Background Intestinal inflammation is a common and serious health problem in piglet production,especially enteritis caused by pathogenic Escherichia coli(E.coli).This condition often leads to high mortality,slow weigh...Background Intestinal inflammation is a common and serious health problem in piglet production,especially enteritis caused by pathogenic Escherichia coli(E.coli).This condition often leads to high mortality,slow weight gain,and significant economic losses.Results In this study,we isolated an E.coli strain,SKLAN202302,from the colon of diarrheal piglets to create an intestinal inflammation model for evaluating the protective effects of baicalin.Piglets infected with E.coli exhibited significant reductions in body weight,feed intake,small intestine length,and ileal goblet cell count(P<0.05),along with deteriorated ileal morphology.However,baicalin supplementation resulted in body weights,feed intake,and intestinal morphology similar to those of the control group.Notably,there was a significant increase in the colonization of Lactobacillus species,particularly Lactobacillus_reuteri,Lactobacillus_amylovorus,and Lactobacillus_johnii,compared to the E.coli group(P<0.05).At the metabolic and transcriptional levels,E.coli infection increased inflammatory mediators,including eicosanoids(leukotriene F4,prostaglandin F1a,leukotriene E4,thromboxane B2,prostaglandin G2,and PGH2),monosaccharides,and TCA cycle intermediates(oxoglutaric acid,glutaric acid,adipic acid,citric acid,and isocitric acid)in the ileum.It also promoted the expression of genes related to autoimmune diseases and the Th17 differentiation signaling pathway(CTLA4,IFN-ALPHA-8,IL12RB2,TRAV3,TRAV16,FOS,and VEGFA),as well as inflammatory factors.Conversely,baicalin supplementation not only counteracted these effects but also enhanced the presence of metabolites such as phospholipids[including lyso PC(P-18:1(9Z)/0:0),PC(17:0/0:0),lyso PC(16:1(9Z)/0:0),PC(18:0/0:0),lyso PC(18:0/0:0),PA(10:0/i-16:0),and PA(10:0/8:0)]and amino acids.It also regulated genes within the IL-17 signaling pathway(IL4,CCL17,CXCL10,IFNG,and CXCL2),suggesting a mechanism by which baicalin mitigates E.coli-induced intestinal and microbial disturbances.Subsequent flow cytometry analysis showed that E.coli infection increased the numbers of CD3+and Foxp3+cells,decreased IL-17A+cells,and reduced Th17/Treg ratios.Baicalin supplementation restored these parameters to control levels.Conclusions Baicalin supplementation effectively alleviates E.coli-induced intestinal inflammation and microbial disturbances in piglets by enhancing beneficial Lactobacillus colonization,counteracting inflammatory mediators,and regulating immune-related gene expression and the Th17/Treg balance.These findings highlight baicalin's potential in alleviating intestinal inflammation.展开更多
Background Colitis caused by bacterial infection is a major global health challenge.Unfortunately,current treatment options are limited.We previously disclosed that L.reuteri SXDT-32 was enriched in the feces of an an...Background Colitis caused by bacterial infection is a major global health challenge.Unfortunately,current treatment options are limited.We previously disclosed that L.reuteri SXDT-32 was enriched in the feces of an ancient diarrhearesistant pig breed(Mashen pig)in China over 2500 years old.As diarrhea is often closely associated with intestinal inflammation,L.reuteri SXDT-32 was identified as a potential beneficial bacterium to prevent intestinal inflammation.However,the precise mechanisms involved remained unclear.Results Our tests showed that L.reuteri SXDT-32 alleviated colonic damage induced by pathogenic E.coli SKLAN202302 in weaned pigs by enhancing barrier integrity and inhibiting inflammation.The transcriptomics revealed that L.reuteri SXDT-32 protected against inflammatory injury by inhibiting the PI3K-AKT signaling pathway.Metabolite analysis indicated that the content of shikimic acid(SA)was substantially elevated in the colonic mucosa of L.reuteri SXDT-32-fed piglets(P<0.05).In addition,Liquid Chromatography-Mass Spectrometer(LC-MS)analysis showed significant increases in SA content in both the colonic chyme of L.reuteri SXDT-32-fed piglets and the supernatant of in vitro grown cultures of L.reuteri SXDT-32(P<0.05).Polymerase chain reaction(PCR)analysis identified gene aroE from L.reuteri SXDT-32,which is a key gene directly linked to SA synthesis,and elevated shikimate dehydrogenase(SD,encoded by aroE)was also detected in both L.reuteri SXDT-32 and the colonic mucosa of piglets fed L.reuteri SXDT-32(P<0.01).In vitro Caco-2 cell experiments demonstrated that SA,L.reuteri SXDT-32,and the supernatant from in vitro grown cultures of L.reuteri SXDT-32 exhibited comparable inhibitory effects on the PI3K-Akt pathway to those of the PI3K inhibitor LY294002.Conclusions L.reuteri SXDT-32 alleviated intestinal inflammation in piglets by producing SA that inhibits the PI3K-Akt pathway.This study provides an innovative approach for the treatment and prevention of colitis caused by bacterial infection.展开更多
