Abstract: 【Objective】 The aim of this study was to understand the effect of Xiaochengqi powder on the intestinal microbiota of sows with constipation and investigate the mechanism of Xiaochengqi powder to alleviate constipation.【Method】 A total of 27 bi-crossbreeding sows (Yorkshire×Landrace,3-5 fetal periods) were selected and divided into healthy control group,constipation group and experimental group according to fecal conditions,each group had 3 replicates and each replicate had 3 pigs.The pigs in healthy control group and pigs in constipation group were given normal diets,and experimental group were added Xiaochengqi powder to the diet (60 g/(head·d)) once daily for three consecutive days.The fresh fecal samples of each group were collected on the fourth day,and the total DNA of the microbial genome was extracted.The microbial community diversity of the samples was detected using Illumina MiSeq sequencing technology.【Result】 The microbial flora in the feces of constipation group was significantly changed,and the Simpson index was significantly different from healthy control group and experimental group (P＜0.05).At the phylum level,there was a significant decrease in Firmicutes and Bacteroidetes (P＜0.05) and extremely significant increase in Proteobacteria (P＜0.01) in the gut microbiome of the sows in constipation group compared to healthy control group.Compared with constipation group,Bacteroidetes were significantly increased (P＜0.05),and Firmicutes had on increating tendency (P>0.05), and Proteobacteria were extremely significantly reduced (P＜0.01) in experimental group.At the genus level,Lactobacillus and Prevotella were extremely significantly decreased (P＜0.01),Clostridium_ⅪVa,Ruminococcaceae and Lachnospiraceae were significantly decreased (P＜0.05),while Acinetobacter and Escherichia_Shigella were extremely significantly increased(P＜0.01),Clostridium_sensu_stricto and Romboutsia were both significantly increased (P＜0.05) in the intestinal microbiome of sows in constipation group compared to healthy control group.In experimental group,there was an extremely significant increase in Prevotella (P＜0.01),a significant increase in Lachnospiraceae (P＜0.05),and an extremely significant decrease in Acinetobacter compared to constipation group (P＜0.01).Acetic acid,butyric acid,and propionic acid concentrations in the stools of sows in experimental group were all be considerably increased compared to constipation group (P＜0.05).【Conclusion】 Xiaochengqi powder might enhance the intestinal microbiome structure of sows with constipation,increase the amount of short-chain fatty acids (SCFAs) in the intestine,and accomplish a new balance of intestinal microorganisms.

Key words: Xiaochengqi powder; constipation sows; intestinal microbial community; short-chain fatty acids