Lactobacillus plantarum AR495 improves stress-induced irritable bowel syndrome in rats by targeting gut microbiota and Mast cell-PAR2-TRPV1 signaling pathway

Probiotics have great potential in regulating intestinal pain.In this study,the effects of Lactobacillus plantarum AR495 on the visceral sensitivity and gut microbiota of irritable bowel syndrome(IBS)rats were studied.The results showed that tryptase released after mast cell activation and degranulation plays a key role in visceral pain,and L.plantarum AR495 reduced the stimulation of colonic mast cells and the expression of protease-activated receptor 2(PAR2)and TRPV1 in dorsal root ganglia.Research further showed that supplementation with L.plantarum AR495 increased the level of short-chain fatty acids(SCFAs)and enhanced the barrier function of the colon.In addition,the microbiota analysis of the colon indicated that L.plantarum AR495 promoted the proliferation of Bifidobacterium and inhibited the proliferation of Lachnospiraceae,which alleviated the imbalance of the intestinal microbiota caused by IBS to a certain extent.In total,L.plantarum AR495 might reduce visceral sensitivity through the Mast cell-PAR2-TRPV1 signaling pathway by maintaining the homeostasis of the intestinal barrier.

Effect of intestinal flora from children with Henoch-Sch?nlein purpura on visceral sensitivity, gastrointestinal hormones and cytokines secretion in pseudo-sterile rats

Objective:To investigate the effect of intestinal flora from Henoch-Schönlein purpura(HSP)on visceral sensitivity,gastrointestinal hormones and cytokines in pseudo-sterile rats.Methods:The pseudo-sterile rat model was established.The rats were was given fecal microbiota solutions of children with abdominal HSP and healthy children,respectively.The visceral sensitivity was determined by abdominal withdrawal reflex(AWR)which was induced by rectal balloon distention in all the rats.And serum gastrin(Gas),motilin(MTL),cholecystokinin(CCK),substance P(SP),tumor necrosis factor(TNF)-αand interleukin(IL)-6 levels in rats were measured with ELISA method.Results:The volume of rectum water injection under the score 3 of AWR in the rats administrated with fecal microbiota solution from HSP children(HSP group)was significantly decreased compared with that in the rats administrated with fecal microbiota solution from healthy children(HC group),and there was significant difference between these two groups(P<0.05).The serum Gas,MTL,CCK and SP levels were higher in HSP group than those in HC group.And serum MTL,CCK and SP levels in HSP group were significantly different from those in the HC group.The serum TNF-αandIL-6 levels were higher in HSP group than those in HC group,there was significant difference between these two groups(P<0.05).Conclusion:Intestinal flora from HSP can induce the production of visceral sensitivity,inhibit gastrointestinal hormone secretion and prompt cytokine production.

Effect of electroacupuncture on the expression of CGRP and 5-HT in the serum and colon of IBS-C rats

Objective:To investigate the effects of electricity on the expression of procalcitonin(CGRP)and serotonin(5-HT)in serum and colon in rats with constipation-type irritable bowel syndrome(IBS-C).Methods:50 rats were randomly divided into three groups:normal control group,model group,electroacupuncture group with four single points(tianshu electroacupuncture group,Colonic acupuncture group,Quchi electroacupuncture group,Shangjuxu acupoint group,and bilateral acupoint alternating between left and right),and non-meridian non-acupoint group(non-meridian non-acupoint group on both hip of electroacupuncture rats).The IBS-C model was replicated in the other three groups,except the normal control group,using the cold-fear-starvation synthesis method.After successful replication of the model,the four electroacupuncture single-point group and the non-acupoint group began electroacupuncture treatment once a day for 3 consecutive days.The visceral sensitivity and the expression of CGRP and 5-HT in serum and colon were observed.Results:Compared with the normal control group,the minimum volume threshold of abdominal retractile reflex(AWR)in the model group decreased(P<0.05),and the expressions of 5-HT and CGRP in serum and colon increased(P<0.05).Compared with the model group,AWR minimum volume threshold was increased in the electroacupuncture group with four single acupuncture points(P<0.05),the expression of 5-ht and CGRP in serum and colon was significantly decreased(P<0.05),and there was no significant change in each indicator in the non-acupuncture point group(P>0.05).Conclusion:Electroacupuncture combined with four single points can effectively improve the visceral sensitivity of IBS-C rats and regulate the levels of 5-HT and CGRP in serum and colon of rats,thus providing experimental basis for the clinical treatment of IBS-C.