Juan F. Alcala-Diaz

Monounsaturated fatty acid enriched high fat-diets impede adipose NLRP3 inflammasome mediated IL-1β secretion and insulin resistance despite obesity

Saturated fatty acid (SFA) high-fat diets (HFDs) enhance interleukin (IL)-1β–mediated adipose inflammation and insulin resistance. However, the mechanisms by which different fatty acids regulate IL-1β and the subsequent effects on adipose tissue biology and insulin sensitivity in vivo remain elusive. We hypothesized that the replacement of SFA for monounsaturated fatty acid (MUFA) in HFDs would reduce pro-IL-1β priming in adipose tissue and attenuate insulin resistance via MUFA-driven AMPK activation. MUFA-HFD–fed mice displayed improved insulin sensitivity coincident with reduced pro-IL-1β priming, attenuated adipose IL-1β secretion, and sustained adipose AMPK activation compared with SFA-HFD–fed mice. Furthermore, MUFA-HFD–fed mice displayed hyperplastic adipose tissue, with enhanced adipogenic potential of the stromal vascular fraction and improved insulin sensitivity. In vitro, we demonstrated that the MUFA oleic acid can impede ATP-induced IL-1β secretion from lipopolysaccharide- and SFA-primed cells in an AMPK-dependent manner. Conversely, in a regression study, switching from SFA- to MUFA-HFD failed to reverse insulin resistance but improved fasting plasma insulin levels. In humans, high-SFA consumers, but not high-MUFA consumers, displayed reduced insulin sensitivity with elevated pycard-1 and caspase-1 expression in adipose tissue. These novel findings suggest that dietary MUFA can attenuate IL-1β–mediated insulin resistance and adipose dysfunction despite obesity via the preservation of AMPK activity.

Intestinal Microbiota Is Influenced by Gender and Body Mass Index.

Intestinal microbiota changes are associated with the development of obesity. However, studies in humans have generated conflicting results due to high inter-individual heterogeneity in terms of diet, age, and hormonal factors, and the largely unexplored influence of gender. In this work, we aimed to identify differential gut microbiota signatures associated with obesity, as a function of gender and changes in body mass index (BMI). Differences in the bacterial community structure were analyzed by 16S sequencing in 39 men and 36 post-menopausal women, who had similar dietary background, matched by age and stratified according to the BMI. We observed that the abundance of the Bacteroides genus was lower in men than in women (P<0.001, Q = 0.002) when BMI was > 33. In fact, the abundance of this genus decreased in men with an increase in BMI (P<0.001, Q<0.001). However, in women, it remained unchanged within the different ranges of BMI. We observed a higher presence of Veillonella (84.6% vs. 47.2%; X2 test P = 0.001, Q = 0.019) and Methanobrevibacter genera (84.6% vs. 47.2%; X2 test P = 0.002, Q = 0.026) in fecal samples in men compared to women. We also observed that the abundance of Bilophila was lower in men compared to women regardless of BMI (P = 0.002, Q = 0.041). Additionally, after correcting for age and sex, 66 bacterial taxa at the genus level were found to be associated with BMI and plasma lipids. Microbiota explained at P = 0.001, 31.17% variation in BMI, 29.04% in triglycerides, 33.70% in high-density lipoproteins, 46.86% in low-density lipoproteins, and 28.55% in total cholesterol. Our results suggest that gut microbiota may differ between men and women, and that these differences may be influenced by the grade of obesity. The divergence in gut microbiota observed between men and women might have a dominant role in the definition of gender differences in the prevalence of metabolic and intestinal inflammatory diseases.

Two Healthy Diets Modulate Gut Microbial Community Improving Insulin Sensitivity in a Human Obese Population

CONTEXT Gut microbiota, which acts collectively as a fully integrated organ in the host metabolism, can be shaped by long-term dietary interventions after a specific diet. OBJECTIVE The aim was to study the changes in microbiota after 1 years consumption of a Mediterranean diet (Med diet) or a low-fat, high-complex carbohydrate diet (LFHCC diet) in an obese population. DESIGN Participants were randomized to receive the Med diet (35% fat, 22% monounsaturated) and the LFHCC diet (28% fat, 12% monounsaturated). SETTING AND PARTICIPANTS The study was conducted in 20 obese patients (men) within the Coronary Diet Intervention With Olive Oil and Cardiovascular Prevention (CORDIOPREV) study, an ongoing prospective, randomized, opened, controlled trial in patients with coronary heart disease. MAIN OUTCOME MEASURE We evaluated the bacterial composition and its relationship with the whole fecal and plasma metabolome. RESULTS The LFHCC diet increased the Prevotella and decreased the Roseburia genera, whereas the Med diet decreased the Prevotella and increased the Roseburia and Oscillospira genera (P = .028, .002, and .016, respectively). The abundance of Parabacteroides distasonis (P = .025) and Faecalibacterium prausnitzii (P = .020) increased after long-term consumption of the Med diet and the LFHCC diet, respectively. The changes in the abundance of 7 of 572 metabolites found in feces, including mainly amino acid, peptide, and sphingolipid metabolism, could be linked to the changes in the gut microbiota. CONCLUSIONS Our results suggest that long-term consumption of the Med and LFHCC diets exerts a protective effect on the development of type 2 diabetes by different specific changes in the gut microbiota, increasing the abundance of the Roseburia genus and F. prausnitzii, respectively.

