Grimm P, Philippeau C, Julliand V
1UMR PAM A 02.102 Université Bourgogne-Franche-Comté/AgroSup Dijon,26 Boulevard Docteur Petitjean,F-21079 Dijon,France.
2AgroSup Dijon,26 Boulevard Docteur Petitjean,F-21079 Dijon,France.
Animal. 2017 Jul;11(7):1136-1145. doi: 10.1017/S1751731116002779. Epub 2017 Jan 9.
Faeces could be used for evaluating the balance of the equine hindgut microbial ecosystem, which would offer a practical method for assessing gut health and how this relates to disease. However, previous studies concluded that faeces microbial ecosystem was not representative of the proximal hindgut (caecum and ventral colon). This study aimed to evaluate if variations of the faecal microbial ecosystem were similar to those observed in the proximal hindgut. Six horses, fistulated in the caecum and right ventral (RV) colon, were subjected to a gradual change of diet, from a 100% hay (high fibre) diet (2.2 DM kg/day per 100 kg BW) to a 57% hay+43% barley (high starch) diet (0.8 DM kg/day per 100 kg BW hay and 0.6 DM kg/day per 100 kg BW barley). The two diets were iso-energetic and fed over a 3-week trial period. Samples of digesta from the caecum, RV colon and faeces were collected two times on the 10th and 20th day of the trial, for each diet to assess the microbial ecosystem parameters by both classical culture technics and biochemical methods. The variations observed in the caecal and colonic bacterial composition (increase in total anaerobic, amylolytic and lactate-utilizing and decrease in cellulolytic bacteria concentrations) and microbial activity (changes in volatile fatty acids concentrations and increase in lactate concentrations) demonstrated that the hay+barley diet caused changes in the hindgut microbial ecosystem. Similar variations were observed in the faecal microbial ecosystem. Feeding the hay+barley diet resulted in higher concentrations of faecal lipopolysaccharides. The functional bacterial group concentrations (cellulolytics, amylolytics and lactate utilizers) were significantly correlated between caecum and faeces and between colon and faeces. From analyses of the metabolites produced from microbial activity, only valerate concentration in the caecum and the proportion of propionate were significantly correlated with the same parameters in the faeces. Results of the principal component analysis performed between all the caecal/faecal and colonic/faecal parameters revealed that the total anaerobic and cellulolytic bacteria concentrations, as well as valerate, l-lactate and lipopolysaccharide concentrations were strongly correlated with several microbial parameters in the caecum (P|0.45|) and in the colon (P|0.50|). This demonstrated that faecal samples and their bacterial analyses could be used to represent caecum and RV colon hindgut microbial ecosystem in terms of variations during a change from a high-fibre to a high-starch diet, and thus could be markers of particular interest to diagnostic proximal hindgut microbial disturbances.
粪便可用于评估马后肠微生物生态系统的平衡，这将为评估肠道健康及其与疾病的关系提供一种实用方法。然而，先前的研究得出结论，粪便微生物生态系统不能代表近端后肠（盲肠和腹侧结肠）。本研究旨在评估粪便微生物生态系统的变化是否与近端后肠中观察到的变化相似。六匹在盲肠和右腹侧（RV）结肠处做了造瘘的马，经历了饮食的逐渐变化，从100%干草（高纤维）日粮（每100千克体重每天2.2干物质千克）转变为57%干草 + 43%大麦（高淀粉）日粮（每100千克体重每天0.8干物质千克干草和每100千克体重每天0.6干物质千克大麦）。这两种日粮能量相等，在为期3周的试验期内投喂。在试验的第10天和第20天，针对每种日粮，从盲肠、RV结肠和粪便中采集消化物样本两次，通过经典培养技术和生化方法评估微生物生态系统参数。在盲肠和结肠中观察到的细菌组成变化（总厌氧菌、淀粉分解菌和利用乳酸菌增加，纤维素分解菌浓度降低）以及微生物活性变化（挥发性脂肪酸浓度变化和乳酸浓度增加）表明，干草 + 大麦日粮导致了后肠微生物生态系统的变化。在粪便微生物生态系统中也观察到了类似的变化。投喂干草 + 大麦日粮导致粪便中脂多糖浓度升高。盲肠与粪便之间以及结肠与粪便之间的功能性细菌群浓度（纤维素分解菌、淀粉分解菌和利用乳酸菌）显著相关。从微生物活性产生的代谢物分析来看，只有盲肠中的戊酸浓度和丙酸比例与粪便中的相同参数显著相关。对所有盲肠/粪便和结肠/粪便参数进行主成分分析的结果表明，总厌氧菌和纤维素分解菌浓度以及戊酸、L - 乳酸和脂多糖浓度与盲肠（P|0.45|）和结肠（P|0.50|）中的几个微生物参数密切相关。这表明，在从高纤维日粮转变为高淀粉日粮的过程中，粪便样本及其细菌分析可用于代表盲肠和RV结肠后肠微生物生态系统的变化，因此可能是诊断近端后肠微生物紊乱特别值得关注的指标。
