Effects of intestinal microbiota of patients with chronic constipation on the expression of serotonin transporter and the bowel movement in mice / 中华消化杂志

ABSTRACT

Objective To investigate the effects of intestinal microbiota of patients with chronic constipation on the expression of serotonin transporter (SERT) and the bowel movement in mice.Methods Fecal samples of patients with slow transit constipation met Rome Ⅲ criteria and healthy normal controls were collected and made into fecal microbiota solution.Twenty specfic pathogen free (SPF) mice were divided into experiment group and control group.The mice of two groups were both pre-treated with streptomycin to establish the germ-free mice model.The mice of control group were gavaged with mixed fecal microbiota solution of healthy normal controls and the mice of experiment group were gavaged with mixed fecal microbiota solution of patients with chronic constipation.Mice were sacrificed after fed for 15 days.Defecation parameters and ink discharge time of mice were detected.The expressions of SERT mRNA and SERT protein in mice intestinal tissues were detected with real time-polymerase chain reaction and Western blotting.The 5-hydroxytryptamine (5-HT) levels of mice intestinal tissues were evaluated by enzyme-linked immunosorbent assay (ELISA) and double immunofluorescent staining.The methods of t test and Chi-square test were performed for statistical analysis.Results On the 15th day,the total number of the feces within 2 h of the experiment group and control group was 8.55±1.83 and 12.14±2.90,respectively,and the difference was statistically significant (t=3.33,P＜0.05).The weight of feces were (151.90 ± 32.42) mg and (246.72 ± 64.01) mg,respectively,and the difference was statistically significant (t=4.18,P＜0.01).The dry weight of feces were (65.52±11.76) mg and (92.93±23.07) mg,respectively,and the difference was statistically significant (t=3.37,P＜0.05).The water content of feces were (56.63 ± 3.01) ％ and (61.95 ± 3.70) ％,respectively,and the difference was statistically significant (t=3.57,P＜0.05).The defecating time of first black feces of the experiment group and control group were (83.24±11.31) min and (69.06±2.72) min,respectively,and the difference was statistically significant (t=-2.74,P＜0.05).The expressions of SERT mRNA and SERT protein levels in mice intestine tissues of the experiment group were significantly higher than those of the control group (t =2.61,-6.89;both P＜0.05).5-HT level of mice intestinal tissues of the experimental group and control group were (151.69± 10.18) ng/mL and (198.77 ± 25.99) ng/mL,respectively,and the difference was statistically significant (t=-4.13,P＜0.01).Conclusion Intestinal microbiota of patients with chronic constipation may influence the expression of SERT in the mice intestinal tissues,and then decrease the level of 5-HT,slowing the bowel movement in mice.