New metrics of dietary carbohydrate quality.

PURPOSE OF REVIEW: The aim of this study was to introduce novel metrics of dietary carbohydrates quality relevant for products and diets. RECENT FINDINGS: Carbohydrate quality has long been associated with a low glycemic index. More recently, novel metrics of carbohydrate quality featuring variations of total carbohydrates-fibers-free sugars ratios have been applied to carbohydrate-rich foods, including grains, beans, vegetables, and fruit. High scoring products had higher levels of health-promoting nutrients (protein, dietary fiber, iron, magnesium, zinc, potassium, selenium, and various B-vitamins) and lower levels of nutrients of public health concern (total sugar, added/free sugars, and fat profile). Cross-sectional studies also found variants of carbohydrate quality metrics to be associated with better markers of cardiometabolic disease, including lower levels of blood triglycerides:high-density lipoprotein cholesterol ratio, homeostatic model assessment of insulin resistance, and SBP. SUMMARY: New ratio-based carbohydrate quality metrics are built around high fiber and whole grain content, combined with a low free sugar content. Such metrics allow the identification of food products of higher overall nutritional quality, and are associated with improved diet quality and certain health outcomes.

Measures of carbohydrate quality and their association with diet quality and cardiometabolic health outcomes in Singapore middle-aged and older adults.

BACKGROUND AND AIMS: Carbohydrate quality may play a key role in cardiometabolic health and disease risk. This study aimed to assess the dietary carbohydrate quality of the free-living middle-aged and older adults in Singapore, and its association with overall diet quality and cardiometabolic health. METHODS AND RESULTS: This cross-sectional study examined the diet and cardiometabolic disease risk indicators of middle-aged and older adults in Singapore (n = 104). Dietary carbohydrate quality was assessed as the pass and fail rate of the population to four measures of carbohydrate quality: (i) dietary fiber recommended daily allowance (RDA), (ii) whole-grain recommendation, (iii) free sugar recommendation, and (iv) carbohydrate metrics. The association between each carbohydrate quality measure and diet quality, as well as cardiometabolic health, was assessed. Except for free sugar recommendation, the carbohydrate quality of the population was found to be poor with a low adherence (20-36%) to three measures. Subjects meeting these measures had generally higher intakes of fiber, protein, and most micronutrients compared with subjects who failed. Meeting different variants of the carbohydrate metrics was associated with 60% lower odds of pre-hypertensive blood pressure (p = 0.037; p = 0.047), and meeting the dietary fiber RDA was associated with lower waist circumference (p = 0.021). CONCLUSION: An improvement in carbohydrate quality is warranted among free-living middle-aged and older adults in Singapore. Not all measures of carbohydrate quality were equally effective in preserving overall diet quality; the carbohydrate metrics and dietary fiber RDA can be identified as effective measures in relation to cardiometabolic disease risk. CLINICAL TRIAL REGISTRATION: https://clinicaltrials.gov/ CLINICAL TRIAL REGISTRATION: NCT03554954, 13 Sept. 2018.

A meta-analysis comparing the effectiveness of alternate day fasting, the 5:2 diet, and time-restricted eating for weight loss.

OBJECTIVE: The objective of this meta-analysis was to compare the effectiveness of different intermittent fasting (IF) regimens on weight loss, in the general population, and compare these to traditional caloric energy restriction (CER). METHODS: Three databases were searched from 2011 to June 2021 for randomized controlled trials (RCTs) that assessed weight loss and IF, including alternate day fasting (ADF), the 5:2 diet, and time-restricted eating (TRE). A random effect network analysis was used to compare the effectiveness between the three regimens. Meta-regression analysis was presented as weighted mean differences of body weight loss. RESULTS: The exploratory random effects network analysis of 24 RCTs (n = 1768) ranked ADF as the most effective, followed by CER and TRE. The meta-analysis showed that IF regimens resulted in similar weight loss to CER (mean difference 0.26 kg, 95% CI: -0.31 to 0.84; p = 0.37). Compliance was generally high (>80%) in trials shorter than 3 months. CONCLUSIONS: The present meta-analysis concludes that IF is comparable to CER and a promising alternative for weight loss. Among the three regimens, ADF showed the highest effectiveness for weight loss, followed by CER and TRE. Further well-powered RCTs with longer durations of intervention are required to draw solid conclusions.

