We collected fecal samples twice from 8 subjects and obtained 160 isolates of lactobacilli. The isolates were genetically fingerprinted and identified by pulsed-field gel electrophoresis (PFGE) and 16S rDNA sequence analysis, respectively. The numbers of lactobacilli detected in fecal samples varied greatly among the subjects. The isolates were divided into 37 strains by PFGE. No common strain was detected in the feces of different subjects. Except for one subject, at least one strain, unique to each individual, was detected in both fecal samples. The strains detected in both fecal samples were identified as Lactobacillus amylovorus, L. gasseri, L. fermentum, L. delbrueckii, L. crispatus, L. vaginalis and L. ruminis. They may be the indigenous Lactobacillus species in Japanese adults.
{"title":"Analysis of the Composition of Lactobacilli in Humans","authors":"K. Kimura, T. Nishio, C. Mizoguchi, A. Koizumi","doi":"10.12938/BIFIDUS.29.47","DOIUrl":"https://doi.org/10.12938/BIFIDUS.29.47","url":null,"abstract":"We collected fecal samples twice from 8 subjects and obtained 160 isolates of lactobacilli. The isolates were genetically fingerprinted and identified by pulsed-field gel electrophoresis (PFGE) and 16S rDNA sequence analysis, respectively. The numbers of lactobacilli detected in fecal samples varied greatly among the subjects. The isolates were divided into 37 strains by PFGE. No common strain was detected in the feces of different subjects. Except for one subject, at least one strain, unique to each individual, was detected in both fecal samples. The strains detected in both fecal samples were identified as Lactobacillus amylovorus, L. gasseri, L. fermentum, L. delbrueckii, L. crispatus, L. vaginalis and L. ruminis. They may be the indigenous Lactobacillus species in Japanese adults.","PeriodicalId":90114,"journal":{"name":"Bioscience and microflora","volume":"29 1","pages":"47-50"},"PeriodicalIF":0.0,"publicationDate":"2010-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66339593","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Shiga toxin-producing Escherichia coli and Salmonella, causative bacteria of food poisoning (intestinal infectious disease) in humans, are still serious problems. Shiga toxin-producing E. coli O157:H7 (STEC) grows and produces Shiga toxin (Stx) in the intestine, and causes hemorrhagic enteritis. A typical etiologic agent of Salmonella food poisoning, Salmonella enterica serovar Typhimurium (S. Typhimurium), grows in the intestine and invades the body via the intestinal epithelium, causing inflammation. The importance of the prevention of STEC- and S. Typhimurium-induced food poisoning has been stressed because they frequently cause outbreaks, the course is rapid, and only a very small number of bacteria (10 1 to 10 3 CFU) is needed to induce a severe infection. Probiotics are defined as 'Live microorganisms which when administered in adequate amounts confer a health benefit on the host'. Bifidobacteria, major constituents of the intestinal flora, are typical probiotics which are expected to help prevent intestinal infection. In this study, we investigated the anti-infectious activity of bifidobacteria against STEC and S. Typhimurium infections using a mouse intestinal infection model, and analyzed the infection-preventive mechanism. For STEC infection, a novel mouse fatal infection model was prepared by combining STEC infection at 5 x 10 3 CFU and Mitomycin C (MMC) treatment (for the induction of stx gene expression) in the late logarithmic phase of intestinal STEC growth. The anti-infectious activity of the orally administered probiotic Bifidobcterium breve strain Yakult (BbY) was investigated using this mouse intestinal STEC infection model. STEC-induced death was strongly inhibited in BbY-treated mice. Interestingly, STEC growth in the intestine was not inhibited, but stx gene expression and Stx production were strongly inhibited. In addition, the intestinal environment was improved in the BbY-treated mice through normalization of the intestinal level of acetic acid, a major organic acid in the intestine, and pH. When STEC was grown in vitro in a medium reproducing the acetic acid level and pH in the cecum, Stx production was completely inhibited, suggesting that the expression of this pathogenic factor was inhibited by BbY-induced improvement of the intestinal environment. In the mouse intestinal S. Typhimurium infection model, BbY inhibited the abnormal growth of S. Typhimurium and improved the intestinal environment, resulting in the inhibition of systemic S. Typhimurium infection. This study, using an experimental animal model, clarified the preventive effect of the probiotic BbY on food poisoning (intestinal infectious disease) caused by STEC and S. Typhimurium. Improvements of the intestinal environment, such as elevation of the acetic acid concentration and decrease in pH level, induced by intestinal BbY colonization, are suggested to be important defense mechanisms for the inhibition of pathogenic factors production induce by intestina
