玉米紫色植株花色苷色素对小鼠肠道菌群的影响

目的了解玉米紫色植株花色苷色素对小鼠肠道菌群的影响。方法按中华人民共和国卫生部《保健食品检验与评价技术规范》中的动物实验调节肠道菌群功能的检验方法,观察玉米紫色植株色素对小鼠肠道中肠杆菌、乳杆菌、双歧杆菌数量的影响。结果灌服后小鼠肠道乳杆菌、双歧杆菌数量变化差异均无显著性,低剂量组肠扦菌数量明显低于灌服前（P〈0．05）,其他组肠杆菌数量变化差异无显著性。结论玉米紫色植株色素对小鼠肠道菌群可能有影响。     

SCID小鼠肠道菌群失调对深部白色念珠菌感染的影响研究

目的建立重度联合免疫缺陷（SCID）小鼠白色念珠菌感染模型,探讨肠道菌群失调与深部白色念珠菌感染的联系。方法SCID小鼠随机口服万古霉素水溶液7d,饥饿24h后给予白色念珠菌灌胃,建立小鼠白色念珠菌感染模型,观察小鼠死亡情况。荧光定量PCR检测肠道细菌总量、基质辅助激光解析电离飞行时间质谱仪鉴定肠道菌群种类,并应用扫描电镜观察肠壁黏膜组织超微结构的改变。结果应用万古霉素可致肠道菌群失调,肠道黏膜完整性受损。在万古霉素致肠道菌群失调的基础上,外源性白色念珠菌攻击可加重肠道菌群失调和肠壁黏膜损伤程度,促进深部白色念珠菌感染的发生。结论肠道菌群失衡可以导致深部白色念珠菌感染的发生,肠壁黏膜的完整性可能参与了肠道白色念珠菌播散过程。     

合生元益生菌冲剂对小鼠肠道菌群调节作用的研究

目的 研究合生无益生菌冲剂对小鼠肠道菌群的调节作用.方法 将小鼠分为阴性对照组、合生元益生菌冲剂组.阴性对照组灌服蒸馏水14 d,合生元益生菌冲剂组灌服1 g/kg·d剂量的台生元益生菌冲剂14 d,检测实验前后肠道菌群数量.结果 灌服后小鼠肠道菌群与灌服前比较,,双歧杆菌数量有显著性增加（P＜0.05）,肠杆菌、肠球菌、乳杆菌和产气荚膜梭菌数量有无显著性变化（P＞0.05）.结论 合生元益生菌冲剂对小鼠肠道菌群具有一定的调节作用.     

中草药对小鼠肠道菌群影响的实验研究

目的研究党参、茯苓、白术、白芍和陈皮五味中药制成的复方合剂对肠道菌群调节作用。方法将小鼠分为正常对照组、低剂量组、中剂量组和高剂量组。对照组灌服蒸馏水14 d,低剂量组、中剂量组和高剂量组灌服不同剂量的复方合剂14 d,检测实验前后肠道菌群数量。结果灌服后小鼠肠道菌群与灌服前比较,乳杆菌、双歧杆菌数量明显增加,肠球菌数量明显减少,肠杆菌数量差异无统计学意义。结论党参、茯苓、白术、白芍和陈皮五味中药制成的复方合剂对小鼠肠道菌群具有一定的调节作用。     

中药91—4对抗生素相关性腹泻小鼠肠道膜菌群及腔菌群的影响

本实验以肠道菌检测与电镜观察法,初步研究了中药９１－４对抗生素相关性腹泻小鼠肠道菌群的影响。结果表明,盐酸林可霉素对小鼠肠道膜菌群、腔菌群干扰显著、乳酸杆菌、双歧杆菌及肠杆菌等比正常对照组明显减少,致小鼠腹泻或肠炎;中药９１－４能够促进肠道乳酸杆菌、双歧杆菌等生长繁殖,对肠道膜菌群、腔菌群均具有调整作用,加速肠粘膜病变的愈合及修复,可有效地控制ＡＡＤ模型小鼠的腹泻症状。     

