Objective:The differences of ovarian morphology,reproductive hormones,glucose and lipid metabolism and intestinal bacteria in rats with polycystic ovary syndrome(PCOS)induced by triazole were compared.Method:Eighteen ...Objective:The differences of ovarian morphology,reproductive hormones,glucose and lipid metabolism and intestinal bacteria in rats with polycystic ovary syndrome(PCOS)induced by triazole were compared.Method:Eighteen 21 SPF female SD rats were randomly divided into group A(3-week group),group B(5-week group)and group D(control group)by random number table.Group A received letrozole+CMC-Na mixture by gavage in the first 3 weeks and CMC-Na solution by gavage in the last 2 weeks,group B received letrozole+CMC-Na mixture by gavage for 5 weeks,and group D received CMC-Na solution by gavage for 5 weeks,and all three groups of rats were fed with normal diet.At the end of gavage,the body weight of rats in each group was observed,the histological changes of ovaries were observed by hematoxylin-eosin(HE)staining,the serum levels of estradiol(E2),follicle stimulating hormone(FSH),luteinizing hormone(LH),testosterone(T),total cholesterol(TC),triglyceride(TG),fasting blood glucose(Glu),fasting insulin(FINS)and lipopolysaccharide(LPS)were measured by enzyme-linked immunosorbent assay(ELISA),and the LH/FSH ratio and insulin resistance index(HOMA IR)were calculated;the intestinal bacteria of rats were detected by 16S rRNA technique.Result:1.Comparison of ovary histomorphology:Under light microscope,multiple luteum and oocytes were observed in mature follicles in group D,and granulosa cells were orderly arranged and multilayered,without cystic dilated follicles.There were no mature follicles in the ovarian tissues of group A and GROUP B.The follicles were irregular in structure and more cystic dilated follicles were visible.The number of granular cells in some follicles decreased or even disappeared.2.Comparison of sex hormone levels:compared with group D,T level in group B was significantly increased(P<0.001),and T level in group A had an upward trend(P>0.05);The LH/FSH levels in group A and B were significantly increased(P<0.001;P<0.001).Compared with group A,E2 in group B was significantly decreased(P<0.05)and T was significantly increased(P<0.01).3.Comparison of glucose and lipid metabolism levels:Compared with group D,TC levels in groups A and B were significantly increased(P<0.01;P<0.01).Compared with group A,TG in group B was significantly increased(P<0.05).There were no significant differences in Glu,FINS and HOMA-IR levels among all groups.4.Comparison of LPS levels:Compared with group D,the serum LPS levels of rats in groups A and B were significantly increased(P<0.001;P<0.01).5.Intestinal flora analysis and comparison:At the phylum level,compared with group D,the abundance of Firmicutes in group B increased(P<0.01),Firmicutes in group A showed an upward trend(P>0.05),and the abundance of Bacteroidetes in groups A and B decreased(P<0.05).At the genus level,compared with group D,Lactobacillus in group B increased(P<0.01).The results of LEfSe analysis showed that there were differences in the composition of various intestinal bacteria among the three groups(LDA>3).Conclusion:The phenotype of PCOS rats was related to the length of modeling,and the phenotypic characteristics of PCOS in rats at 5 weeks of modeling were more typical than those in rats at 3 weeks of modeling;PCOS can cause changes in intestinal flora,and the changes in the structure of intestinal flora between groups are related to different modeling duration.展开更多
AIM To investigate the diversity of bacterial lactase genes in the intestinal contents of mice with antibiotics-induced diarrhea.METHODS Following 2 d of adaptive feeding, 12 specific pathogenfree Kunming mice were ra...AIM To investigate the diversity of bacterial lactase genes in the intestinal contents of mice with antibiotics-induced diarrhea.METHODS Following 2 d of adaptive feeding, 12 specific pathogenfree Kunming mice were randomly divided into the control group and model group. The mouse model of antibiotics-induced diarrhea was established by gastric perfusion with mixed antibiotics(23.33 m L·kg^(-1)·d^(-1)) composed of gentamicin sulfate and cephradine capsules administered for 5 days, and the control group was treated with an equal amount of sterile water. Contents of the jejunum and ileum were then collected