{"title":"Preventive Effect of Probiotic Bifidobacteria against Shiga Toxin-Producing Escherichia Coli and Salmonella Infections","authors":"T. Asahara","doi":"10.12938/BIFIDUS.29.11","DOIUrl":"https://doi.org/10.12938/BIFIDUS.29.11","url":null,"abstract":"Shiga toxin-producing Escherichia coli and Salmonella, causative bacteria of food poisoning (intestinal infectious disease) in humans, are still serious problems. Shiga toxin-producing E. coli O157:H7 (STEC) grows and produces Shiga toxin (Stx) in the intestine, and causes hemorrhagic enteritis. A typical etiologic agent of Salmonella food poisoning, Salmonella enterica serovar Typhimurium (S. Typhimurium), grows in the intestine and invades the body via the intestinal epithelium, causing inflammation. The importance of the prevention of STEC- and S. Typhimurium-induced food poisoning has been stressed because they frequently cause outbreaks, the course is rapid, and only a very small number of bacteria (10 1 to 10 3 CFU) is needed to induce a severe infection. Probiotics are defined as 'Live microorganisms which when administered in adequate amounts confer a health benefit on the host'. Bifidobacteria, major constituents of the intestinal flora, are typical probiotics which are expected to help prevent intestinal infection. In this study, we investigated the anti-infectious activity of bifidobacteria against STEC and S. Typhimurium infections using a mouse intestinal infection model, and analyzed the infection-preventive mechanism. For STEC infection, a novel mouse fatal infection model was prepared by combining STEC infection at 5 x 10 3 CFU and Mitomycin C (MMC) treatment (for the induction of stx gene expression) in the late logarithmic phase of intestinal STEC growth. The anti-infectious activity of the orally administered probiotic Bifidobcterium breve strain Yakult (BbY) was investigated using this mouse intestinal STEC infection model. STEC-induced death was strongly inhibited in BbY-treated mice. Interestingly, STEC growth in the intestine was not inhibited, but stx gene expression and Stx production were strongly inhibited. In addition, the intestinal environment was improved in the BbY-treated mice through normalization of the intestinal level of acetic acid, a major organic acid in the intestine, and pH. When STEC was grown in vitro in a medium reproducing the acetic acid level and pH in the cecum, Stx production was completely inhibited, suggesting that the expression of this pathogenic factor was inhibited by BbY-induced improvement of the intestinal environment. In the mouse intestinal S. Typhimurium infection model, BbY inhibited the abnormal growth of S. Typhimurium and improved the intestinal environment, resulting in the inhibition of systemic S. Typhimurium infection. This study, using an experimental animal model, clarified the preventive effect of the probiotic BbY on food poisoning (intestinal infectious disease) caused by STEC and S. Typhimurium. Improvements of the intestinal environment, such as elevation of the acetic acid concentration and decrease in pH level, induced by intestinal BbY colonization, are suggested to be important defense mechanisms for the inhibition of pathogenic factors production induce by intestina","PeriodicalId":90114,"journal":{"name":"Bioscience and microflora","volume":"29 1","pages":"11-21"},"PeriodicalIF":0.0,"publicationDate":"2010-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66339777","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The resident microbiota of the mammalian intestine influences diverse homeostatic functions of the gut, including regulation of cellular growth, restitution after injury, maintenance of barrier function, and modulation of immune responses. However, it is unknown how commensal prokaryotic organisms mechanistically influence eukaryotic signaling networks. We have shown that epithelia contacted by enteric commensal bacteria in vitro and in vivo rapidly generate reactive oxygen species (ROS), and distinct microbial taxa have markedly different potencies in stimulating this response. This physiologically generated ROS is known to participate in a variety of cellular signal pathways via the rapid and transient oxidative inactivation of a number of regulatory enzymes. We show that these oxidant sensitive enzymes include key control points in the proinflammatory NF-κB pathway and in the regulation of cytoskeletal dynamics. Accordingly, we show various commensal bacterial have the ability to suppress inflammatory signaling and stimulate cell motility both in cell culture and in animal models. These events are consistent with known effects of the microbiota and selected probiotics. Collectively, our studies outline a molecular mechanism that may account for aspects of microbial-host cross-talk in the intestine in normal physiology and during therapeutic intervention with probiotics.