态平胶囊对肠道菌群影响的实验研究

目的研究态平胶囊的特性及功效。方法通过检测实验鼠服用态平胶囊前后肠道菌群的变化．观察态平胶囊的作用。结果灌服态平胶囊后,小鼠肠道内双歧杆菌及乳杆菌数量显著增加．肠球菌及肠杆菌数量显著下降。结论态平胶囊具有调节肠道菌群改善肠道内环境的功能。     

中药91－4对抗生素相关性腹泻小鼠肠道膜菌群及腔菌群的影响

本实验以肠道菌群检测与电镜观察法,初步研究了中药９１－４对抗生素相关性腹泻（ＡＡＤ）小鼠肠道菌群的影响。结果表明,盐酸林可霉素对小鼠肠道膜菌群、腔菌群干扰显著,乳酸杆菌、双歧杆菌及肠杆菌等比正常对照组明显减少,致小鼠腹泻或肠炎;中药９１－４能够促进肠道乳酸杆菌、双歧杆菌等生长繁殖,对肠道膜菌群、腔菌群均具有调整作用,加速肠粘膜病变的愈合及修复,可有效地控制ＡＡＤ模型小鼠的腹泻症状。     

扶正固本丸对小鼠肠道菌群的影响

本文报告应用扶正固本丸对小鼠肠道内与人类关系密切的主要菌群的影响。用大黄水煎液灌胃予小鼠,造成实验性脾虚模型,引起小鼠肠道内菌群紊乱,其中双歧杆菌,乳杆菌量均下降,与对照组相比有显著性差异。当服用扶正固本丸后,双歧杆菌、乳杆菌均上升至正常水平。本研究表明,扶正固本丸对小鼠肠道菌群失调具有一定的调整作用。     

螺旋藻对腹泻模型小鼠肠道菌群的影响

为评价螺旋藻对肠道菌群的影响, 采用注射氨苄青霉素的方法, 制造小鼠腹泻模型, 造模成功后灌服不同剂量螺旋藻进行治疗, 取不同治疗时间的粪便样品, 检测双歧杆菌、乳杆菌、大肠杆菌、肠球菌、拟杆菌、产气荚膜梭菌菌群的数量,并在螺旋藻灌胃8 d后, 测定小鼠不同肠段各指标菌群的数量。结果表明, 中高剂量组螺旋藻对腹泻模型小鼠肠道菌群有明显调整作用, 有效缩短了肠道菌群由失调到平衡的时间;粪便样品同各肠段内容物所反映的菌群的变化趋势相同, 即治疗恢复组的双歧杆菌、乳杆菌数量总体上高于生理盐水组, 肠杆菌、肠球菌、拟杆菌、产气荚膜梭菌数量均低于生理盐水组, 但取样位置不同, 各指标菌群的数量明显存在差异。     

枸杞子提取物对小鼠肠道菌群失衡的调整作用

本研究旨在探讨枸杞子不同浓度提取物对小鼠肠道菌群失衡的调整作用,为枸杞子的进一步开发利用提供理论依据。使用抗生素建立肠道菌群失衡模型,将小鼠随机分为正常对照组、枸杞子提取物高浓度组、低浓度组、模型组和自然恢复组,以双歧杆菌、乳酸杆菌、肠杆菌、肠球菌等肠道正常菌群为对象,利用传统菌落计数法研究各组肠道菌群失衡及恢复调整情况。枸杞子提取物对乳酸杆菌和双歧杆菌的生长具有恢复作用,且低浓度提取物的增殖作用优于高浓度,而对肠球菌和肠杆菌的作用并不明显。枸杞子提取物对小鼠肠道菌群失衡有一定的调整作用,能够纠正抗生素相关性菌群失调。     