Importance of Carbohydrate Quality: What Does It Mean and How to Measure It?

Dietary carbohydrates are our main source of energy. Traditionally, they are classified based on the polymer length between simple and complex carbohydrates, which does not necessarily reflect their impact on health. Simple sugars, such as fructose, glucose, and lactose, despite having a similar energy efficiency and caloric content, have very distinct metabolic effects, leading to increased risk for various chronic diseases when consumed in excess. In addition, beyond the absolute amount of carbohydrate consumed, recent data point out that the food form or processing level can modulate both the energy efficiency and the cardiometabolic risk associated with specific carbohydrates. To account for both of these aspects-the quality of carbohydrates as well as its food form-several metrics can be proposed to help identifying carbohydrate-rich food sources and distinguish between those that would favor the development of chronic diseases and those that may contribute to prevent these. This review summarizes the findings presented during the American Society of Nutrition Satellite symposium on carbohydrate quality, in which these different aspects were presented.

Micronutrient Profile and Carbohydrate Microstructure of Commercially Prepared and Home Prepared Infant Fruit and Vegetable Purees.

Large variability exists in ingredient selection and preparation of home prepared infant purees and there is a lack of data on nutritional quality in comparison to commercially prepared purees. This work had two aims. Study 1 compared the nutritional value of commercially prepared and home prepared infant purees. Food profiles from national food composition databases were used as a proxy for home prepared puree and served as the benchmark for the commercially prepared infant purees. Study 2 focused on a subset of produce that underwent molecular weight analysis to determine differences in carbohydrate profiles. Eighty-eight percent of the measurable micronutrients fell within or above the home prepared norm range with micronutrients falling below the range explained by differences in soil and growing conditions. Physicochemical characterization showed similar carbohydrate profiles with >90% of the carbohydrate fraction in the water extract constituted by low molecular weight sugars for purees produced with home preparation and commercial preparation. The estimated glycemic load (eGL) showed comparable potential impact on blood sugar levels with all purees having a low eGL (<10 glucose equivalent). In conclusion, these data suggest that both preparations provide similar micronutrient density and carbohydrate profiles.

Balanced carbohydrate ratios are associated with improved diet quality in Australia: A nationally representative cross-sectional study.

BACKGROUND: Carbohydrate quality influences major health outcomes; however, the best criteria to assess carbohydrate quality remain unknown. OBJECTIVE: The objectives were to: i) evaluate whether a diet that meets a carbohydrate ratio (simple, modified or dual ratio) is associated with higher nutrient intakes and diet quality, and ii) model the impact of substituting carbohydrate foods that meet the proposed ratios in place of foods that do not, on nutrient intakes. DESIGN: A secondary analysis of cross-sectional data from the 2011-12 Australian National Nutrition and Physical Activity Survey. PARTICIPANTS/SETTING: National data from participants aged 2 years and older (n = 12,153). MAIN OUTCOME MEASURES: Ratios were defined as (i) simple ratio, 10:1 (10g carbohydrate:≥1g dietary fiber); (ii) modified ratio, 10:1:2 (10g carbohydrate:≥1g dietary fiber:≤2g free sugars); and (iii) dual ratio, 10:1 & 1:2 (10g carbohydrate:≥1g dietary fiber & ≤2g free sugars per 1g dietary fiber). Ratios were compared to nutrient intakes obtained via automated multiple-pass 24-hour dietary recall and diet quality calculated using the Australian Healthy Eating Index. STATISTICAL ANALYSES PERFORMED: Substitution dietary modelling was performed. Data were analyzed using paired and independent sample t-tests. RESULTS: Ratio adherence was highest for simple (50.2% adults; 28.6% children), followed by dual (40.6% adults; 21.7% children), then modified (32.7% adults; 18.6% children) ratios. Participants who met any ratio reported higher nutrient intake and diet quality compared to those who failed to meet the respective ratio (P < .001 for all), with the greatest nutrient intakes found for those who met modified or dual ratios. Dietary modelling improved nutrient intakes for all ratios, with the greatest improvement found for the dual ratio. CONCLUSIONS: All carbohydrate ratios were associated with higher diet quality, with a free sugars constraint in the dual ratio providing the greatest improvements.

