肠道微生物预测宫颈癌及子宫内膜癌患者放疗后放射性肠炎的初步研究

目的 探索宫颈癌及子宫内膜癌患者肠道微生物与放疗期间放射性肠炎的严重程度的关系。方法 收集37例宫颈癌和子宫内膜癌接受放射治疗的患者粪便样本。包括根治性放疗（RR）和术后放疗（PR）患者。根据CTCAE 5.0中腹泻和直肠炎的级别记录症状,任何症状2级及以上记为高症状级别（HG）,否则记为低症状级别（LG）。用16S rRNA测序方法对粪便样本的DNA进行测序及生物统计分析,分析指标包括α多样性、β多样性、线性判别分析效应量（LEfSe）和MetagenomeSeq分析。结果 放疗前LG患者的肠道微生物α多样性高于HG患者（P<0.05）。两组的β多样性也存在差异（stress<0.2）。放疗前HG组患者样本中的Ruminococcus gnavus明显高于LG组患者（P<0.05）。这种微生物有可能成为放疗前预测放射性肠炎的标志物种。另外,根治性放疗（RR）患者与术后放疗（PR）患者相比,放疗前肠道微生物群多样性更高,且放疗后放射性肠炎的发生率更低。Faecalibacterium prausnitzii在放疗前根治组中较高（P<0.05）,可能与放疗不良反应呈负相关。结论 宫颈癌及子宫内膜癌患者的肠道微生物群特征与放疗期间放射性肠炎的严重程度密切相关。手术等治疗可能会改变宫颈癌及子宫内膜癌患者的肠道微生物群状态,降低患者的辐射耐受性,使其更容易发生更为严重的放射性肠炎。     

溃疡性结肠炎患者TLR9表达变化的研究

目的 从Toll样受体9(TLR9)的角度探讨溃疡性结肠炎(ulcerative colitis,UC)的发病机制和微生态制剂治疗UC的作用机制.方法 采用随机、对照设计,将30例轻、中度活动期的UC患者分为:美常安联合柳氮磺胺吡啶(SASP)组(A组)10例、丽珠肠乐联合SASP组(B组)10例、SASP组(C组)10例,疗程均为4周;正常对照组10例(肠镜及结肠病检均示正常).于治疗前后取病变肠组织,用免疫组化法检测TLR9的表达水平,以逆转录聚合酶链反应(RT-PCR)检测TLR9 mRNA的表达,比较UC患者与正常对照组TLR9蛋白和mRNA在结肠组织中的表达水平,及UC患者治疗前后TLR9蛋白和mRNA在结肠组织中的表达变化,并对3组UC患者治疗前后的Sutherland疾病活动性指数(DAI)、肠镜分级积分、病理组织学分级积分、大便菌群变化进行比较.结果 ①免疫组化显示TLR9在UC结肠上皮和炎症细胞中的表达均高于正常对照组(P＜0.01).RT-PCR检测UC患者结肠组织可见TLR9 mRNA表达,而正常对照组未检出TLR9 mRNA的表达.且TLR9与Sutherland DAI、肠镜分级积分、病理组织学分级积分及大便菌群积分呈正相关性.②免疫组化及RT-PCR检测显示A、B、C3组治疗前病变肠组织中TLR9及TLR9 mRNA均为阳性表达,治疗后均为弱阳性或阴性表达,各组治疗前后3组组内比较差异有统计学意义(P＜0.05);3组组间比较,A、B组间无差异,C组与A、B组比较,差异均有统计学意义(P＜0.01).③3组治疗前后Sutherland DAI、肠镜分级积分、病理组织学分级积分变化均具有统计学意义(P＜0.05或P＜0.01);3组(组间)比较:Sutherland DAI、肠镜分级积分、病理组织学分级变化差值A、B组间差异无统计学意义,与C组比较差异均有统计学意义(P＜0.01).大便菌群变化A、B组治疗前后具有统计学意义,C组治疗前后大便菌群变化无统计学意义.结论 TLR9失调可能参与溃疡性结肠炎发病机制;微生态制剂能有效降低UC患者的TLR9表达水平,TLR9下调可能是益生菌治疗UC的作用机制之一.     

