益生菌与肥胖ppt课件

益生菌与肥胖,1,Introduction（gutmicrobiota）,Tentrillionto100trillion(1014)microorganismspopulatetheadultintestines.Thevastmajorityresideinthecolon,wheredensitiesapproach10111012cells/mL.Almostalloftheseorganismsarebacteria,andaminorityarearchaeons,eukaryotes,andvirusesThetwomostabundantbacterialphylainhumansandinmicearetheFirmicutes(6080%)andtheBacteroidetes(2040%)Thegutmicrobiotacompositiondependsonage,sex,geography,ethnicity,family,anddiet,andcanbemodulatedbyprebiotics,probiotics,andantibiotics.,M.Millionetal.Gutbacterialmicrobiotaandobesity.2013,2,Introduction（obesity）,Themechanismsbywhichgutmicrobiotaaffectobesityinhumansarecomplicatedandlargelyunknown,theproposedstatementsmayconsistof:anexcessivebodilyenergyharvest,higherlevelsofSCFAstopromoteadipogenesis,overexpressionoftheobesity-relatedgenes,andincreasedproductionofLPSbygutmicrobiotacausingobesityandInflammationSCFAsincreaseintestinalabsorptionofmonosaccharides，modulatehostappetiteandfoodintake，influencelipidmetabolismbyincreas-inglipogenesis9andinhibitingfattyacidsoxidation,DavideFestietal.Gutmicrobiotaandmetabolicsyndrome.2014JiaChenetal.DietEffectsinGutMicrobiomeandObesity.2014,3,JiaChenetal.DietEffectsinGutMicrobiomeandObesity.JournalofFoodSciencerVol.79,Nr.4,2014,4,肠道菌群与肥胖,5,肠道菌群与肥胖,肠道菌群被认为与人类的疾病、健康有着密切的联系。除了对胃肠道功能的影响，还涉及肝脏、大脑、脂肪组织等。目前新的研究认为肠道菌群与肥胖有着密切的联系。肥胖人群的与正常人群相比，除能量代谢不平衡，在肠道菌群的组成上也存在差异。据说肥胖与肠道中两种菌（厚壁菌拟杆菌）的比例相关。,TulikaAroraetal.Probiotics:Interactionwithgutmicrobiomeandantiobesitypotential.2013,6,肠道菌群与肥胖,12名obeseadults随机分为2组，分别给予low-fat、low-CHO饮食1年；与leanadults（normalweight）相比，这些obeseadults肠道中拟杆菌（Bacteroidetes）数量少，厚壁菌拟杆菌（ratioofFirmicutesBacteroidetes）比值更高；leanadults减肥成功后，比值回到正常水平25overweightorobese与24normalweightchildren相比，双歧杆菌含量更低，金黄色葡萄球菌的含量更高,MarinaSanchezetal.ChildhoodObesity:ARoleforGutMicrobiota?2015,肥胖人群在肠道菌群的组成上与正常人存在差异,7,肠道菌群与肥胖,围产期益生菌干预对胎儿体重增长10年的观察研究159名孕妇随机分成2组，在预产期前4周及产后6个月分别给予乳酸菌和麦芽糊精，结果显示，这种早期的益生菌干预能预防胎儿过多的体重增加,母亲的肠道菌群影响胎儿肠道菌群，早期益生菌调节能预防胎儿过多的体重增加,MarinaSanchezetal.ChildhoodObesity:ARoleforGutMicrobiota?2015,8,？影响肠道菌群,9,不同国家饮食习惯存在差异，肠道菌群的组成也有差异。美国人肠道中厚壁菌水平高，日本人肠道中放线菌水平高，韩国人和中国人肠道中拟杆菌水平高。plant-richdiet与low-fiberdiet相比，前者厚壁菌水平更低，后者肠杆菌（志贺氏杆菌、埃希氏杆菌）水平更高vegetariandiet与Westerndiet相比，前者肠道中以Clostridiumcoccoides，Clostridiumramosum为主，缺少Faecalibacteriumprausnitzii.,饮食与肠道菌群,NamY-Detal.ComparativeanalysisofKoreanhumangutmicrobiotabybarcodedpyrosequencing.2011,10,肠壁的通透性,高脂饮食改变改变肠道菌群的组成，并改变某些紧密结合蛋白（tightjunctionproteins，ZO-1andoccludin）的分布，影响肠道的通透性肠壁通透性增加使血液中LPS（细菌内毒素）增加，LPS与TLR4/CD14受体结合，促进TNF-、IL-6的释放，增加动脉粥样硬化、肥胖、胰岛素抵抗的风险。