血糖生成指数、血糖负荷与人类疾病

该文介绍血糖指数(GI)和血糖负荷(GL)概念,影响GI、GL测定因素,及高低GI、GL食物对肥胖、糖尿病影响,指出GI、GL意义及应用前景。     

米饭饮食与血糖控制

米饭作为亚洲多数国家的主食,对饮食健康具有重要的影响。米饭通常被认为是一种高血糖指数的食物,但米饭摄入与2型糖尿病风险是否相关仍存在争议。本文梳理了有关米饭摄入和2型糖尿病风险之间的流行病学和人体实验证据,综述了稻米品种、加工方式、烹调方式、储藏和食用温度以及不同食物搭配对米饭餐血糖指数和人体餐后血糖变化的影响。目前证据表明,通过选择合适的大米品种、合理的烹调加工和搭配进食,可以有效调节米饭餐的血糖反应。     

Low-glycemic-load diets: impact on obesity and chronic diseases

Historically, carbohydrates have been thought to play only a minor role in promoting weight gain and in predicting the risk of development of chronic disease. Most of the focus had been on reducing total dietary fat. During the last 20 years, fat intake decreased, while the number of individuals who were overweight or developed a chronic conditions have dramatically increased. Simultaneously, the calories coming from carbohydrate have also increased. Carbohydrates can be classified by their post-prandial glycemic effect, called the glycemic index or glycemic load. Carbohydrates with high glycemic indexes and high glycemic loads produce substantial increases in blood glucose and insulin levels after ingestion. Within a few hours after their consumption, blood sugar levels begin to decline rapidly due to an exaggerated increase in insulin secretion. A profound state of hunger is created. The continued intake of high-glycemic load meals is associated with an increased risk of chronic diseases such as obesity, cardiovascular disease, and diabetes. In this review, the terms glycemic index and glycemic load are defined, coupled with an overview of short- and long-term changes that occur from eating diets of different glycemic indexes and glycemic loads. Finally, practical strategies for how to design low-glycemic-load diets consisting primarily of low-glycemic carbohydrates are provided.     

Diet Effects in Gut Microbiome and Obesity

The 100 trillion microbes in human gut coevolve with the host and exert significant influences on human health. The gut microbial composition presents dynamic changes correlated with various factors including host genotypes, age, and external environment. Effective manipulation of the gut microbiota through diets (both long‐term and short‐term diet patterns), probiotics and/or prebiotics, and antibiotics has been proved being potential to prevent from metabolic disorders such as obesity in many studies. The dietary regulation exerts influences on microbial metabolism and host immune functions through several pathways, of which may include selectively bacterial fermentation of nutrients, lower intestinal barrier function, overexpression of genes associated with disorders, and disruptions to both innate and adaptive immunity. Discoveries in the interrelationship between diet, intestinal microbiome, and body immune system provide us novel perceptions to the specific action mechanisms and will promote the development of therapeutic approaches for obesity.     

高脂膳食与肠道微生态相关性研究进展

近年来,随着人们的生活习惯向高脂膳食转变,高脂膳食诱发的食源性肥胖、心血管疾病、糖尿病等相关 慢性代谢疾病已经成为困扰全球的公共卫生问题。越来越多的研究表明,肠道微生态和高脂膳食诱发的代谢紊乱关 系密切。受膳食、遗传背景和生活方式等因素的影响,肠道微生态的组成存在着很大的个体差异。膳食不仅仅为宿 主提供营养物质,也是肠道微生物营养的来源,能影响肠道微生态的组成和功能。宿主的能量代谢、肠道通透性的 保持以及一些炎症反应和免疫反应均与肠道微生态的改变相关。本文综述了高脂膳食、肠道微生态和宿主健康之间 的相互影响及其可能的作用机理。虽然目前的研究结果还无法证实肠道微生态与高脂膳食诱发的相关慢性代谢疾病 是否存在因果关系,但肠道微生态与宿主健康之间的相互影响为肥胖及其相关代谢疾病的防治提供了新思路。     

