雌马酚产出相关细菌研究进展

大豆异黄酮的苷元主要为染料木素和大豆素,可预防和改善多种疾病.近年来,大量研究表明大豆异黄酮的生物作用某种程度上归因于雌马酚.大豆素在肠道内由特定菌群转化为雌马酚,并不是所有人都可以产生雌马酚.本文综述了人体和动物肠道中与雌马酚产出有关的细菌,重点介绍了目前分离得到的能够直接将大豆素转化为雌马酚的菌株.可产雌马酚的相关细菌经体外厌氧培养能产生雌马酚.     

肠道菌群调节在非酒精性脂肪性肝病中西医治疗中的研究进展

目前研究发现,肠道微生物可以在非酒精性脂肪性肝病(NAFLD)治疗中发挥作用,肠道菌群调节将为NAFLD的治疗提供新思路。综述了肠道菌群调节在NAFLD中西医治疗中的研究进展,探究益生菌、粪便菌群移植、抗生素及中药治疗对于调节肠道菌群和改善NAFLD方面的研究现状,为临床提供依据。     

肠道菌群与心力衰竭关系的研究进展

肠道菌群与心力衰竭(心衰)密切相关。心衰伴发的血流动力学改变如肠道内低灌注和淤血可改变肠道的形态、通透性、功能以及肠道菌群的生长和组成,进而破坏肠道屏障,出现微生物或内毒素移位,加剧全身炎症反应。肠道菌群的代谢产物氧化三甲胺是偶联肠道菌群与心衰的关键介质。目前针对肠道菌群的干预策略包括饮食调节、抗生素、微生态制剂、菌群移植等,但安全性和有效性尚需证实。     

大肠杆菌O157∶H7对小鼠感染的实验研究

目的　采用肠出血性大肠杆菌埃希氏菌 (EHEC)国际代表株O15 7∶H7-EDL933株 ,实验感染小鼠 (ICR) ,观察其感染和带菌消长情况。方法　ICR小鼠经口感染 ,剂量为 0 1～ 0 9ml(菌悬液浓度为 7 0× 10 8～ 4 0× 10 9CFU/ml) ,并在SPF动物实验室中饲养。结果　不同实验动物微生物等级的ICR小鼠对EDL933株表现出不同感染类型 ,Ⅰ级小鼠感染未成功 ;Ⅱ级小鼠为一过性排菌 (M =4h) ;Ⅲ级小鼠粪排菌中位数为 2 4h ,是Ⅱ级小鼠的 6倍。Ⅲ级小鼠发现盲肠带菌 ,阳性率为31 5 8% (6 / 19)。结论　研究结果提示 ,鼠可成为EHECO15 7∶H7的贮存宿主 ,可能是潜在的人类感染的传染源。不同实验动物微生物等级的ICR小鼠对EDL933株所表现出的感染类型 ,提示预防O15 7∶H7感染 ,可经口服菌苗来实现的可能性     

抗生素对肠道细菌变迁影响的研究进展

正常肠道内,以大肠为中心寄生着100多种细菌,其数量超过100万亿之多,它们集聚成团,生活在肠道中,称为"肠内细菌",肠内细菌分为"有益细菌"和"有害细菌"以及一些厌氧菌群,这些菌群在我们的肠道中和平共处,维持平衡状态。抗生素在治疗细菌和致病微生物感染中起着重要作用,但它在杀灭外来微生物的同时,也会使体内的一些"有益细菌"被抑制或杀灭,因此,常用抗生素会破坏肠道内微生态平衡,造成菌群失调。该文就抗生素对肠道细菌变迁影响的研究进展作一综述。     

甘露低聚糖对小鼠肠道菌群的调节作用

[目的]研究甘露低聚糖(MOS)对小鼠肠道菌群的调节作用.[方法]40只小鼠随机分为空白对照组及MOS大、中、小剂量组.于不同剂量的MOS灌胃10 d前后分别采集小鼠粪便,检查肠道内双歧杆菌、乳杆菌、肠杆菌及肠球菌.[结果]MOS中、大剂量组灌胃MOS 10 d前后比较,小鼠肠道内双歧杆菌、乳杆菌数量明显增加(P＜0.01),肠杆菌、肠球菌数量无明显变化(P＞0.05).[结论]MOS能有效调节肠道菌群,增殖双歧杆菌及乳杆菌.     