The protective effects of fecal microbiota transplantation in an experimental model of necrotizing enterocolitis

BackgroundNecrotizing enterocolitis (NEC) is a serious disease that affects premature neonates, causing high mortality. In the search for new options of treatment it was investigated whether fecal microbiota transplantation (FMT) decreased the inflammatory response during NEC development in experimental model.MethodsWistar rats were used and divided as follows: naïve, control (NEC induction), FMT-before (transplantation of microbiota before insult) and FMT-after (microbiota transplantation after insult). The microbiota transplantation was performed by administering a feces solution obtained from an adult donor rat. The induction of enterocolitis involves feeding by artificial formula, hypothermia, hypoxia and endotoxin administration. MPO activity, TNF-α, IL-1β and IL-6 levels, oxidative and nitrosative damage and the grade of intestinal mucosa lesion were analyzed.ResultsThe control group had a significant increase of inflammatory and oxidative parameters when compared to naive animals. Both FMT-before and after decreased all inflammatory and oxidative damage parameters when compared to control group. This was also true to the intestinal mucosa damage.ConclusionFMT administered just before or after NEC induction improved gut and systemic inflammation, and gut oxidative damage and intestinal injury.     

广谱抗生素对大鼠肠道菌群多样性影响的16S rDNA基因测序研究

目的探讨基于16SrDNA基因测序技术的广谱抗生素对大鼠肠道菌群多样性的影响。方法将24只Wistar大鼠随机分为一次应用抗生素组、多次应用抗生素组和对照组,每组8只。取用药前和用药结束后大鼠粪便做16SrDNA基因测序分析,比较各组大鼠用药前后肠道菌群多样性的变化。结果一次及多次应用抗生素组大鼠的肠道菌群种类多样性指数Chao1、ACE、Shannon用药后较用药前降低,Simpson指数用药后较用药前升高,差异均有统计学意义（t=5.3~12.7,P〈0.05）。多次应用抗生素组大鼠肠道菌群用药前后的变化与一次应用抗生素组相比,多样性指数Chao1、ACE、Shannon降低幅度更明显,Simpson指数升高幅度也更明显（t=4.1~5.7,P〈0.05）。对照组大鼠肠道菌群多样性指数Chao1、ACE、Shannon及Simpson用药前后变化均无统计学意义（P〉0.05）。结论广谱抗生素可显著降低大鼠肠道菌群多样性,且用药时间越长,其降低幅度越明显。     

肠道菌群影响无菌小鼠对卵清蛋白的敏感性

目的 通过观察过敏和无过敏反应小鼠肠道菌群在无菌小鼠肠道内定植后对卵清蛋白(OVA)刺激的反应,探究肠道菌群在食物过敏中的作用.方法 采集用卵清蛋白成功诱导出的过敏和无过敏反应SPF级小鼠的粪便,分别移植给无菌小鼠(各10只),为过敏组(FA组)和无过敏反应组(NR组).粪菌移植后第3周,两组分别随机抽取7只再用OVA激发为实验组(FA-o组、NR-o组),余3只为生理盐水对照组(FA-c组、NR-c组).用变性梯度凝胶电泳(DGGE)技术评价粪菌移植后肠道菌群在肠道内的定植情况,比较FA组和NR组肠道菌群的差别.观察两组再用OVA激发后的临床表现,HE染色观察小鼠空肠组织形态学改变.结果 (1)粪菌移植后第3周,与供体小鼠相比,FA组与NR组小鼠肠道菌群的DGGE条带多数一致,而FA组与NR组肠道菌群比较,DGGE条带有明显不同,聚类分析和主成分分析(principal component analysis,PCA)两组均能很好分离,测序结果也表明无过敏反应组中厚壁菌门的细菌占优势,过敏组中变形菌门的细菌占优势;(2)移植粪菌的无菌鼠再次用OVA激发时,FA-o组有临床表现,NR-o组无明显临床表现;HE染色可见FA-o组较NR-o组小鼠空肠绒毛上皮细胞局灶性坏死、脱落,炎性细胞浸润明显严重.结论 肠道菌群不同使无菌小鼠对OVA的敏感性不同,说明肠道菌群的变化可能是食物过敏的始动因素,肠道菌群可传递宿主对食物过敏的敏感性.     