Mucosal damage and neutropenia are required for Candida albicans dissemination

Candida albicans fungemia in cancer patients is thought to develop from initial gastrointestinal (GI) colonization with subsequent translocation into the bloodstream after administration of chemotherapy. It is unclear what components of the innate immune system are necessary for preventing C. albicans dissemination from the GI tract, but we have hypothesized that both neutropenia and GI mucosal damage are critical for allowing widespread invasive C. albicans disease. We investigated these parameters in a mouse model of C. albicans GI colonization that led to systemic spread after administration of immunosuppression and mucosal damage. After depleting resident GI intestinal flora with antibiotic treatment and achieving stable GI colonization levels of C. albicans, it was determined that systemic chemotherapy with cyclophosphamide led to 100% mortality, whereas selective neutrophil depletion, macrophage depletion, lymphopenia or GI mucosal disruption alone resulted in no mortality. Selective neutrophil depletion combined with GI mucosal disruption led to disseminated fungal infection and 100% mortality ensued. GI translocation and dissemination by C. albicans was also dependent on the organism's ability to transform from the yeast to the hyphal form. This mouse model of GI colonization and fungemia is useful for studying factors of innate host immunity needed to prevent invasive C. albicans disease as well as identifying virulence factors that are necessary for fungal GI colonization and dissemination. The model may also prove valuable for evaluating therapies to control C. albicans infections.     

The intestinal microflora during the first weeks of life

Bacterial colonization of the neonatal gastrointestinal tract begins during birth when the neonate comes into contact with the maternal cervical and vaginal flora. In infants delivered by Caesarean section, bacteria colonizing the neonate gastrointestinal tract are provided by the environment. The first bacteria encountered in the majority of healthy infants, are facultative anaerobes, which remain predominant during the first 2 weeks of life. Among them, Staphylococcus, Enterobacteriaceae and Streptococcus were the genera most commonly isolated from the newborn faecal flora at birth. Facultative anaerobic bacteria are followed closely by Bifidobacterium sp. Clostridium perfringens is present within 2 days with an increase incidence in newborns delivered by a Caesarean section. Clostridium perfringens seems to be the precursor for installation of other anaerobic putrefactive bacteria, as Bacteroides and other Clostridium sp. The impact of Caesarean section and the period and quality of hospitalization are mainly implicated in changes of the normal newborn flora. Feeding seems to modulate the colonization pattern. In humans, breast milk plays a role in passive immunization of the neonatal intestine, and contains factors that promote the growth of Bifidobacterium bifidum in the intestinal flora. Formula feeding seems to promote implantation and persistence of Clostridium perfringens, and clearly enhances intestinal colonization of C. difficile in newborns.     

The effects of Bifidobacterium bifidum OFR9, a strain resistant to antituberculosis and antileprosy agents,on fecal flora in mice

Since Bifidobacterium bifidum, one of the strains of medical preparations used for human intestinal disorders, is sensitive to rifampicin (RFP) and fluoroquinolones, its therapeutic effect cannot be guaranteed when it is administered concomitantly with these antibiotics. To develop new strains of B. bifidum that are resistant to these drugs, B. bifidum RFR61, which is highly resistant to RFP, was selected by the N-methyl-N'-nitrosoguanidine (MNNG) mutation method. Then, B. bifidum OFR9 was selected in vitro from B. bifidum RFR61 by serial passage to increasing concentrations of ofloxacin (OFLX) on a solid medium. The minimal inhibition concentrations (MIC) of RFP and fluoroquinolones for B. bifidum OFR9 were >256 mg/ml and 16-256 &mgr;g/ml, respectively. We investigated the effects of B. bifidum OFR9 on the fecal bacterial flora of mice administered with both antibiotics and B. bifidum OFR9. The results showed that the concurrent use of B. bifidum OFR9 and antibiotics prevented the decrease of bifidobacteria, and quickly restored the flora to normal as compared with the use of antibiotic or parent strain therapy alone. The survival of Shigella organisms in mouse feces rapidly decreased, and were removed within two days as a result of the oral administration of B. bifidum OFR9.     

实验性痴呆动物的肠道菌群和粘附性研究

用ＡＦ６４Ａ复制实验性痴呆动物模型,分析该动物的肠道菌群,并以双歧杆菌和大肠杆菌作为肠道菌的代表,初步探讨它们对实验性痴呆动物肠道粘膜上皮细胞表面的粘附特性。结果表明,实验性痴呆动物的肠道菌群是紊乱的,二种试验菌均能粘附到正常小鼠肠上皮细胞上,双歧杆菌的粘附率明显高于大肠杆菌,而双歧杆菌对实验性痴呆小鼠肠上皮细胞的粘附率明显低于对照组小鼠,大肠杆菌则相反。     

Role of extracellular transaldolase from Bifidobacterium bifidum in mucin adhesion and aggregation

