Objective:In order to investigate the genetic diversity of mitochondrial cytochrome b (Cytb) gene of Taenia asiatica ( T. asiatica) in Dali Bai Autonomous Prefecture (Dali Prefecture), Yunnan Province. Methods:From May 2019 to August 2021, a total of 131 samples of Taenia were collected from patients admitted to the Dali Prefecture Institute of Schistosomiasis Control, involving five locations (i.e., five groups), including Dali City (58 samples), Weishan Yi and Hui Autonomous County (Weishan County, 14 samples), Midu County (18 samples), Yangbi Yi Autonomous County (Yangbi County, 24 samples) and Eryuan County (17 samples). Primers were designed based on mitochondrial Cytb gene sequence, and part of the Cytb gene sequence was amplified by PCR, then sequenced and homology comparisons were performed. MEGA 7.0 and DNASP 5.10.01 were used to analyze the measured sequence, and data such as base composition, genetic distance, genetic diversity parameters, genetic differentiation index and gene flow were obtained. Results:The amplified fragments of Cytb gene in 131 samples of Taenia were 235 bp. After homology comparisons, they were all T. asiatica. The average contents of A, T, G and C bases were 23.8%, 42.3%, 24.0% and 9.9%, respectively. Of the 131 samples of T. asiatica, 12 haplotypes were defined. The haplotype diversity and nucleic acid diversity were 0.295 9 and 0.006 0, respectively. The ranges of genetic differentiation index and gene flow among the five groups were-0.053 00 to 0.050 40 and 4.710 31 to 162.087 66, respectively. The genetic distance between the five groups ranged from 0.003 5 to 0.009 0, of which the genetic distance between Midu County and Weishan County was the largest, and the genetic distance between Dali City and Yangbi County was the smallest. Conclusions:The mitochondrial Cytb gene of T. asiatica in Dali Prefecture has rich genetic diversity. There is frequent gene exchange among the five groups, and no significant genetic differentiation has been formed.

OBJECTIVE：To study the improvement effect of Shenling baizhu p owder on irritable bowel syndrome with diarrhea（IBS-D）model mice with anxiety ，and to elucidate its mechanism from the point of view of intestinal microecology. METHODS：C57 BL/6 mice were randomly divided into blank control group ，model group ，Shenling baizhu powder group （3.6 g/kg），with 8 mice in each group. Except for blank control group ，IBS-D model with anxiety was established in model group and Shenling baizhu powder group by giving corticosterone subcutaneously combined with intragastric administration of Folium Sennae decoction and chronic restraint treatment. After modeling ， blank control group and model group were given intragastric administration of normal saline ，and Shenling baizhu powder group was given relevant medicine intragastrically ，for consecutive 4 weeks. After last medication ，loose stools rate ，diarrhea index ，body weight ，sugar water preference percentage ，the times of crosssing open field center area and minimum pain threshold as well as the levels of BDNF in hippocampal tissue and 5-HT in serum were detected in each group. The cecal contents of mice in each group were extracted for microbial DNA extraction and sequencing； the abundance and diversity of intestinal microorganisms were analyzed by Alpha and Beta diversity analysis. RESULTS ： Compared with blank control group ，body weight ，sugar water preference percentage ，the times of crossing open field center area and minimum pain threshold as well as the levels of BDNF in hippocampal tissue ，relative abundance of Firmicutes phylum microorganism in intestine ， relative abundance of Lachnospiraceae_NK4A136_group genus microorganism were decreased significantly （P＜0.05）；loose stools rate，diarrhea index ，serum level of 5-HT，relative abundance of Verrucomicrobia phylum microorganism and relative abundance of Ackermann phylum microorganism were increased significantly （P＜0.05），and there were great differences in the types of intestinal microorganisms. Compared with model group ，body weight ，sugar water preference percentage ，the times of crossing open field center area ，minimum pain threshold ，BDNF level of hippocampus ，relative abundance of Firmicutes phylum microorganism，relative abundance of Lachnospiraceae_NK4A136_group genus microorganism were increased significantly （P＜ 0.05 or P＜0.01）；loose stools rate ，diarrhea index ，serum level of 5-HT，relative abundance of Verrucomicrobia phylum microorganism and relative abundance of Ackermann phylum microorganism were decreased significantly （P＜0.05），and and there were great differences in the types of intestinal microorganisms. CONCLUSION ：Shenling baizhu powder can improve the diarrhea and anxiety behavior of IBS-D model mice with anxiety ，increase the level of BDNF in hippocampus and decrease serum level of 5-HT. Its mechanism may be related to decreasing relative abundance of Verrucomicrobia phylum microorganism and Ackermann phylum microorganism ，increasing the relative abundance of Firmicutes phylum and Lachnospiraceae_NK4A136_group genus microorganism.