and metagenomic DNA was extracted, after which analysis of bacterial lactase genes using operational taxonomic units(OTUs) was carried outafter amplification and sequencing.RESULTS OTUs were 871 and 963 in the model group and control group, respectively, and 690 of these were identical. There were significant differences in Chao1 and ACE indices between the two groups(P < 0.05). Principal component analysis, principal coordination analysis and nonmetric multidimensional scaling analyses showed that OTUs distribution in the control group was relatively intensive, and differences among individuals were small, while in the model group, they were widely dispersed and more diversified. Bacterial lactase genes from the intestinal contents of the control group were related to Proteobacteria, Actinobacteria, Firmicutes and unclassified bacteria. Of these, Proteobacteria was the most abundant phylum. In contrast, the bacterial population was less diverse and abundant in the model group, as the abundance of Bradyrhizobium sp. BTAi1, Agrobacterium sp. H13-3, Acidovorax sp. KKS102, Azoarcus sp. KH32 C and Aeromonas caviae was lower than that in the control group. In addition, of the known species, the control group and model group had their own unique genera, respectively.CONCLUSION Antibiotics reduce the diversity of bacterial lactase genes in the intestinal contents, decrease the abundance of lactase gene, change the lactase gene strains, and transform their structures.展开更多
BACKGROUND While colorectal polyps are not cancerous,some types of polyps,known as adenomas,can develop into colorectal cancer over time.Polyps can often be found and removed by colonoscopy;however,this is an invasive...BACKGROUND While colorectal polyps are not cancerous,some types of polyps,known as adenomas,can develop into colorectal cancer over time.Polyps can often be found and removed by colonoscopy;however,this is an invasive and expensive test.Thus,there is a need for new methods of screening patients at high risk of developing polyps.AIM To identify a potential association between colorectal polyps and small intestine bacteria overgrowth(SIBO)or other relevant factors in a patient cohort with lactulose breath test(LBT)results.METHODS A total of 382 patients who had received an LBT were classified into polyp and non-polyp groups that were confirmed by colonoscopy and pathology.SIBO was diagnosed by measuring LBTderived hydrogen(H)and methane(M)levels according to 2017 North American Consensus recommendations.Logistic regression was used to assess the ability of LBT to predict colorectal polyps.Intestinal barrier function damage(IBFD)was determined by blood assays.RESULTS H and M levels revealed that the prevalence of SIBO was significantly higher in the polyp group than in the non-polyp group(41%vs 23%,P<0.01;71%vs 59%,P<0.05,respectively).Within 90 min of lactulose ingestion,the peak H values in the adenomatous and inflammatory/hyperplastic polyp patients were significantly higher than those in the non-polyp group(P<0.01,and P=0.03,respectively).In 227 patients with SIBO defined by combining H and M values,the rate of IBFD determined by blood lipopolysaccharide levels was significantly higher among patients with polyps than those without(15%vs 5%,P<0.05).In regression analysis with age and gender adjustment,colorectal polyps were most accurately predicted with models using M peak values or combined H and M values limited by North American Consensus recommendations for SIBO.These models had a sensitivity of≥0.67,a specificity of≥0.64,and an accuracy of≥0.66.CONCLUSION The current study made key associations among colorectal polyps,SIBO,and IBFD and demonstrated that LBT has moderate potential as an alternative noninvasive screening tool for colorectal polyps.展开更多