The ability of bifidobacteria to establish in the intestine of mammals is among the main factors considered to be important for achieving probiotic effects. The role of surface molecules from Bifidobacterium bifidum taxon in mucin adhesion capability and the aggregation phenotype of this bacterial species was analyzed. Adhesion to the human intestinal cell line HT29 was determined for a collection of 12 B. bifidum strains. In four of them-B. bifidum LMG13195, DSM20456, DSM20239, and A8-the involvement of surface-exposed macromolecules in the aggregation phenomenon was determined. The aggregation of B. bifidum A8 and DSM20456 was abolished after treatment with proteinase K, this effect being more pronounced for the strain A8. Furthermore, a mucin binding assay of B. bifidum A8 surface proteins showed a high adhesive capability for its transaldolase (Tal). The localization of this enzyme on the surface of B. bifidum A8 was unequivocally demonstrated by immunogold electron microscopy experiments. The gene encoding Tal from B. bifidum A8 was expressed in Lactococcus lactis, and the protein was purified to homogeneity. The pure protein was able to restore the autoaggregation phenotype of proteinase K-treated B. bifidum A8 cells. A recombinant L. lactis strain, engineered to secrete Tal, displayed a mucin- binding level more than three times higher than the strain not producing the transaldolase. These findings suggest that Tal, when exposed on the cell surface of B. bifidum, could act as an important colonization factor favoring its establishment in the gut.     

抗生素对新生大鼠肠道菌群和肠道免疫发育的影响

目的通过建立动物模型,探讨口服抗生素对新生大鼠肠道菌群的变化及肠道免疫发育的影响。方法选用30只7日龄新生SD大鼠,随机分为3组：抗生素组（A）、益生菌干预组（B）及对照组（C）,每组10只,A组给予头孢克洛灌胃,B组先给头孢克洛灌胃,2h后再灌长双歧杆菌,C组每天灌以等量的生理盐水,持续2周后处死大鼠,留取盲肠内容物按照张秀荣方法进行肠道菌群检测,免疫组化方法进行肠组织CD4、CD8的测定。结果A组与B、C组相比,革兰阳性杆菌占肠道总细菌数比例明显下降,革兰阴性杆菌及革兰阳性球菌占总细菌数比例明显升高,差异均有显著性（P〈0．05）;A组肠组织中CD4、CD8表达程度受到抑制,与B、C组相比差异有显著性（P〈0．05）,B、C两组所有的指标差异均无显著性。结论抗生素的应用会抑制肠道菌群的正常定植,引起菌群紊乱,进而影响肠道免疫系统发育。     

双歧杆菌防治鼠伤寒沙门菌感染的实验研究

目的　以小鼠为模型,研究双歧杆菌在体内对鼠伤寒沙门菌（Ｓａｌｍｏｎｅｌｌａ ｔｙｐｈｉｍｕｒｉｕｍ ,ＳＴＭ） 感染的防治作用。方法　分别用大剂量悉复欢、Ｂ．ｂｉｆｉｄｕｍ 、生理盐水（ＮＳ） 给三组小鼠灌胃,再用ＳＴＭ 攻击,观察小鼠经上述不同处理前后肠道双歧杆菌数量和ＳＴＭ 攻击后粪便ＳＴＭ 培养阳性率,阳性标本ＳＴＭ 分离值及小鼠ＳＴＭ 感染率;同时用双歧杆菌、悉复欢、双歧杆菌加悉复欢分别治疗ＳＴＭ 感染的小鼠,观察并比较疗效。结果　１． 大剂量悉复欢使用可使小鼠肠道内双歧杆菌明显降低,而双歧杆菌灌胃则肠道双歧杆菌明显增多。双歧杆菌灌胃的小鼠粪便ＳＴＭ培养阳性率、阳性粪便ＳＴＭ 值明显低于用大剂量悉复欢和ＮＳ 的小鼠,小鼠ＳＴＭ 感染发病率也明显较低。２． 对于ＳＴＭ 感染鼠,双歧杆菌与悉复欢联合治疗效果最好。结论　１． 双歧杆菌在体内对ＳＴＭ 有拮抗作用;能预防和减少ＳＴＭ 感染发生;２． 在ＳＴＭ 感染时,先用悉复欢,再用双歧杆菌可以达到预期疗效,双歧杆菌对鼠伤寒沙门菌感染有辅助治疗作用。     

