Wu Wen-Chi, Inui Akio, Chen Chih-Yen
Department of Medicine, Taipei Veterans General Hospital, Taipei 11217, Taiwan.
Pharmacological Department of Herbal Medicine, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima 890-8544, Japan.
World J Diabetes. 2020 Feb 15;11(2):26-32. doi: 10.4239/wjd.v11.i2.26.
The prevalence of overweight and obesity has increased worldwide. Obesity is a well-known risk factor of type 2 diabetes mellitus and cardiovascular disease and raises public health concerns. Many dietary guidelines encourage the replacement of refined grains with whole grains (WGs) to enhance body weight management. Current evidence regarding interrelationships among WGs, body weight, and gut microbiota is limited and inconclusive. In this editorial, we comment on the article by Roager et al published in the recent issue of the 2019; 68(1): 83-93. In the study, obese patients (25 < body mass index < 35 kg/m) were randomly assigned to receive two 8-wk dietary controlling periods with WGs and refined grain-rich diet. The results showed significantly decreased body weight in the WG group. Either the composition of gut microbiota or short-chain fatty acids, the leading end product of fermentation of non-digestible carbohydrate by gut microbiota, did not differ between the two groups. The study highly indicated that a WG-rich diet reduced body weight independent of gut microbiota. We then raised some plausible mechanisms of how WGs might influence body weight and demonstrated more literature in line with WGs enhance body weight control through a microbiota-independent pathway. Possible mechanisms include: (1) The abundant dietary fiber contents of WGs increase satiety, satiation, energy excretion from stool, and energy expenditure simultaneously decreasing energy absorption and fat storage; (2) The plentiful amount of polyphenols of WGs improve energy expenditure by hampering adipocyte maturation and function; (3) The sufficient magnesium and zinc of WGs guarantee lean body mass growth and decrease fat mass; (4) The effect of WGs on brown adipose tissue is a key component of non-shivering thermogenesis; and (5) The increase of adiponectin by WGs enhances glucose utilization, lipid oxidation, and energy expenditure.
超重和肥胖在全球范围内的患病率都有所上升。肥胖是2型糖尿病和心血管疾病的一个众所周知的危险因素，引发了公众对健康的担忧。许多饮食指南鼓励用全谷物替代精制谷物以加强体重管理。目前关于全谷物、体重和肠道微生物群之间相互关系的证据有限且尚无定论。在这篇社论中，我们对Roager等人发表在近期《[期刊名称]2019年；68(1):83 - 93》上的文章进行评论。在该研究中，肥胖患者（体重指数25＜体重指数＜35kg/m²）被随机分配接受两个为期8周的饮食控制期，分别食用全谷物饮食和富含精制谷物的饮食。结果显示全谷物组体重显著下降。两组之间肠道微生物群的组成或肠道微生物群对不可消化碳水化合物发酵的主要终产物短链脂肪酸均无差异。该研究强烈表明富含全谷物的饮食可独立于肠道微生物群减轻体重。然后我们提出了一些全谷物可能影响体重的合理机制，并展示了更多与全谷物通过不依赖微生物群的途径增强体重控制相关的文献。可能的机制包括：（1）全谷物丰富的膳食纤维含量同时增加饱腹感、满足感、粪便能量排泄和能量消耗，从而减少能量吸收和脂肪储存；（2）全谷物中大量的多酚通过阻碍脂肪细胞成熟和功能来改善能量消耗；（3）全谷物中充足的镁和锌保证瘦体重增长并减少脂肪量；（4）全谷物对棕色脂肪组织的作用是非寒战产热的关键组成部分；（5）全谷物使脂联素增加，从而增强葡萄糖利用、脂质氧化和能量消耗。