An Assessment of Three Carbohydrate Metrics of Nutritional Quality for Packaged Foods and Beverages in Australia and Southeast Asia.

Carbohydrate quality is an aetiological factor of diet-related disease. Indices of carbohydrate quality featuring various ratios of carbohydrates-to-dietary fibre-to-sugar have been associated with improved product and/or diet quality in westernised countries. Carbohydrate intake is especially high in Asia Pacific. Thus, this study evaluated the ability of such carbohydrate metrics to discriminate the nutritional quality of carbohydrate-rich packaged foods and beverages in Australia, Malaysia, Singapore, Thailand and the Philippines, with an additional focus on beverages. This evaluation was conducted by comparing product nutritional composition and assessing products against three national nutrient profiling models. Results showed that Australia had the highest proportion of products meeting all metrics, compared to the Southeast Asian countries. Beverages had a low adherence to all metrics compared to solid foods. Across the five countries, both processed food and beverages meeting the metrics generally contained higher dietary fibre, protein, and certain vitamins and minerals whilst having lower energy, total sugars, free sugars, trans fat and cholesterol content compared to products not meeting the metrics. The metrics were also aligned with national nutrient profiling models to identify nutritious products. In conclusion, these metrics allowed us to discriminate product nutritional quality in the countries assessed and are applicable to beverages.

Cereal B-Glucans: The Impact of Processing and How It Affects Physiological Responses.

Cereal ß-glucans are dietary fibres primarily found in oats and barley, and have several positive effects on health, including lowering the postprandial glucose response and the improvement of blood cholesterol levels. Cereal ß-glucans have a specific combination of ß-(1→4) and ß-(1→3) linkages into linear long-chain polysaccharides of high molecular weight. Due to their particular structure, cereal ß-glucans generate viscosity within the intestinal tract, which is thought to be the main mechanism of action responsible for their positive health effects. However, cereal grains are rarely consumed raw; at least one cooking step is generally required before they can be safely eaten. Cooking and processing methods more generally will modify the physicochemical characteristics of ß-glucans, such as molecular weight, extractability and the resulting viscosity. Therefore, the health impact of ß-glucans will depend not only on the dose administered, but also on the ways they are processed or converted into food products. This review aims at summarizing the different parameters that can affect ß-glucans efficacy to improve glucose and lipid metabolism in humans.

Predicting Glycemic Index and Glycemic Load from Macronutrients to Accelerate Development of Foods and Beverages with Lower Glucose Responses.

Low glycemic index (GI) and/or low glycemic load (GL) are associated with decreased risks of type-2 diabetes and cardiovascular disease. It is therefore relevant to consider GI and GL in the early phases of the development of packaged foods and beverages. This paper proposes a model that predicts GI and GL from macronutrient composition, by quantifying both the impact of glycemic carbohydrates and the GI-lowering effects of nutrients such as proteins, fats and fibers. The precision of the model is illustrated using data on 42 breakfast cereals. The predictions of GI (r = 0.90, median residual = 2.0) and GL (r = 0.96, median residual = 0.40 g) compete well with the precision of the underlying in-vivo data (Standard Error SE = 3.5 for GI). This model can guide product development towards lowering GI and GL, before final confirmation by in vivo testing.

The scientific basis for healthful carbohydrate profile.

