Table_3_Functional Effects of EPS-Producing Bifidobacterium Administration on Energy Metabolic Alterations of Diet-Induced Obese Mice.docx

Obesity has been recognized by the World Health Organization as a global epidemic. The gut microbiota is considered as a factor involved in the regulation of numerous metabolic pathways by impacting several functions of the host. It has been suggested that probiotics can modulate host gene expression and metabolism, and thereby positively influence host adipose tissue development and obesity related-metabolic disorders. The aim of the present work was to evaluate the effect of an exopolysaccharide (EPS)-producing Bifidobacterium strain on host glucose and lipid metabolism and the gut microbial composition in a short-term diet-induced obesity (DIO) in mice. C57BL/6J male mice were randomly divided into three groups: a control group that received control standard diet, a group fed a high-fat diet (HF), and a group fed HF supplemented with Bifidobacterium animalis IPLA R1. Fasting serum insulin as well as triglycerides accumulation in the liver were significantly reduced in the group receiving B. animalis IPLA R1. The treatment with the EPS-producing B. animalis IPLA R1 tended to down-regulate the expression of host genes involved in the hepatic synthesis of fatty acids which was concomitant with an upregulation in the expression of genes related with fatty acid oxidation. B. animalis IPLA R1 not only promoted the increase of Bifidobacterium but also the levels of Bacteroides-Prevotella. Our data indicate that the EPS-producing Bifidobacterium IPLA R1 strain may have beneficial effects in metabolic disorders associated with obesity, by modulating the gut microbiota composition and promoting changes in lipids metabolism and glucose homeostasis.

世界卫生组织（World Health Organization）已将肥胖认定为全球性流行病。肠道菌群被认为是通过影响宿主多项功能，参与调控众多代谢通路的因素之一。已有研究表明，益生菌可调节宿主基因表达与代谢，进而对宿主脂肪组织发育及肥胖相关代谢紊乱产生积极影响。本研究旨在评估一株产胞外多糖（exopolysaccharide, EPS）的双歧杆菌（Bifidobacterium）菌株，对短期饮食诱导肥胖（diet-induced obesity, DIO）小鼠模型的宿主糖脂代谢及肠道菌群组成的影响。实验将C57BL/6J雄性小鼠随机分为三组：给予标准对照饲料的对照组、高脂饮食（high-fat diet, HF）组，以及补充动物双歧杆菌（Bifidobacterium animalis）IPLA R1的高脂饮食组。结果显示，摄入动物双歧杆菌IPLA R1的实验组，其空腹血清胰岛素水平与肝脏甘油三酯蓄积量均显著降低。该产EPS的动物双歧杆菌IPLA R1处理组可趋于下调肝脏脂肪酸合成相关宿主基因的表达，同时伴随脂肪酸氧化相关基因表达的上调。此外，动物双歧杆菌IPLA R1不仅促进了双歧杆菌属的增殖，还提升了拟杆菌-普雷沃氏菌属的水平。本研究数据表明，产EPS的双歧杆菌IPLA R1菌株可通过调控肠道菌群组成、改善脂质代谢与葡萄糖稳态，对肥胖相关代谢紊乱发挥有益作用。