Dietary Influences on Gut Microbiota with a Focus on Metabolic Syndrome.

There is a clear correlation between gut microbiota, diet, and metabolic outcomes. A diet high in fiber has been shown to decrease inflammation, increase insulin sensitivity, and reduce dyslipidemias whereas a diet high in fat and sugar leads to dyslipidemia, insulin resistance, and low-grade inflammation. There is recent evidence suggesting that the human gut microbiota has a significant role in the development or the resolution of metabolic syndrome (MetS) and associated conditions. Leading a stressful, sedentary lifestyle with limited or no physical activity and consuming an unhealthy diet high in saturated fat, simple carbohydrates, and sodium and low in dietary fiber and in high-quality protein are some of the contributing factors. Unhealthy diets have been shown to induce alterations in the gut microbiota and contribute to the pathogenesis of MetS by altering microbiota composition and disrupting the intestinal barrier, which leads to low-grade systemic inflammation. In contrast, healthy diets can lead to changes in microbiota that increase gut barrier function and increase the production of anti-inflammatory biomarkers. This review aims at providing a more in-depth discussion of diet-induced dysbiosis of the gut microbiota and its effect on MetS. Here, we discuss the possible mechanisms involved in the development of the metabolic biomarkers that define MetS, with an emphasis on the role of sugar and dietary fiber in microbiome-mediated changes in low-grade systemic inflammation and metabolic dysfunction.

Corrigendum to "Assessment of Dietary Patterns Represents a Potential, Yet Variable, Measure of Inflammatory Status: A Review and Update".

[This corrects the article DOI: 10.1155/2019/3102870.].

Assessment of Dietary Patterns Represents a Potential, Yet Variable, Measure of Inflammatory Status: A Review and Update.

Chronic low-grade, systemic inflammation is a well-characterized risk factor in the development of chronic metabolic diseases, such as cardiovascular disease, type 2 diabetes, and metabolic syndrome. Diet could be an effective strategy for reducing inflammation associated with chronic disease. While anti-inflammatory properties of isolated dietary bioactive and functional foods have been routinely studied, the evaluation of dietary patterns on inflammation warrants further review-especially given the recent inclusion of dietary pattern recommendations into dietary guidelines and policies. Therefore, the objective of this narrative review is to examine current evidence linking diet to low-grade, systemic inflammation within the context of chronic disease. Specifically, we provide an update on the findings from human trials that have characterized anti-inflammatory properties of dietary patterns, defined by various methods and indexes. Given the complexity of interpreting results from dietary pattern analysis, we further present recent evidence on the anti-inflammatory roles of isolated bioactive nutrients and functional foods that are common components of distinct dietary patterns, in addition to considerations for interpreting dietary pattern research, population-specific dietary recommendations, and future studies. Overall, we observe a vast range of variability in the evidence from observational studies that have evaluated the relationships between healthy dietary patterns and inflammatory markers. These studies highlight the need for additional intervention studies with study designs that account for metabolic status, diversity in populations, breadth of inflammatory measurements, fasting vs. postprandial effects of diet, and control of confounding factors (e.g., genotype, microbiome profiles, and dietary adherence) in order to better understand the effect that diet has, as a whole, on inflammation. These strategies will help to strengthen diet recommendations aimed at reducing inflammation and chronic disease risk.

Triglyceride screening may improve cardiometabolic disease risk assessment in Latinos with poorly controlled type 2 diabetes.

To characterize metabolic syndrome (MetS) prevalence and cardiometabolic risk, HbA1c, fasting plasma glucose (FPG), plasma lipids, blood pressure, BMI, and waist circumference were measured in 211 Latino adults with type 2 diabetes. Participants were obese (BMI=33.7±7.8 kg/m2) and had poor glycemic control (HbA1c=9.6±1.8 %; FPG=190±85 mg/dL), but normal LDL and HDL cholesterol concentrations (98±38 mg/dL, and 52±14 mg/dL, respectively). Relative to the lowest, participants in the highest quintile of plasma triglycierides had higher total cholesterol (23%; p<.0001), FPG (47%; p<.0001), systolic blood pressure (3%; p<.05) and diastolic blood pressure (6%; p<.05), and lower HDL cholesterol (23%; p<.01). Comparable relationships were observed in an age-adjusted regression model. Framingham risk was equivalent to 9.4±6.4% and 12.2±9.6% 10-year CHD risk in men and women, respectively (p<.05). Cardiometabolic risk in this population is associated with a high prevalence of the MetS despite the relatively low cholesterol concentrations. Triglyceride screening may help identify individuals at higher risk.

