舍得老酒对大鼠肠屏障功能及肠道菌群的影响

探究舍得老酒对大鼠肠屏障功能及其肠道菌群构成的影响。

将28只SPF级180～220 g SD雄性大鼠随机分为4组（n = 7）：对照组、乙醇组、舍得老酒1组及舍得老酒2组。分别灌胃生理盐水、酒精（7.6 mL/kg）及舍得老酒（3.8 mL/kg和7.6 mL/kg 2个剂量）,连续灌胃4周。检测结肠紧密连接蛋白mRNA表达水平,血清炎症相关分子水平;采用流式细胞仪检测脾脏免疫细胞水平;采用测序检测粪便肠道菌群构成。

乙醇组大鼠紧密连接蛋白mRNA表达水平较低,血清中的肿瘤坏死因子-α浓度较高,白介素10浓度较低,而舍得老酒2个剂量组均不同程度地改善了乙醇对大鼠肠屏障功能的不良反应。舍得老酒7.6 mL/kg剂量组可能通过降低CD4⁺ T细胞比例而减少炎症的发生。舍得老酒3.8 mL/kg组大鼠肠道菌群alpha多样性高于其他3组。4组大鼠肠道菌群组成具有一定差异,门水平上,乙醇组拟杆菌门相对丰度较其他组高,厚壁菌门与拟杆菌门比值（F/B）低于其他3组;属水平上,乙醇组Ruminiclostridium_6、Prevotella_9及Lachnospiraceae_NK4A136_group丰度较对照组增加,舍得老酒3.8 mL/kg组的接近对照组,乙醇组Lactobacillus丰度降低,舍得老酒3.8 mL/kg组Lactobacillus丰度增加。

低剂量组舍得老酒可改善大鼠肠屏障功能,并可通过增加肠道菌群丰度及多样性、抑制部分肠道致病菌的生长及增加有益菌,从而起到一定的调节肠道菌群的作用。

     

适量饮酒对大鼠肠道菌群与血脂水平的影响及二者相关性

探究适量饮酒对大鼠肠道菌群和血脂水平的影响以及肠道菌群与血脂水平相关性。

28只雄性SD大鼠随机分为4组：对照组、乙醇组、低剂量白酒1组及低剂量白酒2组。分别灌胃生理盐水、酒精（1.83 g/kg）、白酒（1.83 g/kg和3.66 g/kg两个剂量）,连续灌胃30 d。检测大鼠血清高密度脂蛋白（HDL）、三酰甘油（TG）和总胆固醇（TC）水平,采用16S rDNA测序分析各组肠道菌群差异菌种并分析肠道菌群与血脂水平相关性。

实验表明适量饮用白酒组较乙醇组可降低大鼠血清TG和TC水平。16S rDNA测序分析显示适量饮酒组较乙醇组可增加肠道脱硫弧菌属（Desulfovibrio）、瘤胃球菌属（Ruminococcaceae_UCG-005）、罗氏菌属（Roseburia）、别样棒菌属（Allobaculum）及粪杆菌属（Faecalibaculum）相对丰度。其中Desulfovibrio与TG和TC水平呈负相关,Ruminococcaceae_UCG-005和Allobaculum与TC水平呈负相关,Roseburia与HDL水平呈负相关,Faecalibaculum与HDL、TG和TC水平均呈负相关。

适量饮酒可增加肠道菌群中与血脂水平成负相关的有益菌数量,从而对血脂代谢起到一定的改善作用。

     

呼吸窘迫综合征新生儿肠道菌群的改变

探究呼吸窘迫综合征新生儿肠道菌群的改变,为该类患儿的治疗提供参考。

选取我院2020年4月至2022年4月收治的83例呼吸窘迫综合征新生儿作为试验组,另选我院同期健康新生儿83例作为对照组,收集两组对象粪便标本。对比两组对象肠道菌群的变化情况。

与对照组相比,试验组患儿肠道菌群Chaol指数和Shannon指数显著降低,Ace指数显著升高,差异均有统计学意义（均P＜0.05）。两组对象肠道厚壁菌门、变形菌门、链球菌属相对丰度对比差异均有统计学意义（均P＜0.05）。