山药多糖对昆明种小鼠生长性能及肠道菌群的影响

目的分析山药多糖对昆明种小鼠的生长性能及盲结肠乳酸杆菌、双歧杆菌、肠杆菌及肠球菌的影响。方法选取48只健康昆明种小鼠,雌雄各半,分为空白对照组(灌胃生理盐水)、山药多糖高剂量组(400 mg/kg)、中剂量组(200 mg/kg)和低剂量组(100 mg/kg),每天对小鼠体重及采食量进行准时记录。采集第28天的小鼠盲结肠,检测肠道菌群变化。结果当灌胃高、中剂量山药多糖28 d时,小鼠体重与对照组相比有统计学意义(P<0.05);同时,在高剂量的小鼠盲结肠内,肠杆菌与肠球菌的菌群数量与对照之间存在显著差异(P<0.01),而双歧杆菌和乳酸杆菌的增殖与对照相比,在高剂量和中剂量组均有统计学意义(P<0.01或P<0.05)。结论长期灌胃山药多糖对小鼠的生长性能和肠道菌群有显著影响。     

大肠杆菌O157：H7对小鼠感染的实验研究

目的　采用肠出血性大肠杆菌埃希氏菌 (EHEC)国际代表株O15 7∶H7-EDL933株 ,实验感染小鼠 (ICR) ,观察其感染和带菌消长情况。方法　ICR小鼠经口感染 ,剂量为 0 1～ 0 9ml(菌悬液浓度为 7 0× 10 8～ 4 0× 10 9CFU/ml) ,并在SPF动物实验室中饲养。结果　不同实验动物微生物等级的ICR小鼠对EDL933株表现出不同感染类型 ,Ⅰ级小鼠感染未成功 ;Ⅱ级小鼠为一过性排菌 (M =4h) ;Ⅲ级小鼠粪排菌中位数为 2 4h ,是Ⅱ级小鼠的 6倍。Ⅲ级小鼠发现盲肠带菌 ,阳性率为31 5 8% (6 / 19)。结论　研究结果提示 ,鼠可成为EHECO15 7∶H7的贮存宿主 ,可能是潜在的人类感染的传染源。不同实验动物微生物等级的ICR小鼠对EDL933株所表现出的感染类型 ,提示预防O15 7∶H7感染 ,可经口服菌苗来实现的可能性     

肠道菌群促进血管紧张素Ⅱ诱导的高血压和血管功能障碍

正肠道微生物对宿主生理反应及对免疫功能的发展来说必不可少。肠道菌群对血压和全身血管功能等这些由免疫细胞功能决定的生理过程的影响知之甚少。方法:与常规饲养的小鼠(conventionally raised rats,CONV-R)比较,未受任何细菌影响的无菌小鼠(GF)表现出较为严重的全身性辅助性T细胞1型滞后。GF的肠道中建立的普通肠道菌群可诱导T淋巴细胞T盒mRNA转录和表达,导致轻度血管内皮功能障     

肠道菌群与代谢综合征

<正>在人体的肠道内寄居着数以万亿的细菌,这些细菌组成了人体最大的微生物群,即肠道菌群。在婴儿时期影响肠道菌群结构的因素有以下几种,生产方式、婴儿喂养方式、住院接受医疗的情况(包括抗生素的使用情况)以及是否早熟[1]。从婴儿出生后肠道菌群就与宿主作为一个整体一起参与多种疾病的发生发展。宿主与肠道菌群以一种相互依赖的方式协同进化存在,宿主为肠道菌群的生长提供一个舒适的、独一无二的居住环境,肠道菌群为宿主提供一些宿主     

胃肠舒泰颗粒对大鼠胃泌素含量及小鼠胃肠运动功能的影响

目的 :观察胃肠舒泰颗粒对阿托品引起的小鼠胃排空及小肠推进功能抑制作用的影响 ,对正常大鼠血清胃泌素 (GAS)含量的影响。方法 :ICR小鼠 12 0只 ,胃排空实验、小肠推进实验各选 6 0只 ,分别随机分为 6组 ,即阴性对照组、模型对照组、胃肠舒泰颗粒小、中、大剂量组与普瑞博思组 ,以阿托品为抑制剂 ,观察各组胃排空及小肠推进率。SD大鼠 5 0只 ,分 5组 ,观察胃肠舒泰颗粒对大鼠血清 GAS含量的影响。结果 :胃肠舒泰颗粒可促进阿托品抑制的小鼠胃排空率及小肠推进率 ,并可增加正常大鼠血清 GAS的相对含量。结论 :胃肠舒泰颗粒对阿托品引起的小鼠胃排空及小肠推进功能抑制有良好的拮抗作用 ,同时具有升高动物血清 GAS含量的作用 ,这可能是其治疗胃肠动力障碍性疾病的药理学基础。     

Effect of lysed Enterococcus faecalis FK-23 on allergen-induced immune responses and intestinal microflora in antibiotic-treated weaning mice.