A Mediterranean-style, low-glycemic-load diet decreases atherogenic lipoproteins and reduces lipoprotein (a) and oxidized low-density lipoprotein in women with metabolic syndrome.

The objective was to assess the impact of a Mediterranean-style, low-glycemic-load diet (control group, n = 41) and the same diet plus a medical food (MF) containing phytosterols, soy protein, and extracts from hops and Acacia (MF group, n = 42) on lipoprotein atherogenicity in women with metabolic syndrome. Plasma lipids, apolipoproteins (apos), lipoprotein subfractions and particle size, low-density lipoprotein (LDL) oxidation, and lipoprotein (a) were measured at baseline, week 8, and week 12 of the intervention. Three-day dietary records were collected at the same time points to assess compliance. Compared with baseline, women decreased energy intake from carbohydrate (P < .001) and fat (P < .001), whereas they increased energy intake from protein (P < .001). A significant increase in energy from monounsaturated fatty acids was also observed as well as increases in eicosapentaenoic acid and docosahexaenoic acid, whereas trans-fatty acid intake was reduced (P < .00001). The atherogenic lipoproteins, large very low-density lipoprotein (P < .0001) and small LDL (P < .0001), were reduced, whereas the ratio of large high-density lipoprotein to smaller high-density lipoprotein particles was increased (P < .0001). Apolipoprotein B was reduced for all women (P < .0001), with a greater reduction in the MF group (P < .025). Oxidized LDL (P < .05) and lipoprotein (a) (P < .001) were reduced in both groups at the end of the intervention. Consumption of a Mediterranean-style diet reduces the risk for cardiovascular disease by decreasing atherogenic lipoproteins, oxidized LDL, and apo B. Inclusion of an MF may have an additional effect in reducing apo B.

A Mediterranean-style low-glycemic-load diet improves variables of metabolic syndrome in women, and addition of a phytochemical-rich medical food enhances benefits on lipoprotein metabolism.

BACKGROUND: The high prevalence of metabolic syndrome (MetS) has highlighted the need for effective dietary interventions to combat this growing problem. OBJECTIVE: To assess the impact of a Mediterranean-style low-glycemic-load diet (control arm, n = 44) or the same diet plus a medical food containing phytosterols, soy protein, and extracts from hops and acacia (intervention arm, n = 45) on cardiometabolic risk variables in women with MetS. METHODS: In this 12-week, 2-arm randomized trial, baseline, week 8 and 12, fasting blood samples were drawn to measure plasma lipids, apolipoproteins, and homocysteine. Dietary records were also collected and analyzed. RESULTS: There were decreases in fat and sugar intake (P < .001 for both) and increases in docosahexaenoic acid and eicosapentaenoic acid intake (P < .001 for both) over time, consistent with the prescribed diet. Regarding MetS variables, there were decreases in waist circumference, systolic and diastolic blood pressure, and plasma triglycerides in all subjects (P < .001 for all) with no differences between arms. Plasma low-density lipoprotein cholesterol, non-high-density lipoprotein cholesterol, apolipoprotein (apo) B, and apo B/apo A1 were reduced over time but to a greater extent in the intervention arm (P < .05 for all), indicating the medical food had a greater effect in altering lipoprotein metabolism. Further, medical food intake was associated with reduced plasma homocysteine (P < .01) compared to the control arm. CONCLUSION: A Mediterranean-style low-glycemic-load diet effectively reduces the variables of MetS. Addition of the medical food results in a less atherogenic lipoprotein profile and lower plasma homocysteine.