BACKGROUND The pathogenesis of gastroesophageal reflux disease(GERD)is closely associated with the intestinal bacteria composition and their metabolites.AIM To investigate whether washed microbiota transplantation(WMT...BACKGROUND The pathogenesis of gastroesophageal reflux disease(GERD)is closely associated with the intestinal bacteria composition and their metabolites.AIM To investigate whether washed microbiota transplantation(WMT)improves symptoms of nonerosive reflux disease(NERD)with proton pump inhibitor(PPI)dependency.METHODS Patients with recurrent NERD and PPI dependency at the First Affiliated Hospital of Guangdong Pharmaceutical University from 2017 to 2018 were included and divided into a WMT or PPI group treated with PPI with/without WMT.The endpoint was NERD symptom frequency evaluated 1 mo after WMT using reflux disease questionnaire(RDQ)and GERD questionnaire(GERDQ)scores,remission time,PPI dose,and the examination of intestinal mucosal barrier function.RESULTS In the WMT(n=15)and PPI(n=12)groups,the total remission rate at 1 mo after treatment was 93.3%vs 41.7%.Compared with the PPI group,the WMT group showed better results in GERDQ(P=0.004)and RDQ(P=0.003)and in remission months(8 vs 2,P=0.002).The PPI dose was reduced to some extent for 80%of patients in the WMT group and 33.3%in the PPI group.In 24 patients,intestinal mucosal barrier function was examined before treatment,and changes in the degree of damage were observed in 13 of these patients after treatment.Only one of the 15 patients had minor side effects,including a mushy stool two or three times a day,which resolved on their own after 1 wk.CONCLUSION This study is the first to demonstrate that WMT may be safe and effective for relieving NERD symptoms and reducing PPI dependency and recurrence.展开更多
Inflammatory bowel disease(IBD)is an inflammatory disorder of the gastrointestinal tract that affects millions of patients worldwide.It has a complex and multifactorial etiology leading to excessive exposure of intest...Inflammatory bowel disease(IBD)is an inflammatory disorder of the gastrointestinal tract that affects millions of patients worldwide.It has a complex and multifactorial etiology leading to excessive exposure of intestinal epithelium to microbial antigens,inappropriate activation of the immune system and ultimately to the damage of intestinal tissues.Although numerous efforts have been made to improve the disease management,IBD remains persistently recurring and beyond cure.This is due largely to the gaps in our understanding of the pathogenesis of IBD that hamper the development of timely diagnoses and effective treatment.However,some recent discoveries,including the beneficial effects of interleukin-22(IL-22)on the inflamed intestine,have shed light on a self-protective mechanism in IBD.Regenerating islet-derived(REG/Reg)proteins are small secretory proteins which function as IL-22’s downstream effectors.Mounting studies have demonstrated that IBD patients have significantly increased REG expressions in the injured intestine,but with undefined mechanisms and roles.The reported functions of REG/Reg proteins in intestinal homeostasis,such as those of antibacterial,anti-inflammatory and tissue repair,lead us to discuss their potential mechanisms and clinical relevance in IBD in order to advance IBD research and management.展开更多
The biosurfactants rhamnolipids and the “soil ecosystem engineers” earthworms are often used to remediate contaminated soils. However, the effects of rhamnolipids on earthworm intestinal flora and microbial communit...The biosurfactants rhamnolipids and the “soil ecosystem engineers” earthworms are often used to remediate contaminated soils. However, the effects of rhamnolipids on earthworm intestinal flora and microbial community in soil containing earthworms are not clearly understood. In our study, a 21-d microcosm experiment was carried out to reveal the effects of rhamnolipids on microbial abundance, composition, and metabolism, as well as contaminant degradation capacity. Both rhamnolipids and earthworms had positive effects on soil bacteria. Rhamnolipid-amended soil(RT) showed higher bacterial abundance and metabolic activity than earthworm-amended soil(ET), while the improvement in bacterial composition and contaminant degradation capacity by rhamnolipids was lower than that by earthworms. Notably, these effects were further amplified by the combined treatment of rhamnolipids and earthworms(RET). Specifically, the bacterial abundance(log-transferred) increased from 9.5 copies g-1in the control with no addition to 10.3, 10.6, and 11.1 copies g-1in ET, RT, and RET, respectively. Compared to ET, the relative abundance of the dominant phylum, Proteobacteria, increased from 41.66% to 51.67% in RET,and more pollutant-degrading bacteria were also enriched in RET. Therefore, the increases in bacterial abundance and contaminant-degrading bacteria led to the following ranking of soil dioxin removal rate: RET(77.28%) > ET(59.83%) > RT(24.65%) > control(4.71%). Moreover, the