Abstract: The effects of co-administration of a mixed probiotic culture of Lactobaccillus acidophilus and Clostridium butyricum and litchi polyphenol on the intestinal morphology and intestinal flora of mice with diarrhea were explored. A mouse model of diarrhea was established by intragastrical administration of castor oil. After four days of treatment with different medications, the duodenum, jejunum and ileum of mice were harvested and fixed in formalin solution for paraffin sectioning and HE staining, and then examined under an inverted microscope. Intestinal villus length and crypt depth were measured and the ratio of villus length to crypt depth (V/C) was also calculated. Feces were sterilely obtained for analysis of the change in intestinal microbiota by polymerase chain reaction (PCR)-denaturing gradient gel electrophoresis (DGGE). The dominant DGGE bands were recovered, cloned and sequenced, and the sequences were analyzed by BLAST. Results showed that Lactobacilli acidophilus alone and in combination with Clostridium butyricum could increase the V/C ratio of duodenum and jejunum, and the combination of the mixed probiotic culture and litchi polyphenol could improve the V/C ratio of jejunum and ileum. The DGGE fingerprint and the sequencing results showed that Lactobacilli acidophilus, the mixed probiotic culture alone and in combination with litchi polyphenol could increase the abundance and micro-ecological stability of intestinal flora in mice with diarrhea. In addition, the mixed probiotics could also increase the complexity of the intestinal bacterial community. More dominant bands were observed for all three treatment groups compared with the normal and model groups. Furthermore, new bands were also obtained with the mixed probiotics and its combination with litchi polyphenol. The best effect was observed with the mixed probiotics.

Key words: compound probiotics-litchi polyphenol, diarrhea, intestinal structure, intestinal flora