肠道菌群的改变刺激CB1receptors，激活内源性大麻素系统（endocannabinoidsystem），增加肠道的通透性，刺激脂肪生成；通过抑制PPARmolecules刺激脂肪生成肠道菌群失调减少肌肉和肝脏中AMPK，减少脂肪氧化，增加脂肪生成,MarinaSanchezetal.ChildhoodObesity:ARoleforGutMicrobiota?2015,11,激素与肠道菌群,肠道菌群的改变影响胃肠激素GLP-1、PYY、ghrelin（胃饥饿素）的分泌，这些激素影响血糖的调节、饱腹感和能量的摄入。补充益生元能抑制GLP-1、PYY，增加ghrelin分泌，抑制胃肠动力延缓胃排空。肠道菌群紊乱减少FIAFprotein（aninhibitoroflipoproteinlipase，LPL）的表达，增加LPL（脂蛋白脂肪酶）活性，增加脂肪的存储,MarinaSanchezetal.ChildhoodObesity:ARoleforGutMicrobiota?2015,12,Figure1.Dysbiosisinthegutmicrobiotamayleadtoobesityviadifferentmechanisms.(A)AnimbalanceinintestinalmicrobiotaleadstoanincreaseinSCFAandgutpermeabilityanddecreaseinFIAFandAMPK;and(B)Arestoredmicrobiotabyprebioticsand/orprobioticsmayinhibitthemechanismsdescribedin(A)andleadtoanincreaseinthehormonesPYYandGLP-1anddecreaseinghrelin.,益生菌调节肠道菌群,MarinaSanchezetal.ChildhoodObesity:ARoleforGutMicrobiota?2015,13,益生菌与体重控制,14,相关研究,（1）onestudyinvestigatingtheeffectofconsumingVLS3,acombinationofeightprobioticstrains,forfourmonthsonnon-alcoholicfattyliverdiseasein48children,foundasignificantincreaseinGLP-1concentrationsandreductioninBMIcomparedtoplacebo（2）dairybeveragesfermentedwithL.acidophilusandProprionibacteriumfreudenreichiiincreasedsatietycomparedwithanon-fermenteddairybeverageinhealthynormalweightfemaleindividuals（3）Inastudyexaminingtheeffectofaformulationofprobiotics(Lactobacillusrhamnosus)andprebiotics(oligofructose+inulin)andmaltodextrinplaceboonweightlossover24weeksin126obeseindividuals,itwasfoundthatwomenconsumingtheformulationlostapproximatelytwicetheweightthanwomenconsumingtheplacebo,15,相关研究,（4）Inarandomized,controlledintervention,87healthyoverweightadultsconsumingfermentedmilkcontainingLactobacillusgasseriSBT2055(200g/day)for12weeksreducedtheirvisceralandsubcutaneousfat,bodyweightandBMIcomparedwiththecontrolgroup.（5）Bervoetsetal.recentlyinvestigatedthegutmicrobiotaof26overweight/obeseand27leanchildrenandfoundthatobesechildrenhadahigherratioofFirmicutes/Bacteroidetes（6）Inanotherstudy,fecalsampleswereanalyzedin15obeseand15normalweightchildrentocomparedifferencesinthegutbacterialcommunity.SignificantlyhigherconcentrationsoftheSCFA,butyrateandpropionate,andsignificantlylowerconcentrationsofintermediatemetabolitesinobesechildrenwereobservedcomparedtothosewithnormalweight.,16,参考文献,(1)M.Millionetal.Gutbacterialmicrobiotaandobesity.2013(2)DavideFestietal.Gutmicrobiotaandmetaboli