Serum and Urine Metabolites in Healthy Men after Consumption of Acidified Milk and Yogurt

The identification of molecular biomarkers that can be used to quantitatively link dietary intake to phenotypic traits in humans is a key theme in modern nutritional research. Although dairy products (with and without fermentation) represent a major food group, the identification of markers of their intake lags behind that of other food groups. Here, we report the results from an analysis of the metabolites in postprandial serum and urine samples from a randomized crossover study with 14 healthy men who ingested acidified milk, yogurt, and a non-dairy meal. Our study confirms the potential of lactose and its metabolites as markers of lactose-containing dairy foods and the dependence of their combined profiles on the fermentation status of the consumed products. Furthermore, indole-3-lactic acid and 3-phenyllactic acid are two products of fermentation whose postprandial behaviour strongly discriminates yogurt from milk intake. Our study also provides evidence of the ability of milk fermentation to increase the acute delivery of free amino acids to humans. Notably, 3,5-dimethyloctan-2-one also proves to be a specific marker for milk and yogurt consumption, as well as for cheese consumption (previously published data). These molecules deserve future characterisation in human interventional and observational studies.     

Physicochemical and functional properties of micronized jincheng orange by-products (Citrus sinensis Osbeck) dietary fiber and its application as a fat replacer in yogurt

Orange by-products from juice extraction are generally discarded or used in animal feed due to their low market value. However, orange by-products show potential as dietary fiber (DF) and fat replacers in products such as yogurt. This study assessed the benefits of using orange by-products in DF-enriched materials such as DF powders (OP) and micronized DF with ball-milling (MDF). The study also investigated the effects of adding different levels of OP and MDF on the quality of low-fat yogurt. Results show that MDF showed better physicochemical and functional properties than OP, and that 2% MDF as a fat replacer in yogurt retained most of the textural and sensory properties of full-fat yogurt. Therefore, this study showed that MDF is a promising alternative as a fat replacer in low-fat yogurt, without sacrificing good taste and other qualities of full-fat yogurt.     