基金supported by the National Natural Science Foundation of China(32102582)the Youth innovation of Chinese Academy of Agricultural Sciences(Y2023QC09)+1 种基金Zhejiang Province Traditional Chinese Medicine Science and technology Project(2022ZB270)the Agricultural Science and Technology Innovation Program(ASTIPIAS07,cxgc-ias-16)。
文摘Background Intestinal inflammation is a common and serious health problem in piglet production,especially enteritis caused by pathogenic Escherichia coli(E.coli).This condition often leads to high mortality,slow weight gain,and significant economic losses.Results In this study,we isolated an E.coli strain,SKLAN202302,from the colon of diarrheal piglets to create an intestinal inflammation model for evaluating the protective effects of baicalin.Piglets infected with E.coli exhibited significant reductions in body weight,feed intake,small intestine length,and ileal goblet cell count(P<0.05),along with deteriorated ileal morphology.However,baicalin supplementation resulted in body weights,feed intake,and intestinal morphology similar to those of the control group.Notably,there was a significant increase in the colonization of Lactobacillus species,particularly Lactobacillus_reuteri,Lactobacillus_amylovorus,and Lactobacillus_johnii,compared to the E.coli group(P<0.05).At the metabolic and transcriptional levels,E.coli infection increased inflammatory mediators,including eicosanoids(leukotriene F4,prostaglandin F1a,leukotriene E4,thromboxane B2,prostaglandin G2,and PGH2),monosaccharides,and TCA cycle intermediates(oxoglutaric acid,glutaric acid,adipic acid,citric acid,and isocitric acid)in the ileum.It also promoted the expression of genes related to autoimmune diseases and the Th17 differentiation signaling pathway(CTLA4,IFN-ALPHA-8,IL12RB2,TRAV3,TRAV16,FOS,and VEGFA),as well as inflammatory factors.Conversely,baicalin supplementation not only counteracted these effects but also enhanced the presence of metabolites such as phospholipids[including lyso PC(P-18:1(9Z)/0:0),PC(17:0/0:0),lyso PC(16:1(9Z)/0:0),PC(18:0/0:0),lyso PC(18:0/0:0),PA(10:0/i-16:0),and PA(10:0/8:0)]and amino acids.It also regulated genes within the IL-17 signaling pathway(IL4,CCL17,CXCL10,IFNG,and CXCL2),suggesting a mechanism by which baicalin mitigates E.coli-induced intestinal and microbial disturbances.Subsequent flow cytometry analysis showed that E.coli infection increased the numbers of CD3+and Foxp3+cells,decreased IL-17A+cells,and reduced Th17/Treg ratios.Baicalin supplementation restored these parameters to control levels.Conclusions Baicalin supplementation effectively alleviates E.coli-induced intestinal inflammation and microbial disturbances in piglets by enhancing beneficial Lactobacillus colonization,counteracting inflammatory mediators,and regulating immune-related gene expression and the Th17/Treg balance.These findings highlight baicalin's potential in alleviating intestinal inflammation.
基金supported by National Natural Science Foundation of China(U22 A20515)National High-Level Talents Special Support Program of China(2021-WR-01)Agricultural Science and Technology Innovation Program(ASTIPIAS07).
文摘Background Colitis caused by bacterial infection is a major global health challenge.Unfortunately,current treatment options are limited.We previously disclosed that L.reuteri SXDT-32 was enriched in the feces of an ancient diarrhearesistant pig breed(Mashen pig)in China over 2500 years old.As diarrhea is often closely associated with intestinal inflammation,L.reuteri SXDT-32 was identified as a potential beneficial bacterium to prevent intestinal inflammation.However,the precise mechanisms involved remained unclear.Results Our tests showed that L.reuteri SXDT-32 alleviated colonic damage induced by pathogenic E.coli SKLAN202302 in weaned pigs by enhancing barrier integrity and inhibiting inflammation.The transcriptomics revealed that L.reuteri SXDT-32 protected against inflammatory injury by inhibiting the PI3K-AKT signaling pathway.Metabolite analysis indicated that the content of shikimic acid(SA)was substantially elevated in the colonic mucosa of L.reuteri SXDT-32-fed piglets(P<0.05).In addition,Liquid Chromatography-Mass Spectrometer(LC-MS)analysis showed significant increases in SA content in both the colonic chyme of L.reuteri SXDT-32-fed piglets and the supernatant of in vitro grown cultures of L.reuteri SXDT-32(P<0.05).Polymerase chain reaction(PCR)analysis identified gene aroE from L.reuteri SXDT-32,which is a key gene directly linked to SA synthesis,and elevated shikimate dehydrogenase(SD,encoded by aroE)was also detected in both L.reuteri SXDT-32 and the colonic mucosa of piglets fed L.reuteri SXDT-32(P<0.01).In vitro Caco-2 cell experiments demonstrated that SA,L.reuteri SXDT-32,and the supernatant from in vitro grown cultures of L.reuteri SXDT-32 exhibited comparable inhibitory effects on the PI3K-Akt pathway to those of the PI3K inhibitor LY294002.Conclusions L.reuteri SXDT-32 alleviated intestinal inflammation in piglets by producing SA that inhibits the PI3K-Akt pathway.This study provides an innovative approach for the treatment and prevention of colitis caused by bacterial infection.