addition of rhamnolipids enhanced the abundance of bacterial functional genes involved in metabolism and environmental information processing. In addition, the composition and diversity of bacteria in the gut of earthworms were conspicuously affected by rhamnolipids, and the relative abundance of Microbacterium and Shewanella increased significantly(P < 0.05). Therefore, this study revealed that rhamnolipids remarkably influenced the abundance, composition, and metabolism of the microbial community in earthworm gut, further promoting the degradation rate of dioxin, providing theoretical support for optimizing the combined application of rhamnolipids and earthworms in soil bioremediation engineering and for the assessment of the ecological impact of rhamnolipids.展开更多
Lactic acid bacteria(LAB)are a representative probiotic.As the dominant flora in the human intestinal tract,LAB can regulate the balance of human intestinal flora and improve host health.The purpose of this study was ...Lactic acid bacteria(LAB)are a representative probiotic.As the dominant flora in the human intestinal tract,LAB can regulate the balance of human intestinal flora and improve host health.The purpose of this study was to isolate and screen LAB that are well suited to the intestinal characteristics of the Chinese population,with excellent probiotics and high antibacterial activity.After 16S ribosomal RNA(rRNA)homology and phylogenetic tree analysis,potential probiotics were tested for their antibacterial activity,resistance to artificial gastrointestinal fluid and drugs,surface hydrophobicity,and safety.Three strains of LAB with acid resistance,bile salt resistance,epithelial cell adhesion,and no multidrug resistance were selected:Lactobacillus salivarius,Leuconostoc lactis,and Lactobacillus paracasei.Analysis of the antibacterial active substances in the three strains and their fermentation broths revealed that the main antibacterial substances of L.lactis were organic acids,whereas those of L.salivarius and L.paracasei were organic acids and bacteriocins with broad-spectrum antibacterial activity.These three strains of probiotic LAB with high antibacterial activity were identified as bacterial resources that could potentially be used to develop probiotic preparations for the prevention and treatment of intestinal diseases caused by intestinal pathogens.展开更多
Colorectal cancer(CRC)is one of the most prevalent,most lethal cancers in the world.Increasing evidence suggests that the intestinal microbiota is closely related to the pathogenesis and prognosis of CRC.The normal mi...Colorectal cancer(CRC)is one of the most prevalent,most lethal cancers in the world.Increasing evidence suggests that the intestinal microbiota is closely related to the pathogenesis and prognosis of CRC.The normal microbiota plays an essential role in maintaining gut barrier function and the immune microenvironment.Recent studies have identified carcinogenic bacteria such as enterotoxigenic Bacteroides fragilis(ETBF)and Streptococcus gallolyticus(S.gallolyticus),as well as protective bacterial such as Akkermansia muciniphila(A.muciniphila),as potential targets of CRC treatment.Gut microbiota modulation aims to restore gut dysbiosis,regulate the intestinal immune system and prevent from pathogen invasion,all of which are beneficial for CRC prevention and prognosis.The utility of probiotics,prebiotics,postbiotics,fecal microbiota transplantation and dietary inventions to treat CRC makes them novel microbe-based management tools.In this review,we describe the mechanisms involved in bacteria-derived colorectal carcinogenesis and summarized novel bacteria-related therapies for CRC.In summary,we hope to facilitate clinical applications of intestinal bacteria for preventing and treating CRC.展开更多
