益生菌与肥胖 1 Introduction gutmicrobiota Tentrillionto100trillion 1014 microorganismspopulatetheadultintestines Thevastmajorityresideinthecolon wheredensitiesapproach1011 1012cells mL Almostalloftheseorganismsarebacteria andaminorityarearchaeons eukaryotes andvirusesThetwomostabundantbacterialphylainhumansandinmicearetheFirmicutes 60 80 andtheBacteroidetes 20 40 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 inglipogenesis 9 andinhibitingfattyacidsoxidation 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 ratioofFirmicutes Bacteroidetes 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 Gutmicrobiotaandmetabolicsyndrome 2014 3 TulikaAroraetal Probiotics Interactionwithgutmicrobiomeandantiobesitypotential 2013 4 MarinaSanchezetal Chil