The contribution of yogurt to nutrient intakes across the life course

Yogurt is a nutrient‐dense food within the milk and dairy products food group. The nutritional content of yogurt varies depending on the processing method and ingredients used. Like milk, it is a good source of protein and calcium, and can be a source of iodine, potassium, phosphorus and the B vitamins – riboflavin (B₂) and vitamin B₁₂ (depending on type). Some yogurt products are also fortified with vitamin D. The nutritional value of dairy products (milk, cheese and yogurt) and the importance of the nutrients they provide for bone health are well recognised. These foods are collected together as one of the four main food groups within the UK's eatwell plate model that illustrates a healthy, balanced diet. Studies exploring the nutritional and health attributes of yogurt are limited but some research has suggested benefits in relation to bone mineral content, weight management, type 2 diabetes and metabolic profile. Yogurt consumption has also been associated with diet quality. The aim of this paper is to use national survey data to examine yogurt consumption in the UK and consider its contribution to nutrient intakes at different life stages within the context of nutritional challenges in each age group. The contribution of yogurt to energy and nutrient intakes across the life course was calculated via secondary analysis of data from the Diet and Nutrition Survey of Infants and Young Children (2011) and the National Diet and Nutrition Survey (2008/2009–2010/2011). The products categorised within the ‘yogurt group’ included all yogurt, fromage frais and dairy desserts, and fortified products. Comparisons were also made between specific sub‐categories of yogurt, namely ‘yogurt’, ‘fromage frais’ and ‘dairy desserts’. Nutrients included in the analyses were energy; the macronutrients; micronutrients that yogurt can be defined as a ‘source of’; micronutrients that may be of concern in the UK population; and vitamin D for fortified products. A simple dietary modelling exercise was also undertaken to investigate the potential impact of including an additional pot of yogurt per day on the nutrient intakes of adolescents. Children aged 3 years and under had the highest intakes of yogurt [mean intake 43.8 g/day (SD 39.7 g) in 4–18 month‐olds; 46.7 g/day (SD 39.1 g) in 1.5–3 year‐olds], and adolescents (11–18 years) consumed the least [21 g/day (SD 38.0 g)]. In adults, highest mean consumption [35.7 g/day (SD 55.0 g)] was during middle age (50–64 years), equivalent to less than a third of a standard 125 g pot. Around 80% of young children (aged 3 years and under) but only a third of teenagers and young adults had consumed any yogurt product during the survey period of 4 days. Average yogurt consumption was twice as high in women as men among older adults (65 years and over), while gender differences in consumption were less apparent in children. Fromage frais and fortified yogurt products were most commonly consumed by younger children, as were dairy desserts in those aged 4–18 years. Among adults, yogurt per se was most commonly consumed. Children aged 4–10 years exhibited the most variety in the types of yogurt consumed. Low‐fat yogurt (including those with added fruit, nuts and cereals) was the most commonly consumed yogurt type when all ages were combined. More than a third of all yogurt products consumed by children aged 3 years and under were fortified, compared with 18% in those aged 4–10 years. During adulthood, the consumption of fortified products was negligible. The yogurt group made a useful contribution to micronutrient intakes in children aged 4 months to 10 years, particularly vitamin B₁₂ (4–18 months: 7.6%; 1.5–3 years: 5.3%; 4–10 years: 3.8%), riboflavin (7.8%, 6.9%, and 5.7%, respectively), calcium (9.5%, 8.2%, and 5.9%, respectively), iodine (7.2%, 7.6%, and 7%, respectively) and phosphorus (8.1%, 6.3%, and 4.3%, respectively). It also provided 3.9% of the total intake of vitamin D in those aged 4–18 months and 10.5% in those aged 1.5–3 years. Although the contribution to total dietary energy intake was low (4.9% at 4–18 months and 4.2% at 1.5–3 years), yogurt contributed a high proportion of non‐milk extrinsic sugars (NMES) to the diets of young children (22.7% and 11.1% in 4–18 months and 1.5–3 years, respectively). However, the total NMES intake was comparatively low in children aged 4–18 months (6.7% total energy), and 11.6% in 1.5–3 year‐olds (compared to 15.3% total energy in children aged 11–18 years in this survey). As children aged, the contribution of yogurt (all categories combined) to micronutrient intake, as well as to NMES, decreased, reflecting the increasing amounts and variety of foods in the diet. Yogurt made a small contribution to energy and macronutrient intakes during adulthood, with the greatest proportions mostly in the older age group (65 years and over) (energy: 1.7%; fat: 1.3%; saturated fatty acids: 2.1%; NMES: 4%). As intake was higher among women, yogurt made a greater contribution to their micronutrient intakes compared with men, providing >5% of the reference nutrient intakes (RNIs) for phosphorus, iodine, calcium, vitamin B₁₂ and riboflavin. Simple dietary modelling was carried out to investigate the hypothetical change in mean nutrient intakes among adolescents aged 11–14 and 15–18 years, if they were all to add an extra 125 g pot of low‐fat fruit yogurt to their current diet. This showed an increase in average intake, as a percentage of the RNI, for several micronutrients for which there is some evidence of low intakes in this age group, notably calcium in boys and girls (11–18 years) and iodine in girls (11–18 years). Although some benefits for micronutrient intakes were noted, such advice would impact on energy and macronutrient intakes (including NMES), and would need to be given in the context of the wider diet (e.g. as ‘swaps’ for less nutrient‐dense foods). In conclusion, yogurt makes a small but valuable contribution to nutrient intakes in the UK, particularly in young children. Among adolescents, the addition of a low‐fat yogurt would help meet recommended intakes for several micronutrients, particularly calcium and iodine, which are of concern in some teenage diets. Advice to replace some types of snacks and desserts, particularly those high in fat and sugars and low in micronutrients, with a pot of yogurt or similar dairy product may improve the nutrient density of their diet.     