{"title":"Molecular Analysis of Microbiota-Host Cross-Talk in the Intestine","authors":"A. Neish","doi":"10.12938/BIFIDUS.29.1","DOIUrl":"https://doi.org/10.12938/BIFIDUS.29.1","url":null,"abstract":"The resident microbiota of the mammalian intestine influences diverse homeostatic functions of the gut, including regulation of cellular growth, restitution after injury, maintenance of barrier function, and modulation of immune responses. However, it is unknown how commensal prokaryotic organisms mechanistically influence eukaryotic signaling networks. We have shown that epithelia contacted by enteric commensal bacteria in vitro and in vivo rapidly generate reactive oxygen species (ROS), and distinct microbial taxa have markedly different potencies in stimulating this response. This physiologically generated ROS is known to participate in a variety of cellular signal pathways via the rapid and transient oxidative inactivation of a number of regulatory enzymes. We show that these oxidant sensitive enzymes include key control points in the proinflammatory NF-κB pathway and in the regulation of cytoskeletal dynamics. Accordingly, we show various commensal bacterial have the ability to suppress inflammatory signaling and stimulate cell motility both in cell culture and in animal models. These events are consistent with known effects of the microbiota and selected probiotics. Collectively, our studies outline a molecular mechanism that may account for aspects of microbial-host cross-talk in the intestine in normal physiology and during therapeutic intervention with probiotics.","PeriodicalId":90114,"journal":{"name":"Bioscience and microflora","volume":"29 1","pages":"1-10"},"PeriodicalIF":0.0,"publicationDate":"2010-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66339758","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Short chain fatty acids (SCFAs) are major anions in the large intestine. They are produced by bacterial fermentation of dietary fiber. However, the mechanism by which intraluminal SCFAs are sensed is unknown. Free fatty acids including SCFAs have recently been demonstrated to act as ligands for several G-protein-coupled receptors (GPCRs: FFA1, FFA2, FFA3, GPR84, GPR109A and GPR120). SCFAs are ligands for FFA2 and FFA3. These receptors are proposed to play a variety of physiological and pathophysiological roles in the intestine. In rat and human colons, FFA2 and/or FFA3 are located in mucosal enteroendocrine cells containing peptide YY (PYY) and are related to energy balance. Among SCFAs, propionate and butyrate induce concentration-dependent phasic and tonic contractions in rat colonic circular muscle. These responses are not observed in mucosal free preparations. Thus, FFA2 and FFA3 are important molecular devices for monitoring the chemical composition in the colonic lumen. For the local function of SCFAs, it should be stressed that individual SCFAs have different modes of action on colonic smooth muscles. These different actions may be due to the relative contributions of FFA2 and FFA3 to the control of intestinal muscle activity. FFA2 and FFA3 may also contribute to the whole body energy balance through the release of gastrointestinal hormones related to feeding and satiety control. This review summarizes recent findings about the roles of deorphanized FFA receptors, especially, FFA2 and FFA3 and their contributions to the regulation of colonic motility.
{"title":"Roles of Short-Chain Fatty Acids and their Receptors in Colonic Motility","authors":"S. Karaki, A. Kuwahara","doi":"10.12938/BIFIDUS.29.31","DOIUrl":"https://doi.org/10.12938/BIFIDUS.29.31","url":null,"abstract":"Short chain fatty acids (SCFAs) are major anions in the large intestine. They are produced by bacterial fermentation of dietary fiber. However, the mechanism by which intraluminal SCFAs are sensed is unknown. Free fatty acids including SCFAs have recently been demonstrated to act as ligands for several G-protein-coupled receptors (GPCRs: FFA1, FFA2, FFA3, GPR84, GPR109A and GPR120). SCFAs are ligands for FFA2 and FFA3. These receptors are proposed to play a variety of physiological and pathophysiological roles in the intestine. In rat and human colons, FFA2 and/or FFA3 are located in mucosal enteroendocrine cells containing peptide YY (PYY) and are related to energy balance. Among SCFAs, propionate and butyrate induce concentration-dependent phasic and tonic contractions in rat colonic circular muscle. These responses are not observed in mucosal free preparations. Thus, FFA2 and FFA3 are important molecular devices for monitoring the chemical composition in the colonic lumen. For the local function of SCFAs, it should be stressed that individual SCFAs have different modes of action on colonic smooth muscles. These different actions may be due to the relative contributions of FFA2 and FFA3 to the control of intestinal muscle activity. FFA2 and FFA3 may also contribute to the whole body energy balance through the release of gastrointestinal hormones related to feeding and satiety control. This review summarizes recent findings about the roles of deorphanized FFA receptors, especially, FFA2 and FFA3 and their contributions to the regulation of colonic motility.","PeriodicalId":90114,"journal":{"name":"Bioscience and microflora","volume":"29 1","pages":"31-40"},"PeriodicalIF":0.0,"publicationDate":"2010-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.12938/BIFIDUS.29.31","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66339918","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
T. Fujisawa, A. Sadatoshi, Y. Ohashi, T. Orihashi, Kiyotaka Sakai, Kenji Sera, M. Kanbe
The influence of Prebio Support™ (PS), which is a mixture of fermented products of Lactobacillus gasseri OLL2716 and Propionibacterium freudenreichii ET-3, on the fecal microbiota and fecal metabolites in calves were investigated. During the intake of PS, the number of bifidobacteria was significantly higher (p<0.05), and the fecal water content (p<0.05) and fecal ammonia (p<0.05) were significantly lower in the PS intake group than in the control group. Furthermore, fecal concentrations of sulfide tended to decrease and short-chain fatty acids (acetic, butyric, and propionic acids) tended to increase through the intake of PS. The numbers of other fecal bacteria and the fecal pH of the PS intake group did not differ from those of the control group. The fecal condition, such as hardness, in calves given PS was better than that of the control group. These findings indicate that PS intake effectively improves the fecal environment, and there is a possibility of it alleviating clinical symptoms.
