Department of Molecular Sciences, Swedish University of Agricultural Sciences, Uppsala, Sweden.
Unit of Diet, Genes and Environment, Danish Cancer Society Research Center, Copenhagen, Denmark.
Am J Clin Nutr. 2020 Apr 1;111(4):864-876. doi: 10.1093/ajcn/nqaa026.
A whole-grain (WG)-rich diet has shown to have potential for both prevention and treatment of the metabolic syndrome (MetS), which is a cluster of risk factors that increase the risk of type 2 diabetes and cardiovascular disease. Different WGs may have different health effects. WG rye, in particular, may improve glucose homeostasis and blood lipids, possibly mediated through fermentable dietary fiber and lignans. Recent studies have also suggested a crucial role of the gut microbiota in response to WG.
The aim was to investigate WG rye, alone and with lignan supplements [secoisolariciresinol diglucoside (SDG)], and WG wheat diets on glucose tolerance [oral-glucose-tolerance test (OGTT)], other cardiometabolic outcomes, enterolignans, and microbiota composition. Moreover, we exploratively evaluated the role of gut microbiota enterotypes in response to intervention diets.
Forty men with MetS risk profile were randomly assigned to WG diets in an 8-wk crossover study. The rye diet was supplemented with 280 mg SDG at weeks 4-8. Effects of treatment were evaluated by mixed-effects modeling, and effects on microbiota composition and the role of gut microbiota as a predictor of response to treatment were analyzed by random forest plots.
The WG rye diet (± SDG supplements) did not affect the OGTT compared with WG wheat. Total and LDL cholesterol were lowered (-0.06 and -0.09 mmol/L, respectively; P < 0.05) after WG rye compared with WG wheat after 4 wk but not after 8 wk. WG rye resulted in higher abundance of Bifidobacterium [fold-change (FC) = 2.58, P < 0.001] compared with baseline and lower abundance of Clostridium genus compared with WG wheat (FC = 0.54, P = 0.02). The explorative analyses suggest that baseline enterotype is associated with total and LDL-cholesterol response to diet.
WG rye, alone or with SDG supplementation, compared with WG wheat did not affect glucose metabolism but caused transient LDL-cholesterol reduction. The effect of WG diets appeared to differ according to enterotype. This trial was registered at www.clinicaltrials.gov as NCT02987595.
富含全谷物（WG）的饮食已被证明对代谢综合征（MetS）的预防和治疗具有潜在作用，代谢综合征是一组增加 2 型糖尿病和心血管疾病风险的危险因素。不同的 WG 可能具有不同的健康影响。特别是 WG 黑麦可能通过可发酵膳食纤维和木脂素改善葡萄糖稳态和血脂。最近的研究还表明，肠道微生物群在对 WG 的反应中起着至关重要的作用。
本研究旨在单独和补充木脂素（松柏脂素二葡萄糖苷（SDG））以及 WG 小麦饮食对葡萄糖耐量[口服葡萄糖耐量试验（OGTT）]、其他心血管代谢结果、肠内木脂素和微生物群组成的影响。此外，我们还探索性地评估了肠道微生物群肠型在干预饮食中的作用。
40 名具有代谢综合征风险特征的男性被随机分配到 8 周交叉研究中的 WG 饮食中。在第 4 至 8 周时，黑麦饮食补充 280mg SDG。通过混合效应模型评估治疗效果，并通过随机森林图分析微生物群组成和肠道微生物群作为治疗反应预测因子的作用。
与 WG 小麦相比，WG 黑麦（± SDG 补充剂）饮食对 OGTT 没有影响。与 WG 小麦相比，WG 黑麦在 4 周后但在 8 周后降低了总胆固醇和 LDL 胆固醇（分别降低了 0.06 和 0.09mmol/L；P<0.05）。与基线相比，WG 黑麦使双歧杆菌的丰度增加[倍数变化（FC）=2.58，P<0.001]，与 WG 小麦相比，梭菌属的丰度降低[FC=0.54，P=0.02]。探索性分析表明，基线肠型与饮食对总胆固醇和 LDL 胆固醇的反应有关。
与 WG 小麦相比，单独或补充 SDG 的 WG 黑麦饮食并未影响葡萄糖代谢，但导致 LDL 胆固醇短暂降低。WG 饮食的影响似乎根据肠型而有所不同。该试验在 www.clinicaltrials.gov 上注册为 NCT02987595。