BACKGROUND: Recent epidemiological studies have indicated that early life receipt of antibiotics may be associated with an increased risk of developing atopic disorder. Lysed Enterococcus faecalis FK-23 (LFK), a probiotic product of E faecalis, has been shown to have inhibitory effects on allergen-induced immune responses in mice. OBJECTIVE: The purpose of this study was to evaluate the effects of LFK on immune responses and intestinal microflora in antibiotic-treated, and allergen-sensitized weaning mice. METHODS: Three-week-old BALB/c mice were sensitized with cedar pollen allergen to establish the experimental model. The allergen-induced peritoneal accumulation of eosinophils, serum levels of total and allergen-specific immunoglobulin (Ig) E and IgG2a, and the intestinal bacterial flora were determined in the control, antibiotic, LFK and antibiotic-LFK groups (n = 7 in all groups). Orally administered erythromycin, one kind of macrolide antibiotic, was used for the experiments. RESULTS: There was no significant difference in the allergen-induced peritoneal accumulation of eosinophils and serum specific IgE and IgG2a levels in erythromycin-treated mice compared to a control group. However, the ratio of serum total IgE to IgG2a levels was significantly increased in erythromycin-treated mice relative to that found either in LFK-treated mice or in erythromycin-treated mice with LFK supplementation. The total aerobes, total anaerobes and Enterococcus species of intestinal microflora were not significantly different among all groups. Lactobacillus species were distinctly eliminated in the mice exposed to erythromycin on day 7 and totally recovered in erythromycin-treated mice with LFK intervention on day 28, but could not be recovered in the erythromycin-treated mice without LFK intervention. CONCLUSIONS: Our results suggest that LFK may improve the intestinal ecosystem disturbed by antibiotic use, and thereby prevent subsequent development of atopy. However, whether different antibiotics have different effects on immune responses needs to be addressed further.     

Effects of traditional Chinese herbal medicine San-HuangXie-Xin-Tang on gastrointestinal motility in mice

AIM: To investigate the effects of San-Huang-Xie-XinTang(SHXXT), a herbal product used in traditional Chinese medicine, on gastrointestinal(GI) motility in mice.METHODS: The in vivo effects of SHXXT on GI motility were investigated by measuring the intestinal transit rates(ITRs) using Evans blue in normal mice and in mice with experimentally induced GI motility dysfunction(GMD).RESULTS: In normal ICR mice, ITRs were significantly and dose-dependently increased by SHXXT(0.1-1 g/kg). GMD was induced by injecting acetic acid or streptozotocin intraperitoneally. The ITRs of GMD mice were significantly reduced compared to normal mice, and these reductions were significantly and dose-dependently inhibited by SHXXT(0.1-1 g/kg).CONCLUSION: These results suggest that SHXXT is a novel candidate for the development of a prokinetic agent that may prevent or alleviate GMD.     

Genistein and daidzein prevent diabetes onset by elevating insulin level and altering hepatic gluconeogenic and lipogenic enzyme activities in non-obese diabetic (NOD) mice