{"title":"Influences of Prebio SupportTM (Mixture of Fermented Products of Lactobacillus gasseri OLL2716 and Propionibacterium freudenreichii ET-3) on the Composition and Metabolic Activity of Fecal Microbiota in Calves","authors":"T. Fujisawa, A. Sadatoshi, Y. Ohashi, T. Orihashi, Kiyotaka Sakai, Kenji Sera, M. Kanbe","doi":"10.12938/BIFIDUS.29.41","DOIUrl":"https://doi.org/10.12938/BIFIDUS.29.41","url":null,"abstract":"The influence of Prebio Support™ (PS), which is a mixture of fermented products of Lactobacillus gasseri OLL2716 and Propionibacterium freudenreichii ET-3, on the fecal microbiota and fecal metabolites in calves were investigated. During the intake of PS, the number of bifidobacteria was significantly higher (p<0.05), and the fecal water content (p<0.05) and fecal ammonia (p<0.05) were significantly lower in the PS intake group than in the control group. Furthermore, fecal concentrations of sulfide tended to decrease and short-chain fatty acids (acetic, butyric, and propionic acids) tended to increase through the intake of PS. The numbers of other fecal bacteria and the fecal pH of the PS intake group did not differ from those of the control group. The fecal condition, such as hardness, in calves given PS was better than that of the control group. These findings indicate that PS intake effectively improves the fecal environment, and there is a possibility of it alleviating clinical symptoms.","PeriodicalId":90114,"journal":{"name":"Bioscience and microflora","volume":"50 1","pages":"41-45"},"PeriodicalIF":0.0,"publicationDate":"2010-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.12938/BIFIDUS.29.41","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66339961","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Kenji Yamamoto, T. Katayama, M. Kitaoka, S. Fushinobu
Many bifidobacteria produce an endo-α-N-acetylgalactosaminidase that liberates the O-linked galactosyl β-1,3N-acetylgalactosamine (GNB) from intestinal mucin glycoproteins. The molecular cloning of the Bifidobacterium longum enzyme was completed using information in public databases. The enzyme constitutes a novel glycoside hydrolase (GH) family 101 member. The gene encoding a specific 1,2-α -L-fucosidase was cloned from B. bifidum. The recombinant enzyme specifically hydrolyzes the terminal α-1,2-fucosidic linkages of various oligosaccharides, including human milk oligosaccharides and blood group substances. Analysis of its primary structure revealed that this enzyme constitutes a novel GH family 95 member. We also solved the crystal structure of its catalytic domain. We assumed that these bifidobacterial enzymes are involved in the metabolism of oligosaccharides in mucin glycoproteins that are abundant in the intestine. Some bifidobacteria strains produce a lacto-N-biosidase that releases galactosyl β- 1,3N-acetylglucosamine (LNB) from human milk oligosaccharides, but the other enteric bacteria do not. This disaccharide is one of the building blocks in human milk oligosaccharides and is rarely found in other mammalian milks. The lacto-N-biosidase gene was cloned from B.bifidum and we hypothesized that this enzyme is crucially involved in the degradation of human milk oligosaccharides. The genes encoding sialidase and α-1,3/4-L-fucosidase were also cloned from B.bifidum. These enzymes release modified sialic acid and L-fucose from human milk oligosaccharides, respectively. A solute-binding protein of a putative ABC transporter specific for GNB and LNB was also discovered, and its gene was cloned from B.longum. We named it GNB/LNB-binding protein and crystallized it. Isothermal titration calorimetry measurements revealed that this protein specifically binds GNB and LNB. We speculate that bifidobacteria have a novel GNB/LNB metabolic pathway.
