Assessment of oral ciprofloxacin impaired gut barrier integrity on gut bacteria in mice

Gut bacteria and gut barrier plays important roles in body homeostasis. Ciprofloxacin (CPFX) is widely used to treat bacterial infections. However, whether high dosage of CPFX has side effects on gut barrier integrity is still unclear. Our results indicated that the High CPFX treatment (1 mg/ml) caused weight loss, nervousness, anorexia, and increased apoptosis cells in gut, but less influence was observed in the Low CPFX group (0.2 mg/ml). Meanwhile, the High CPFX treatment impaired tight junction molecules Ocln/ZO-1 level and down-regulated antibacterial genes expression (reg3γ, pla2g2α and defb1). Further, the High CPFX treatment increased pro-inflammatory cytokine IL-1β in intestinal tract, decreased IL-17A of duodenum but increased IL-17A of colon at day 37. In addition, the gut bacterial diversity and richness behaved significantly loss regarding CPFX treatment, especially in the High CPFX group during the experiment. Indole exhibited sharply decline in both Low and High CPFX groups at day 7, and the High CPFX mice needed longer time on restoring indole level. Meanwhile, CPFX treatment strongly decreased the concentrations of butyric acid and valeric acid at day 1. Correlation analysis indicated that the linked patterns between the key bacteria (families Bacteroidales_S247, Ruminococcaceae and Desulfovibrionaceae) and metabolites (indole and butyric acid) were disturbed via the CPFX treatment. In conclusion, the High CPFX treatment impaired the gut barrier with the evidence of reduced expression of tight junction proteins, increased apoptosis cells and inflammatory cells, decreased the bacterial diversity and composition, which suggesting a proper antibiotic-dosage use should be carefully considered in disease treatment.     

Resveratrol attenuates high-fat diet-induced non-alcoholic steatohepatitis by maintaining gut barrier integrity and inhibiting gut inflammation through regulation of the endocannabinoid system

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Effects of bombesin and gastrin-releasing peptide on memory processing

We have previously shown that feeding mice immediately following training enhances memory retention and that one of the gastrointestinal hormones released during a meal, cholecystokinin, also enhances retention after peripheral administration. In the studies reported here we demonstrate that another gastrointestinal peptide, gastrin-releasing peptide (GRP), enhances retention after peripheral administration, as does its amphibian counterpart, bombesin. GRP_14–27 had the same effect as the intact peptide, while GRP_1–16 was ineffective at enhancing retention. The dose-response curves showed a characteristic inverted U-shape with high doses of both GRP and bombesin being amnestic. The effect of both peptides was time-dependent and both reversed amnesia induced by the anticholinergic, scopolamine. I.c.v. administration of the peptides required higher doses to produce an effect on memory retention. suggesting that the effect was mediated predominantly through a peripheral mechanism. Doses of the peptides that enhanced memory retention after peripheral administration failed to increase serum glucose, suggesting that glucose modulation was not the mechanism by which GRP and bombesin modulate memory processing. Vagotomy inhibited the memory-enhancing effects of both GRP and bombesin, suggesting that these peptides produced their effect by stimulating ascending vagal pathways. These studies, together with our previous study with cholecystokinin, suggest the existence of a gastrointestinal hormonal system, which is activated by the passage of food through the intestine, that enhances memory retention.     

表皮生长因子改善移植小肠黏膜屏障功能的实验研究

目的了解表皮生长因子(epidermalgrowthfactor,EGF)对移植小肠通透性及细菌易位的作用。方法以Wistar大鼠为供体,SD大鼠为受体行异位全小肠移植,并以环孢素A(CsA,6mg.kg-1.d-1,im)抑制排斥反应。表皮生长因子组(EGF组)用微量输液泵持续均匀输入EGF200μg.kg-1.d-1;对照组输入等量生理盐水。第7天以乳果糖及甘露醇行移植肠灌注并收集尿液行高效液相色谱仪分析乳果糖及甘露醇含量,第8天采集移植肠系膜淋巴结及门静脉血行细菌培养。结果对照组尿液中乳果糖含量[(0.093±0.008)vs(0.015±0.002),P=0.0001]及乳果糖/甘露醇比值[(0.132±0.021)vs(0.020±0.005),P=0.0001]明显高于基准,EGF组乳果糖含量[(0.043±0.008)vs(0.015±0.002),P=0.0054]及乳果糖/甘露醇比值[(0.060±0.017)vs(0.020±0.005),P=0.0029]也较基准增加,EGF组乳果糖含量[(0.043±0.008)vs(0.093±0.008),P=0.0067)及乳果糖/甘露醇比值[(0.060±0.017)vs(0.132±0.021),P=0.0116]显著低于对照组。EGF组移植肠系膜淋巴结细菌阳性率为10%,对照组阳性率为60%,明显高于EGF组(P=0.028)。EGF组与对照组门静脉血培养阳性率比较差异无统计学意义(P>0.05)。结论本研究提示EGF能够降低同种移植小肠的通透性及细菌易位率,改善肠黏膜屏障功能。     

