Ability of lactulose breath test results to accurately identify colorectal polyps through the measurement of small intestine bacterial overgrowth

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.

Combined probiotic bacteria promotes intestinal epithelial barrier function in interleukin-10-gene-deficient mice

AIM:To investigate the protective effects of combinations of probiotic(Bifico)on interleukin(IL)-10-genedeficient(IL-10 KO)mice and Caco-2 cell monolayers.METHODS:IL-10 KO mice were used to assess the benefits of Bifico in vivo.IL-10 KO and control mice received approximately 1.5×108 cfu/d of Bifico for 4 wk.Colons were then removed and analyzed for epithelial barrier function by Ussing Chamber,while an ELISA was used to evaluate proinflammatory cytokines.The colon epithelial cell line,Caco-2,was used to test the benefit of Bifico in vitro.Enteroinvasive Escherichia coli(EIEC)and the probiotic mixture Bifico,or single probiotic strains,were applied to cultured Caco-2 monolayers.Barrier function was determined by measuring transepithelial electrical resistance and tight junction protein expression.RESULTS:Treatment of IL-10 KO mice with Bifico partially restored body weight,colon length,and epithelial barrier integrity to wild-type levels.In addition,IL-10 KO mice receiving Bifico treatment had reduced mucosal secretion of tumor necrosis factor-αand interferon-γ,and attenuated colonic disease.Moreover,treatment of Caco-2 monolayers with Bifico or singlestrain probiotics in vitro inhibited EIEC invasion and reduced the secretion of proinflammatory cytokines.CONCLUSION:Bifico reduced colon inflammation in IL-10 KO mice,and promoted and improved epithelialbarrier function,enhanced resistance to EIEC invasion,and decreased proinflammatory cytokine secretion.

Diversity of bacterial lactase genes in intestinal contents of mice with antibiotics-induced diarrhea

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.

Predisposing factors for positive D-Xylose breath test for evaluation of small intestinal bacterial overgrowth:A retrospective study of 932 patients

AIM: To investigate, in the largest cohort to date, patient characteristics and associated risk factors for developing small intestinal bacterial overgrowth(SIBO) using the D-Xylose breath test(XBT).METHODS: We performed a retrospective crosssectional study to analyze patient characteristics who underwent the XBT for evaluation of SIBO. Diagnostic testing with the XBT was performed based on a clinical suspicion for SIBO in patients with symptoms of bloating, abdominal pain, abdominal distension, weight loss, diarrhea, and/or constipation. Consecutive electronicmedical records of 932 patients who completed the XBT at the University of Florida between 2005 and 2009 were reviewed. A two-way Analysis of Variance(ANOVA) was used to test for several associations including age, gender, and body mass index(BMI) with a +XBT. A two-way ANOVA was also performed to control for the differences and interaction with age and between genders. A similar analysis was repeated for BMI. Associations between medical conditions and prior surgical histories were conducted using the Mantel-Haenszel method for 2 by 2 contingency tables, stratified for gender. Reported odds ratio estimates reflect the odds of the prevalence of a condition within the +XBT group to that of the-XBT group. P values of less than 0.05(two-sided) were considered statistically significant.RESULTS: In the 932 consecutive eligible subjects studied, 513 had a positive XBT. A positive association was found between female gender and a positive XBT(P = 0.0025), and females with a positive test were, on average, greater than 5 years older than those with a negative test(P = 0.024). The mean BMI of positive XBT subjects was normal(24.5) and significantly lower than the subjects with a negative XBT(29.5)(P = 0.0050). A positive XBT was associated with gastroesophageal reflux disease(GERD)(OR = 1.35; 95%CI: 1.02-1.80, P = 0.04), peptic ulcer disease(PUD)(OR = 2.61; 95%CI: 1.48-4.59, P < 0.01), gastroparesis(GP)(OR = 2.04; 95%CI: 1.21-3.41, P < 0.01) and steroid use(OR = 1.35; 95%CI: 1.02-1.80, P = 0.01). Irritable bowel syndrome, independent protonpump inhibitor(PPI) usage, or previous abdominal surgery was not significantly associated with a positive XBT. No single subdivision by gender or PPI use was associated with a significant difference in the odds ratios between any of the subsets. CONCLUSION: Female gender, lower BMI, steroid use, PUD, GERD(independent of PPI use), and GP were more prevalent in patients with SIBO, determined by a positive XBT. Increasing age was associated with SIBO in females, but not in males.