呼吸窘迫综合征新生儿肠道菌群改变较大。

     

芹菜素改善酒精性骨质疏松症大鼠肠道菌群、调节骨钙代谢——

探究芹菜素改善酒精性骨质疏松症大鼠肠道菌群、调节骨钙代谢的作用。

60只SD健康大鼠采用随机数字表法分为模型组、正常组、常规治疗组以及芹菜素低、中、高剂量组,每组10只。模型组大鼠每天上午用白酒（10 mL/kg）灌胃+生理盐水（10 mL/kg）灌胃;正常组大鼠每天上午用生理盐水（10 mL/kg）灌胃+生理盐水（10 mL/kg）灌胃;常规治疗组大鼠每天上午用白酒（10 mL/kg）灌胃+碳酸钙、阿法D3混悬液（分别以85 mg/kg、0.05 μg/kg剂量溶于10 mL/kg生理盐水）灌胃;芹菜素低、中、高剂量组每天上午分别用白酒（10 mL/kg）灌胃+芹菜素溶液（分别以20、40、80 mg/kg剂量溶于10 mL/kg生理盐水）灌胃,每天1次,持续16周。使用双能X线骨密度检测仪测定各组大鼠右侧股骨骨密度;苏木素–伊红（HE）染色观察各组股骨组织病理学改变;16S核糖体脱氧核糖核酸（16S rDNA）测序技术检测各组肠道菌群多样性及门、属水平相对丰度;Connectify法测定各组骨钙（Ca）含量,改良Neuman-Lorgan法测定各组骨羟脯氨酸（HOP）含量,并计算二者比值。

模型组大鼠骨松质结构改变,骨小梁稀疏松散、粗细不匀,大量断裂,骨髓腔扩大明显,有大量纤维组织。常规治疗组和芹菜素3个剂量组以上病变情况均有不同程度改善,且芹菜素作用呈剂量依赖性,芹菜素中剂量组与常规治疗组差异不显著。与正常组比,模型组、常规治疗组和芹菜素3个剂量组大鼠骨密度、骨Ca、骨HOP含量及二者比值、Chao1指数、Ace指数以及肠道菌群厚壁菌门、毛螺旋菌属、粪球菌属、乳杆菌属、普氏菌属、罗氏菌属和布劳特菌属水平相对丰度降低,拟杆菌门、变形菌门、拟杆菌属、肠杆菌属和别样棒菌属水平相对丰度升高,差异均有统计学意义（均P＜0.05）;与模型组比,常规治疗组和芹菜素3个剂量组大鼠骨密度、骨Ca、骨HOP含量及二者比值、Chao1指数、Ace指数以及肠道菌群厚壁菌门、毛螺旋菌属、粪球菌属、乳杆菌属、普氏菌属、罗氏菌属和布劳特菌属水平相对丰度均升高,拟杆菌门、变形菌门、拟杆菌属、肠杆菌属和别样棒菌属水平相对丰度降低,差异均有统计学意义（均P＜0.05）,芹菜素对骨密度、骨Ca、骨HOP含量及二者比值、Chao1指数、Ace指数以及肠道菌群门、属水平相对丰度作用呈剂量依赖性,且芹菜素中剂量组与常规治疗组骨密度、骨Ca、骨HOP含量及二者比值、Chao1指数、Ace指数以及肠道菌群门、属水平相对丰度比较差异均无统计学意义（均P＞0.05）。

芹菜素能够提高酒精性骨质疏松症大鼠骨密度和骨Ca、骨HOP含量,推测是通过调节肠道菌群相对丰度,促进有益菌群生长,抑制致病菌群生长实现的。

     