Postprandial coagulation activation in overweight individuals after weight loss: Acute and long-term effects of a high-monounsaturated fat diet and a low-fat diet

Diet is important in the prevention of cardiovascular disease, and it has been suggested that a high-MUFA diet is more cardioprotective than a low-fat diet. We hypothesised that the postprandial thrombotic risk profile is improved most favourably by a high-MUFA diet compared with a low-fat diet. This was tested in a parallel intervention trial on overweight individuals (aged 28.4 (SD 4.7) years) randomly assigned to a MUFA-diet (35-45% of energy as fat; > 20% as MUFA, n = 21) or a low-fat (LF) diet (20-30% of energy as fat, n = 22) for 6 months after a weight loss of ~ 10%. All foods were provided free of charge from a purpose-built supermarket. Meal tests designed after the same principles were performed before and after the dietary intervention, and blood samples were collected at 8.00 h (fasting), 12.00 h, and 18.00 h and analysed for factor VII coagulant activity (FVII:C), activated FVII, fibrinogen, prothrombin fragment 1 + 2 (F1 + 2), D-dimer, plasminogen activator inhibitor (PAI:Ag), and thrombin activatable fibrinolysis inhibitor. There were significant postprandial increases in F1 + 2 and D-dimer before and after dietary intervention, with significantly lower values after 6 months. No significant differences were observed between the postprandial changes induced by the two diets. The postprandial decrease in FVII:C and PAI:Ag did not differ before and after intervention, irrespective of the diets. Our findings suggest postprandial coagulation activation in overweight subjects with more pronounced acute than long-term effects. We observed similar effects of the MUFA diet and the LF diet on the postprandial prothrombotic risk profile.     

Influence of apolipoprotein A-1 promoter polymorphism on lipid levels and responses to dietary change in Finnish adults

Objectives. To analyse the association between the G/A polymorphism in the apolipoprotein A-1 (apo A-1) promoter region and plasma lipid levels, as well as their responses to dietary change, in Finnish adults.
Subjects and design. Blood samples from 86 subjects (42 men, 44 women) who attended a dietary intervention study carried out in North Karelia in 1993 were available for the current analysis. The diet study consisted of a 2-week baseline period, followed by an 8-week intervention period, and an 8-week switchback period.
Intervention. Diet was modified to a low-fat, low-cholesterol diet during the dietary intervention.
Main outcome measures. Fasting plasma lipid, lipoprotein and apolipoprotein levels were determined.
Results. At baseline, the high-density lipoprotein (HDL) cholesterol and apo A-1 levels were higher ( P <0.01) and the triglyceride levels were lower ( P <0.05) in men, but not in women, with the A allele. The differences in HDL cholesterol and apo A-1 levels between genotypes remained during the low-fat, low-cholesterol diet and switchback periods. Apart from the difference between responses in apo A-1 during switchback to the original diet, lipid responses to dietary change did not differ significantly between genotypes.
Conclusion. Our findings indicate a significant association between the apo A-1 promoter polymorphism and plasma apo A-1 and HDL-cholesterol in men. In theory, the higher plasma HDL-cholesterol and apo A-1 levels in the GA/AA group may confer some protection against coronary artery disease. The differences in HDL-cholesterol and apo A-1 levels between genotypes persisted during different diets suggesting that the possible benefit is independent of fat and cholesterol intake.     