许多双歧杆菌产生内切α- n -乙酰半乳糖苷酶，从肠粘蛋白糖蛋白中释放o-连接半乳糖β- 1,3n -乙酰半乳糖胺(GNB)。利用公共数据库的信息完成了长双歧杆菌酶的分子克隆。该酶构成了一种新的糖苷水解酶(GH)家族101成员。从两歧双歧杆菌中克隆出特异性的1,2-α - l -聚焦酶基因。重组酶特异性水解多种低聚糖末端α-1,2-聚焦键，包括人乳低聚糖和血型物质。初步结构分析表明，该酶是GH家族95的新成员。我们还解出了其催化域的晶体结构。我们假设这些双歧杆菌酶参与了肠道中丰富的粘蛋白糖蛋白中低聚糖的代谢。一些双歧杆菌菌株产生一种乳酸- n -生物苷酶，从人乳低聚糖中释放半乳糖β- 1,3n -乙酰氨基葡萄糖(LNB)，但其他肠道细菌则没有。这种双糖是人类牛奶中低聚糖的组成部分之一，在其他哺乳动物的牛奶中很少发现。从双歧双歧杆菌中克隆了乳n -生物苷酶基因，我们推测该酶在人乳低聚糖的降解中起着至关重要的作用。从双歧杆菌中克隆到了唾液酸酶和α-1,3/4- l -聚焦酶的编码基因。这些酶分别从人乳低聚糖中释放改性唾液酸和L- focus。此外，还发现了一种推测为GNB和LNB特异性的ABC转运蛋白的溶质结合蛋白，其基因是从B.longum中克隆出来的。我们将其命名为GNB/ lnb结合蛋白并进行结晶。等温滴定量热法测定表明，该蛋白特异性结合GNB和LNB。我们推测双歧杆菌具有一种新的GNB/LNB代谢途径。
{"title":"Analyses of Bifidobacterial Glycosidases Involved in the Metabolism of Oligosaccharides","authors":"Kenji Yamamoto, T. Katayama, M. Kitaoka, S. Fushinobu","doi":"10.12938/BIFIDUS.29.23","DOIUrl":"https://doi.org/10.12938/BIFIDUS.29.23","url":null,"abstract":"Many bifidobacteria produce an endo-α-N-acetylgalactosaminidase that liberates the O-linked galactosyl β-1,3N-acetylgalactosamine (GNB) from intestinal mucin glycoproteins. The molecular cloning of the Bifidobacterium longum enzyme was completed using information in public databases. The enzyme constitutes a novel glycoside hydrolase (GH) family 101 member. The gene encoding a specific 1,2-α -L-fucosidase was cloned from B. bifidum. The recombinant enzyme specifically hydrolyzes the terminal α-1,2-fucosidic linkages of various oligosaccharides, including human milk oligosaccharides and blood group substances. Analysis of its primary structure revealed that this enzyme constitutes a novel GH family 95 member. We also solved the crystal structure of its catalytic domain. We assumed that these bifidobacterial enzymes are involved in the metabolism of oligosaccharides in mucin glycoproteins that are abundant in the intestine. Some bifidobacteria strains produce a lacto-N-biosidase that releases galactosyl β- 1,3N-acetylglucosamine (LNB) from human milk oligosaccharides, but the other enteric bacteria do not. This disaccharide is one of the building blocks in human milk oligosaccharides and is rarely found in other mammalian milks. The lacto-N-biosidase gene was cloned from B.bifidum and we hypothesized that this enzyme is crucially involved in the degradation of human milk oligosaccharides. The genes encoding sialidase and α-1,3/4-L-fucosidase were also cloned from B.bifidum. These enzymes release modified sialic acid and L-fucose from human milk oligosaccharides, respectively. A solute-binding protein of a putative ABC transporter specific for GNB and LNB was also discovered, and its gene was cloned from B.longum. We named it GNB/LNB-binding protein and crystallized it. Isothermal titration calorimetry measurements revealed that this protein specifically binds GNB and LNB. We speculate that bifidobacteria have a novel GNB/LNB metabolic pathway.","PeriodicalId":90114,"journal":{"name":"Bioscience and microflora","volume":"29 1","pages":"23-30"},"PeriodicalIF":0.0,"publicationDate":"2010-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66339909","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The stress response affects virtually every organ in the body and constitutes a coordinated behavioral and physiological response to potentially threatening stimuli that may be physiological or psychological in nature. There is a substantial amount of research focusing on how the stress response affects health, but relatively few studies have focused on the ability of the stress response to affect indigenous populations of bacteria in the intestines, referred to as the intestinal microbiota. Research from our lab, and from others, have demonstrated that psychological stressors early in the life span significantly changes the levels of different types of microbiota that are shed from the intestines in the stool. In our studies, stress in young rhesus monkeys, and even in the prenatal period, led to a significant reduction in the levels of lactobacilli and bifidobacteria shed in the stool. In rodents, prolonged restraint stress resulted in a significant overgrowth of aerobic microbiota, particularly Gram-negative aerobes, in the intestines. Interestingly, there is increasing evidence that alterations in the microbiota are associated with a variety of diseases that are known to be exacerbated during periods of psychological stress, including irritable bowel syndrome and the inflammatory bowel diseases. Thus, our data provide a compelling rationale to test the hypothesis that stress-induced exacerbations of intestinal diseases are in part due to stress-induced alterations of the microbiota.