Even though Paranosema locustae is widely used in China as a biological agent for controlling grasshoppers,the mortality rate is initially quite low.This study sought to determine whether the simultaneous use of P.loc...Even though Paranosema locustae is widely used in China as a biological agent for controlling grasshoppers,the mortality rate is initially quite low.This study sought to determine whether the simultaneous use of P.locustae and Beauveria bassiana would be a more effective control strategy.Additionally,changes in the intestinal microbial communities of migratory locusts infected with the two pathogens were analyzed to investigate the roles of gut microbes in pathogen-host interactions.The mortality rate of locusts inoculated with B.bassiana and P.locustae simultaneously was not significantly higher than expected but the mortality rates of locusts inoculated with B.bassiana 3,6,and 9 days after inoculation with P.locustae were significantly higher than if their effects were additive,indicating synergism.A MiSeq analysis found that Weissella was the most common bacterium,representing 41.48%and 51.62%of the total bacteria in the mid-and hindguts,respectively,and the bacterial declines were greatest during dual infections with B.bassiana and P.locustae.The appropriately timed combined application of P.locustae and B.bassiana was more effective against locusts than either treatment alone.Moreover,the combined inoculation of the two pathogens changed the gut microflora of locusts,indicating the potential relevancy of their synergistic effects on locust control.展开更多
基金National Natural Science Foundation of China(No.81674011)。
文摘Objective:The differences of ovarian morphology,reproductive hormones,glucose and lipid metabolism and intestinal bacteria in rats with polycystic ovary syndrome(PCOS)induced by triazole were compared.Method:Eighteen 21 SPF female SD rats were randomly divided into group A(3-week group),group B(5-week group)and group D(control group)by random number table.Group A received letrozole+CMC-Na mixture by gavage in the first 3 weeks and CMC-Na solution by gavage in the last 2 weeks,group B received letrozole+CMC-Na mixture by gavage for 5 weeks,and group D received CMC-Na solution by gavage for 5 weeks,and all three groups of rats were fed with normal diet.At the end of gavage,the body weight of rats in each group was observed,the histological changes of ovaries were observed by hematoxylin-eosin(HE)staining,the serum levels of estradiol(E2),follicle stimulating hormone(FSH),luteinizing hormone(LH),testosterone(T),total cholesterol(TC),triglyceride(TG),fasting blood glucose(Glu),fasting insulin(FINS)and lipopolysaccharide(LPS)were measured by enzyme-linked immunosorbent assay(ELISA),and the LH/FSH ratio and insulin resistance index(HOMA IR)were calculated;the intestinal bacteria of rats were detected by 16S rRNA technique.Result:1.Comparison of ovary histomorphology:Under light microscope,multiple luteum and oocytes were observed in mature follicles in group D,and granulosa cells were orderly arranged and multilayered,without cystic dilated follicles.There were no mature follicles in the ovarian tissues of group A and GROUP B.The follicles were irregular in structure and more cystic dilated follicles were visible.The number of granular cells in some follicles decreased or even disappeared.2.Comparison of sex hormone levels:compared with group D,T level in group B was significantly increased(P<0.001),and T level in group A had an upward trend(P>0.05);The LH/FSH levels in group A and B were significantly increased(P<0.001;P<0.001).Compared with group A,E2 in group B was significantly decreased(P<0.05)and T was significantly increased(P<0.01).3.Comparison of glucose and lipid metabolism levels:Compared with group D,TC levels in groups A and B were significantly increased(P<0.01;P<0.01).Compared with group A,TG in group B was significantly increased(P<0.05).There were no significant differences in Glu,FINS and HOMA-IR levels among all groups.4.Comparison of LPS levels:Compared with group D,the serum LPS levels of rats in groups A and B were significantly increased(P<0.001;P<0.01).5.Intestinal flora analysis and comparison:At the phylum level,compared with group D,the abundance of Firmicutes in group B increased(P<0.01),Firmicutes in group A showed an upward trend(P>0.05),and the abundance of Bacteroidetes in groups A and B decreased(P<0.05).At the genus level,compared with group D,Lactobacillus in group B increased(P<0.01).The results of LEfSe analysis showed that there were differences in the composition of various intestinal bacteria among the three groups(LDA>3).Conclusion:The phenotype of PCOS rats was related to the length of modeling,and the phenotypic characteristics of PCOS in rats at 5 weeks of modeling were more typical than those in rats at 3 weeks of modeling;PCOS can cause changes in intestinal flora,and the changes in the structure of intestinal flora between groups are related to different modeling duration.
