Salmonella enterica serovar Typhimurium is a representative foodborne pathogen that induces acute enteritis,accompanied by disruption of the intestinal barrier and gut microbiota dysbiosis.In this study,four Bifido-ba...Salmonella enterica serovar Typhimurium is a representative foodborne pathogen that induces acute enteritis,accompanied by disruption of the intestinal barrier and gut microbiota dysbiosis.In this study,four Bifido-bacterium strains isolated from the feces of healthy infants were evaluated for their effects on host intestinal inflammation,mucus barrier integrity,and the structure and function of the gut microbiota.The results demonstrated pronounced strain-specific differences in the mechanisms by which Bifidobacterium alleviated in-testinal injury.These regulatory effects were not limited to alterations in microbial composition but also involved the modulation of key functional pathways and characteristic microbial networks.Notably,B.bifidum 3469 tended to preserve microbial homeostasis and protect the mucus barrier,whereas B.longum 8216 promoted the reconstruction of an alternative microbial community and facilitated the restoration of Occludin-containing tight junctions.Collectively,these findings elucidate the strain-specific roles of infant-derived Bifidobacterium in mitigating Salmonella infection from the perspectives of host-microbe interactions and microecological functional regulation,providing a theoretical basis for the selection and functional development of human-derived probiotics.展开更多
Bacillus coagulans can help ameliorate or prevent gastrointestinal diseases, but the genetic relationships among B. coagulans isolates are not well studied. Multilocus sequence typing analysis was conducted on 57 isol...Bacillus coagulans can help ameliorate or prevent gastrointestinal diseases, but the genetic relationships among B. coagulans isolates are not well studied. Multilocus sequence typing analysis was conducted on 57 isolates of B. coagulans from 22 provinces or autonomous regions in China. B. coagulans isolates were highly diverse and a total of 33(sequence typings) STs were found. These isolates had a weak clonal population structure and strong indications of intraspecies recombination. The evolution direction of B. coagulans was not correlated with geography or isolation source. Fifteen strains were selected for further analysis based on proximity relationships from the phylogenetic tree. Five isolates(B. coagulans-1, B. coagulans-10, B. coagulans-39, B. coagulans-70 and B. coagulans-71) with good spore-forming ability relative to the rest of the isolates were evaluated for constipation relief. B. coagulans-39 significantly relieved constipation symptoms in mice by regulating intestinal flora, increasing the production of short-chain fatty acids and restoring the level of gastrointestinal regulatory peptides. Comparative genomic analysis showed the beneficial effects of B. coagulans-39 might be associated with specific functional genes that are involved in the utilization of various carbohydrates as primary substrates and short-chain fatty acid production.展开更多
The reasons for the differences in the abundance of various species within the Bifidobacterium genus are currently unclear,thus further restricting the selection of Bifidobacteria strains that occupy a dominant abunda...The reasons for the differences in the abundance of various species within the Bifidobacterium genus are currently unclear,thus further restricting the selection of Bifidobacteria strains that occupy a dominant abundance in the gut.By comparing different species of Bifidobacteria in terms of carbon and nitrogen utilization ability,cell adhesion ability,and adaptability to the simulated colon environment,it was found that Bifidobacterium longum has a strong ability to utilize carbon sources,especially D-xylose and fructooligosaccharides,which may be an important reason for its abundance advantage.Through in vitro fermentation experiments,it was verified that B.longum can regain its abundance advantage through the efficient use of carbon sources under conditions where B.longum does not occupy an abundance advantage.A set of screening methods for strains with the potential to occupy a high abundance in the intestinal tract is summarized,which can provide theoretical support for the application of probiotics.展开更多
Comparative Genomic Hybridization (CGH) microarray analysis was used tocompare the genomic compositions of all eighteen Shigella boydii serotype representative strains.The results indicated the genomic ''backb...Comparative Genomic Hybridization (CGH) microarray analysis was used tocompare the genomic compositions of all eighteen Shigella boydii serotype representative strains.The results indicated the genomic ''backbone'' of this subgroup contained 2552 ORFs homologous tononpatho-genic E. coli K12. Compared with the genome of K12199 ORFs were found to be absent in allS. boydii serotype representatives, including mainly outer membrane protein genes and O-antigenbiosynthesis genes. Yet the specific ORFs of S. boydii subgroup contained basically bacteriophagegenes and the function unknown (FUN) genes. Some iron metabolism, transport and type Ⅱ secretionsystem related genes were found in most representative strains. According to the CGH phylogeneticanalysis, the eighteen S. boydii serotype representatives were divided into four groups, in whichserotype C13 strain was remarkably distinguished from the other serotype strains. This groupingresult corresponded to the distribution of some metabolism related genes. Furthermore, the analysisof genome backbone genes, specific genes, and the phylogenetic trees allowed us to discover theevolution laws of S. boydii and to find out important clues to pathogenesis research, vaccinationand the therapeutic medicine development.展开更多
基金the National Natural Science Foun-dation of China(No.32572551No.32372311)+3 种基金Fundamental Research Funds for the Central University(CXCYL2026005)International Sci-ence&Technology Cooperation Program of Hainan Province(No.GHYF2023009)Sanya Science and Technology Innovation Project(No.2022325)Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD).