Waist circumference is positively correlated with markers of inflammation and negatively with adiponectin in women with metabolic syndrome.

The purpose of this study was to correlate biomarkers of metabolic syndrome (MetS), with markers of inflammation and macronutrient intake in 89 women (25-72 years) with MetS. We hypothesized that waist circumference (WC) would have the stronger correlations with inflammatory parameters and would correlate with carbohydrate intake. Values for WC (108.7 ± 11.1 cm) and plasma triglycerides (202.7 ± 52.1 mg/dL) were elevated, whereas plasma glucose levels varied from 66 to 179 mg/dL, with 42% of women having insulin resistance. Plasma levels of interleukin 6 (0.2-15.9 mg/L), tumor necrosis factor α (1.47-12.3 mg/L), and high-sensitivity C-reactive protein (0.06-3.08 mg/dL) varied widely, with most women being above values considered normal. Subjects had high intake of total sugar (92.3 ± 56.4 g/d), high glycemic index (59.8 ± 6.5), and glycemic load (127.2 ± 56.1), whereas dietary fiber (17.1 ± 9.1 g/d) was below recommended intake. Waist circumference was positively correlated with insulin (r = 0.275, P < .01) and with the inflammatory markers interleukin 6 (r = 0.307, P < .01) and tumor necrosis factor α (r = 0.228, P < .05) and negatively correlated with plasma adiponectin (r = -0.309, P < .0001). In addition, WC was positively correlated with total carbohydrate, added sugar, and glycemic load (P < .05) but not with fat or protein. These results are consistent with central obesity being a key marker of the inflammatory state, and they also suggest that carbohydrates, particularly those that are digested rapidly, contribute to increased risk of central obesity and development of MetS.

Determinants of fasting plasma glucose and glycosylated hemoglobin among low income Latinos with poorly controlled type 2 diabetes.

The objective of this study was to identify demographic, socio-economic, acculturation, lifestyle, sleeping pattern, and biomedical determinants of fasting plasma glucose (FPG) and glycosylated hemoglobin (HbA1c), among Latinos with type 2 diabetes (T2D). Latino adults (N = 211) with T2D enrolled in the DIALBEST trial were interviewed in their homes. Fasting blood samples were also collected in the participants' homes. Because all participants had poor glucose control, above-median values for FPG (173 mg/dl) and HbA1c (9.2%) were considered to be indicative of poorer glycemic control. Multivariate analyses showed that receiving heating assistance (OR: 2.20; 95% CI: 0.96-4.96), and having a radio (3.11, 1.16-8.35), were risk factors for higher FPG levels, and lower income (10.4, 1.54-69.30) was a risk factor for higher HbA1c levels. Lower carbohydrate intake during the previous day (0.04; 0.005-0.37), as well as regular physical activity (0.30; 0.13-0.69), breakfast (2.78; 1.10-6.99) and dinner skipping (3.9; 1.03-14.9) during previous week were significantly associated with FPG concentrations. Being middle aged (2.24, 1.12-4.47), 30-60 min of sleep during the day time (0.07, 0.01-0.74) and having medical insurance (0.31, 0.10-0.96) were predictors of HbA1c. Results suggest that contemporaneous lifestyle behaviors were associated with FPG and contextual biomedical factors such as health care access with HbA1c. Lower socio-economic status indicators were associated with poorer FPG and HbA1c glycemic control.

Effects of resistance training on the inflammatory response.