大气细菌粒子浓度的时间分布特征及最佳采样时间的研究

用ＭＦ－４５型和ＨＴＫ－２０１型空气微生物采样器分别在北京、天津和沈阳三地观测了不同季节和一天中大气细菌粒子的浓度及其变化。结果表明：京、津二地春季大气细菌粒子浓度高，分别为２０５３个／ｍ３和２５５６个／ｍ３；夏季低，分别为９９５个／ｍ３和１０６４个／ｍ３。沈阳秋季大气细菌粒子浓度高，为１０１０８个／ｍ３；冬季低，为１２９４个／ｍ３。一天中，大气细菌粒子浓度呈双峰型变化，６：００～７：００和１８：００时大气细菌粒子浓度高，１１：００～１３：００和１：００～２：００时大气细菌粒子浓度低。根据大气细菌粒子浓度的季节变化和一天中大气细菌粒子浓度的时间分布特征，经过京、津、沈三地一天中分别１２次、８次、６次和４次不同采样时间组合的大气细菌粒子浓度的数理统计分析，大气细菌粒子浓度的监测拟集中在一年冬、春、夏、秋四季的中间月份，即１月、４月、７月、１０月进行；一天中采样８次的时间序列可为７：００、１０：００、１３：００、１６：００、１９：００、２２：００、１：００、４：００一天采样４次的时间序列可为５：００、１１：００、１７：００、２３：００。白天采样４次的时间序列可为春、秋季６：００、９：００、１２：００、１５：００?     

肺部、肠道菌群及其相互作用与慢性阻塞性肺疾病发生发展的研究进展

慢性阻塞性肺疾病（COPD）是一种常见的慢性呼吸系统疾病,对人类健康造成极大威胁。研究发现,COPD患者与健康人群相比,肺部菌群及肠道菌群的组成结构发生了显著改变,导致黏膜屏障功能及机体免疫稳态被破坏,进而加重病情。积极调节肺部、肠道菌群平衡对于干预COPD的发生、发展有着至关重要的作用,但目前关于肺部、肠道菌群及其相互作用机制在COPD中作用的总结和认识还有待进一步阐明。本文就健康人群以及COPD患者肺部、肠道菌群的组成特点及可能的相互作用机制,以及现阶段基于肺部、肠道菌群及其相互作用防治COPD的最新研究成果进行综述,以期为COPD的发病机制、早期诊断、预防与治疗研究提供新思路。     

高脂饮食诱导的内脏肥胖小鼠模型存在性别差异

目的:比较不同性别BALB/c小鼠采用高脂饮食建立肥胖模型的差异。方法:32只4周龄无特定病原体级BALB/c小鼠（雌雄各半）随机分为雌性对照组、雌性高脂组、雄性对照组和雄性高脂组,每组8只。雌性对照组和雄性对照组采用普通饮食,雌性高脂组和雄性高脂组采用高脂饲料喂养,喂养12周后测量小鼠体重、内脏脂肪比、空腹血糖、葡萄糖耐量、血脂、代谢相关激素水平,并采用16S rRNA测序检测小鼠粪便菌群构成。结果:高脂饮食干预导致雄性小鼠体重和内脏脂肪比明显增加,病理表现为单个脂肪面积明显增大,肝脏脂肪滴堆积,总胆固醇、空腹血糖、口服糖耐量试验时间-血糖曲线下面积以及血清胰岛素水平明显上升（均P<0.05）,并出现明显胰岛素抵抗（P<0.01）。而雌性高脂组体重、内脏脂肪比、血清胰岛素和瘦素水平与雌性对照组差异均无统计学意义（均P>0.05）。高脂干预后小鼠肥胖相关肠道菌群相对丰度显著变化并存在性别差异,其中雄性高脂组肥胖相关菌属（如布劳特菌）相对丰度明显增加,菌群结构变化更明显。结论:高脂饮食喂养12周4周龄BALB/c雄性小鼠可稳定建立以内脏脂肪堆积、代谢功能紊乱和肠道菌群变...