文摘Salmonella enterica serovar Typhimurium is a representative foodborne pathogen that induces acute enteritis,accompanied by disruption of the intestinal barrier and gut microbiota dysbiosis.In this study,four Bifido-bacterium strains isolated from the feces of healthy infants were evaluated for their effects on host intestinal inflammation,mucus barrier integrity,and the structure and function of the gut microbiota.The results demonstrated pronounced strain-specific differences in the mechanisms by which Bifidobacterium alleviated in-testinal injury.These regulatory effects were not limited to alterations in microbial composition but also involved the modulation of key functional pathways and characteristic microbial networks.Notably,B.bifidum 3469 tended to preserve microbial homeostasis and protect the mucus barrier,whereas B.longum 8216 promoted the reconstruction of an alternative microbial community and facilitated the restoration of Occludin-containing tight junctions.Collectively,these findings elucidate the strain-specific roles of infant-derived Bifidobacterium in mitigating Salmonella infection from the perspectives of host-microbe interactions and microecological functional regulation,providing a theoretical basis for the selection and functional development of human-derived probiotics.
基金supported by the National Natural Science Foundation of China Program[No.31871773 and No.31820103010]Projects of Innovation and Development Pillar Program for Key Industries in Southern Xinjiang of Xinjiang Production and Construction Corps[2018DB002]+2 种基金National First-Class Discipline Program of Food Science and Technology[JUFSTR20180102]the BBSRC Newton Fund Joint Centre AwardCollaborative Innovation Center of Food Safety and Quality Control in Jiangsu Province。
文摘Bacillus coagulans can help ameliorate or prevent gastrointestinal diseases, but the genetic relationships among B. coagulans isolates are not well studied. Multilocus sequence typing analysis was conducted on 57 isolates of B. coagulans from 22 provinces or autonomous regions in China. B. coagulans isolates were highly diverse and a total of 33(sequence typings) STs were found. These isolates had a weak clonal population structure and strong indications of intraspecies recombination. The evolution direction of B. coagulans was not correlated with geography or isolation source. Fifteen strains were selected for further analysis based on proximity relationships from the phylogenetic tree. Five isolates(B. coagulans-1, B. coagulans-10, B. coagulans-39, B. coagulans-70 and B. coagulans-71) with good spore-forming ability relative to the rest of the isolates were evaluated for constipation relief. B. coagulans-39 significantly relieved constipation symptoms in mice by regulating intestinal flora, increasing the production of short-chain fatty acids and restoring the level of gastrointestinal regulatory peptides. Comparative genomic analysis showed the beneficial effects of B. coagulans-39 might be associated with specific functional genes that are involved in the utilization of various carbohydrates as primary substrates and short-chain fatty acid production.
基金supported by the National Natural Science Foundation of China[No.U23A20259,32202009 and 32122067]supported by the Fundamental Research Funds for the Central Universities JUSRP622013.
文摘The reasons for the differences in the abundance of various species within the Bifidobacterium genus are currently unclear,thus further restricting the selection of Bifidobacteria strains that occupy a dominant abundance in the gut.By comparing different species of Bifidobacteria in terms of carbon and nitrogen utilization ability,cell adhesion ability,and adaptability to the simulated colon environment,it was found that Bifidobacterium longum has a strong ability to utilize carbon sources,especially D-xylose and fructooligosaccharides,which may be an important reason for its abundance advantage.Through in vitro fermentation experiments,it was verified that B.longum can regain its abundance advantage through the efficient use of carbon sources under conditions where B.longum does not occupy an abundance advantage.A set of screening methods for strains with the potential to occupy a high abundance in the intestinal tract is summarized,which can provide theoretical support for the application of probiotics.
文摘Comparative Genomic Hybridization (CGH) microarray analysis was used tocompare the genomic compositions of all eighteen Shigella boydii serotype representative strains.The results indicated the genomic ''backbone'' of this subgroup contained 2552 ORFs homologous tononpatho-genic E. coli K12. Compared with the genome of K12199 ORFs were found to be absent in allS. boydii serotype representatives, including mainly outer membrane protein genes and O-antigenbiosynthesis genes. Yet the specific ORFs of S. boydii subgroup contained basically bacteriophagegenes and the function unknown (FUN) genes. Some iron metabolism, transport and type Ⅱ secretionsystem related genes were found in most representative strains. According to the CGH phylogeneticanalysis, the eighteen S. boydii serotype representatives were divided into four groups, in whichserotype C13 strain was remarkably distinguished from the other serotype strains. This groupingresult corresponded to the distribution of some metabolism related genes. Furthermore, the analysisof genome backbone genes, specific genes, and the phylogenetic trees allowed us to discover theevolution laws of S. boydii and to find out important clues to pathogenesis research, vaccinationand the therapeutic medicine development.
