BACKGROUND Hepatic encephalopathy(HE)can be considered a result of dysregulated gutliver-brain axis function,where cognitive impairment can be reversed or prevented by the beneficial effects induced by"gut-centri...BACKGROUND Hepatic encephalopathy(HE)can be considered a result of dysregulated gutliver-brain axis function,where cognitive impairment can be reversed or prevented by the beneficial effects induced by"gut-centric"therapies,such as the administration of nonabsorbable disaccharides,nonabsorbable antibiotics,probiotics and prebiotics.AIM To assess the short-term efficacy and safety of the probiotic Escherichia coli Nissle(EcN)1917 strain compared to lactulose and rifaximin in patients with minimal/mild HE.METHODS From January 2017 to March 2020,a total of 45 patients with HE were enrolled in this prospective,single-centre,open-label,randomized study.Participants were randomly assigned at a ratio of 1:1:1 to one of the treatment groups:The EcN group(n=15),lactulose group(n=15)or rifaximin group(n=15)for a 1 mo intervention period.The main primary outcomes of the study were changes in serum ammonia and Stroop test score.The secondary outcomes were markers of a chronic systemic inflammatory response(ІL-6,ІL-8,and IFN-γ)and bacteriology of the stool flora evaluated by specialized nonculture techniques after a 1 mo intervention period.RESULTS Patients who were given rifaximin or EcN showed a more significant reduction in serum ammonia and normalization of Bifidobacteria and Lactobacilli abundance compared to the lactulose group.However,the most pronounced restoration of the symbiotic microflora was associated with EcN administration and characterized by the absence of E.coli with altered properties and pathogenic enterobacteria in patient faeces.In the primary outcome analysis,improvements in the Stroop test parameters in all intervention groups were observed.Moreover,EcN-treated patients performed 15%faster on the Stroop test than the lactulose group patients(P=0.017).Both EcN and rifaximin produced similar significant reductions in the proinflammatory cytokines INF-γ,IL-6 and IL-8.EcN was more efficient than lactulose in reducing proinflammatory cytokine levels.CONCLUSION The use of the probiotic EcN strain was safe and quite efficient for HE treatment.The probiotic reduced the ammonia content and the level of serum proinflammatory cytokines,normalized the gut microbiota composition and improved the cognitive function of patients with HE.The application of the EcN strain was more effective than lactulose treatment.展开更多
Escherichia coli is the most well-studied model prokaryote and has become an indispensable host for the biotech-nological production of proteins and biochemicals.In particular,the probiotic status of one E.coli strain...Escherichia coli is the most well-studied model prokaryote and has become an indispensable host for the biotech-nological production of proteins and biochemicals.In particular,the probiotic status of one E.coli strain,E.coli Nissle 1917(EcN)has helped it become a new favorite amongst synthetic biologists.To broaden its potential applications,here we assemble a comparative study on the genomes,transcriptomes,and metabolic properties of E.coli strains EcN,BL21(DE3),and MG1655.Comparative genomics data suggests that EcN possesses 1404 unique CDSs.In particular,EcN has additional iron transport systems which endow EcN with a higher tolerance to iron scarcity when compared to two other E.coli strains.EcN transcriptome data demonstrates that E.coli strains EcN,BL21(DE3),and MG1655 all have comparable activities of the central metabolic pathway,however only EcN inherits the arginine deiminase pathway.Additionally,we found that EcN displayed a lower expres-sion of ribosomal proteins compared to BL21(DE3)and MG1655.This comparative study on E.coli strains EcN,BL21(DE3),and MG1655 aims to provide a reference for further engineering EcN as a biotechnological tool.展开更多