Small intestinal bacteria overgrowth decreases small intestinalmotility in the NASH rats

AIM: To explore the relationship between small intestinalmotility and small intestinal bacteria overgrowth(SIBO) in Nonalcoholic steatohepatitis (NASH), andto investigate the effect of SIBO on the pathogenesisof NASH in rats. The effect of cidomycin in alleviatingseverity of NASH is also studied. METHODS: Forty eight rats were randomly dividedinto NASH group (n = 16), cidomycin group (n = 16)and control group (n = 16). Then each group weresubdivided into small intestinal motility group (n = 8),bacteria group (n = 8) respectively. A semi-solid coloredmarker was used for monitoring small intestinal transit.The proximal small intestine was harvested under sterilecondition and processed for quantitation for aerobes(E. coli) and anaerobes (Lactobacilli). Liver pathologicscore was calculated to qualify the severity of hepatitis.Serum ALT, AST levels were detected to evaluate theseverity of hepatitis. RESULTS: Small intestinal transit was inhibited inNASH group (P < 0.01). Rats treated with cidomycinhad higher small intestine transit rate than rats in NASHgroup (P < 0.01). High fat diet resulted in quantitativealterations in the aerobes (E. coli ) but not in theanoerobics (Lactobacill). There was an increase in thenumber of E. coli in the proximal small intestinal florain NASH group than in control group (1.70 ± 0.12 log10(CFU/g) vs 1.28 ± 0.07 log10 (CFU/g), P < 0.01). TNF-αconcentration was significantly higher in NASH groupthan in control group (1.13 ± 0.15 mmol/L vs 0.57 ±0.09 mmol/L, P < 0.01). TNF-α concentration was lowerin cidomycin group than in NASH group (0.63 ± 0.09mmol/L vs 1.13 ± 0.15 mmol/L, P < 0.01). Treatmentwith cidomycin showed its effect by significantly loweringserum ALT, AST and TNF-α levels of NASH rats. CONCLUSION: SIBO may decrease small intestinalmovement in NASH rats. SIBO may be an importantpathogenesis of Nash. And treatment with cidomycin by mouth can alleviate the severity of NASH.

Effects of psychological stress on small intestinal motility and bacteria and mucosa in mice

AIM: To investigate the effects of psychological stress on small intestinal motility and bacteria and mucosa in mice,and to explore the relationship between small intestinal dysfunction and small intestinal motility and bacteria and mucosa under psychological stress.METHODS: Sixty mice were randomly divided into psychological stress group and control group. Each group were subdivided into small intestinal motility group (n = 10),bacteria group (n = 10), and D-xylose administered to stomach group (n = 10). An animal model with psychological stress was established housing the mice with a hungry cat in separate layers of a two-layer cage. A semi-solid colored marker (carbon-ink) was used for monitoring small intestinal transit. The proximal small intestine was harvested under sterile condition and processed for quantitation for aerobes (Escherichia coli) and anaerobes (Lactobacilli). The quantitation of bacteria was expressed as log10(colony forming units/g). D-xylose levels in plasma were measured for estimating the damage of small intestinal mucosa.RESULTS: Small intestinal transit was inhibited (39.80±9.50% vs 58.79±11.47%, P＜0.01) in mice after psychological stress, compared with the controls. Psychological stress resulted in quantitative alterations in the aerobes (E. coli).There was an increase in the number of E. coli in the proximal small intestinal flora (1.78±0.30 log10(CFU/g) vs 1.37±0.21 log10(CFU/g), P＜0.01), and there was decrease in relative proportion of Lactobacilli and E. coli of stressed mice (0.53±0.63 vs 1.14±1.07, P＜0.05), while there was no significant difference in the anaerobes (Lactobacilli) between the two groups (2.31±0.70 log10 (CFU/g) vs 2.44±0.37 log10(CFU/g), ,P＞0.05). D-xylose concentrations in plasma in psychological stress mice were significantly higher than those in the control group (2.90±0.89 mmol/L vs 0.97±0.33 mmol/L, P＜0.01).CONCLUSION: Small intestinal dysfunction under psychological stress may be related to the small intestinal motility disorder and dysbacteriosis and the damage of mucosa probably caused by psychological stress.

