度洛西汀对肠易激综合征小鼠内脏高敏感及微生物群落的影响OACSTPCD

Objective To investigate the effects of duloxetine on visceral sensitivity in mice with irritable bowel syndrome(IBS)in-duced by water avoidance stress(WAS),and explore its effect on fecal microbiota and biochemical indicators related to tumor necrosis factor-α(TNF-α)and oxidative stress in intestinal tissues.Methods Eighteen 8-week-old C57BL/6 mice were randomly divided into three groups:control group,WAS+PBS group,and WAS+duloxetine group,with six mice in each group.The mice in control group were placed on the central platform of an empty water tank for 1 h daily and administered with 200 µL PBS by gavage.The mice in WAS+PBS group received 200 µL PBS by gavage after WAS.The mice in WAS+duloxetine group were administered with 200 µL PBS containing 3 mg/mL duloxetine by gavage after WAS.The WAS model was established through continuous stimulation of water avoidance stress for 10 d.After modeling,the abdominal wall retraction reflex(AWR)score was used to assess the changes of visceral sensitivity.16S rDNA sequencing and fungal ribosomal DNA internal transcribed spacer(ITS)sequencing were employed to analyze the diversity,the species composition,and the differential species of bacteria and fungi in the feces of mice in each group.Simulta-neously,TNF-α and oxidative stress-related biochemical indicators,including total superoxide dismutase(T-SOD),glutathione peroxi-dase(GSH-Px),and malondialdehyde(MDA),were measured in the duodenal and ascending colonic tissues.Results Compared with control group,the visceral sensitivity of mice was significantly increased in WAS+PBS group(P<0.05);compared with WAS+PBS group,the visceral sensitivity of mice was significantly decreased in WAS+duloxetine group(P<0.05).In terms of α-diversity,Chao index of bacterial communities in WAS+duloxetine group was significantly lower than that in control group(P<0.05),while other indices showed no significant differences between two groups.For fungal communities,both Chao index and Sobs index were signifi-cantly lower in WAS+PBS group and WAS+duloxetine group than in control group(P<0.05),while other indicators showed no signifi-cant change.In terms of β-diversity,there were significant differences in the fecal bacterial composition among the three groups(P<0.05),with a distinct separation between water avoidance stress+duloxetine group and the other two groups.LDA analysis using LefSe revealed that the bacteria mainly included Erysipelotrichaceae,Allobaculum,Akkermansia,and Verrucomicrobiales in control group,Eubacterium_siraeum_group in WAS+PBS group,and Lactobacillus and Desulfovibrio in WAS+duloxetine group.For fungi,the bio-markers encompassed Ceratocystidaceae,Plectosphaerellaceae,Chordomycetes,Candida,and some unclassified genera in control group,Microascaceae in WAS+PBS group,and Dipodascaceae and an unclassified genus within this family in WAS+duloxetine group.Biochemical test results showed that compared with control group,TNF-α level was significantly increased in the duodenal and ascending colonic tissues of mice in WAS+PBS group(P<0.05),while TNF-α level did not increase significantly in WAS+duloxetine group(P>0.05).There were no significant differences in oxidative stress-related biochemical indicators(T-SOD,GSH-Px,MDA)between the three groups(P>0.05).Conclusion Duloxetine can reduce the visceral hypersensitivity induced by WAS and exert the certain effect on intestinal microbiota,but it has no significant impacts on TNF-α and oxidative stress-related biochemical indicators in duodenal and ascending colonic tissues.