbiome. Complete homogenisation of the whole stool is therefore recommended.
为了解宿主与肠道微生物群之间的相互作用，犬类粪便微生物种群和代谢组正受到越来越多的研究。然而，犬类粪便中细菌类群和微生物代谢物的分布研究不足，目前也尚未提出犬类粪便样本采集、储存和制备的指导原则。在此，我们评估了不同采样点对犬类粪便中选定微生物种群丰度和细菌代谢物的影响。从五只健康成年犬获取了新鲜的完整粪便样本。沿着粪便条的长度轴，从表面到内部以及从三个大小相等的区域（头端、中部、尾端）采集粪便子样本。所有样本最终进行匀浆，并对匀浆前后进行比较。分析了厚壁菌门、拟杆菌门、第一类群、 属、 属和 属种群，以及pH值、氨和短链脂肪酸（SCFA）浓度。与粪便表面相比，内部子样本的SCFA和氨浓度更高，pH值更低。微生物类群的qPCR检测在子样本之间未显示出任何差异。粪便匀浆不影响微生物和代谢组数据的变异性。尽管细菌种群和代谢物的分布模式仍不清楚，但我们发现粪便子采样会产生矛盾的结果和偏差，在研究犬类微生物群时可能会影响最终结果。因此，建议对整个粪便进行完全匀浆。