不同比例碳水化合物和油脂饮食对机体代谢和健康影响的研究进展

碳水化合物和油脂是人体重要的能量来源,饮食中必须保证足够的脂肪和碳水化合物。高脂、高碳水化合物饮食能够提供丰富营养,同时也会诱发脂肪肝、肥胖、心血管疾病、高血糖、高血脂以及影响子代发育等。综述了不同比例碳水化合物和油脂饮食对脂肪代谢、糖代谢、繁殖发育等方面影响,并介绍了植物提取物对不同比例油脂与碳水化合物饮食引起的疾病的治疗作用,以期为人们合理膳食提供参考。     

The Gluten-Free Diet and Glycaemic Index in the Management of Coeliac Disease Associated with Type 1 Diabetes

ABSTRACT

Type 1 diabetes (T1D) is frequently associated with coeliac disease (CD). Individuals with concomitant diseases, should adhere to a strict gluten-free diet (GFD) and control glycaemia to avoid the complications associated with both conditions. However, many aspects of the GFD which is a highly eliminative diet is inferior, compared to conventional gluten-containing diet. In this review, the management of CD associated with T1D are presented and the treatment dilemmas concerning a GFD are discussed in the context of the glycaemic response of gluten-free products. A great deal was also focused on glycaemia control as potential protection against chronic diseases.     

Obesogenic Diet Cycling Produces Graded Effects on Cognition and Microbiota Composition in Rats

Scope

The effects of diet cycling on cognition and fecal microbiota are not well understood.

Method and Results

Adult male Sprague-Dawley rats were cycled between a high-fat, high-sugar “cafeteria” diet (Caf) and regular chow. The impairment in place recognition memory produced by 16 days of Caf diet was reduced by switching to chow for 11 but not 4 days. Next, rats received 16 days of Caf diet in 2, 4, 8, or 16-day cycles, each separated by 4-day chow cycles. Place recognition memory declined from baseline in all groups and was impaired in the 16- versus 2-day group. Finally, rats received 24 days of Caf diet continuously or in 3-day cycles separated by 2- or 4-day chow cycles. Any Caf diet access impaired cognition and increased adiposity relative to controls, without altering hippocampal gene expression. Place recognition and adiposity were the strongest predictors of global microbiota composition. Overall, diets with higher Caf > chow ratios produced greater spatial memory impairments and larger shifts in gut microbiota species richness and beta diversity.

Conclusion

Results suggest that diet-induced cognitive deficits worsen in proportion to unhealthy diet exposure, and that shifting to a healthy chow for at least a week is required for recovery under the conditions tested here.     

大豆不溶性膳食纤维对高脂饮食诱导小鼠肥胖的预防作用

目的:研究大豆不溶性膳食纤维(Soybean insoluble dietary fiber,SIDF)对高脂饮食(High fat diet,HFD)诱导小鼠肥胖的预防作用及其机理。方法:将50只C57BL/6J小鼠随机分为正常饮食对照组(Normal diet,ND)、高脂饮食对照组(HFD)和大豆不溶性膳食纤维低(Low-dose soybean insoluble dietary fiber,LSIDF)(250 mg/kg BW/d)、中(Middle-dose soybean insoluble dietary fiber,MSIDF)(500 mg/kg BW/d)、高剂量组(High-dose soybean insoluble dietary fiber,HSIDF)(1 g/kg BW/d),ND组饲喂正常饲料,其余各组饲喂高脂饲料,连续喂养20周。实验结束后统计体质量、肝脏和脂肪湿质量,制作肝脏组织病理切片,测定血清及肝脏脂质水平,实时荧光定量聚合酶链式反应测定小鼠肝脏中脂代谢相关基因表达水平。结果:与HFD组比,SIDF各剂量组可显著减缓小鼠体重增加,降低其血清和肝脏中总胆固醇(Total cholesterol,TC)、甘油三酯(Triglyceride,TG)水平(P<0.05),并且HSIDF组效果优于LSIDF、MSIDF组;小鼠肝脏指数(P<0.05)和脂肪系数(P<0.001)显著降低,其中MSIDF和HSIDF组小鼠腹部脂肪(P<0.001)和肾周脂肪重量(P<0.001)显著减少;HSIDF组显著下调小鼠肝脏中脂肪酸合成酶(Fatty acid synthase,FAS)、二酰甘油酰基转移酶1(Diacylglycerol acyltransferase-1,DGAT1)、二酰甘油酰基转移酶2(Diacylglycerol acyltransferase-2,DGAT2)、硬脂酰辅酶A去饱和酶1(Stearyl-coenzyme A dehydrogenase-1,SCD1)基因表达水平(P<0.05),同时上调过氧化物酶体增殖物激活受体α(Peroxisome proliferators-activated receptor-α,PPARα)、肉毒碱棕榈酰基转移酶1a(Carnitine palmtoyl transferase-1a,CPT1a)基因表达水平(P<0.05)。结论:IDFS对HFD诱导小鼠肥胖具有预防作用,可能与减少脂质合成,加快脂肪酸氧化有关,其可作为一种潜在的膳食补充剂。     