Tauroursodeoxycholic acid(TUDCA)improves intestinal barrier function associated with TGR5-MLCK pathway and the alteration of serum metabolites and gut bacteria in weaned piglets

Background:Tauroursodeoxycholic acid(TUDCA),a hydrophilic bile acid,is the main medicinal component of bear bile and is commonly used to treat a variety of hepatobiliary diseases.Meanwhile,TUDCA has been shown to modulate the intestinal barrier function and alleviate DSS-induced colitis in mice.However,the effect of TUDCA on the intestinal barrier of weaned piglets remains largely unclear.Methods:The weaned piglets and porcine IPEC-J2 intestinal epithelial cells were used to investigate the effects of TUDCA on intestinal barrier function in weaned piglets and explore the possible underlying mechanisms.In vivo,72 healthy weaned piglets were randomly allocated into 2 groups according to their gender and body weight,and piglets were fed the basal diet with 0(control,CON)and 200 mg/kg TUDCA for 30 d,respectively.Three female and three male piglets reflecting the average bodyweight were slaughtered in each group and samples were collected.In vitro,IPEC-J2 cells were subjected to 100μmol/L TUDCA to explore the possible underlying mechanisms.Results:Our results demonstrated that dietary TUDCA supplementation significantly reduced the diarrhea incidence of weaned piglets,possibly attributing to the TUDCA-enhanced intestinal barrier function and immunity.In addition,TUDCA supplementation altered serum metabolites and the relative abundance of certain gut bacteria,which might contribute to the improved intestinal barrier function.Furthermore,the in-vitro results showed that TUDCA improved the E.coli-induced epithelial barrier impairment of IPEC-J2 cells and increased Takeda G-coupled protein receptor 5(TGR5)protein expression.However,knockdown of TGR5 and inhibition of myosin light chain kinase(MLCK)pathway abolished the TUDCA-improved epithelial barrier impairment in E.coli-treated IPEC-J2 cells,indicating the involvement of TGR5-MLCK in this process.Conclusions:These findings showed that TUDCA improved intestinal barrier function associated with TGR5-MLCK pathway and the alteration of serum metabolites and gut bacteria in weaned piglets,suggesting the potential application of TUDCA in improving gut health in piglet production.

In vitro assessment of gastrointestinal viability of two photosynthetic bacteria,Rhodopseudomonas palustris and Rhodobacter sphaeroides

The objectives of this study were to assess the potential of two photosynthetic bacteria (PSB), Rhodopseudomonas palustris HZ0301 and Rhodobacter sphaeroides HZ0302, as probiotics in aquaculture. The viability of HZ0301 and HZ0302 in simulated gastric transit conditions (pH 2.0, pH 3.0 and pH 4.0 gastric juices) and in simulated small intestinal transit conditions (pH 8.0, with or without 0.3% bile salts) was tested. The effects of HZ0301 and HZ0302 on the viability and permeability of intestinal epithelial cell in primary culture of tilapias, Oreochromis nilotica, were also detected. All the treatments were deter-mined with three replicates. The simulated gastric transit tolerance of HZ0301 and HZ0302 strains was pH-dependent and cor-respondingly showed lower viability at pH 2.0 after 180 min compared with pH 3.0 and pH 4.0. Both HZ0301 and HZ0302 were tolerant to simulated small intestine transit with or without bile salts in our research. Moreover, there was no significant difference (P>0.05) among three treatments including the control and the groups treated with HZ0301 or HZ0302 both in intestinal epithelial cell viability and membrane permeability, showing no cell damage. In summary, this study demonstrated that HZ0301 and HZ0302 had high capacity of upper gastrointestinal transit tolerance and were relatively safe for intestinal epithelial cells of tilapias.