Production of anti-Candida antibodies in mice with gut colonization of Candida albicans

BACKGROUND: Production of antibodies that are specific for allergens is an important pathological process in inflammatory allergic diseases. These contain the antibodies against antigens of Candida albicans, one of the normal microbial flora in an intestinal tract. We studied the effects of the prednisolone administration on the production of anti-Candida antibodies in the gastrointestinally C. albicans-colonized mice. METHODS AND MATERIALS: BALB/c mice, treated with antibacterial antibiotics to decontaminate indigenous intestinal bacterial flora, were inoculated intragastrically with C. albicans. The mice, in which C. albicans grows intestinally, were administered prednisolone to induce temporary immunosuppression. The Candida growth in their intestinal tract and their antibody response to Candida were examined. RESULTS: Antibiotic treatment allowed establishment of C. albicans gastrointestinal colonization, but did not cause subsequent systemic dissemination of C. albicans in all the animals. When these animals received an additional treatment with prednisolone, they showed a significantly higher population of C. albicans in their feces than those of animals treated with antibiotics alone, and the organisms were recovered even from their kidney. This systemic dissemination by C. albicans appeared to be temporal, because all the mice survived without any symptoms for more than 2 months. Examination of the serum titers of total immunoglobulin (Ig)E antibodies and specific IgE and IgG antibodies against Candida antigens demonstrated that titers of total IgE increased, partially by day 14 and clearly at day 27, in prednisolone-treated Candida-colonized mice. Without prednisolone treatment, an increment of the serum titer was scarcely observed. By day 27, corresponding to the increase of total IgE, the anti-Candida IgE and IgG titer increased in mice of the prednisolone-treated group. CONCLUSION: Administration of prednisolone to Candida-colonized mice can induce production of the IgG, IgE antibodies against Candida antigens, perhaps through temporal systemic dissemination of Candida from the intestinal tract.     

Increased resistance of mice to Salmonella enterica serovar Typhimurium infection by synbiotic administration of Bifidobacteria and transgalactosylated oligosaccharides

AIMS: The anti-infectious activity of Bifidobacteria in combination with transgalactosylated oligosaccharides (TOS) against Salmonella enterica serovar Typhimurium LT-2 in an opportunistic antibiotic-induced murine infection model in mice was examined. METHODS AND RESULTS: B. breve (strain Yakult) with natural resistance to streptomycin sulphate (SM, MIC: > 4 mg ml(-1)), when given daily at a dose of 108 cfu/mouse orally under SM treatment was constantly excreted at 10(10) cfu g(-1) faeces so long as SM was administered, even at 2 weeks after discontinuing administration of B. breve. Explosive intestinal growth and subsequent extra-intestinal translocation of orally infected LT-2 under SM treatment were inhibited by B. breve colonization, and this anti-infectious activity was strengthened by synbiotic administration of TOS with B. breve. Comparison of anti-Salmonella activity among several Bifidobacterium strains with natural resistance to SM revealed that strains such as B. bifidum ATCC 15696 and B. catenulatum ATCC 27539T conferred no activity, even when they reached high population levels similar those of effective strains such as strain Yakult and B. pseudocatenulatum DSM 20439. Both the increase in the concentration of organic acids and the lowered pH in the intestine due to bifidobacterial colonization correlated with the anti-infectious activity. Moreover, the crude cecal extract of B. breve-colonized mice exerted growth-inhibitory activity against LT-2 in vitro, whereas that of the ineffective B. bifidum-colonized cecum showed much lower activity. CONCLUSIONS: Intestinal colonization by bifidobacteria given exogenously together with TOS during antibiotic treatment prevents the antibiotic-induced disruption of colonization resistance to oral infection with S. enterica serovar Typhimurium, and the metabolic activity needed to produce organic acids and lower the intestinal pH is important in the anti-infectious activity of synbiotics against enteric infection with Salmonella. SIGNIFICANCE AND IMPACT OF THE STUDY: These results indicate that certain bifidobacteria together with prebiotics may be used for the prophylaxis against opportunistic intestinal infections with antibiotic-resistant pathogens.