Dietary guidelines indicate that complex carbohydrates should provide around half of the calories in a balanced diet, while sugars (i.e., simple carbohydrates) should be limited to no more than 5-10% of total energy intake. To achieve this public health goal a collective effort from different entities including governments, food & beverage industries and consumers is required. Some food companies have committed to continually reduce sugars in their products. Different solutions can be used to replace sugars in food products but it is important to ensure that these solutions are more healthful than the sugars they replace. The objectives of this paper are, (1) to identify carbohydrates and carbohydrates sources to promote and those to limit for dietary intake and food product development, based on current knowledge about the impact of carbohydrates on the development of dental caries, obesity and cardio-metabolic disorders (2) to evaluate the impact of food processing on the quality of carbohydrates and (3) to highlight the challenges of developing healthier products due to the limitations and gaps in food regulations, science & technology and consumer education.

Impact of Cereal Seed Sprouting on Its Nutritional and Technological Properties: A Critical Review.

Sprouting induces activation and de novo synthesis of hydrolytic enzymes that make nutrients available for plant growth and development. Consumption of sprouted grains is suggested to be beneficial for human health. Positive consumer perceptions about sprouted cereals have resulted in new food and beverage product launches. However, because there is no generally accepted definition of "sprouting," it is unclear when grains are to be called sprouted. Moreover, guidelines about how much sprouted grain material food products should contain to exert health benefits are currently lacking. Accordingly, there is no regulatory base to develop appropriate food labeling for "sprouted foods." This review describes the nutritional and technological properties of sprouted grains in relation to processing conditions and provides guidelines to optimize sprouting practices in order to maximize nutritive value. Relatively long sprouting times (3 to 5 days) and/or high processing temperatures (25 to 35 °C) are needed to maximize the de novo synthesis and/or release of plant bioactive compounds. Nutrient compositional changes resulting from sprouting are often associated with health benefits. However, supportive data from clinical studies are very scarce, and at present it is impossible to draw any conclusion on health benefits of sprouted cereals. Finally, grains sprouted under the above-mentioned conditions are generally unfit for use in traditional food processing and it is challenging to use sprouted grains as ingredients without compromising their nutrient content. The present review provides a basis for better defining what "sprouting" is, and to help further research and development efforts in this field as well as future food regulations development.

Perspective: A Definition for Whole-Grain Food Products-Recommendations from the Healthgrain Forum.

Whole grains are a key component of a healthy diet, and enabling consumers to easily choose foods with a high whole-grain content is an important step for better prevention of chronic disease. Several definitions exist for whole-grain foods, yet these do not account for the diversity of food products that contain cereals. With the goal of creating a relatively simple whole-grain food definition that aligns with whole-grain intake recommendations and can be applied across all product categories, the Healthgrain Forum, a not-for-profit consortium of academics and industry working with cereal foods, established a working group to gather input from academics and industry to develop guidance on labeling the whole-grain content of foods. The Healthgrain Forum recommends that a food may be labeled as "whole grain" if it contains ≥30% whole-grain ingredients in the overall product and contains more whole grain than refined grain ingredients, both on a dry-weight basis. For the purposes of calculation, added bran and germ are not considered refined-grain ingredients. Additional recommendations are also made on labeling whole-grain content in mixed-cereal foods, such as pizza and ready meals, and a need to meet healthy nutrition criteria. This definition allows easy comparison across product categories because it is based on dry weight and strongly encourages a move from generic whole-grain labels to reporting the actual percentage of whole grain in a product. Although this definition is for guidance only, we hope that it will encourage more countries to adopt regulation around the labeling of whole grains and stimulate greater awareness and consumption of whole grains in the general population.

What is the appropriate upper limit for added sugars consumption?

Dramatic increases in obesity and diabetes have occurred worldwide over the past 30 years. Some investigators have suggested that these increases may be due, in part, to increased added sugars consumption. Several scientific organizations, including the World Health Organization, the Scientific Advisory Council on Nutrition, the Dietary Guidelines Advisory Committee 2015, and the American Heart Association, have recommended significant restrictions on upper limits of sugars consumption. In this review, the scientific evidence related to sugars consumption and its putative link to various chronic conditions such as obesity, diabetes, heart disease, nonalcoholic fatty liver disease, and the metabolic syndrome is examined. While it appears prudent to avoid excessive calories from sugars, the scientific basis for restrictive guidelines is far from settled.