Resistance training (RT) is associated with reduced risk of low grade inflammation related diseases, such as cardiovascular disease and type 2 diabetes. The majority of the data studying cytokines and exercise comes from endurance exercise. In contrast, evidence establishing a relationship between RT and inflammation is more limited. This review focuses on the cytokine responses both following an acute bout, and after chronic RT. In addition, the effect of RT on low grade systemic inflammation such as individuals at risk for type 2 diabetes is reviewed. Cytokines are secreted proteins that influence the survival, proliferation, and differentiation of immune cells and other organ systems. Cytokines function as intracellular signals and almost all cells in the body either secrete them or have cytokine receptors. Thus, understanding cytokine role in a specific physiological situation such as a bout of RT can be exceedingly complex. The overall effect of long term RT appears to ameliorate inflammation, but the specific effects on the inflammatory cytokine, tumor necrosis factor alpha are not clear, requiring further research. Furthermore, it is critical to differentiate between chronically and acute Interleukin-6 levels and its sources. The intensity of the RT and the characteristics of the training protocol may exert singular cytokine responses and as a result different adaptations to exercise. More research is needed in the area of RT in healthy populations, specifically sorting out gender and age RT acute responses. More importantly, studies are needed in obese individuals who are at high risk of developing low grade systemic inflammatory related diseases. Assuring adherence to the RT program is essential to get the benefits after overcoming the first acute RT responses. Hence RT could be an effective way to prevent, and delay low grade systemic inflammatory related diseases.

Low Plasma Hdl Cholesterol and Elevated C Reactive Protein further Increase Cardiovascular Disease Risk in Latinos with Type 2 Diabetes.

The purpose of this study was to determine whether low plasma HDL and high C reactive protein (CRP) concentrations would further increase cardiovascular disease (CVD) risk in Latinos with poorly controlled type-2 diabetes, already at high risk for CVD. Subjects (n = 68) were grouped into High-HDL (≥ or 1.03 or 1.3 mmol/L) or Low-HDL (<1.03 or 1.3 mmol/L) for men and women, respectively. Following classification, risk factors for CVD including apolipoproteins, lipoprotein size and subfraction distribution were assesed. Similarly, participants were divided according to their CRP levels (≥ or < 3mg/L) and key inflammatory markers as well as leptin and adiponectin were analyzed. The Low-HDL group had higher concentrations of the atherogenic particles, large and medium VLDL and the smaller LDL subfractions compared to the High-HDL group (p<0.001). Consistently, VLDL diameter was larger and LDL diameter smaller in the Low HDL group (p<0.001). The High-CRP group had larger waist circumference (p<0.001) and body mass index (p<0.001) than the Low-CRP group. Leptin was also higher in the High- CRP group (p< 0.01). These data suggest that Latinos with type-2 diabetes having either Low-HDL or High-CRP concentrations are at a higher risk for atherosclerosis and CVD than their counterparts who have High-HDL or Low-CRP.

Carbohydrate restriction, as a first-line dietary intervention, effectively reduces biomarkers of metabolic syndrome in Emirati adults.

The prevalence of diabetes mellitus (DM) in the United Arab Emirates is among the highest world-wide. Metabolic syndrome (MetS) predisposes individuals to DM; therefore, dietary interventions targeting MetS biomarkers are a high priority. We evaluated whether a carbohydrate-restricted diet (CRD) could effectively be used as a first-line therapy intervention in adult Emirati to improve the characteristics of MetS. A total of 39 participants (14 men, 25 women) 18-50 y, classified with MetS, followed a CRD (20-25% carbohydrate, 50-55% fat, 25-30% protein energy distribution). After 6 wk, 19 participants were randomly switched to the AHA diet (55% carbohydrate, 25-30% fat, 15-20% protein) whereas 20 participants continued with the CRD diet for an additional 6 wk. Fasting plasma lipids, 24-h dietary recalls, body composition, anthropometrics, blood pressure (BP), glucose, insulin, and plasma markers of inflammation were measured at baseline, wk 6, and wk 12. Dietary analysis indicated high compliance. At wk 6, the CRD (n = 39) resulted in decreased body weight (-13%), waist circumference (-4.5%), body fat (-10.6%), and plasma triglycerides (TG) (-38.7%) (P < 0.001). Significant decreases in LDL cholesterol, BP, glucose, insulin, and inflammatory markers and increases in adiponectin (P < 0.05) also occurred. After 12 wk, positive changes persisted for all participants, independent of diet. However, body weight and plasma TG and insulin were lower in the CRD (P < 0.05) group than in the CRD + AHA group. Results from this study suggest that a 6-wk CRD can effectively be used as a first-line diet therapy to rapidly improve features of MetS and cardiovascular risk in adult Emirati.