BACKGROUND: Non-obese diabetic (NOD) mice are regarded as being excellent animal models of human type 1 diabetes or insulin dependent diabetes (IDDM). This study investigated the beneficial effects of genistein and daidzein on IDDM, an autoimmune disease. METHODS: Female NOD mice were divided into control, genistein (0.02%, w/w) and daidzein (0.02%, w/w) groups. Blood glucose level, plasma biomarkers, hepatic glucose and lipid regulating enzyme activities and pancreas immunohistochemistry analysis were examined after a 9-week experimental period. RESULTS: Blood glucose levels of genistein and daidzein groups were 40 and 36% of control value at the end of study (9th week). The genistein and daidzein supplements increased insulin/glucagon ratio and C-peptide level with preservation of insulin staining beta-cell of pancreas in the NOD mice. In the liver, genistein and daidzein supplements resulted in lowering glucose-6-phosphatase (G6Pase) and phosphoenolpyruvate carboxykinase (PEPCK) activities, while increasing two lipogenic enzymes activities, malic enzyme and glucose-6-phosphate dehydrogenase (G6PD), compared to the control group. Significantly, genistein and daidzein supplementation lowered the activities of fatty acid beta-oxidation and carnitine palmitoyltransferase (CPT) in these mice. Genistein and daidzein also improved plasma triglyceride and free fatty acid (FFA) concentrations compared to the control group. CONCLUSIONS: These results suggest that genistein and daidzein play important roles in regulation of glucose homeostasis in type 1 diabetic mice by down-regulating G6Pase, PEPCK, fatty acid beta-oxidation and CPT activities, while up-regulating malic enzyme and G6PD activities in liver with preservation of pancreatic beta-cells. The supplementation of genistein and daidzein are seemingly helpful for preventing IDDM onset.     

阪崎肠杆菌新疆分离株侵袭乳鼠肠组织的病变

目的对阪崎肠杆菌新疆分离株侵袭乳鼠肠组织引起病变的特征进行分析。方法阪崎肠杆菌新疆分离株经产毒培养后,灌胃ICR乳鼠,7d后,无菌解剖取肠组织,制做切片,HE染色后镜下观察。结果乳鼠小肠、结肠、直肠发生明显病变。结论阪崎肠杆菌新疆分离株对机体具有潜在危害。     

The role of the resident intestinal flora in acute and chronic dextran sulfate sodium-induced colitis in mice

OBJECTIVE: There is increasing evidence that the intestinal microflora plays an important role in the pathogenesis of inflammatory bowel disease. In the present study, we examined the role of the resident intestinal flora in our model of dextran sulfate sodium (DSS)-induced acute and chronic colitis in mice. METHODS: Acute colitis was induced in BALB/c mice with 5% DSS in their drinking water for 7 days. Chronic colitis was established after four cycles of feeding 5% DSS for 7 days and water for 10 days. For eliminating intestinal bacteria, mice were injected intraperitoneally with metronidazole and ciprofloxacin. We analysed four parameters: (1) body weight, (2) length of the colon, (3) histological score, and (4) myeloperoxidase activity. RESULTS: In acute DSS colitis treatment with antibiotics led to an improvement of the histological parameters (epithelial damage, P< 0.05; inflammatory infiltrate, P< 0.05) and colon length (P < 0.0028). A significant reduction in granulocyte infiltration was indicated by a 52.6% reduced myeloperoxidase activity in colonic biopsies. By contrast, in chronic colitis, treatment of mice with antibiotics failed to show significant effects. CONCLUSION: In acute DSS-induced colitis bacteria and/or bacterial products play a major role in initiation of inflammation but not in chronic DSS colitis.     

胃肠舒泰颗粒对鼠血胃动素及胃肠运动的影响

[目的]观察胃肠舒泰(WCST)颗粒对小鼠胃排空及小肠推进作用和大鼠血清胃动素(MOT)的影响.[方法]ICR小鼠100只,胃排空实验、小肠推进实验各选50只,分别随机分为5组,空白对照组、WCST颗粒小、中、大剂量组及西沙比利组,观察各组胃排空及小肠推进率.SD大鼠50只,亦分5组,观察WCST颗粒对大鼠血清MOT的影响.[结果]WCST颗粒大、中剂量组小鼠胃排空率及小肠推进率较空白对照组均明显增快(P＜0.05～＜0.01),大、中剂量组大鼠血清中MOT亦明显增高(P＜0.05～0.01).[结论]WCST颗粒具有促进小鼠胃排空及小肠推进率和升高大鼠血清MOT的作用.这一机制可能与促进内源性MOT释放有关.     