Fructose overfeeding in first-degree relatives of type 2 diabetic patients impacts energy metabolism and mitochondrial functions in skeletal muscle.

SCOPE: The aim of the study was to assess the effects of a high-fructose diet (HFrD) on skeletal muscle transcriptomic response in healthy offspring of patients with type 2 diabetes, a subgroup of individuals prone to metabolic disorders. METHODS AND RESULTS: Ten healthy normal weight first-degree relatives of type 2 diabetic patients were submitted to a HFrD (+3.5 g fructose/kg fat-free mass per day) during 7 days. A global transcriptomic analysis was performed on skeletal muscle biopsies combined with in vitro experiments using primary myotubes. Transcriptomic analysis highlighted profound effects on fatty acid oxidation and mitochondrial pathways supporting the whole-body metabolic shift with the preferential use of carbohydrates instead of lipids. Bioinformatics tools pointed out possible transcription factors orchestrating this genomic regulation, such as PPARα and NR4A2. In vitro experiments in human myotubes suggested an indirect action of fructose in skeletal muscle, which seemed to be independent from lactate, uric acid, or nitric oxide. CONCLUSION: This study shows therefore that a large cluster of genes related to energy metabolism, mitochondrial function, and lipid oxidation was downregulated after 7 days of HFrD, thus supporting the concept that overconsumption of fructose-containing foods could contribute to metabolic deterioration in humans.

Sugar replacers: from technological challenges to consequences on health.

PURPOSE OF REVIEW: Dietary sugars play a role in noncommunicable diseases and represent a clear target for reduction. In this context, product reformulation can have a positive impact on health. Several technological solutions are available to replace sugar, all with benefits and limitations. The goal of this review is to describe the main sugar replacement alternatives and discuss their impact on health and product physicochemical properties. RECENT FINDINGS: Although high intensity sweeteners and polyols have been used for a long time to replace sucrose and despite no clear evidence of harm, the trend is today to look for alternatives such as sweet enhancers or alternative sugars such as allulose or tagatose, which are both low caloric. To replace the physical properties of sugars, new trends are to substitute widely used maltodextrins by dietary fibres to confer added health benefits. SUMMARY: A wide range of solutions is currently available to replace dietary sugars and compensate for the impact on bulking properties and sweetness profile of food products.

Health effects of fructose and fructose-containing caloric sweeteners: where do we stand 10 years after the initial whistle blowings?

Suspicion that fructose-containing caloric sweeteners (FCCS) may play a causal role in the development of metabolic diseases has elicited intense basic and clinical research over the past 10 years. Prospective cohort studies converge to indicate that FCCS, and more specifically sugar-sweetened beverages (SSBs), consumption is associated with weight gain over time. Intervention studies in which FCCS or SSB consumption is altered while food intake is otherwise left ad libitum indicate that increased FCCS generally increases total energy intake and body weight, while FCCS reduction decreases body weight gain. Clinical trials assessing the effects of SSB reduction as a sole intervention however fail to observe clinically significant weight loss. Many mechanistic studies indicate that excess FCCS can cause potential adverse metabolic effects. Whether this is associated with a long-term risk remains unknown. Scientific evidence that excess FCCS intake causes more deleterious effects to health than excess of other macronutrients is presently lacking. However, the large consumption of FCCS in the population makes it one out of several targets for the treatment and prevention of metabolic diseases.

Pioglitazone improves fat distribution, the adipokine profile and hepatic insulin sensitivity in non-diabetic end-stage renal disease subjects on maintenance dialysis: a randomized cross-over pilot study.