Ready‐to‐eat snack products: the role of extrusion technology in developing consumer acceptable and nutritious snacks

Consumer appeal for ready‐to‐eat (RTE) products is forecast to grow rapidly over the next 5 years as consumers demand convenient snacks with exciting sensory and textural properties. Extrusion technology has been used extensively in the production of cereal RTE snacks due to its ease of operation and ability to produce a variety of textures and shapes which appeal to consumers. Many of the existing RTE products are relatively high in sugar and salt, thus being regarded as energy dense but nutritionally poor foods. However, there exists a potential to manipulate the nutritional status of extruded RTEs by altering the digestion potentials of starch and protein, and by the incorporation of bioactive components such as dietary fibre. The review article explores some of the recent research in this field and illustrates opportunities by which the global food industry could react to consumers' requirements for healthful RTE snack products in the coming years.     

白藜芦醇对高脂诱导肥胖小鼠生长性能及肝脏糖脂代谢、能量代谢的影响

研究添加白藜芦醇对高脂日粮诱导肥胖小鼠的体重、采食量、脂质代谢、糖代谢及能量代谢的影响。选取40只C57BL/6J雄性小鼠,随机分成4组,分别采用低脂日粮(LFD)、低脂日粮+0.0276%白藜芦醇(LR)、高脂日粮(HFD)、高脂日粮+0.04%白藜芦醇(HR)饲喂12周。结果表明:与饲喂低脂日粮小鼠相比,高脂日粮组小鼠的体重显著增加(p<0.05),前4周的采食量显著减少(p<0.05),血清中谷草转氨酶(AST)和谷丙转氨酶(ALT)活性显著升高(p<0.05),肝脏中ALT和AST活性显著下降(p<0.05),脂质过氧化物(LPO)和丙二醛(MDA)含量均显著升高(p<0.05),己糖激酶(HK)、丙酮酸激酶(PK)和琥珀酸脱氢酶(SDH)活力显著下降(p<0.05);另外,饲喂高脂日粮小鼠肝脏MDH1、Sdha、PGC-1α mRNA的表达量显著下降(p<0.05)。饲喂添加了白藜芦醇的高脂日粮后,与高脂日粮组比,小鼠的体重显著降低(p<0.05),采食量显著增加(p<0.05),血清中AST和ALT活性显著降低(p<0.05),肝脏中AST活性显著升高(p<0.05),LPO和MDA含量显著降低(p<0.05),HK和PK活力显著升高(p<0.05)。另外,饲喂白藜芦醇对高脂日粮导致的肝脏中Hk2、Pkm、Cs、MDH1、Sdha mRNA表达量降低有显著的提高作用(p<0.05)。综上所述,日粮中添加0.04%的白藜芦醇能一定程度地缓解高脂日粮造成小鼠机体损伤,修复机体的脂质代谢、糖代谢和能量代谢。     

