超重和正常体重孕妇的肠道微生物群组成
超重和正常体重孕妇的肠道微生物群组成
Distinct composition of gut microbiotaduring pregnancy in overweight and normal-weight women
Collado et al. Am JClin Nutr (2008)
DOI 10.1093/ajcn/88.4.894
当肠道微生物的组成发生改变时，人体可能通过葡萄糖耐量下降、内源性脂多糖增加使能量过度储存、从而引起肥胖的发生。妊娠期超重的孕妇通过母体传递，给胎儿提供了过多的能量，导致出生体重增加，并有可能引起母亲和新生儿并发症。
本研究通过检测妊娠早期和晚期的肠道微生物组成，发现肥胖孕妇与正常体重孕妇的肠道微生物组成有显著差异，并且发现孕期体重增加也与微生物组成的改变有关。
Abstract
Background: Results of experimentalstudies suggest that deviations in gut microbiota composition predispose toexcessive energy storage and obesity. The mother influences the originalinoculum and the development of infant microbiota, which in turn is associatedwith later weight gain.
Objective: We characterizedthe gut microbiota in women according to their body mass index (BMI) and theeffect of weight gain over pregnancy on the composition of microbiota beforedelivery.
Design: Overweight women (n=18)were selected according to their prepregnancy BMI from a prospective follow-upstudy. Normal-weight women (n=36) were selected as controls inconsecutive order of recruitment. Excessive weight gain during pregnancy wasdefined as >16.0 kg for normal-weight and >11.5 kg for overweight statesaccording to Institute of Medicine recommendations. The composition of gutmicrobiota was analyzed by fluorescent in situ hybridization coupled with flowcytometry (FCM-FISH) and by quantitative real-time polymerase chain reaction (qPCR).
Results: Bacteroides and Staphylococcus were significantly higher in theoverweight state than in normal-weight women as assessed by FCM-FISH and qPCR.Mother’s weight and BMI before pregnancy correlated with higher concentrationsof Bacteroides, Clostridium, and Staphylococcus. Microbialcounts increased from the first to third trimester of pregnancy. High Bacteroidesconcentrations were associated with excessive weight gain over pregnancy (P=0.014).
Conclusions: Gut microbiotacomposition and weight are linked, and mother’s weight gain is affected bymicrobiota. Microbiota modification before and during pregnancy may offer newdirections for preventive and therapeutic applications in reducing the risk ofoverweight and obesity.
研究对象：受试者是根据其怀孕前的身体质量指数(BMI，kg/m2)从256名女性的前瞻性随访研究中选出18名BMI超过30的超重孕妇，36名正常体重孕妇做为对照组。
入组条件：白人健康女性；大部分为首次怀孕；足月生产。
研究方法：收集受试者粪便样本，分析妊娠初期(妊娠10 - 15wk)和妊娠后期(妊娠30 - 35wk)肠道微生物组成。为了分析孕期体重增加对微生物群的影响，根据美国医学研究所对孕妇体重增加总量的建议，将孕妇分为正常体重增加组和孕期体重增加过度组两组。
检测方法：肠道微生物分析采用荧光原位杂交结合流式细胞仪(FCM-FISH)和实时定量聚合酶链反应(qPCR)。
研究结果：
超重妇女所生的婴儿往往比正常体重妇女的婴儿重；
妊娠前正常体重孕妇与超重孕妇的肠道微生物组成有显著差异。超重孕妇肠道内的拟杆菌（Bacteroides）和葡萄球菌（Staphylococcus）的数量显著增加。孕早期葡萄球菌（Staphylococcus）和梭菌（Clostridium）群浓度与体重指数也有相关性。这些微生物丰度增加时易导致能量储存和肥胖增加，降低对全身低级别炎症的控制；
孕期正常体重组的细胞总数减少更多，而超重组的梭状芽胞杆菌（Clostridium）浓度增加更多。对组织梭状芽胞杆菌组（Clostridium histolyticum）作为厚壁菌门（Firmicutes）的代表进行分析发现，其在肥胖孕妇中的丰度较高。
在孕晚期，拟杆菌（Bacteroides）与妊娠前体重、体重指数、妊娠期体重增加呈正相关。每增加一公斤体重，拟杆菌数就增加0.006个对数单位。
作为微生物与肥胖关联性的理论基础，研究者提出了3种可能的机制。第一，肠道微生物群可使难消化多糖水解为易于吸收的单糖，激活脂蛋白脂肪酶。因此，在肝脏源性甘油三酯的从头合成过程中，葡萄糖被迅速吸收，脂肪酸被过度储存;这两种现象都会增加体重。第二，特定的微生物群组成可以调节诱导节食的脂肪细胞因子。第三种可能的解释是AMP激活蛋白激酶，从而抑制合成代谢并诱导分解代谢途径。
本研究认为，除了能量的获取和储存外，肠道微生物群的特定菌株所具有的促炎和抗炎特性也可能与肥胖作用机制有关。
知几未来研究院正在搭建一个“疾病-肠道菌群”知识库。
你可以在公众号对话框回复“IBD”或“肠易激综合征”，查看与疾病相关的菌群；
也可以回复“双歧杆菌”或“Hp”，查看与细菌相关的疾病。
👇👇👇点击阅读原文，了解更多人体微生态研究