16S rDNA测序研究高脂饮食诱导的高脂血症大鼠肠道菌群变化

通过高脂饮食诱导大鼠高脂血症, 采用16S rDNA测序检测高脂血症大鼠肠道菌群变化情况。

SD大鼠20只(清洁级), 按体质量随机分为模型组和对照组, 对照组大鼠给予维持饲料, 模型组大鼠给予高脂饲料。1周后检测血清总胆固醇(TC)、三酰甘油(TG)、低密度脂蛋白胆固醇(LDL-C)和高密度脂蛋白胆固醇(HDL-C)水平。采集大鼠粪便, 采用16S rDNA测序法对大鼠肠道菌群进行分析, 考察高脂血症大鼠肠道菌群变化情况。

高脂血症大鼠肠道菌群生物多样性(Alpha多样性和Beta多样性)发生显著变化, 肠型与对照组差异明显, 在门、科、属等多个水平差异均具有统计学意义。其中, 厚壁菌门(Firmicutes)和念珠菌门(Candidatus saccharibacteria)数量显著下降, 拟杆菌门(Bacteroidetes)、疣微菌门(Verrucomicrobia)、变形菌门(Proteobacteria)和放线菌门(Actinobacteria)数量显著升高。

高脂饮食诱导的高脂血症可引起大鼠肠道菌群发生显著变化。

     

规定饮食条件下不同性别和年龄恒河猴的肠道菌群差异探讨

探讨规范统一的饮食在不受饮食因素干扰前提下不同性别和年龄恒河猴肠道菌群的差异。

将38只恒河猴按性别和年龄分为6组,规定饮食喂养3个月,收集粪便标本,应用16S rRNA测序和生物信息学分析探讨不同性别和年龄恒河猴肠道菌群的差异。

雄性和雌性恒河猴肠道菌群多样性无显著差异,但雌性群体中Epsilonproteobacteria和Helicobacter macacae的丰度显著增加。成年和老年恒河猴肠道菌群的多样性均显著高于幼年,Rikenellaceae、Christensenellaceae和Prevotella的丰度在老年群体中显著增加。

恒河猴的肠道菌群受性别和年龄的影响,尤其是与代谢和精神疾病相关的Rikenellaceae、Christensenellaceae和Prevotella在老龄恒河猴肠道菌群丰度更高。这些特定肠道菌群在不同性别和不同生命阶段调节机体生理或行为过程中的功能有待进一步研究。

     

铁皮石斛对脾虚便秘小鼠肠道菌群多样性的影响

探讨铁皮石斛对脾虚便秘小鼠肠道菌群的影响,为铁皮石斛对脾虚便秘的疗效机制及临床组方提供依据。

选取12只SPF级昆明小鼠随机分为正常组、模型组、铁皮石斛组和枳术汤组,每组3只。造模阶段正常组灌胃无菌水,模型组和治疗组采用番泻叶水煎液灌胃7 d后,限制饮食饮水8 d,建立脾虚便秘模型。造模成功后,正常组和模型组灌胃无菌水,治疗组分别以铁皮石斛和枳术汤水煎液干预5 d。治疗结束后,收集各组小鼠盲肠内容物样本进行16S rDNA高通量测序。

脾虚便秘小鼠排便量减少,粪便细小,干燥,质硬,呈黄色。铁皮石斛和枳术汤分别治疗后,小鼠排便量增加,粪便软硬适中,呈黑褐色。测序分析发现,正常组与铁皮石斛组的共有OTU数最多,与枳术汤组的共有OTU数最少。α−多样性指数与PCA结果表明,铁皮石斛组菌属结构较其余两组更接近正常组小鼠。物种相对丰度及组成结果表明,铁皮石斛增加了脾虚便秘小鼠双歧杆菌属相对丰度,抑制了乳杆菌属、拟杆菌属相对丰度,但对菌群丰度的调节作用不及枳术汤;LEfSe分析与随机森林分析鉴定出布劳特菌属和活泼瘤胃球菌是铁皮石斛组与其他组别的差异菌群。

铁皮石斛能恢复脾虚便秘小鼠肠道菌群的多样性,可调节肠道菌群相对丰度,布劳特菌属和活泼瘤胃球菌可能是铁皮石斛干预脾虚便秘小鼠的肠道关键指示菌。

     