The Effects of Carbohydrate versus Fat Restriction on Lipid Profiles in Highly Trained,Recreational Distance Runners: A Randomized,Cross-Over Trial

A growing number of endurance athletes have considered switching from a traditional high-carbohydrate/low-fat (HCLF) to a low-carbohydrate/high-fat (LCHF) eating pattern for health and performance reasons. However, few studies have examined how LCHF diets affect blood lipid profiles in highly-trained runners. In a randomized and counterbalanced, cross-over design, athletes (n = 7 men; VO_2max: 61.9 ± 6.1 mL/kg/min) completed six weeks of two, ad libitum, LCHF (6/69/25% en carbohydrate/fat/protein) and HCLF (57/28/15% en carbohydrate/fat/protein) diets, separated by a two-week washout. Plasma was collected on days 4, 14, 28, and 42 during each condition and analyzed for: triglycerides (TG), LDL-C, HDL-C, total cholesterol (TC), VLDL, fasting glucose, and glycated hemoglobin (HbA1c). Capillary blood beta-hydroxybutyrate (BHB) was monitored during LCHF as a measure of ketosis. LCHF lowered plasma TG, VLDL, and TG/HDL-C (all p < 0.01). LCHF increased plasma TC, LDL-C, HDL-C, and TC/HDL-C (all p < 0.05). Plasma glucose and HbA1c were unaffected. Capillary BHB was modestly elevated throughout the LCHF condition (0.5 ± 0.05 mmol/L). Healthy, well-trained, normocholesterolemic runners consuming a LCHF diet demonstrated elevated circulating LDL-C and HDL-C concentrations, while concomitantly decreasing TG, VLDL, and TG/HDL-C ratio. The underlying mechanisms and implications of these adaptive responses in cholesterol should be explored.     

沈阳市部分市售酸奶乳酸菌的分离鉴定

目的：探讨沈阳市部分市售酸奶和益生菌饮品的活菌数量和种类与国家规定标准的符合情况.方法：利用倍比稀释法分离酸奶和益生菌饮品中的乳酸菌并进行活菌计数,对分离得到的菌株进行革兰染色及生化反应鉴定.结果：本次调查的4个厂家的11种产品活菌计数范围为1.6 ×104 ～3×108 cfu/ml （g）,乳酸菌含量符合国家规定标准的占81.8％.分离的38个菌株包含革兰阳性杆菌26株,革兰阳性球菌12株.标识菌名与实际相符的达到72.7％,标明含有益生菌的6个样品与标识的菌名相符的仅有3种,标明含有双歧杆菌的样品本次实验未检出双歧杆菌.结论：本次调查的普通酸奶和益生菌饮品的活菌计数和种类基本符合国家规定标准.但是部分市售酸奶和益生菌饮品所添加的菌种和活菌计数与产品包装上标识不符.     

酸牛乳抑制1,2-二甲基肼诱发小鼠大肠癌的实验研究

106只小鼠随机分成5组,每组18至23只。1～3组小鼠皮下注射1,2-二甲基肼(DMH),剂量20mg/kg体重,每周一次,连续20周。实验结束前,动物分别自由饮用自来水(第一组),水加嗜酸乳酸杆菌酸牛乳(第二组)及水加牛乳(第三组)。第4组和第5组为对照组,动物分别皮下注射1mM EDTA和蒸馏水。 27周诱癌期后,对照组小鼠未发生肿瘤。DMH处理动物中,第2组的结肠癌发生率为44.4％,比第1组(80％)和第3组(100％)明显降低(P<0.05)。此外,实验期间第2组动物的存活率(100％) 比第1组(80％)和第3组(74％)都高。结论是喂饲嗜酸乳酸杆菌(Shahani株)制备的酸牛乳能显著降低DMH诱发的小鼠癌肿和死亡率,而单纯牛乳则能增加。本研究的资料提示,食物中添加活嗜酸乳酸杆菌可能有助于预防结肠癌。     

IN VIVO DIGESTION OF YOGURT LACTOSE BY YOGURT LACTASE

The intrinsic lactose in yogurt is more efficiently digested and absorbed by lactase-deficient subjects than an equivalent amount of lactose from whole milk. Yogurt contains a β-galactosidase that has lactase activity in the human gut.