{"title":"The Effects of Psychological Stressors on the Intestinal Microbiota","authors":"M. Bailey","doi":"10.12938/BIFIDUS.28.125","DOIUrl":"https://doi.org/10.12938/BIFIDUS.28.125","url":null,"abstract":"The stress response affects virtually every organ in the body and constitutes a coordinated behavioral and physiological response to potentially threatening stimuli that may be physiological or psychological in nature. There is a substantial amount of research focusing on how the stress response affects health, but relatively few studies have focused on the ability of the stress response to affect indigenous populations of bacteria in the intestines, referred to as the intestinal microbiota. Research from our lab, and from others, have demonstrated that psychological stressors early in the life span significantly changes the levels of different types of microbiota that are shed from the intestines in the stool. In our studies, stress in young rhesus monkeys, and even in the prenatal period, led to a significant reduction in the levels of lactobacilli and bifidobacteria shed in the stool. In rodents, prolonged restraint stress resulted in a significant overgrowth of aerobic microbiota, particularly Gram-negative aerobes, in the intestines. Interestingly, there is increasing evidence that alterations in the microbiota are associated with a variety of diseases that are known to be exacerbated during periods of psychological stress, including irritable bowel syndrome and the inflammatory bowel diseases. Thus, our data provide a compelling rationale to test the hypothesis that stress-induced exacerbations of intestinal diseases are in part due to stress-induced alterations of the microbiota.","PeriodicalId":90114,"journal":{"name":"Bioscience and microflora","volume":"28 1","pages":"125-134"},"PeriodicalIF":0.0,"publicationDate":"2009-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66339110","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
L -Glutamate is involved in the perception of umami taste, intermediary metabolism, and excitatory neurotransmission. In addition, recent studies have uncovered a variety of physiological roles for dietary glutamate, as evidenced by the fact that intragastric glutamate infusions induce flavor preference learning in rats. Moreover, glutamate increases digestive juice secretion and gastric emptying of protein-rich meals. Glutamate levels in blood and brain remain stable all day long even after the food intake since most of glutamate absorbed is oxidized in the mucosa of the small intestine as a primary energy source. Chronic ad libitum ingestion of glutamate solution contributes to reducing weight gain, fat deposition, and plasma leptin levels in comparison to ingestion of water. Glutamate receptors and their cellular transduction molecules have recently been identified in gut epithelial cells. Stimulation of gut glutamate receptors enhances the apical expression of glutamate transporters and also triggers the release of nitric oxide. Nitric oxide in its turn induces gut serotonin release, which increases vagal afferent inputs to different brain regions. Notably, three brain areas, i.e., the medial preoptic area, the dorsomedial nucleus of the hypothalamus, and the habenular nucleus are activated by intragastric glutamate infusions. Total subdiaphragmatic vagotomy abolishes this response. Consistent with the above, vagotomy specifically reduces the overall intake of glutamate. Taken together, these findings contribute to the growing body of evidence indicating that glutamate signaling via dedicated taste and gut receptors influences multiple physiological functions including gut secretion, motility, digestion, absorption, metabolism and energy homeostasis.
