Emerging evidence suggests that the gut microbiome plays an important role in the pathophysiology of both obesity and type 2 diabetes mellitus. We previously reported that dietary annatto-extracted tocotrienol exerts beneficial effects by modulating inflammatory responses in mice fed a high-fat diet (HFD). The purpose of this study was to test the hypothesis that tocotrienol supplementation when combined with an HFD would result in an altered gut microbiota composition. For 14 weeks, forty-eight male C57BL/6J mice were assigned to 4 groups-low-fat diet, HFD, HFD supplemented with annatto-extracted tocotrienol at 800 mg/kg diet (AT), and HFD supplemented with metformin at 200 mg/kg diet. Glucose homeostasis was assessed by glucose and insulin tolerance tests, serum and pancreas insulin levels, and histological assessments of insulin and glucagon in pancreatic tissue. The concentrations of adipokines were measured in white adipose tissues. For the gut microbiome analysis, cecal content was collected, DNA was extracted, and 16S rRNA gene sequencing was performed. AT supplementation improved glucose homeostasis and lowered resistin, leptin, and interleukin-6 levels in white adipose tissue. Relative to the HFD group, AT-supplemented mice showed a decrease in the Firmicutes to Bacteroidetes ratio and had a lower abundance of Ruminococcus lactaris, Dorea longicatena, and Lachnospiraceae family. The relative abundance of Akkermansia muciniphila was increased in the AT group compared to the low-fat diet group. The association between the metabolic improvements and the identified bacterial taxa suggests a potential metabolic modulation caused by AT supplementation through the gut microbiota composition in mice fed an HFD.

中文翻译：

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胭脂树提取的生育三烯酚对葡萄糖稳态、炎症和肠道微生物组的代谢益处

新出现的证据表明，肠道微生物组在肥胖和 2 型糖尿病的病理生理学中起着重要作用。我们之前曾报道，膳食中提取的胭脂树生育三烯酚通过调节喂食高脂肪饮食 (HFD) 的小鼠的炎症反应而发挥有益作用。本研究的目的是检验补充生育三烯酚与 HFD 结合会导致肠道微生物群组成改变的假设。在 14 周内，48 只雄性 C57BL/6J 小鼠被分配到 4 组 - 低脂饮食、HFD、HFD 补充了 800 毫克/公斤饮食 (AT) 的胭脂树提取的生育三烯酚，HFD 补充了 200 毫克二甲双胍/公斤饮食。通过葡萄糖和胰岛素耐受性测试、血清和胰腺胰岛素水平、胰腺组织中胰岛素和胰高血糖素的组织学评估。在白色脂肪组织中测量脂肪因子的浓度。对于肠道微生物组分析，收集盲肠内容物，提取 DNA，并进行 16S rRNA 基因测序。AT 补充剂改善了葡萄糖稳态并降低了白色脂肪组织中的抵抗素、瘦素和白细胞介素 6 水平。相对于 HFD 组，补充了 AT 的小鼠的厚壁菌门与拟杆菌门的比率降低，并且乳酸瘤胃球菌、长链球菌和毛螺菌科的丰度较低。与低脂饮食组相比，AT 组中 Akkermansia muciniphila 的相对丰度有所增加。