16S rDNA实时荧光定量PCR检测大蒜提取物对小鼠肠道菌群的调节作用

探究蒜氨酸、大蒜辣素、大蒜粉对小鼠肠道菌群的调节作用。

将SPF级C57BL/6J小鼠分为空白对照组、蒜氨酸组、大蒜辣素组和大蒜粉组, 每组10只。空白对照组小鼠灌服蒸馏水30 d, 蒜氨酸组、大蒜辣素组、大蒜粉组小鼠灌服不同浓度的受试物溶液30 d, 采用16S rDNA实时荧光定量PCR检测实验前后小鼠粪便样本中乳杆菌、双歧杆菌、肠杆菌、肠球菌、产气荚膜梭菌水平变化。

给药30 d后, 与空白对照组相比、实验前后自身对比, 蒜氨酸组、大蒜辣素组、大蒜粉组小鼠的肠杆菌、肠球菌水平无明显变化; 乳杆菌、双歧杆菌水平显著增加; 产气荚膜梭菌水平显著降低。

蒜氨酸、大蒜辣素、大蒜粉对肠道菌群具有有益的调节作用, 是一种良好的天然有益于肠道菌群的食品。

     

人体肠道菌群对二甲基亚砜的体外降解作用——

通过二甲基亚砜（DMSO）与肠道菌群相互作用机制的研究,为DMSO的降解及其在药物研究中的应用提供肠道菌群方面的理论依据。

采用分批发酵、气相色谱、气质联用和高通量测序技术研究DMSO的降解量与肠道菌群结构间的关系。

发酵液中主要检测到甲硫醚、二甲基砜、二甲基二硫醚及甲基硫代磺酸甲酯等DMSO相关代谢产物;与其他他汀相比,生理浓度氟伐他汀组菌群的DMSO降解效果最佳,可能与Proteobacteria及Solobacterium和Escherichia-Shigella等菌群的相对丰度增加有关。不同肠道菌群产二甲基硫醚（DMS）水平差异明显,DMS分解可能与硫代谢途径相关,涉及的微生物主要是Desulfovibrio。

人体肠道菌群可降解DMSO,其降解效率可能与Escherichia-Shigella的相对丰度有关,降解产物对人体肠道菌群结构无影响。

     

YNS益肤面霜对豚鼠皮肤变态反应及肠道菌群的影响

建立豚鼠皮肤变态反应模型,并使用YNS益肤面霜对皮肤变态反应模型进行干预,探讨这种面霜对改善及修复受损皮肤的作用及其对豚鼠肠道菌群的影响。

豚鼠24只,随机分成4组：对照组、阳性组、化妆品组和治疗组,每组6只。致敏接触后进行激发反应。提取4组豚鼠粪便标本DNA,使用16S rRNA高通量测序检测肠道菌群构成。

治疗组豚鼠皮肤致敏率为16.7%。益肤面霜治疗对肠道菌群alpha多样性影响不大,但有降低厚壁菌门（Firmicutes）与拟杆菌门（Bacteroidetes）比值（F/B）及粪球菌属（Coprococcus）相对丰度的趋势,有利于皮肤变态反应豚鼠肠道菌群组成的恢复。

YNS益肤面霜对皮肤具有改善及修复作用,并对豚鼠肠道菌群具有一定影响。

     

肠道菌群在应激诱发大鼠高血压中的作用

观察应激性高血压大鼠肠道菌群的变化,探索肠道菌群在应激性高血压发生中的作用。应激性高血压模型的制备:大鼠每天2次接受足底电刺激加噪声的应激,每次2 h,中间间隔4 h,共14 d。血压的测量:大鼠股动脉插管,Powerlab系统记录血压。伪无菌鼠的制备:在大鼠的饮用水中加入氨苄西林(1 g/L)、万古霉素(500 mg/L)、新霉素(1 g/L)和甲硝唑(1 g/L)4种抗生素,共持续4周。采用Illumina MiSeq测序技术,测定大鼠粪便中微生物16S rRNA V3-V4区序列,并对群落结构和多样性进行比较分析。慢性应激导致大鼠血压升高,心率加快,血清去甲肾上腺素浓度增加;α多样性分析显示应激大鼠肠道菌群丰富度和多样性下降,β多样性分析显示应激组大鼠肠道菌群物种组成变少,差异性变大;伪无菌鼠的肠道菌群物种单一,仅有少量的变形菌门。给予伪无菌鼠相同的慢性应激,不能引起大鼠血压升高、心率增快,血清去甲肾上腺素浓度未升高。应激引起大鼠肠道菌群紊乱,应激性高血压的发生可能依赖于肠道菌群的状态。     

