不同蛋白质水平饲粮对肥胖犬体况、血清生化指标、粪便短链脂肪酸浓度及肠道菌群结构的影响

Effects of Diets with Different Protein Levels on Body Condition,Serum Biochemical Indexes,Short Chain Fatty Acid Concentrations in Feces and Gut Microbiota Structure of Obese Dogs

本试验旨在评估不同蛋白质水平饲粮对肥胖犬体况、血清生化指标、粪便短链脂肪酸浓度及肠道菌群结构的影响。选取30只肥胖型拉布拉多猎犬,随机等分为3组:低蛋白质组(LP组),饲喂粗蛋白质含量为20.58%的低蛋白质饲粮;中蛋白质组(MP组),饲喂粗蛋白质含量为27.77%的中蛋白质饲粮;高蛋白质组(HP组),饲喂粗蛋白质含量为39.04%的高蛋白质饲粮)。试验期为45 d。结果表明:1)与LP组和MP组比较,HP组犬体重、体脂率以及血清甘油三酯(TG)、总胆固醇(TC)、低密度脂蛋白(LDL)含量显著降低(P<0.05)。2)与LP组和MP组比较,HP组粪便中乙酸及总短链脂肪酸浓度显著或极显著降低(P<0.05或P<0.01),丁酸浓度显著升高(P<0.05);体脂率与粪便中乙酸及总短链脂肪酸浓度呈正相关关系,与丁酸浓度呈负相关关系。3)与LP组和MP组比较,HP组肠道菌群Simpson指数显著升高(P<0.05),厚壁菌门相对丰度显著升高(P<0.05),拟杆菌门相对丰度显著降低(P<0.05),拟杆菌门/厚壁菌门比值显著降低(P<0.05);在属水平,HP组主要富集梭菌属、瘤胃球菌属及普拉梭菌属等细菌;HP组肠道菌群基因功能主要富集在黄酮和黄酮醇生物合成、色氨酸代谢及柠檬烯和蒎烯降解等7个第3层级KEGG通路上。综上所述,高蛋白质饲粮可改善肥胖犬肠道菌群结构及短链脂肪酸代谢,有减重降脂作用。

The aim of this study was to evaluate the effects of diets with different protein levels on body condi⁃tion,serum biochemical indexes,short chain fatty acid concentrations in feces and gut microbiota structure of obese dogs.Thirty obese Labrador dogs were randomly and equally divided into three groups:low protein group(LP group),dogs in this groups were fed low protein diet which had 20.58%crude protein;medium protein group(MP group),dogs in this groups were fed medium protein diet which had 27.77%crude pro⁃tein;high protein group(HP group),dogs in this groups were fed high protein diet which had 39.04%crude protein.The experimental period was 45 days.The results showed as follows:1)compared with LP group and MP group,the body weight,body fat rate,and the contents of serum triglyceride(TG),total cholesterol(TC)and low density lipoprotein(LDL)in HP group were significantly decreased(P<0.05).2)Compared with LP group and MP Group,the concentrations of acetic acid and total short chain fatty acids in feces of HP group were significantly decreased(P<0.05 or P<0.01),and butyric acid concentration was significantly in⁃creased(P<0.05).Body fat rate was positively correlated with the concentrations of acetic acid and total short chain fatty acids in feces,but negatively correlated with butyric acid concentration.3)The Simpson index of gut microbiota and the relative abundance of Firmicutes were significantly increased(P<0.05),while the rela⁃tive abundance of Bacteroides and the ratio of Bacteroides/Firmicutes were decreased in HP group compared with those in LP group and MP group(P<0.05).At genus level,Clostridium,Ruminococcus,Faecalibacteri⁃um and so on were mainly enriched in HP group.The gene functions of gut microbiota in HP group were main⁃ly concentrated in seven KEGG pathways(level 3),including flavone and flavonol biosynthesis,tryptophan metabolism,limonene and pinene degradation and so on.In summary,high protein diet can regulate the gut microflora structure and short chain fatty acids metabolism,and promote the effect of weight loss and lipid re⁃duction in obese dogs.