慢性乙型肝炎以及肝硬化患者肠道微生物研究

目的：探讨慢性乙型肝炎以及肝硬化患者的肠道菌群变化及其与细胞因子、肝功能之间的关系。方法选取30例健康志愿者、50例肝炎后肝硬化患者以及50例慢性乙型肝炎患者,采用实时荧光定量 PCR 法检测粪便中九种肠道菌群含量,比较三组间肠道菌群变化;同时采用 ELISA 法检测慢性乙型肝炎患者血清中细胞因子如白介素-17A(IL-17)、白介素-1β( IL-1β)、白介素-6( IL-6)、干扰素-α( INF-α)、CXC 趋化因子(CXCL-13)的浓度,分析肠道菌群与细胞因子以及肝功能之间的关系。结果与健康对照组相比,慢性乙型肝炎以及肝硬化患者体内的双歧杆菌、乳酸杆菌、拟杆菌属以及瘤胃球菌属含量减少;肠杆菌科细菌、肠球菌、梭菌属、白色念珠菌以及普雷沃氏菌含量明显增加。慢性乙型肝炎患者体内的肠杆菌科细菌与凝血酶原时间(PT)呈正相关性,肠球菌与谷丙转氨酶(ALT)、谷草转氨酶(AST)呈正相关性;双歧杆菌与 AST、碱性磷酸酶(AKP)以及 HBV DNA水平呈负相关性,普雷沃氏菌属与 AST、AKP 以及 PT 呈负相关性,拟杆菌属与 AST 和 PT 呈负相关性,瘤胃球菌属与白蛋白(ALB)呈负相关性。另外,9种肠道菌群中只有肠球菌与 IL-17A 呈正相关性。结论慢性乙型肝炎以及肝硬化患者体内存在不同程度的肠道菌群失调,其中乙肝患者体内过度繁殖的肠球菌与 IL-17A 协同参与肝脏炎症反应过程,以致于肝功能受损呈恶性循环状态。     

Chicory: Understanding the Effects and Effectors of This Functional Food

Industrial chicory has been the subject of numerous studies, most of which provide clinical observations on its health effects. Whether it is the roasted root, the flour obtained from the roots or the different classes of molecules that enter into the composition of this plant, understanding the molecular mechanisms of action on the human organism remains incomplete. In this study, we were interested in three molecules or classes of molecules present in chicory root: fructose, chlorogenic acids, and sesquiterpene lactones. We conducted experiments on the murine model and performed a nutrigenomic analysis, a metabolic hormone assay and a gut microbiota analysis, associated with in vitro observations for different responses. We have highlighted a large number of effects of all these classes of molecules that suggest a pro-apoptotic activity, an anti-inflammatory, antimicrobial, antioxidant, hypolipidemic and hypoglycemic effect and also an important role in appetite regulation. A significant prebiotic activity was also identified. Fructose seems to be the most involved in these activities, contributing to approximately 83% of recorded responses, but the other classes of tested molecules have shown a specific role for these different effects, with an estimated contribution of 23–24%.     