Polydatin alleviates bleomycin-induced pulmonary fibrosis and alters the gut microbiota in a mouse model

To investigate the effect and mechanism of polydatin on bleomycin (BLM)-induced pulmonary fibrosis in a mouse model. The lung fibrosis model was induced by BLM. The contents of TNF-α, LPS, IL-6 and IL-1β in lung tissue, intestine and serum were detected by ELISA. Gut microbiota diversity was detected by 16S rDNA sequencing; R language was used to analyse species composition, α-diversity, β-diversity, species differences and marker species. Mice were fed drinking water mixed with four antibiotics (ampicillin, neomycin, metronidazole, vancomycin; antibiotics, ABx) to build a mouse model of ABx-induced bacterial depletion; and faecal microbiota from different groups were transplanted into BLM-treated or untreated ABx mice. The histopathological changes and collagen I and α-SMA expression were determined. Polydatin effectively reduced the degree of fibrosis in a BLM-induced pulmonary fibrosis mouse model; BLM and/or polydatin affected the abundance of the dominant gut microbiota in mice. Moreover, faecal microbiota transplantation (FMT) from polydatin-treated BLM mice effectively alleviated lung fibrosis in BLM-treated ABx mice compared with FMT from BLM mice. Polydatin can reduce fibrosis and inflammation in a BLM-induced mouse pulmonary fibrosis model. The alteration of gut microbiota by polydatin may be involved in the therapeutic effect.     

Fungi of the Murine Gut: Episodic Variation and Proliferation during Antibiotic Treatment

Antibiotic use in humans has been associated with outgrowth of fungi. Here we used a murine model to investigate the gut microbiome over 76 days of treatment with vancomycin, ampicillin, neomycin, and metronidazole and subsequent recovery. Mouse stool was studied as a surrogate for the microbiota of the lower gastrointestinal tract. The abundance of fungi and bacteria was measured using quantitative PCR, and the proportional composition of the communities quantified using 454/Roche pyrosequencing of rRNA gene tags. Prior to treatment, bacteria outnumbered fungi by >3 orders of magnitude. Upon antibiotic treatment, bacteria dropped in abundance >3 orders of magnitude, so that the predominant 16S sequences detected became transients derived from food. Upon cessation of treatment, bacterial communities mostly returned to their previous numbers and types after 8 weeks, though communities remained detectably different from untreated controls. Fungal communities varied substantially over time, even in the untreated controls. Separate cages within the same treatment group showed radical differences, but mice within a cage generally behaved similarly. Fungi increased ∼40-fold in abundance upon antibiotic treatment but declined back to their original abundance after cessation of treatment. At the last time point, Candida remained more abundant than prior to treatment. These data show that 1) gut fungal populations change radically during normal mouse husbandry, 2) fungi grow out in the gut upon suppression of bacterial communities with antibiotics, and 3) perturbations due to antibiotics persist long term in both the fungal and bacterial microbiota.     