L -谷氨酸参与鲜味感知、中间代谢和兴奋性神经传递。此外，最近的研究发现了膳食谷氨酸的多种生理作用，如谷氨酸灌胃可诱导大鼠的风味偏好学习。此外，谷氨酸增加消化液分泌和富含蛋白质食物的胃排空。即使在食物摄入后，血液和大脑中的谷氨酸水平也会全天保持稳定，因为大部分被吸收的谷氨酸作为主要能量来源在小肠粘膜中被氧化。与喝水相比，长期随意摄入谷氨酸溶液有助于减少体重增加、脂肪沉积和血浆瘦素水平。最近在肠上皮细胞中发现了谷氨酸受体及其细胞转导分子。肠道谷氨酸受体的刺激增强了谷氨酸转运体的顶端表达，也触发了一氧化氮的释放。一氧化氮反过来诱导肠道血清素释放，从而增加迷走神经传入输入到不同的大脑区域。值得注意的是，胃内注入谷氨酸激活了三个脑区，即内侧视前区、下丘脑背内侧核和缰核。全膈下迷走神经切开术消除了这种反应。与上述一致，迷走神经切开术特别减少了谷氨酸的总摄入量。综上所述，这些发现提供了越来越多的证据，表明谷氨酸信号通过专门的味觉和肠道受体影响多种生理功能，包括肠道分泌、运动、消化、吸收、代谢和能量稳态。
{"title":"Physiological significance of glutamate signaling in gut-brain communication.","authors":"T. Kondoh, H. Mallick, K. Torii","doi":"10.12938/BIFIDUS.28.109","DOIUrl":"https://doi.org/10.12938/BIFIDUS.28.109","url":null,"abstract":"L -Glutamate is involved in the perception of umami taste, intermediary metabolism, and excitatory neurotransmission. In addition, recent studies have uncovered a variety of physiological roles for dietary glutamate, as evidenced by the fact that intragastric glutamate infusions induce flavor preference learning in rats. Moreover, glutamate increases digestive juice secretion and gastric emptying of protein-rich meals. Glutamate levels in blood and brain remain stable all day long even after the food intake since most of glutamate absorbed is oxidized in the mucosa of the small intestine as a primary energy source. Chronic ad libitum ingestion of glutamate solution contributes to reducing weight gain, fat deposition, and plasma leptin levels in comparison to ingestion of water. Glutamate receptors and their cellular transduction molecules have recently been identified in gut epithelial cells. Stimulation of gut glutamate receptors enhances the apical expression of glutamate transporters and also triggers the release of nitric oxide. Nitric oxide in its turn induces gut serotonin release, which increases vagal afferent inputs to different brain regions. Notably, three brain areas, i.e., the medial preoptic area, the dorsomedial nucleus of the hypothalamus, and the habenular nucleus are activated by intragastric glutamate infusions. Total subdiaphragmatic vagotomy abolishes this response. Consistent with the above, vagotomy specifically reduces the overall intake of glutamate. Taken together, these findings contribute to the growing body of evidence indicating that glutamate signaling via dedicated taste and gut receptors influences multiple physiological functions including gut secretion, motility, digestion, absorption, metabolism and energy homeostasis.","PeriodicalId":90114,"journal":{"name":"Bioscience and microflora","volume":"28 1","pages":"109-118"},"PeriodicalIF":0.0,"publicationDate":"2009-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66339248","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Nguyen Thi Bich Thuy, K. Takeshi, A. Kusumoto, S. Makino, K. Kawamoto
Salmonella is the most common food-borne pathogen worldwide. Rapid dissemination of multidrug-resistant strains, in particular from animal origins, is a growing concern to human and animal health, and it is mostly attributed to conjugative DNA exchange in the intestinal tract of food animals. To understand the potential role of pigs as a reservoir for antimicrobial-resistant Salmonella, we isolated Salmonella from slaughtered pigs and examined their drug resistance and gene transfer ability. We collected fecal and carcass swabs from 104 healthy pigs at an abattoir in Obihiro, Hokkaido, Japan. A total of 15 Salmonella strains were isolated, the most common serotypes being S. Typhimurium (7/15), S. Derby (2/15), S. Southampton (2/15) and S. 04:d:-(4/15). All of S. Typhimurium isolates were resistant to at least one of five antibiotics (ampicillin, kanamycin, sulfisoxazole, tetracycline and streptomycin). Pulsed-field gel electrophoresis (PFGE) profiles after Xbal and BlnI digestion were analyzed. S. Typhimurium isolates from 3 farms located in different regions clustered together and showed genetic relatedness. In conjugation experiments, one multidrug-resistant S. Typhimurium isolate showed the ability to transfer not only antibiotic resistance genes but also virulence genes such as spvABC to recipient bacteria. These results suggest that the spread of S. Typhimurium had occured in pig farms and that asymptomatic Salmonella-infected pigs should be considered as a significant source of antibiotic-resistant bacteria.
