目的 研究饲用丁酸梭菌Clostridium butyricum (CB)芽孢对凡纳滨对虾幼虾生长性能、血清生化指标、肠道菌群组成及5种短链脂肪酸含量的影响。方法 分别将质量分数为0(对照)、0.050%、0.075%和0.100%的丁酸梭菌芽孢制剂添加到基础饲料中(饲料中的活菌数分别为0、2.50×105、3.75×105、5.00×105 CFU/g)，饲喂初始体质量为(1.42±0.02) g的凡纳滨对虾幼虾30 d，然后检测生长性能、血清生化指标、肠道菌群组成以及短链脂肪酸含量。结果 与对照组相比，饲喂30 d后对虾的体质量在0.050%和0.075% CB组显著提高(P<0.05)，质量增加率则在0.050% CB组显著提高(P<0.05)；0.075% CB组对虾的血清葡萄糖、0.100% CB组的血清尿素氮浓度显著降低(P<0.05)，0.050% CB组血清磷浓度显著上升(P<0.05)。与对照组相比，0.050% CB组浮霉菌门Planctomycetes和髌骨菌门Patescibacteria丰度显著提高(P<0.05)；0.050%和0.075% CB组弧菌属Vibrio的丰度显著降低(P<0.05)。多样性分析表明，0.050%和0.075% CB组的肠道菌群组成相似度更高，且明显不同于对照组和0.100% CB组。肠道内容物中5种短链脂肪酸的含量均随丁酸梭菌添加量的升高而增加。结论 饲料中添加CB芽孢制剂可能通过抑制肠道内潜在病原菌丰度、提高肠道短链脂肪酸的含量，改善营养物质的利用，从而提高凡纳滨对虾的生长性能。本研究中CB芽孢制剂在饲料中的适宜添加量为2.50×105或3.75×105 CFU/g。
Objective To investigate the effects of feeding Clostridium butyricum (CB) spores on the growth performance, biochemical parameters in serum, intestinal flora composition and contents of five short-chain fatty acids of Paneaus vannamei juvenile. Method Basic diets were supplemented with CB spore product of 0, 0.050%, 0.075% and 0.100% mass fraction (The viable counts of bacteria in the diets were 0, 2.50×105, 3.75×105 and 5.00×105 CFU/g respectively). The P. vannamei juveniles with (1.42 ± 0.02) g initial body weight of each were fed for 30 days，and growth performance, serum biochemical indicators, intestinal flora composition and short chain fatty acid contents were detected.Result Compared to the control group, the final body weights of the shrimps after 30 days feeding trial in the 0.050% and 0.075% CB groups significantly increased (P<0.05), and the weight gain rate significantly increased in the 0.050% CB group (P<0.05). The glucose concentration in serum of the 0.075% CB group and urea nitrogen concentration in serum of the 0.100% CB group significantly reduced (P<0.05), while the phosphorus concentration in serum of the 0.050% CB group significantly increased (P<0.05). Compared to the control group, the relative abundance of Planctomycetes and Patescibacteria significantly increased in the 0.050% CB group (P<0.05), while the relative abundance of Vibrio significantly reduced in the 0.050% and 0.075% CB groups (P<0.05). The diversity analysis indicated that the intestinal flora compositions were similar between the 0.050% and 0.075% CB groups, which were quite different from those of the control and 0.100% CB group. The intestinal contents of five short-chain fatty acids increased with dietary CB addition. Conclusion The supplementation of CB spore in diets helps to inhibit the proliferation of intestinal pathogens and increase the contents of intestinal short chain fatty acids, thus may enhance the nutrients utilization and growth performance of P. vannamei juvenile. In this study, the appropriate amount of Clostridium butyricum spore in diet is 2.50×105 or 3.75×105 CFU/g.