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。     

Antimicrobial susceptibility, β-lactamase and enterotoxin production in <Emphasis Type="Italic">Bacillus cereus</Emphasis> isolates from clinical and food samples

The antimicrobial susceptibility of 30 clinical and 30 food Bacillus cereus isolates was determined. All isolates were susceptible to streptomycin, ciprofloxacin and gentamicin, 90 % of them to clindamycin and vancomycin, and 67 % to erythromycin. All isolates were resistant to amoxicillin with clavulanic acid, ampicillin, cefotaxime, ciprofloxacin, cloxacillin, cefotaxime with clavulanic acid and penicillin. The MIC values (determined by E-tests) were 48–256 mg/L for ampicillin, 0.19–1.5 mg/L for gentamicin, 0.125–1.0 mg/L for clindamycin, 0.047–4.0 mg/L for erythromycin and 1.5–16 mg/L for vancomycin. The MICs 4.6–18.75 g/L were observed for penicillin using the microdilution method. The presence of metallo-β-lactamases was detected by E-test for 100 % of strains. Nonhemolytic diarrheal enterotoxin (NHE) was produced by 98.3 % of strains, while 31.7 % of them produced hemolytic diarrheal enterotoxin (HBL). Clinical isolates produced 10 % more HBL than food isolates. The psychrotrophic strains isolated from food samples produced NHE at 6.5 °C in 73 % of cases.     

首荟通便胶囊对术后肠麻痹小鼠肠道功能的影响及机制研究

探讨首荟通便（Shou-Hui Tongbian,SHTB）胶囊对小鼠术后肠麻痹（postoperative ileus,POI）的作用,并从肠道菌群平衡方面探讨其可能的作用机制。

采用经典小肠干扰术建立小鼠POI模型,将30只小鼠随机分成对照组（Control组）、模型组（POI组）、阳性参照莫沙必利组（MSBL组）、SHTB胶囊低剂量组（SHTB-L组）和SHTB胶囊高剂量组（SHTB-H组）,每组6只。Control组和POI组小鼠灌胃生理盐水、MSBL组小鼠灌胃莫沙必利溶液（2.6 mg/kg）、SHTB-L组与SHTB-H组小鼠灌胃SHTB溶液（0.619 g/kg、1.238 g/kg）,每天1次,连续给药2 d。采用墨汁推进法检测小鼠的肠道蠕动能力;应用H&;E染色法观察小鼠肠道组织结构;利用16S rRNA基因高通量测序技术解析肠道菌群结构并确定SHTB胶囊发挥作用的关键菌。

与Control组相比,POI组小鼠肠道蠕动能力显著减弱（q=7.263,P＜0.001）,小肠黏膜中性粒细胞和淋巴细胞增多并伴有充血,组织发生水肿,肠道菌群物种总数降低,有益菌Parvibacter等的相对丰度显著降低（t=3.340,P=0.008）,有害菌Rikenellaceae_RC9_gut_group等的相对丰度显著升高（U=2,P=0.009）;药物治疗后上述变化有不同程度的减轻,与POI组相比,SHTB-L组、SHTB-H组和MSBL组小鼠肠道蠕动能力均显著提升（均P＜0.010）,炎症、水肿和充血等肠道病理改变明显好转;SHTB组小鼠肠道菌群物种总数有所提高,其中Parvibacter等的相对丰度显著升高（U=5,P=0.041）,Rikenellaceae_RC9_gut_group相对丰度显著降低（U=3,P=0.015）。

SHTB胶囊可通过调节小肠黏膜关键菌的平衡来改善POI小鼠肠道病理改变,促进肠道蠕动。

     

In vitro activity of ramoplanin and comparator drugs against anaerobic intestinal bacteria from the perspective of potential utility in pathology involving bowel flora