Colitis is a common disease of the colon that is very difficult to treat.Probiotic bacteria could be an effective treatment.The probiotic Escherichia coli Nissle 1917(EcN)was engineered to synthesize the ketone body(R...Colitis is a common disease of the colon that is very difficult to treat.Probiotic bacteria could be an effective treatment.The probiotic Escherichia coli Nissle 1917(EcN)was engineered to synthesize the ketone body(R)-3-hydroxybutyrate(3HB)for sustainable production in the gut lumen of mice suffering from colitis.Components of heterologous 3HB synthesis routes were constructed,expressed,optimized,and inserted into the EcN genome,combined with deletions in competitive branch pathways.The genome-engineered EcN produced the highest 3HB level of 0.6 g/L under microaerobic conditions.The live therapeutic was found to colonize the mouse gastrointestinal tract over 14 days,elevating gut 3HB and short-chain-length fatty acid(SCFA)levels 8.7-and 3.1-fold compared to those of wild-type EcN,respectively.The sustainable presence of 3HB in mouse guts promoted the growth of probiotic bacteria,especially Akkermansia spp.,to over 31%from the initial 2%of all the microbiome.As a result,the engineered EcN termed EcNL4 ameliorated colitis induced via dextran sulfate sodium(DSS)in mice.Compared to wild-type EcN or oral administration of 3HB,oral EcNL4 uptake demonstrated better effects on mouse weights,colon lengths,occult blood levels,gut tissue myeloperoxidase activity and proinflammatory cytokine concentrations.Thus,a promising live bacterium was developed to improve colonic microenvironments and further treat colitis.This proof-of-concept design can be employed to treat other diseases of the colon.展开更多
The probiotic bacterium Escherichia coli Nissle 1917(EcN)holds significant promise for use in clinical and biological industries.However,the reliance on antibiotics to maintain plasmid-borne genes has overshadowed its...The probiotic bacterium Escherichia coli Nissle 1917(EcN)holds significant promise for use in clinical and biological industries.However,the reliance on antibiotics to maintain plasmid-borne genes has overshadowed its benefits.In this study,we addressed this issue by engineering the endogenous cryptic plasmids pMUT1 and pMUT2.The non-essential elements were removed to create more stable derivatives pMUT1NR△and pMUT2HBC△.Synthetic promoters by integrating binding motifs on sigma factors were further constructed and applied for expression of Bacteroides thetaiotaomicron heparinaseⅢand the biosynthesis of ectoine.Compared to traditional antibiotic-dependent expression systems,our newly constructed antibiotic-free expression systems offer considerable advantages for clinical and synthetic biology applications.展开更多
文摘BACKGROUND Hepatic encephalopathy(HE)can be considered a result of dysregulated gutliver-brain axis function,where cognitive impairment can be reversed or prevented by the beneficial effects induced by"gut-centric"therapies,such as the administration of nonabsorbable disaccharides,nonabsorbable antibiotics,probiotics and prebiotics.AIM To assess the short-term efficacy and safety of the probiotic Escherichia coli Nissle(EcN)1917 strain compared to lactulose and rifaximin in patients with minimal/mild HE.METHODS From January 2017 to March 2020,a total of 45 patients with HE were enrolled in this prospective,single-centre,open-label,randomized study.Participants were randomly assigned at a ratio of 1:1:1 to one of the treatment groups:The EcN group(n=15),lactulose group(n=15)or rifaximin group(n=15)for a 1 mo intervention period.The main primary outcomes of the study were changes in serum ammonia and Stroop test score.The secondary outcomes were markers of a chronic systemic inflammatory response(ІL-6,ІL-8,and IFN-γ)and bacteriology of the stool flora evaluated by specialized nonculture techniques after a 1 mo intervention period.RESULTS Patients who were given rifaximin or EcN showed a more significant reduction in serum ammonia and normalization of Bifidobacteria and Lactobacilli abundance compared to the lactulose group.However,the most pronounced restoration of the symbiotic microflora was associated with EcN administration and characterized by the absence of E.coli with altered properties and pathogenic enterobacteria in patient faeces.In the primary outcome analysis,improvements in the Stroop test parameters in all intervention groups were observed.Moreover,EcN-treated patients performed 15%faster on the Stroop test than the lactulose group patients(P=0.017).Both EcN and rifaximin produced similar significant reductions in the proinflammatory cytokines INF-γ,IL-6 and IL-8.EcN was more efficient than lactulose in reducing proinflammatory cytokine levels.CONCLUSION The use of the probiotic EcN strain was safe and quite efficient for HE treatment.The probiotic reduced the ammonia content and the level of serum proinflammatory cytokines,normalized the gut microbiota composition and improved the cognitive function of patients with HE.The application of the EcN strain was more effective than lactulose treatment.