BACKGROUND: Fat redistribution, increased inflammation and insulin resistance are prevalent in non-diabetic subjects treated with maintenance dialysis. The aim of this study was to test whether pioglitazone, a powerful insulin sensitizer, alters body fat distribution and adipokine secretion in these subjects and whether it is associated with improved insulin sensitivity. TRIAL DESIGN: This was a double blind cross-over study with 16 weeks of pioglitazone 45 mg vs placebo involving 12 subjects. METHODS: At the end of each phase, body composition (anthropometric measurements, dual energy X-ray absorptometry (DEXA), abdominal CT), hepatic and muscle insulin sensitivity (2-step hyperinsulinemic euglycemic clamp with 2H2-glucose) were measured and fasting blood adipokines and cardiometabolic risk markers were monitored. RESULTS: Four months treatment with pioglitazone had no effect on total body weight or total fat but decreased the visceral/sub-cutaneous adipose tissue ratio by 16% and decreased the leptin/adiponectin (L/A) ratio from 3.63 × 10(-3) to 0.76 × 10(-3). This was associated with a 20% increase in hepatic insulin sensitivity without changes in muscle insulin sensitivity, a 12% increase in HDL cholesterol and a 50% decrease in CRP. CONCLUSIONS/LIMITATIONS: Pioglitazone significantly changes the visceral-subcutaneous fat distribution and plasma L/A ratio in non diabetic subjects on maintenance dialysis. This was associated with improved hepatic insulin sensitivity and a reduction of cardio-metabolic risk markers. Whether these effects may improve the outcome of non diabetic end-stage renal disease subjects on maintenance dialysis still needs further evaluation. TRIAL REGISTRATION: ClinicalTrial.gov NCT01253928.

Plasma PCSK9 concentrations during an oral fat load and after short term high-fat, high-fat high-protein and high-fructose diets.

BACKGROUND: PCSK9 (Proprotein Convertase Subtilisin Kexin type 9) is a circulating protein that promotes hypercholesterolemia by decreasing hepatic LDL receptor protein. Under non interventional conditions, its expression is driven by sterol response element binding protein 2 (SREBP2) and follows a diurnal rhythm synchronous with cholesterol synthesis. Plasma PCSK9 is associated to LDL-C and to a lesser extent plasma triglycerides and insulin resistance. We aimed to verify the effect on plasma PCSK9 concentrations of dietary interventions that affect these parameters. METHODS: We performed nutritional interventions in young healthy male volunteers and offspring of type 2 diabetic (OffT2D) patients that are more prone to develop insulin resistance, including: i) acute post-prandial hyperlipidemic challenge (n=10), ii) 4 days of high-fat (HF) or high-fat/high-protein (HFHP) (n=10), iii) 7 (HFruc1, n=16) or 6 (HFruc2, n=9) days of hypercaloric high-fructose diets. An acute oral fat load was also performed in two patients bearing the R104C-V114A loss-of-function (LOF) PCSK9 mutation. Plasma PCSK9 concentrations were measured by ELISA. For the HFruc1 study, intrahepatocellular (IHCL) and intramyocellular lipids were measured by 1H magnetic resonance spectroscopy. Hepatic and whole-body insulin sensitivity was assessed with a two-step hyperinsulinemic-euglycemic clamp (0.3 and 1.0 mU.kg-1.min-1). FINDINGS: HF and HFHP short-term diets, as well as an acute hyperlipidemic oral load, did not significantly change PCSK9 concentrations. In addition, post-prandial plasma triglyceride excursion was not altered in two carriers of PCSK9 LOF mutation compared with non carriers. In contrast, hypercaloric 7-day HFruc1 diet increased plasma PCSK9 concentrations by 28% (p=0.05) in healthy volunteers and by 34% (p=0.001) in OffT2D patients. In another independent study, 6-day HFruc2 diet increased plasma PCSK9 levels by 93% (p<0.0001) in young healthy male volunteers. Spearman's correlations revealed that plasma PCSK9 concentrations upon 7-day HFruc1 diet were positively associated with plasma triglycerides (r=0.54, p=0.01) and IHCL (r=0.56, p=0.001), and inversely correlated with hepatic (r=0.54, p=0.014) and whole-body (r=-0.59, p=0.0065) insulin sensitivity. CONCLUSIONS: Plasma PCSK9 concentrations vary minimally in response to a short term high-fat diet and they are not accompanied with changes in cholesterolemia upon high-fructose diet. Short-term high-fructose intake increased plasma PCSK9 levels, independent on cholesterol synthesis, suggesting a regulation independent of SREBP-2. Upon this diet, PCSK9 is associated with insulin resistance, hepatic steatosis and plasma triglycerides.