A Comparative Study on Rat Intestinal Epithelial Cells and Resident Gut Bacteria (ii) Effect of Arsenite

Objective In order to use facultative gut bacteria as an alternate to animals for the initial gastrointestinal toxicity screening of heavy metals, a comparative study on rat intestinal epithelial cells and resident gut bacteria was undertaken. Methods in vitro growth rate of four gut bacteria, dehydrogenase （DHA） and esterase （EA） activity test, intestinal epithelial and bacterial cell membrane enzymes and in situ effect of arsenite were analysed. Results Growth profile of mixed resident population of gut bacteria and pure isolates of Escherichia coli, Pseudomonas sp., Lactobacillus sp., and Staphylococcus sp. revealed an arsenite （2-20 ppm） concentration-dependent inhibition. The viability pattern of epithelial cells also showed similar changes. DHA and EA tests revealed significant inhibition （40%-72%） with arsenite exposure of 5 and 10 ppm in isolated gut bacteria and epithelial cells. Decrease in membrane alkaline phosphatase and Ca^2＋-Mg^2＋-ATPase activities was in the range of 33%-55% in four bacteria at the arsenite exposure of 10 ppm, whereas it was 60%-65% in intestinal epithelial villus cells, in situ incubation of arsenite using intestinal loops also showed more or less similar changes in membrane enzymes of resident gut bacterial population and epithelial cells. Conclusion The results indicate that facultative gut bacteria can be used as suitable in vitro model for the preliminary screening of arsenical gastrointestinal cytotoxic effects.

Effect of different modeling time on intestinal bacteria in letrozole induced PCOS rats

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.

Comparative quantification of human intestinal bacteria based on cPCR and LDR/LCR

AIM: To establish a multiple detection method based on comparative polymerase chain reaction (cPCR) and ligase detection reaction (LDR)/ligase chain reaction (LCR) to quantify the intestinal bacterial components. METHODS: Comparative quantification of 16S rDNAs from different intestinal bacterial components was used to quantify multiple intestinal bacteria. The 16S rDNAs of different bacteria were amplified simultaneously by cPCR. The LDR/LCR was examined to actualize the genotyping and quantification. Two beneficial (Bifidobacterium , Lactobacillus ) and three conditionally pathogenic bacteria (Enterococcus , Enterobacterium and Eubacterium ) were used in this detection. With cloned standard bacterial 16S rDNAs, standard curves were prepared to validate the quantitative relations between the ratio of original concentrations of two templates and the ratio ofthe fluorescence signals of their final ligation products. The internal controls were added to monitor the whole detection flow. The quantity ratio between two bacteria was tested. RESULTS: cPCR and LDR revealed obvious linear correlations with standard DNAs, but cPCR and LCR did not. In the sample test, the distributions of the quantity ratio between each two bacterial species were obtained. There were significant differences among these distributions in the total samples. But these distributions of quantity ratio of each two bacteria remained stable among groups divided by age or sex. CONCLUSION: The detection method in this study can be used to conduct multiple intestinal bacteria genotyping and quantification, and to monitor the human intestinal health status as well.