Susceptibility of intestinal bacteria to various antimicrobial agents in vitro, together with levels of those agents achieved in the gut, provides information on the likely impact of the agents on the intestinal flora. Orally administered drugs that are poorly absorbed may be useful for treatment of intestinal infections and for certain other situations in which intestinal bacteria may play a role. The antimicrobial activity of ramoplanin (MDL 62,198) against 928 strains of intestinal anaerobic bacteria was determined using the NCCLS-approved Wadsworth brucella laked-blood agar dilution method. The activity of ramoplanin was compared with that of ampicillin, bacitracin, metronidazole, trimethoprim/sulfamethoxazole (TMP/SMX), and vancomycin. The organisms tested included Bacteroides fragilis group (n=89), other Bacteroides species (n=16), other anaerobic Gram-negative rods (n=56) anaerobic cocci (n=114), Clostridium species (n=426), and non-sporeforming anaerobic Gram-positive rods (n=227). The overall MIC(90)s of ramoplanin, ampicillin, bacitracin, metronidazole, and vancomycin were 256, 32, 128, 16, and 128 mcg/ml, respectively. Ramoplanin was almost always highly active vs. Gram-positive organisms and relatively poor in activity against Gram-negative organisms, particularly Bacteroides, Bilophila, Prevotella, and Veillonella. Vancomycin was quite similar to ramoplanin in its activity. Ampicillin was relatively poor in activity vs. organisms that often produce beta-lactamase, including most of the Gram-negative rods as well as Clostridium bolteae and C. clostridioforme. Bacitracin was relatively poor in activity against most anaerobic Gram-negative rods, but better vs. most Gram-positive organisms. Metronidazole was very active against all groups other than bifidobacteria and some strains of other types of non-sporeforming Gram-positive bacilli. TMP/SMX was very poorly active, with an MIC(90) of >2048 mcg/ml.     

短期低剂量饮酒后戒断改变雄性大鼠肠道微生物菌群并与焦虑样行为相关

长期规律性饮酒会改变肠道微生物菌群构成,并影响焦虑抑郁样行为.而短期低剂量饮酒后戒断是否对肠道菌群产生影响及其与酒精戒断后焦虑样行为是否有关,尚无系统研究.本研究以SD大鼠为研究对象,将30只雄性大鼠随机分为酒精处理组(Ethanol-C)、对照组(Ethanol-0)和酒精戒断组(Ethanol-2),每组各10只....     

Comparative Efficacy of Two Types of Antibiotic Mixtures in Gut Flora Depletion in Female C57BL/6 Mice

Over the last decade, interest in the role of the microbiome in health and disease has increased. The use of germ-free animals and depletion of the microbial flora using antimicrobials are 2 methods commonly used to study the microbiome in laboratory mice. Germ-free mice are born, raised, and studied in isolators in the absence of any known microbes; however, the equipment, supplies, and training required for the use of these mice can be costly and time-consuming. The use of antibiotics to decrease the microbial flora does not require special equipment, can be used for any mouse strain, and is relatively inexpensive; however, mice treated in this manner still retain microbes and they do not live in a germ-free environment. One commonly used antibiotic cocktail regimen uses ampicillin, neomycin, metronidazole, and vancomycin in the drinking water for 2 to 4 wk. We found that the palatability of this mixture is low, resulting in weight loss and leading to removal of mice from the study. The addition of sucralose to the medicated water and making wet food (mash) with the medicated water improved intake; however, the low palatability still resulted in a high number of mice requiring removal. The current study evaluated a new combination of antibiotics designed to reduce the gut microbiota while maintaining body weights. C57BL/6NCrl mice were placed on one of the following drinking water regimens: ampicillin/neomycin/metronidazole/vancomycin water (n = 16), enrofloxacin/ampicillin water (n = 12), or standard reverse osmosis deionized water (RODI) (n = 11). During an 8 day regimen, mice were weighed and water consumption was measured. Feces were collected before and after 8 d of treatment. Quantitative real-time PCR (real-time qPCR) for 16S bacterial ribosome was performed on each sample, and values were compared among groups. The combination of enrofloxacin and ampicillin improved water intake, together with a greater reduction in gut flora.