{"title":"Salmonella Typhimurium Isolated from Healthy Pigs and Their Ability of Horizontal Transfer of Multidrug Resistance and Virulence Genes","authors":"Nguyen Thi Bich Thuy, K. Takeshi, A. Kusumoto, S. Makino, K. Kawamoto","doi":"10.12938/BIFIDUS.28.135","DOIUrl":"https://doi.org/10.12938/BIFIDUS.28.135","url":null,"abstract":"Salmonella is the most common food-borne pathogen worldwide. Rapid dissemination of multidrug-resistant strains, in particular from animal origins, is a growing concern to human and animal health, and it is mostly attributed to conjugative DNA exchange in the intestinal tract of food animals. To understand the potential role of pigs as a reservoir for antimicrobial-resistant Salmonella, we isolated Salmonella from slaughtered pigs and examined their drug resistance and gene transfer ability. We collected fecal and carcass swabs from 104 healthy pigs at an abattoir in Obihiro, Hokkaido, Japan. A total of 15 Salmonella strains were isolated, the most common serotypes being S. Typhimurium (7/15), S. Derby (2/15), S. Southampton (2/15) and S. 04:d:-(4/15). All of S. Typhimurium isolates were resistant to at least one of five antibiotics (ampicillin, kanamycin, sulfisoxazole, tetracycline and streptomycin). Pulsed-field gel electrophoresis (PFGE) profiles after Xbal and BlnI digestion were analyzed. S. Typhimurium isolates from 3 farms located in different regions clustered together and showed genetic relatedness. In conjugation experiments, one multidrug-resistant S. Typhimurium isolate showed the ability to transfer not only antibiotic resistance genes but also virulence genes such as spvABC to recipient bacteria. These results suggest that the spread of S. Typhimurium had occured in pig farms and that asymptomatic Salmonella-infected pigs should be considered as a significant source of antibiotic-resistant bacteria.","PeriodicalId":90114,"journal":{"name":"Bioscience and microflora","volume":"28 1","pages":"135-143"},"PeriodicalIF":0.0,"publicationDate":"2009-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66339299","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
While a rationale for the use ofprobiotics can be developed for a number of gastrointestinal symptoms and syndromes and an experimental basis for their use continues to emerge, irritable bowel syndrome (IBS) has become the focus of much interest in this regard. IBS has also attracted attention because of recent revelations with regard to the potential roles of the enteric flora and immune activation in the pathogenesis of IBS, thereby, leading to a re-awakening of interest in bacteriotherapy in this common and challenging disorder. Some recent, randomized, controlled studies attest to the efficacy of some probiotics in alleviating individual IBS symptoms while selected strains have a more global impact. Evidence for long-term efficacy is also beginning to emerge though more studies are needed in this regard. Several other issues complicate the interpretation of much of the literature in this area: lack of quality control, use of many different species and strains and, above all, significant deficiencies in trial methodology.
{"title":"Probiotics and Irritable Bowel Syndrome","authors":"E. Quigley","doi":"10.12938/BIFIDUS.28.119","DOIUrl":"https://doi.org/10.12938/BIFIDUS.28.119","url":null,"abstract":"While a rationale for the use ofprobiotics can be developed for a number of gastrointestinal symptoms and syndromes and an experimental basis for their use continues to emerge, irritable bowel syndrome (IBS) has become the focus of much interest in this regard. IBS has also attracted attention because of recent revelations with regard to the potential roles of the enteric flora and immune activation in the pathogenesis of IBS, thereby, leading to a re-awakening of interest in bacteriotherapy in this common and challenging disorder. Some recent, randomized, controlled studies attest to the efficacy of some probiotics in alleviating individual IBS symptoms while selected strains have a more global impact. Evidence for long-term efficacy is also beginning to emerge though more studies are needed in this regard. Several other issues complicate the interpretation of much of the literature in this area: lack of quality control, use of many different species and strains and, above all, significant deficiencies in trial methodology.","PeriodicalId":90114,"journal":{"name":"Bioscience and microflora","volume":"28 1","pages":"119-124"},"PeriodicalIF":0.0,"publicationDate":"2009-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66339381","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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