柠檬酸甘薯淀粉对齐口裂腹鱼生长及肠道菌群的影响

目的：探讨饲料中添加柠檬酸甘薯淀粉（citrate sweet potato starch，CSPS）对齐口裂腹鱼生长及肠道微环境的影响。方法：选用平均体质量为（75.47±5.43） g的齐口裂腹鱼共180 尾，随机分为5 组，每组3 个重复，每个重复12 尾鱼。对照组饲喂基础日粮，实验组分别饲喂添加3.5%、7%、14%及28%的CSPS的日粮，连续饲喂60 d后解剖齐口裂腹鱼，称质量后计算饵料系数、摄食率、特定生长率，取出肠管测定肠道黏膜皱褶高度，并对肠道菌群进行聚合酶链式反应变性梯度凝胶电泳（polymerase chain reaction-denaturing gradient gel electrophoresis，PCR-DGGE）分析。结果：7%及14%的剂量组的末质量、摄食率、特定生长率显著高于对照组（P＜0.05）；14%、28%剂量组前肠黏膜皱褶高度显著低于对照组（P＜0.05）。在中肠，对照组中肠道菌群与3.5%剂量组相似度最高。在前后肠，对照组与其他各剂量组肠道菌群相似度均较低，但50.0≤q＜75.0（中度相似）。结论：低剂量（7%）的CSPS能够促进生长，而高剂量（28%）会抑制生长，CSPS能影响齐口裂腹鱼的肠道菌群。

Effect of RS4-Type Sweet Potato Resistant Starch on Growth and Intestinal Microenvironment of Schizothorax prenanti Tchang

Objective: To investigate the effect of dietary supplementation of citrate sweet potato starch (CSPS), prepared
using esterification with citric acid, on the growth and intestinal microenvironment of Schizothorax prenanti Tchang.
Methods: Totally 180 fish with an average body weight of (75.47 ± 5.43) g were randomly divided into five groups of 12
fish in each group, with three replicates for each group. Control group was fed a basal diet, and three test groups were fed
a diet supplemented with CSPS at doses of 3.5%, 7%, 14% and 28%, respectively. Sixty days later, all fish were weighed
and dissected, and feed conversion rate, feeding rate and specific growth rate were calculated. After removing the intestine,
the intestinal mucosa height was measured. The intestinal flora was analyzed by PCR-DGGE. Results: Compared with the
control group, final body weight, feeding rate and specific growth rate were significantly increased in 7% and 14% CSPS
groups (P ＜ 0.05). Foregut plica mucosa height was significantly decreased in 14% and 28% CSPS groups (P ＜ 0.05). As
for the midgut, the intestinal flora in 3.5% CSPS group was more similar to in the control group. The foregut and hindgut
intestinal flora revealed an extremely significant difference between the control group and three test groups, despite showing
50.0 ≤ q ＜ 75.0 (moderate similar). Conclusion: The growth of Schizothorax prenanti Tchang is promoted by dietary
supplementation of CSPS at a low dose (7%) but inhibited at a high dose (28%). At the same time, CSPS can affect the
intestinal flora of Schizothorax prenanti Tchang.