基金Supported by the National Natural Science Foundation of China,No.81573951
文摘AIM To investigate the diversity of bacterial lactase genes in the intestinal contents of mice with antibiotics-induced diarrhea.METHODS Following 2 d of adaptive feeding, 12 specific pathogenfree Kunming mice were randomly divided into the control group and model group. The mouse model of antibiotics-induced diarrhea was established by gastric perfusion with mixed antibiotics(23.33 m L·kg^(-1)·d^(-1)) composed of gentamicin sulfate and cephradine capsules administered for 5 days, and the control group was treated with an equal amount of sterile water. Contents of the jejunum and ileum were then collected and metagenomic DNA was extracted, after which analysis of bacterial lactase genes using operational taxonomic units(OTUs) was carried outafter amplification and sequencing.RESULTS OTUs were 871 and 963 in the model group and control group, respectively, and 690 of these were identical. There were significant differences in Chao1 and ACE indices between the two groups(P < 0.05). Principal component analysis, principal coordination analysis and nonmetric multidimensional scaling analyses showed that OTUs distribution in the control group was relatively intensive, and differences among individuals were small, while in the model group, they were widely dispersed and more diversified. Bacterial lactase genes from the intestinal contents of the control group were related to Proteobacteria, Actinobacteria, Firmicutes and unclassified bacteria. Of these, Proteobacteria was the most abundant phylum. In contrast, the bacterial population was less diverse and abundant in the model group, as the abundance of Bradyrhizobium sp. BTAi1, Agrobacterium sp. H13-3, Acidovorax sp. KKS102, Azoarcus sp. KH32 C and Aeromonas caviae was lower than that in the control group. In addition, of the known species, the control group and model group had their own unique genera, respectively.CONCLUSION Antibiotics reduce the diversity of bacterial lactase genes in the intestinal contents, decrease the abundance of lactase gene, change the lactase gene strains, and transform their structures.
基金Supported by the Key-Area Research and Development Program of Guangdong Province,No.2022B1111070006the Guangdong Innovation Research Team for Higher Education,No.2021KCXTD025.
文摘BACKGROUND While colorectal polyps are not cancerous,some types of polyps,known as adenomas,can develop into colorectal cancer over time.Polyps can often be found and removed by colonoscopy;however,this is an invasive and expensive test.Thus,there is a need for new methods of screening patients at high risk of developing polyps.AIM To identify a potential association between colorectal polyps and small intestine bacteria overgrowth(SIBO)or other relevant factors in a patient cohort with lactulose breath test(LBT)results.METHODS A total of 382 patients who had received an LBT were classified into polyp and non-polyp groups that were confirmed by colonoscopy and pathology.SIBO was diagnosed by measuring LBTderived hydrogen(H)and methane(M)levels according to 2017 North American Consensus recommendations.Logistic regression was used to assess the ability of LBT to predict colorectal polyps.Intestinal barrier function damage(IBFD)was determined by blood assays.RESULTS H and M levels revealed that the prevalence of SIBO was significantly higher in the polyp group than in the non-polyp group(41%vs 23%,P<0.01;71%vs 59%,P<0.05,respectively).Within 90 min of lactulose ingestion,the peak H values in the adenomatous and inflammatory/hyperplastic polyp patients were significantly higher than those in the non-polyp group(P<0.01,and P=0.03,respectively).In 227 patients with SIBO defined by combining H and M values,the rate of IBFD determined by blood lipopolysaccharide levels was significantly higher among patients with polyps than those without(15%vs 5%,P<0.05).In regression analysis with age and gender adjustment,colorectal polyps were most accurately predicted with models using M peak values or combined H and M values limited by North American Consensus recommendations for SIBO.These models had a sensitivity of≥0.67,a specificity of≥0.64,and an accuracy of≥0.66.CONCLUSION The current study made key associations among colorectal polyps,SIBO,and IBFD and demonstrated that LBT has moderate potential as an alternative noninvasive screening tool for colorectal polyps.