基金supported by the National Key Re-search and Development Program of China(2021YFC2100800)the Jiangsu Province Natural Science Fund for Distinguished Young Schol-ars(BK20200025)+1 种基金a grant from the Key Technologies R&D Program of Jiangsu Province(BE2019630)the National First-class Discipline Program of Light Industry Technology and Engineering(LITE2018-16).
文摘Escherichia coli is the most well-studied model prokaryote and has become an indispensable host for the biotech-nological production of proteins and biochemicals.In particular,the probiotic status of one E.coli strain,E.coli Nissle 1917(EcN)has helped it become a new favorite amongst synthetic biologists.To broaden its potential applications,here we assemble a comparative study on the genomes,transcriptomes,and metabolic properties of E.coli strains EcN,BL21(DE3),and MG1655.Comparative genomics data suggests that EcN possesses 1404 unique CDSs.In particular,EcN has additional iron transport systems which endow EcN with a higher tolerance to iron scarcity when compared to two other E.coli strains.EcN transcriptome data demonstrates that E.coli strains EcN,BL21(DE3),and MG1655 all have comparable activities of the central metabolic pathway,however only EcN inherits the arginine deiminase pathway.Additionally,we found that EcN displayed a lower expres-sion of ribosomal proteins compared to BL21(DE3)and MG1655.This comparative study on E.coli strains EcN,BL21(DE3),and MG1655 aims to provide a reference for further engineering EcN as a biotechnological tool.
基金This research was financially supported by a grant from the Chunfeng Foundation(2020Z99CFG002)of Tsinghua UniversityOther support includes the National Natural Science Foundation of China(Grant Nos.31870859,21761132013,31771886,and 31971170).
文摘Colitis is a common disease of the colon that is very difficult to treat.Probiotic bacteria could be an effective treatment.The probiotic Escherichia coli Nissle 1917(EcN)was engineered to synthesize the ketone body(R)-3-hydroxybutyrate(3HB)for sustainable production in the gut lumen of mice suffering from colitis.Components of heterologous 3HB synthesis routes were constructed,expressed,optimized,and inserted into the EcN genome,combined with deletions in competitive branch pathways.The genome-engineered EcN produced the highest 3HB level of 0.6 g/L under microaerobic conditions.The live therapeutic was found to colonize the mouse gastrointestinal tract over 14 days,elevating gut 3HB and short-chain-length fatty acid(SCFA)levels 8.7-and 3.1-fold compared to those of wild-type EcN,respectively.The sustainable presence of 3HB in mouse guts promoted the growth of probiotic bacteria,especially Akkermansia spp.,to over 31%from the initial 2%of all the microbiome.As a result,the engineered EcN termed EcNL4 ameliorated colitis induced via dextran sulfate sodium(DSS)in mice.Compared to wild-type EcN or oral administration of 3HB,oral EcNL4 uptake demonstrated better effects on mouse weights,colon lengths,occult blood levels,gut tissue myeloperoxidase activity and proinflammatory cytokine concentrations.Thus,a promising live bacterium was developed to improve colonic microenvironments and further treat colitis.This proof-of-concept design can be employed to treat other diseases of the colon.
基金financially supported by the National Natural Science Foundation of China(32370066,32000058)the Fundamental Research Funds for the Central Universities(JUSRP622003)+1 种基金National First-class Discipline Program of Light Industry Technology and Engineering(QGJC20230202)the Postgraduate Research&Practice Innovation Program of Jiangsu Province(KYCX23_2487).
文摘The probiotic bacterium Escherichia coli Nissle 1917(EcN)holds significant promise for use in clinical and biological industries.However,the reliance on antibiotics to maintain plasmid-borne genes has overshadowed its benefits.In this study,we addressed this issue by engineering the endogenous cryptic plasmids pMUT1 and pMUT2.The non-essential elements were removed to create more stable derivatives pMUT1NR△and pMUT2HBC△.Synthetic promoters by integrating binding motifs on sigma factors were further constructed and applied for expression of Bacteroides thetaiotaomicron heparinaseⅢand the biosynthesis of ectoine.Compared to traditional antibiotic-dependent expression systems,our newly constructed antibiotic-free expression systems offer considerable advantages for clinical and synthetic biology applications.