Relationship between clinical features and intestinal microbiota in Chinese patients with ulcerative colitis

BACKGROUND Dysbacteriosis may be a crucial environmental factor for ulcerative colitis(UC).Further study is required on microbiota alterations in the gastrointestinal tract of patients with UC for better clinical management and treatment.AIM To analyze the relationship between different clinical features and the intestinal microbiota,including bacteria and fungi,in Chinese patients with UC.METHODS Eligible inpatients were enrolled from January 1,2018 to June 30,2019,and stool and mucosa samples were collected.UC was diagnosed by endoscopy,pathology,Mayo Score,and Montreal classification.Gene amplicon sequencing of 16S rRNA gene and fungal internal transcribed spacer gene was used to detect the intestinal microbiota composition.Alpha diversity,principal component analysis,similarity analysis,and Metastats analysis were employed to evaluate differences among groups.RESULTS A total of 89 patients with UC and 33 non-inflammatory bowel disease(IBD)controls were enrolled.For bacterial analysis,72 stool and 48 mucosa samples were obtained from patients with UC and 21 stool and 12 mucosa samples were obtained from the controls.For fungal analysis,stool samples were obtained from 43 patients with UC and 15 controls.A significant difference existed between the fecal and mucosal bacteria of patients with UC.Theα-diversity of intestinal bacteria and the relative abundance of some families,such as Lachnospiraceae and Ruminococcaceae,decreased with the increasing severity of bowel inflammation,while Escherichia-Shigella showed the opposite trend.More intermicrobial correlations in UC in remission than in active patients were observed.The bacteriafungi correlations became single and uneven in patients with UC.CONCLUSION The intestinal bacteria flora of patients with UC differs significantly in terms of various sample types and disease activities.The intermicrobial correlations change in patients with UC compared with non-IBD controls.

Clinical Studies Evaluating Effects of Probiotics on Parameters of Intestinal Barrier Function

The intestinal barrier is important in preventing translocation of bacteria, toxins and antigens from the lumen of the gut into the body. Enhanced permeability, or gut leakiness, has been associated with different diseases. Probiotics can, strain-specifically, improve the epithelial barrier function. However, so far most researches have used cell lines or animal models due to the difficulty of measuring the effects of products on the epithelial barrier function in vivo in humans. Here a systematic literature search was performed to find articles addressing the effects of probiotics on the barrier function in human trials. The Pubmed database was searched (January 2013) to identify human in vivo studies with probiotic products in which parameters for epithelial barrier function were measured. In total 29 studies were identified, but patients, bacterial characteristics and methods to measure intestinal barrier function caused large heterogeneity among these studies. About half of the studies showed positive results of probiotics on the epithelial barrier function, indicating a clear potential of probiotics in this field. In a case series of 14 patients using Ecologica825, a probiotic food supplement with known effect on epithelial barrier function, different markers of intestinal integrity improved significantly. Further studies in this field should consider strain(s), dose and duration of the probiotic supplementation as well as the markers used to measure epithelial barrier function. Besides the lactulose/mannitol test, zonulin and α1-antitrypsin might be valuable markers to measure epithelial barrier function in future experiments.

Intestinal Transport and Biotransformation of Resibufogenin and Cinobufagin in Chan Su via HPLC/APCI-MS^n

In vitro models of human colon carcinoma cell line(Caco-2 cell monolayer) and human intestinal bacteria were used to investigate the intestinal transport and biotransformation of resibufogenin and cinobufagin in Chan Su by HPLC/APCI-MSn. The experimental results of Caco-2 cell monolayer demonstrate that the apparent permeability coefficients(Papp) of resibufogenin and cinobufagin are higher than 10–6 cm/s, which indicates that both resibufogenin and cinobufagin have a good absorption in the small intestine. And the biotransformation result of human intestinal bacteria shows that resibufogenin has been transformed to 3-epiresibufogenin and cinobufagin has been transformed to 3-epicinobufagin, deacetylcinobufagin and 3-epideacetycinobufagin, respectively.

Non-steroidal anti-inflammatory drugs-induced small intestinal injury and probiotic agents

Intestinal bacteria play a role in the development of non-steroidal anti-inflammatory drugs(NSAID)-induced small intestinal injury.Agents such as probiotics,able to modify the gut ecology,might theoretically be useful in preventing small intestinal damage induced by NSAIDs.The clinical studies available so far do suggest that some probiotic agents can be effective in this respect.