Resistant starch promotes equol production and inhibits tibial bone loss in ovariectomized mice treated with daidzein

Daidzein is metabolized to equol in the gastrointestinal tract by gut microflora. Equol has greater estrogenic activity than genistein and daidzein, with its production shown to be promoted by dietary fiber. It is known that resistant starch (RS) is not absorbed in the proximal intestine and acts as dietary fiber in the colon. In this study, we investigated the combined effects of daidzein and RS intake on equol production, bone mineral density, and intestinal microflora in ovariectomized (OVX) mice. Female mice of the ddY strain, aged 8 weeks, were either sham operated (n = 6) or OVX. The OVX mice were randomly divided into 5 groups: OVX control (n = 6), OVX fed 0.1% daidzein–supplemented diet (OVX + Dz, n = 8), OVX fed 0.1% daidzein– and 12% RS–supplemented diet (OVX + Dz + RS, n = 8), OVX fed 12% RS–supplemented diet (OVX + RS, n = 8), and OVX who received daily subcutaneous administration of 17 β-estradiol (n = 6). After 6 weeks, urinary equol concentration was significantly higher in the OVX + Dz + RS group than in the OVX + Dz group. The bone mineral density of the whole tibia was higher in the OVX + Dz +RS group compared with the OVX + Dz group. The occupation ratios of Bifidobacterium spp in the cecal microflora in groups fed RS were significantly higher than those in the other groups. The present study demonstrated that RS may increase the bioavailability of daidzein.     

Radioprotective potential of primitive hematopoietic precursors forming colonies in diffusion chambers in mice

Abstract: The purpose of this study was to determine the radioprotective ability of primitive hematopoietic precursors which form colonies in diffusion chambers in mice (CFU-D). Thirty-two lethally irradiated female ICR mice were injected with 5 to 7 male ICR mouse bone marrow-derived CFU-D colonies each. Fourteen of these mice survived over 30 days and were sacrificed at intervals up to a year. As a control, 20 lethally irradiated female ICR mice received cells from intercolony areas. All of these mice died before day 20. DNA samples obtained from hematopoietic organs and liver from 8 sacrificed mice were analyzed for the presence of CFU-D colony-derived cells. Only in 1 ICR mouse was CFU-D colony origin DNA detected by Southern analysis in all hematopoietic organs: bone marrow, spleen, thymus and lymph nodes. In 6 mice, only selected hematopoietic organs were repopulated by CFU-D colony-derived cells as judged by Southern analysis. In some of these mice, the remaining hematopoietic organs contained small CDU-D-derived cell populations which could be detected by more sensitive polymerase chain reaction (PCR). In 1 mouse, the presence of CFU-D-derived cells in all hematopoietic organs was only demonstrated by PCR. These findings suggest that lethally irradiated mice can be rescued by CFU-D-derived daughter cells. They appear to have the potential to give rise to clones containing lymphoid and myeloid cells in all hematopoietic organs, at least temporarily. Thus, it can be concluded that CFU-D represents a very primitive hematopoietic precursor cell with radioprotective capability.     

Antibiotics with a selective aerobic or anaerobic spectrum have different therapeutic activities in various regions of the colon in interleukin 10 gene deficient mice

BACKGROUND AND AIMS: Multiple rodent models implicate resident intestinal bacteria in the pathogenesis of chronic immune mediated intestinal inflammation. Specific pathogen free (SPF) interleukin 10 gene deficient (IL-10(-/-)) mice develop colitis, which does not occur in the germ free (GF) state. We investigated whether broad or narrow spectrum antibiotics affect onset and progression of disease in various regions of IL-10(-/-) mice. METHODS: Metronidazole, ciprofloxacin, vancomycin-imipenem (50 mg/kg/day), or water (control) was administered orally before (prevention) or two weeks after (treatment) colonisation of GF IL-10(-/-) mice with SPF bacteria. After four weeks, colonic histology scores and cytokine production by colonic explants were determined. Caecal and colonic contents were collected for quantitative bacterial analysis. RESULTS: In the prevention study, all antibiotics decreased inflammation in the caecum and colon. However, in the treatment study, ciprofloxacin and vancomycin-imipenem decreased caecal inflammation, and reduced Escherichia coli and Enterococcus faecalis concentrations, whereas only vancomycin-imipenem lowered direct microscopic bacterial counts. In contrast, metronidazole and vancomycin-imipenem reduced colonic injury and eliminated anaerobic bacteria, including Bacteroides spp. CONCLUSIONS: Both narrow and broad spectrum antibiotics can prevent disease but treatment of established colitis is more selective. Ciprofloxacin is most effective in the treatment of caecal inflammation, metronidazole preferentially treats the colon, whereas vancomycin-imipenem definitively treats both regions. These results suggest that subsets of aerobic or anaerobic bacteria show regional differences in their capacity to mediate experimental colitis in IL-10(-/-) mice.