文摘BACKGROUND The pathogenesis of gastroesophageal reflux disease(GERD)is closely associated with the intestinal bacteria composition and their metabolites.AIM To investigate whether washed microbiota transplantation(WMT)improves symptoms of nonerosive reflux disease(NERD)with proton pump inhibitor(PPI)dependency.METHODS Patients with recurrent NERD and PPI dependency at the First Affiliated Hospital of Guangdong Pharmaceutical University from 2017 to 2018 were included and divided into a WMT or PPI group treated with PPI with/without WMT.The endpoint was NERD symptom frequency evaluated 1 mo after WMT using reflux disease questionnaire(RDQ)and GERD questionnaire(GERDQ)scores,remission time,PPI dose,and the examination of intestinal mucosal barrier function.RESULTS In the WMT(n=15)and PPI(n=12)groups,the total remission rate at 1 mo after treatment was 93.3%vs 41.7%.Compared with the PPI group,the WMT group showed better results in GERDQ(P=0.004)and RDQ(P=0.003)and in remission months(8 vs 2,P=0.002).The PPI dose was reduced to some extent for 80%of patients in the WMT group and 33.3%in the PPI group.In 24 patients,intestinal mucosal barrier function was examined before treatment,and changes in the degree of damage were observed in 13 of these patients after treatment.Only one of the 15 patients had minor side effects,including a mushy stool two or three times a day,which resolved on their own after 1 wk.CONCLUSION This study is the first to demonstrate that WMT may be safe and effective for relieving NERD symptoms and reducing PPI dependency and recurrence.
文摘Inflammatory bowel disease(IBD)is an inflammatory disorder of the gastrointestinal tract that affects millions of patients worldwide.It has a complex and multifactorial etiology leading to excessive exposure of intestinal epithelium to microbial antigens,inappropriate activation of the immune system and ultimately to the damage of intestinal tissues.Although numerous efforts have been made to improve the disease management,IBD remains persistently recurring and beyond cure.This is due largely to the gaps in our understanding of the pathogenesis of IBD that hamper the development of timely diagnoses and effective treatment.However,some recent discoveries,including the beneficial effects of interleukin-22(IL-22)on the inflamed intestine,have shed light on a self-protective mechanism in IBD.Regenerating islet-derived(REG/Reg)proteins are small secretory proteins which function as IL-22’s downstream effectors.Mounting studies have demonstrated that IBD patients have significantly increased REG expressions in the injured intestine,but with undefined mechanisms and roles.The reported functions of REG/Reg proteins in intestinal homeostasis,such as those of antibacterial,anti-inflammatory and tissue repair,lead us to discuss their potential mechanisms and clinical relevance in IBD in order to advance IBD research and management.
基金financially supported by the National Key Research and Development Program of China (No. 2018YFC1803100)the Youth Innovation Promotion Association of Chinese Academy of Sciences (No. 2018350)。
文摘The biosurfactants rhamnolipids and the “soil ecosystem engineers” earthworms are often used to remediate contaminated soils. However, the effects of rhamnolipids on earthworm intestinal flora and microbial community in soil containing earthworms are not clearly understood. In our study, a 21-d microcosm experiment was carried out to reveal the effects of rhamnolipids on microbial abundance, composition, and metabolism, as well as contaminant degradation capacity. Both rhamnolipids and earthworms had positive effects on soil bacteria. Rhamnolipid-amended soil(RT) showed higher bacterial abundance and metabolic activity than earthworm-amended soil(ET), while the improvement in bacterial composition and contaminant degradation capacity by rhamnolipids was lower than that by earthworms. Notably, these effects were further amplified by the combined treatment of rhamnolipids and earthworms(RET). Specifically, the bacterial abundance(log-transferred) increased from 9.5 copies g-1in the control with no addition to 10.3, 10.6, and 11.1 copies g-1in ET, RT, and RET, respectively. Compared to ET, the relative abundance of the dominant phylum, Proteobacteria, increased from 41.66% to 51.67% in RET,and more pollutant-degrading bacteria were also enriched in RET. Therefore, the increases in bacterial abundance and contaminant-degrading bacteria led to the following ranking of soil dioxin removal rate: RET(77.28%) > ET(59.83%) > RT(24.65%) > control(4.71%). Moreover, the addition of rhamnolipids enhanced the abundance of bacterial functional genes involved in metabolism and environmental information processing. In addition, the composition and diversity of bacteria in the gut of earthworms were conspicuously affected by rhamnolipids, and the relative abundance of Microbacterium and Shewanella increased significantly(P < 0.05). Therefore, this study revealed that rhamnolipids remarkably influenced the abundance, composition, and metabolism of the microbial community in earthworm gut, further promoting the degradation rate of dioxin, providing theoretical support for optimizing the combined application of rhamnolipids and earthworms in soil bioremediation engineering and for the assessment of the ecological impact of rhamnolipids.