Fermentative Biohydrogen Production with Enteric Bacteria Isolated from the Intestine of Wild Common Carp Dwelling in Tarim River Basin

The biological hydrogen generating from fermentation of low-cost lignocellulosic feedstocks by hydrogen-producing bacteria has attracted many attentions in recent years. In the present investigation, ten hydrogen-producing bacteria were newly isolated from the intestine of wild common carp (Cyprinus carpio L.), and identified belonging to the genera of Enterobacter and Klebsiella based on analysis of the 16S rDNA gene sequence and examination of the physiological and biochemical characteristics. All the isolates inherently owned the ability to metabolize xylose especially the cotton stalk hydrolysate for hydrogen production with hydrogen yield (HY) higher than 100 mL·L-1. In particular, two isolates, WL1306 and WL1305 obtained higher HY, hydrogen production rate (HPR), and hydrogen production potential (HPP) using cotton stalk hydrolysate as sugar substrate than the mixed sugar of glucose & xylose, which obtained the HY of 249.5 ± 29.0, 397.0 ± 36.7 mL·L-1, HPR of 10.4 ± 1.2, 16.5 ± 1.5 mL·L-1·h-1, HPP of 19.5 ± 2.3, 31.0 ± 2.8 mL·L-1·g-1sugar, separately. The generation of soluble metabolites, such as the lactate, formate, acetate, succinate and ethanol reflected the mixed acid fermentation properties of the hydrogen production pathway.

A new perspective of traditional Chinese and western medicine as a potential remedy to improve intestinal flora in the treatment of chronic kidney disease

Intestinal flora imbalance is closely related to the occurrence and development of various diseases,however,the relationship between intestinal flora and chronic kidney disease has also become a hot topic.Intestinal flora imbalance,intestinal pathogenic bacteria and toxins increase,causing renal damage,chronic kidney disease patients also have a decrease in intestinal beneficial bacteria,an increase in pathogenic bacteria,more and more experimental studies show that the treatment of chronic Kidney disease is closely related to maintaining the balance of intestinal flora.However,at this stage,it has not been widely used in clinical practice by improving the protection of intestinal flora imbalance and delaying the deterioration of renal function.Therefore,this paper mainly discusses the research on the improvement of intestinal flora imbalance in the treatment of chronic kidney disease by traditional Chinese and Western medicine,and provides a new perspective for the treatment of chronic kidney disease.

肠道微生态对子痫前期发病的影响

目的探讨肠道微生态对子痫前期(pre-eclampsia,PE)发病的影响及机制。方法选取2021年1月至2022年6月甘肃省妇幼保健院妇产科收治的40例PE患者及40例健康孕妇作为研究对象,按照孕期不同分为4组,26周PE孕妇作为A1组(n=20),36周PE孕妇作为A2组(n=20);26周健康孕妇作为B1组(n=20),36周健康孕妇作为B2组(n=20)。收集4组研究对象清晨粪便标本,提取粪便细菌DNA基因,采用16S rDNA的扩增及测序,得到肠道菌群α多样性及肠道菌群差异性。结果B2组Chao1及Observed-Species指数均低于B1组(P<0.001);与B1组相比,B2组艰难梭状芽胞杆菌(Clostridium)、马氏羊蹄菌(Fournierella)、普雷沃菌(Prevotella)、梭杆菌属(Fusobacterium)丰度升高,双歧杆菌(Bifidobacterium)及普拉梭菌(Faecalibacterium)的丰度降低。A1组Chao1及Observed-Species指数均低于B1组(P<0.001)。与B1组相比,A1组Clostridium、Fournierella、Prevotella、Fusobacterium丰度升高,Bifidobacterium及Faecalibacterium的丰度降低。A2组Chao1及Observed-Species指数均第于B2组(P<0.001);与B2组相比,A2组Clostridium、Fournierella、Prevotella、Fusobacterium丰度升高,Bifidobacterium及Faecalibacterium的丰度降低。A2组Chao1及Observed-Species指数均低于A1组(P<0.001);与A1组相比,A2组Clostridium、Fournierella、Prevotella、Fusobacterium丰度升高,Bifidobacterium及Faecalibacterium的丰度降低。结论健康孕妇会随着孕周的延长肠道菌群α多样性降低,致病菌丰度增加;PE肠道菌群致病性高于健康孕妇,且α多样性降低;PE会随着孕周的增加,肠道菌群α多样性降低,且上述致病菌丰度升高,有益菌降低,认为加强PE机体肠道菌群的监测对于预防炎症性疾病具有重要意义。

