Abstract: Constipation is a common gastrointestinal disease frequently accompanied by abnormal intestinal motility and flora composition. The in vitro physiological characteristics of 45 strains of Lactobacillus were tested in the current study. Out of these, three strains were screened for in vivo functionality evaluation. Meanwhile, we evaluated the regulatory effect of Lactobacillus on intestinal motility and flora. The results indicated that survival rates of the selected strains, Lactobacillus casei LC9, Lactobacillus fermentum LF37 and Lactobacillus rhamnosus LR45, were all higher than 10% when exposed to acid and bile salt. All three strains were able to utilize oligofructose, xylo-oligosaccharide and galacto-oligosaccharide and the production of short chain fatty acids by each strain exceeded 1.2 mmol/L. Furthermore, a series of improved bowel functions were observed in the probiotic group, as manifested by the increased intestinal propulsion rate, the reduced first black stool defecation time, the augmented water content in feces, and the enhanced intestinal motility. The selected Lactobacillus could increase the relative abundance of beneficial bacteria in the mouse fecal flora and improve the structure of the fecal flora. The above results indicate that the three screened strains can regulate intestinal functions in mice, indicating their application potential.

Key words: Lactobacillus, intestinal motility, intestinal flora, screening