The postprandial inflammatory response after ingestion of heated oils in obese persons is reduced by the presence of phenol compounds

SCOPE Heating during the process of cooking alters the chemical properties of foods and may affect subsequent postprandial inflammation. We tested the effects of four meals rich in different oils subjected to heating on the postprandial inflammatory metabolism of peripheral blood mononuclear cells (PBMCs). METHODS AND RESULTS Twenty obese participants received four breakfasts following a randomized crossover design, consisting of milk and muffins made with different oils (virgin olive oil (VOO), sunflower oil (SFO), and a mixture of seeds oil (SFO/canola oil) with added either dimethylpolysiloxane (SOD), or natural antioxidants from olive mill wastewater alperujo (phenols; SOP)), previously subjected to 20 heating cycles. Postprandial inflammatory status in PBMCs was assessed by the activation of nuclear NF-κB, the concentration in cytoplasm of the NF-κB inhibitor (IκB-α), the mRNA levels of NF-κB subunits and activators (p65, IKKβ, and IKKα) and other inflammatory molecules (TNF-α, IL-1β, IL-6, MIF, and JNK), and lipopolysaccharide (LPS) levels. VOO and SOP breakfasts reduced NF-κB activation, increased IκB-α, and decreased LPS plasma concentration. SFO increased IKKα, IKKβ, p65, IL-1b, IL-6, MIF, and JNK mRNA levels, and plasma LPS. CONCLUSION Oils rich in phenols, whether natural (VOO) or artificially added (SOP), reduce postprandial inflammation, compared with seed oil (sunflower).

The gut microbial community in metabolic syndrome patients is modified by diet

Intestinal microbiota changes may be involved in the development of metabolic syndrome (MetS), which is a multicomponent disorder frequently associated with obesity. The aim of this study was to test the effect of consuming two healthy diets: a Mediterranean diet and a low-fat high-carbohydrate diet, for 2years in the gut microbiota of MetS patients and those in the control group. We analyzed the differences in the bacterial community structure between the groups after 2years of dietary intervention (Mediterranean or low-fat diet) through quantitative polymerase chain reaction using primers, targeting specific bacterial taxa. We observed, at basal time, that the abundance of Bacteroides, Eubacterium and Lactobacillus genera is lower in the control group than in MetS patients, while Bacteroides fragilis group, Parabacteroides distasonis, Bacteroides thetaiotaomicron, Faecalibacterium prausnitzii, Fusobacterium nucleatum, Bifidobacterium longum, Bifidobacterium adolescentis, Ruminococcus flavefaciens subgroup and Eubacterium rectale are depleted in MetS patients (all P values <.05). Additionally, we found that long-term consumption of Mediterranean diet partially restores the population of P. distasonis, B. thetaiotaomicron, F. prausnitzii, B. adolescentis and B. longum in MetS patients (all P values <.05). Our results suggest that the Mediterranean diet could be a useful tool to restore potentially beneficial members of the gut microbiota, although the stability of these changes over time still remains to be assessed.

Beneficial effect of CLOCK gene polymorphism rs1801260 in combination with low-fat diet on insulin metabolism in the patients with metabolic syndrome

Genetic variation at the Circadian Locomotor Output Cycles Kaput (CLOCK) locus has been associated with lifestyle-related conditions such as obesity, metabolic syndrome (MetS) and cardiovascular diseases. In fact, it has been suggested that the disruption of the circadian system may play a causal role in manifestations of MetS. The aim of this research was to find out whether habitual consumption of a low-fat diet, compared with a Mediterranean diet enriched with olive oil, modulates the associations between common CLOCK single nucleotide polymorphisms (SNPs) (rs1801260, rs3749474 and rs4580704) and lipid and glucose-related traits among MetS patients. Plasma lipid and insulin concentrations, indexes related with insulin resistance (homeostasis model assessment of insulin resistance (HOMA-IR) and quantitative insulin sensitivity check index (QUICKI)) and CLOCK SNPs were determined in 475 MetS subjects participating in the CORDIOPREV clinical trial (NCT00924937). Gene–diet interactions were analyzed after a year of dietary intervention (Mediterranean diet (35% fat, 22% monounsaturated fatty acids (MUFA)) versus low-fat diet (28% fat, 12% MUFA)). We found significant gene–diet interactions between rs1801260 SNP and the dietary pattern for insulin concentrations (p = 0.009), HOMA-IR (p = 0.014) and QUICKI (p = 0.028). Specifically, after 12 months of low-fat intervention, subjects who were homozygous for the major allele (TT) displayed lower plasma insulin concentrations (p = 0.032), lower insulin resistance (HOMA-IR; p = 0.027) and higher insulin sensitivity (QUICKI; p = 0.024) compared with carriers of the minor allele C (TC + CC). In contrast, in the Mediterranean intervention group a different trend was observed although no significant differences were found between CLOCK genotypes after 12 months of treatment. Our data support the notion that a chronic consumption of a healthy diet may play a contributing role in triggering glucose metabolism by interacting with the rs1801260 SNP at CLOCK gene locus in MetS patients. Due to the complex nature of gene–environment interactions, dietary adjustment in subjects with the MetS may require a personalized approach.