营养干预对妊娠期血糖异常孕妇糖脂代谢的影响

目的：研究营养干预对妊娠期血糖异常孕妇血糖和血脂代谢的影响.方法：采用随机对照试验设计,选取广东省人民医院产科门诊确诊为妊娠期糖代谢异常的孕妇共83例,随机分为对照组（43例）和强化营养干预组（40例）.分别检测两组孕妇孕中期和孕末期的空腹血糖、餐后2h血糖、血清总胆固醇、总甘油三酯、高密度脂蛋白、低密度脂蛋白和糖化血红蛋白,比较组间差异和前后差异.结果：强化营养干预组孕妇孕末期空腹血糖和餐后2h血糖均显著的低于对照组孕妇（P＜0.05）,但糖化血红蛋白和各血脂水平与对照组差异无显著性（P＞0.05）.强化干预组孕末期的空腹血糖和餐后2h血糖均显著低于孕中期（P＜0.05）,对照组孕末期的空腹血糖显著高于孕中期（P＜0.05）,餐后2h血糖孕末期显著低于孕中期（P＜0.05）.两组孕妇血清甘油三酯孕末期显著高于孕中期水平（P＜0.05）,总胆回醇、高密度脂蛋白、低密度脂蛋白及糖化血红蛋白水平孕末期和孕中期差异无统计学意义（P＞0.05）.结论：妊娠期糖代谢异常孕妇存在着以甘油三酯升高为主的脂代谢紊乱,强化营养干预对控制妊娠期糖代谢异常的妇女的血糖水平有显著作用,但未能发现对血脂的改善作用,其原因有待研究.     

Physical,sensory, in-vitro starch digestibility and glycaemic index of granola bars prepared using sucrose alternatives

Granola bars were prepared using barley flakes, groundnut bits, cocoa powder, sucrose and/or sucrose alternatives (coconut sugar, fructooligosaccharide and inulin). Apart from sensory acceptance, nutritional composition, energy values and glycaemic responses (glycaemic index, GI and glycaemic load, GL) of the bars were evaluated. Physico-chemical properties and sensorial acceptance of granola bar made with coconut sugar and fructooligosaccharide were on par with those made with sucrose. Further, all formulated granola bars, except with inulin, were intermediate moisture foods. GI of all five formulations of granola bars was <55; ranging between 51 and 54.9, corresponding to low glycaemic food. Granola bars with coconut sugar had high GL (≥20), while bars prepared with FOS, inulin and without sugar were in the medium range (>10 to <20). Effect of choice of raw materials, complexity of matrix structure and particle size of ingredients on GI and GL of the bars is explained.     

Natural honey modulates physiological glycemic response compared to simulated honey and D-glucose

The present study is undertaken to find out the relative glycemic tolerance of natural honey compared with simulated honey and D-glucose using oral glucose tolerance tested up to 180 min. Twenty-six healthy human subjects with mean age of 28.6 +/- 9.3 y were randomly divided into 3 groups, that is, natural honey consumers (NHC; n= 13), simulated honey consumers (AHC; n= 6), and D-glucose consumers (DGC; n= 7). After recording fasting blood glucose, the participants consumed either natural honey or simulated honey or D-glucose (1g/kg body weight). Subsequently, additional plasma glucose levels (PGLs) were recorded at 60, 120, and 180 min. At 60 min, DGC and AHC group members exhibited similar PGL elevation (that is, 52% and 47%, respectively) compared to NHC group with only 20% increment. On the other hand, after 180 min, 20% decrease in PGL was observed in the DGC group compared to 9.75% reduction in the NHC group. These observations are primarily in line with earlier studies. Results analyzed by one-way analysis of variance (ANOVA) showed significant differences between all 3 tested groups with F-statistic (19.96) and P value (< 0.005). Coefficient of variation of the NHC, AHC, and DGC groups were 14.8%, 20.2%, and 27.5%, respectively. Posthoc tests showed that glucose response was significantly lower in the NHC group at all time points (P < 0.005) compared to the AHC and DGC groups. In conclusion, natural honey stabilizes physiological glycemic response with rebound recovery of PGL.     

饮食、肠道微生物与健康的关系研究进展

肠道微生物是膳食与人体健康的桥梁,与营养物质的吸收和代谢密切相关,是人体重要的“微生物器官”。同时,研究学者们也已经清楚地认识到这个重要的“微生物器官”与人体生理功能、健康和疾病关系密切,对人体的重要性不容忽视。为此,本文就近几年来有关膳食对肠道微生物结构以及代谢产物影响的研究进行综述,并介绍肠道微生物与人体生理功能及健康的关系,旨在为未来研究饮食、肠道微生物与健康的关系提供参考。