Does fructose consumption contribute to non-alcoholic fatty liver disease?

Fructose is mainly consumed with added sugars (sucrose and high fructose corn syrup), and represents up to 10% of total energy intake in the US and in several European countries. This hexose is essentially metabolized in splanchnic tissues, where it is converted into glucose, glycogen, lactate, and, to a minor extent, fatty acids. In animal models, high fructose diets cause the development of obesity, insulin resistance, diabetes mellitus, and dyslipidemia. Ectopic lipid deposition in the liver is an early occurrence upon fructose exposure, and is tightly linked to hepatic insulin resistance. In humans, there is strong evidence, based on several intervention trials, that fructose overfeeding increases fasting and postprandial plasma triglyceride concentrations, which are related to stimulation of hepatic de novo lipogenesis and VLDL-TG secretion, together with decreased VLDL-TG clearance. However, in contrast to animal models, fructose intakes as high as 200 g/day in humans only modestly decreases hepatic insulin sensitivity, and has no effect on no whole body (muscle) insulin sensitivity. A possible explanation may be that insulin resistance and dysglycemia develop mostly in presence of sustained fructose exposures associated with changes in body composition. Such effects are observed with high daily fructose intakes, and there is no solid evidence that fructose, when consumed in moderate amounts, has deleterious effects. There is only limited information regarding the effects of fructose on intrahepatic lipid concentrations. In animal models, high fructose diets clearly stimulate hepatic de novo lipogenesis and cause hepatic steatosis. In addition, some observations suggest that fructose may trigger hepatic inflammation and stimulate the development of hepatic fibrosis. This raises the possibility that fructose may promote the progression of non-alcoholic fatty liver disease to its more severe forms, i.e. non-alcoholic steatohepatitis and cirrhosis. In humans, a short-term fructose overfeeding stimulates de novo lipogenesis and significantly increases intrahepatic fat concentration, without however reaching the proportion encountered in non-alcoholic fatty liver diseases. Whether consumption of lower amounts of fructose over prolonged periods may contribute to the pathogenesis of NAFLD has not been convincingly documented in epidemiological studies and remains to be further assessed.

Alterations in fecal Lactobacillus and Bifidobacterium species in type 2 diabetic patients in Southern China population.

BACKGROUND: The connection between gut microbiota and metabolism and its role in the pathogenesis of diabetes are increasingly recognized. The objective of this study was to quantitatively measure Bifidobacterium and Lactobacillus species, members of commensal bacteria found in human gut, in type 2 diabetic patients (T2D) patients from Southern China. METHODS: Fifty patients with T2D and thirty control individuals of similar body mass index (BMI) were recruited from Southern China. T2D and control subjects were confirmed with both oral glucose tolerance test (OGTT) and HbA(1c) measurements. Bifidobacterium and Lactobacillus species in feces were measured by real-time quantitative PCR. Data were analyzed with STATA 11.0 statistical software. RESULTS: In comparison to control subjects T2D patients had significantly more total Lactobacillus (+18%), L. bugaricus (+13%), L. rhamnosum (+37%) and L. acidophilus (+48%) (P < 0.05). In contrast, T2D patients had less amounts of total Bifidobacteria (-7%) and B. adolescentis (-12%) (P < 0.05). Cluster analysis showed that gut microbiota pattern of T2D patients is characterized by greater numbers of L. rhamnosus and L. acidophillus, together with lesser numbers of B. adolescentis (P < 0.05). CONCLUSION: The gut microflora in T2D patients is characterized by greater numbers of Lactobacillus and lesser numbers of Bifidobacterium species.