黏附性双歧杆菌对小鼠便秘的缓解作用及对小鼠肠道菌群及肠道形态的影响OA北大核心CSTPCD

Objective:To explore the relieving effect of adhesive Bifidobacterium on constipation and its effect on intestinal flo-ra and intestinal morphology in mice.Methods:Detection of adhesion of 14 strains of Bifidobacterium.Fifty mice were randomly divid-ed into control group,model group,positive drug group,low adhesion group and high adhesion group,with 10 mice in each group.The control group and model group received 0.2 ml sterile double distilled water,the positive drug group received 0.2 ml 1.52 mg/kg lactulose solution,and the low and high adhesion groups received 0.2 ml 109 CFU/ml corresponding to Bifidobacterium solution for 37 days.The constipation model was established from the 31st day.The other 4 groups except the control group were given 0.2 ml 10 mg/(kg·bw)loperamide hydrochloride aseptic aqueous solution for 7 days.After the establishment of the model,each mouse was fed with 0.2 ml activated carbon suspension,and the excretion time of the first black stool was measured.After fasting for 12 hours,the mice were given aseptic double steamed water or loperamide hydrochloride,and 1 hour later,0.2 ml activated carbon suspension was given to the stomach.After 30 min,all the mice were killed.The distance between the intestinal length and the intestinal propul-sion of the activated carbon suspension was measured,and the intestinal propulsion rate was calculated.The fresh feces of mice on the 30th and 36th day were collected within 4 hours,and the fecal moisture content and short chain fatty acid(SCFAs)content were deter-mined.Observation of histology of small intestine by HE staining.The expression of zonula occluden-1(ZO-1)and Occludin was detected by immunofluorescence.Detection of aquaporin,c-kit and serotonin related gene transcription by qRT-PCR.The levels of 5-hydroxytryptamine(5-HT),IL-1β and TNF-α were detected by ELISA.The relative content of intestinal microflora was detected by 16S rRNA high-throughput sequencing.Results:CCFM 622,CCFM 624,CCFM 626,CCFM 641 and CCFM 642 were selected as the bacteria group used in the low adhesion group,and CCFM 16,CCFM 625,CCFM 643,CCFM 666 and CCFM 668 as the bacteria group used in the high adhesion group.Compared with control group,the first black stool excretion time,AQP4,AQP8 mRNA,5-HT,IL-1β and TNF-α levels in the model group,positive drug group,low adhesion group and high adhesion group increased(P<0.05),while the intestinal propulsion rate,fecal water content,ZO-1,Occludin fluorescence intensity,c-kit,5-HT4R,Tph1 mRNA,acetic acid,propionic acid and butyric acid decreased(P<0.05).Compared with positive drug group and high adhesion group,the first black stool excretion time,AQP4,AQP8 mRNA,5-HT,IL-1β and TNF-α in low adhesion group increased(P<0.05),while intestinal pro-pulsion rate,fecal water content,ZO-1,Occludin fluorescence intensity,c-kit,5-HT4R,Tph1 mRNA,acetic acid,propionic acid and butyric acid decreased in low adhesion group(P<0.05).In the control group,the mucosal structure was intact,the small intesti-nal villi were neat and uniform,there was no injury or wrinkle,and the cell structure was intact;in model group,the intestinal villi were seriously ruptured and atrophied,and the goblet cells were incomplete;compared with model group,the morphology of small intestinal villi in positive drug group,low adhesion group and high adhesion group were improved,and the number of goblet cells increased,and the improvement in positive drug group and high adhesion group were more obvious than that in low adhesion group.Compared with control group,the Shannon index and Firmicutes/Bacteroidetes(F to B)ratio in model group decreased(P<0.05),and there were differences in genus level(P<0.05).Compared with model group,Shannon index and F to B ratio increased in positive drug group,low adhesion group and high adhesion group(P<0.05).The sample points in the model group could be distinguished from the control group,positive drug group,low adhesion group and high adhesion group,but the coincidence degree of sample points in control group,positive drug group,low adhesion group and high adhesion group were higher.Conclusion:Bifidobacterium can regu-late intestinal flora of constipation mice,improve intestinal running efficiency and protect intestinal mucus barrier.Bifidobacterium with high adhesion is better than Bifidobacterium with low adhesion in relieving constipation in mice.