基金the National Key Research and Development Program of China(No.2016YFD0400605)。
文摘Lactic acid bacteria(LAB)are a representative probiotic.As the dominant flora in the human intestinal tract,LAB can regulate the balance of human intestinal flora and improve host health.The purpose of this study was to isolate and screen LAB that are well suited to the intestinal characteristics of the Chinese population,with excellent probiotics and high antibacterial activity.After 16S ribosomal RNA(rRNA)homology and phylogenetic tree analysis,potential probiotics were tested for their antibacterial activity,resistance to artificial gastrointestinal fluid and drugs,surface hydrophobicity,and safety.Three strains of LAB with acid resistance,bile salt resistance,epithelial cell adhesion,and no multidrug resistance were selected:Lactobacillus salivarius,Leuconostoc lactis,and Lactobacillus paracasei.Analysis of the antibacterial active substances in the three strains and their fermentation broths revealed that the main antibacterial substances of L.lactis were organic acids,whereas those of L.salivarius and L.paracasei were organic acids and bacteriocins with broad-spectrum antibacterial activity.These three strains of probiotic LAB with high antibacterial activity were identified as bacterial resources that could potentially be used to develop probiotic preparations for the prevention and treatment of intestinal diseases caused by intestinal pathogens.
文摘Colorectal cancer(CRC)is one of the most prevalent,most lethal cancers in the world.Increasing evidence suggests that the intestinal microbiota is closely related to the pathogenesis and prognosis of CRC.The normal microbiota plays an essential role in maintaining gut barrier function and the immune microenvironment.Recent studies have identified carcinogenic bacteria such as enterotoxigenic Bacteroides fragilis(ETBF)and Streptococcus gallolyticus(S.gallolyticus),as well as protective bacterial such as Akkermansia muciniphila(A.muciniphila),as potential targets of CRC treatment.Gut microbiota modulation aims to restore gut dysbiosis,regulate the intestinal immune system and prevent from pathogen invasion,all of which are beneficial for CRC prevention and prognosis.The utility of probiotics,prebiotics,postbiotics,fecal microbiota transplantation and dietary inventions to treat CRC makes them novel microbe-based management tools.In this review,we describe the mechanisms involved in bacteria-derived colorectal carcinogenesis and summarized novel bacteria-related therapies for CRC.In summary,we hope to facilitate clinical applications of intestinal bacteria for preventing and treating CRC.
文摘Even though Paranosema locustae is widely used in China as a biological agent for controlling grasshoppers,the mortality rate is initially quite low.This study sought to determine whether the simultaneous use of P.locustae and Beauveria bassiana would be a more effective control strategy.Additionally,changes in the intestinal microbial communities of migratory locusts infected with the two pathogens were analyzed to investigate the roles of gut microbes in pathogen-host interactions.The mortality rate of locusts inoculated with B.bassiana and P.locustae simultaneously was not significantly higher than expected but the mortality rates of locusts inoculated with B.bassiana 3,6,and 9 days after inoculation with P.locustae were significantly higher than if their effects were additive,indicating synergism.A MiSeq analysis found that Weissella was the most common bacterium,representing 41.48%and 51.62%of the total bacteria in the mid-and hindguts,respectively,and the bacterial declines were greatest during dual infections with B.bassiana and P.locustae.The appropriately timed combined application of P.locustae and B.bassiana was more effective against locusts than either treatment alone.Moreover,the combined inoculation of the two pathogens changed the gut microflora of locusts,indicating the potential relevancy of their synergistic effects on locust control.