乳酸菌和抗生素对中华蜜蜂肠道消化酶活性、免疫基因表达及工蜂存活率的影响

本试验旨在通过在中华蜜蜂糖饲料中添加乳酸菌和抗生素,评价二者对中华蜜蜂肠道消化酶活性、免疫基因表达及工蜂存活率的影响,为其在蜜蜂养殖中的应用提供依据。试验选取0日龄的中华蜜蜂工蜂540只,随机分为3个组,每组3个重复,每个重复60只蜜蜂。对照组饲喂50%(质量分数,下同)蔗糖溶液,试验组分别饲喂添加1×108 CFU/mL植物乳杆菌的50%蔗糖溶液(乳酸菌组)和添加450μg/mL四环素的50%蔗糖溶液(抗生素组)。于15日龄,测定中肠消化酶活性和免疫基因相对表达量;于30日龄,测算工蜂存活率。结果表明:1)与对照组相比,乳酸菌组中华蜜蜂中肠淀粉酶活性显著提高(P<0.05),中肠Abaecin、Toll基因的相对表达量显著提高(P<0.05),中肠Cactus-1基因的相对表达量显著降低(P<0.05),工蜂的平均生存时间显著延长2.75 d(P<0.05)。2)与对照组相比,抗生素组中华蜜蜂中肠淀粉酶和蛋白酶活性均显著降低(P<0.05),中肠防御素-1(Defensin-1)、肽聚糖识别蛋白(PGRP)和Cactus-1基因的相对表达量显著降低(P<0.05),工蜂的平均生存时间显著缩短2.39 d(P<0.05)。由此可知,饲喂乳酸菌可提高中华蜜蜂肠道消化酶活性,增强肠道免疫功能,提高工蜂存活率;饲喂抗生素可降低中华蜜蜂肠道消化酶活性,降低工蜂存活率。

白羽肉鸡小肠内容物中致病性大肠杆菌的鉴定及基因组分析

旨在分析死亡白羽肉鸡肠道中的致病微生物,明确白羽肉鸡的死因,为白羽肉鸡的科学防病和治病提供新思路。采集养鸡场病死白羽肉鸡的肠道内容物,利用宏基因组测序、序列拼接、分箱技术、进化树分析、物种注释鉴定白羽肉鸡肠道中的致病微生物,通过基因组毒力基因和耐药基因的注释,阐述病原微生物的致病和耐药机制。结果显示:病死白羽肉鸡肠道内容物样品中检出的致病微生物为禽类致病性大肠杆菌(avian pathogenic Escherichia coli),经序列拼接和分箱技术得到病原菌全基因组序列,大小为4 998 208 bp,完整度为99.23%。该菌含有毒力基因192种,主要编码鞭毛、纤毛合成相关蛋白、定植相关蛋白、菌素合成相关蛋白,含有耐药基因88种,主要涉及28类抗生素的耐药,表明上述种类抗生素对感染禽类致病性大肠杆菌的白羽肉鸡无治疗作用,最终导致白玉肉鸡死亡。本研究利用宏基因测序技术可有效分析白羽肉鸡的致病微生物及致病、耐药机制,可在白羽肉鸡发病早期帮助养殖者了解病因,并有针对性地指导科学用药,减少经济损失。