Effects of feedstuff contained Clostridium butyricum on intestinal epithelial cells and bacterial community structure in Litopenaeus vannamei

【Objective】 To study effects of feedstuff contained Clostridium butyricum on intestinal epithelial cells and bacterial community structure of Litopenaeus vannamei cultured in higher ponds, and to provide technical support for culture of healthy shrimp.【Method】 C. butyricum-added group and control group were set under feeding frequency of 3 meals per day in 60 d. In C. butyricum-added group, shrimps were fed with 1% C. butyricum every morning for 3 d and stopped for 3 d, which formed a circle;in control group, shrimps were was fed without C. butyricum. Shrimp body length and mass were measured on 0 and 60 d and intestines of shrimp were sliced to analyze bacterial community structure there.【Result】 Final body mass and body length of L. vannamei in the C. butyricum-added group were 9.54±0.38 g and 9.12±0.12 cm, respectively, significantly higher than those in the control group 7.35±0.36 g and 8.25±0.10 cm(P<0.05, the same below). In bacteria-added group, shrimp intestinal tract was full, with stable and regular star-like structure pigment;while in control group, shrimp intestinal tract was empty, where pigment was light red, scattered, without fixed shape. Height of intestinal epithelial cells in the bacteria-added group was up to 40 μm, significantly higher than that of intestinal epithelial cells in the control group(10 μm). In terms of bacterial community structure in shrimp intestinal tract, relative abundance of Firmicutes and Bacteroides on 60 d accounted for 50.44% and 18.62% in bacteria-added group, respectively, which were significantly higher than 0.05% and 3.05% in the control;those of Tenericutes and Proteobacteria accounted for 10.03% and 15.69%, respectively, significantly lower than 56.25% and 38.23% in the control group. At the genus level, relative abundance of Clostridium and Lactobacillus on 60 d in experimental group accounted for 22.49% and 26.45% respectively, significantly higher than 5.02% and 0.03% in the control; Vibrio and Candidatus Bacilloplasma in the experimental group reached 8.16% and 9.18%, respectively, significantly lower than 14.39% and 55.81% in the control.【Conclusion】 Adding 1% C. butyricum to feed can significantly improve the growth performance of L. vannamei, increase intestinal epithelial cell height, alter bacterial community structure in intestinal tract, thus making intestinal beneficial for bacteria growing better, and inhibit harmful bacteria.