Interest in the intestinal microbiome and its role in human health has increased dramatically over the last decade. The microbiota has been implicated in metabolic, infectious, and inflammatory disease, and its role has been investigated not only in the gut,^2,8,18,38 but also in vasculature,^5,6,19,39 kidney,¹³ liver,²⁸ lung,^9,34,37 and brain.^12,15 Animal models have been important in furthering our understanding of the microbiota. Two approaches to studying microbiota in mice are the use of germ-free mice^22,35,42 and depletion of the flora with oral administration of antibiotics.^12,17,18 Both approaches have advantages and disadvantages. Germ-free mice are bred in isolators and are free of microorganisms from birth, allowing studies in mice with no microbes present; mice can then be used to generate gnotobiotic mice in which only known microbes are present. However, to remain germ-free, mice must be maintained in isolators under aseptic housing conditions, which is both costly and labor intensive. In addition, alterations of microbiota in early life may cause sustained effects on body composition¹⁰ and lasting negative consequences on the host immune system.³¹ A more economic approach has been to deplete mouse gut microflora using a combination of broad-spectrum antibiotics given either by oral gavage or in the drinking water. The primary limitation with antibiotic treatment of mice is that not all microbes are eliminated; which can potentially make reproducibility in certain types of studies such as those involving microbial transplantation²⁹ very difficult. However, antibiotic-induced gut dysbiosis can be used on conventionally raised mice without the limitations imposed by maintaining a sterile living environment. Direct handling of the mice is possible, allowing behavioral and imaging assessments, which are not be feasible for mice housed in isolators. Several broad-spectrum antibiotic treatment regimens in the drinking water have been used for gut microbe depletion.^{7,16,20,25-27,41} One of the more commonly used combinations is comprised of 4 antibiotics (ampicillin, neomycin, metronidazole, and vancomycin) added to the drinking water for periods ranging from 1 to 4 wk.^{5,9,13,19,23,30,32,34} This cocktail is effective at depleting gut microbes; however, a previous study in our laboratory found it to be highly unpalatable. Dehydration and weight loss can occur in mice receiving antibiotics in the drinking water, and the magnitude of the effect can be significant, depending on the mouse strain.^21,30,33 The weight loss can result in a substantial number of mice being removed from studies due to animal welfare concerns as reported in a previous study in which 5 of 5 mice given ampicillin, neomycin, metronidazole, and vancomycin reached eighty percent of baseline body weight and were subsequently removed.³³ A reduction in water consumption is also likely to interfere with effective antibiotic treatment and may prolong the time necessary to achieve adequate microbial depletion. Palatability enhancers such as glucose,^5,13 sucrose,⁴¹ and flavored water²³ are sometimes combined with the antibiotics in drinking water. The aim of the current study was to determine whether 8 days of treatment with an alternative mixture comprised of 2 antibiotics (enrofloxacin and ampicillin) was sufficient to deplete the gut flora as compared with the widely used combination of ampicillin, neomycin, metronidazole, and vancomycin. We hypothesized that the combination of 2 antibiotics would be at least equivalent to the combination of 4 antibiotics in reducing the gut flora while causing less weight loss.     

Depletion of murine intestinal microbiota: effects on gut mucosa and epithelial gene expression

Background

Inappropriate cross talk between mammals and their gut microbiota may trigger intestinal inflammation and drive extra-intestinal immune-mediated diseases. Epithelial cells constitute the interface between gut microbiota and host tissue, and may regulate host responses to commensal enteric bacteria. Gnotobiotic animals represent a powerful approach to study bacterial-host interaction but are not readily accessible to the wide scientific community. We aimed at refining a protocol that in a robust manner would deplete the cultivable intestinal microbiota of conventionally raised mice and that would prove to have significant biologic validity.

Methodology/Principal Findings

Previously published protocols for depleting mice of their intestinal microbiota by administering broad-spectrum antibiotics in drinking water were difficult to reproduce. We show that twice daily delivery of antibiotics by gavage depleted mice of their cultivable fecal microbiota and reduced the fecal bacterial DNA load by 400 fold while ensuring the animals'' health. Mice subjected to the protocol for 17 days displayed enlarged ceca, reduced Peyer''s patches and small spleens. Antibiotic treatment significantly reduced the expression of antimicrobial factors to a level similar to that of germ-free mice and altered the expression of 517 genes in total in the colonic epithelium. Genes involved in cell cycle were significantly altered concomitant with reduced epithelial proliferative activity in situ assessed by Ki-67 expression, suggesting that commensal microbiota drives cellular proliferation in colonic epithelium.

Conclusion

We present a robust protocol for depleting conventionally raised mice of their cultivatable intestinal microbiota with antibiotics by gavage and show that the biological effect of this depletion phenocopies physiological characteristics of germ-free mice.