Comparison of mucosa-associated microbiota in Crohn’s disease patients with and without anti-tumor necrosis factor-α therapy

Most studies on the gut microbiome of Crohn’s disease have been conducted using feces, instead of intestinal mucus to analyze the mucosa-associated microbiota. To investigate the characteristics of mucosa-associated microbiota in Crohn’s disease patients and the effect of anti-tumor necrosis factor (TNF)-α therapy on mucosa-associated microbiota, we analyzed microbiota in Crohn’s disease patients using brushing samples taken from terminal ileum. The recruited subjects were 18 Crohn’s disease patients and 13 controls. There were 10 patients with anti-TNF-α therapy in Crohn’s disease group. Crohn’s disease patients had significantly reduced α-diversity in Shannon index compared to the controls. The comparative analysis of the taxonomic composition at the genus level between the Crohn’s disease group and the controls indicated that butyrate-producing bacteria were less abundant in the Crohn’s disease group compared to the controls. There were no differences in the diversity between the patients taking anti-TNF-α therapy and the patients without. The comparative analysis of the taxonomic composition at the genus level between the two groups indicated that some of anti-inflammatory bacteria were less abundant in the anti-TNF-α therapy group than the other. Reduction of specific bacteria producing anti-inflammatory molecules, especially butyrate-producing bacteria may play important roles in the pathophysiology of Crohn’s disease.     

The Impact of Gut Microbiome on Maternal Fructose Intake-Induced Developmental Programming of Adult Disease

Excessive or insufficient maternal nutrition can influence fetal development and the susceptibility of offspring to adult disease. As eating a fructose-rich diet is becoming more common, the effects of maternal fructose intake on offspring health is of increasing relevance. The gut is required to process fructose, and a high-fructose diet can alter the gut microbiome, resulting in gut dysbiosis and metabolic disorders. Current evidence from animal models has revealed that maternal fructose consumption causes various components of metabolic syndrome in adult offspring, while little is known about how gut microbiome is implicated in fructose-induced developmental programming and the consequential risks for developing chronic disease in offspring. This review will first summarize the current evidence supporting the link between fructose and developmental programming of adult diseases. This will be followed by presenting how gut microbiota links to common mechanisms underlying fructose-induced developmental programming. We also provide an overview of the reprogramming effects of gut microbiota-targeted therapy on fructose-induced developmental programming and how this approach may prevent adult-onset disease. Using gut microbiota-targeted therapy to prevent maternal fructose diet-induced developmental programming, we have the potential to mitigate the global burden of fructose-related disorders.     

Effects of Whole Brown Bean and Its Isolated Fiber Fraction on Plasma Lipid Profile,Atherosclerosis, Gut Microbiota,and Microbiota-Dependent Metabolites in Apoe−/− Mice

The health benefits of bean consumption are widely recognized and are largely attributed to the dietary fiber content. This study investigated and compared the effects of whole brown beans and an isolated bean dietary fiber fraction on the plasma lipid profile, atherosclerotic plaque amount, gut microbiota, and microbiota-dependent metabolites (cecal short-chain fatty acids (SCFAs) and plasma methylamines) in Apoe^−/− mice fed high fat diets for 10.5 weeks. The results showed that both whole bean and the isolated fiber fraction had a tendency to lower atherosclerotic plaque amount, but not plasma lipid concentration. The whole bean diet led to a significantly higher diversity of gut microbiota compared with the high fat diet. Both bean diets resulted in a lower Firmicutes/Bacteroidetes ratio, higher relative abundance of unclassified S24-7, Prevotella, Bifidobacterium, and unclassified Clostridiales, and lower abundance of Lactobacillus. Both bean diets resulted in higher formation of all cecal SCFAs (higher proportion of propionic acid and lower proportion of acetic acid) and higher plasma trimethylamine N-oxide concentrations compared with the high fat diet. Whole beans and the isolated fiber fraction exerted similar positive effects on atherosclerotic plaque amount, gut microbiota, and cecal SCFAs in Apoe^−/− mice compared with the control diets.