Metabolic phenotypes of obesity influence triglyceride and inflammation homoeostasis

We examined the degree of postprandial triglyceride (TG) response over the day, representing a highly dynamic state, with continuous metabolic adaptations, among normal‐weight, overweight and obese patients, according to their metabolically healthy or abnormal status.

Hypertriglyceridemia influences the degree of postprandial lipemic response in patients with metabolic syndrome and coronary artery disease: from the CORDIOPREV study.

Objective To determine whether metabolic syndrome traits influence the postprandial lipemia response of coronary patients, and whether this influence depends on the number of MetS criteria. Materials and Methods 1002 coronary artery disease patients from the CORDIOPREV study were submitted to an oral fat load test meal with 0.7 g fat/kg body weight (12% saturated fatty acids, 10% polyunsaturated fatty acids, 43% monounsaturated fatty acids), 10% protein and 25% carbohydrates. Serial blood test analyzing lipid fractions were drawn at 0, 1, 2, 3 and 4 hours during the postprandial state. Total and incremental area under the curves of the different postprandial parameters were calculated following the trapezoid rule to assess the magnitude of change during the postprandial state Results Postprandial lipemia response was directly related to the presence of metabolic syndrome. We found a positive association between the number of metabolic syndrome criteria and the response of postprandial plasma triglycerides (p<0.001), area under the curve of triglycerides (p<0.001) and incremental area under the curve of triglycerides (p<0.001). However, the influence of them on postprandial triglycerides remained statistically significant only in those patients without basal hypertriglyceridemia. Interestingly, in stepwise multiple linear regression analysis with the AUC of triglycerides as the dependent variable, only fasting triglycerides, fasting glucose and waist circumference appeared as significant independent (P<0.05) contributors. The multiple lineal regression (R) was 0.77, and fasting triglycerides showed the greatest effect on AUC of triglycerides with a standardized coefficient of 0.75. Conclusions Fasting triglycerides are the major contributors to the postprandial triglycerides levels. MetS influences the postprandial response of lipids in patients with coronary heart disease, particularly in non-hypertriglyceridemic patients.

Statins do not increase the risk of developing type 2 diabetes in familial hypercholesterolemia: The SAFEHEART study

BACKGROUND Familial Hypercholesterolemia (FH) is the most common monogenic disorder that causes premature coronary artery disease (CAD). Our objective was to examine the risk of new onset type 2 diabetes mellitus (T2DM) among FH patients and unaffected relatives in relation to treatment with different statins in the SAFEHEART cohort study. METHODS This is a cross-sectional and prospective cohort study in 2558 FH and 1265 unaffected relatives with a mean follow-up of 5.9 years. Several pertinent data, such as age, gender, metabolic syndrome, lipid profile, body mass index (BMI), waist circumference, HOMA-IR, dose, duration and type of statins, were obtained and examined as predictors of incident diabetes. RESULTS The new onset diabetes was 1.7% in FH and 0.2% in non FH patients (p=0.001). In multivariate logistic regression, age (OR 1.02, CI 95%: 1.02-1.08), HOMA-IR (OR 1.17, CI 95%: 1.03-1.33), metabolic syndrome (OR 3.3, CI 95%: 1.32-8.28) and specifically plasma glucose, as a component of metabolic syndrome (OR 15.7, CI 95%: 4.70-52.53) were significant predictors of new onset T2DM in the FH group alone. In the adjusted Cox regression model in FH group, age (HR 1.03, CI 95% 1.00-1.06, p=0.031) and metabolic syndrome (HR 4.16, CI 95% 1.58-10.92, p=0.004) remained significant predictors of new onset T2DM. CONCLUSIONS Our data do not support the postulated diabetogenic effect associated with high-dose statins use in our cohort of FH patients.

Nutraceuticals and coronary heart disease.

Purpose of review Although many reviews have focused on diet as a determinant of coronary heart disease (CHD), little is known about the use of specific nutrients or food products. The aim of this review was to examine the role of several functional foods, or nutraceuticals, in the prevention or treatment of CHD. Recent findings CHD continues to be one of the main causes of death in modern societies. Far from diminishing, its prevalence and incidence continue to grow and are probably linked to the increase in metabolic disorders such as obesity, diabetes and metabolic syndrome. Numerous preventive measures and treatments are being considered for these metabolic diseases. In this context, nutraceuticals and functional foods are seen as powerful tools for maintaining health and fighting against cardiometabolic risk factors. For example, the association between saturated fat and the development of CHD has been clearly established. However, the consumption of other sources of fat, such as olive oil enriched in monounsaturated fatty acids, has been associated with beneficial cardiovascular effects. Summary Nutraceuticals have demonstrated physiological effects that have a positive influence on the development of atherosclerosis and therefore of CHD.