Gluten-free diet reduces adiposity, inflammation and insulin resistance associated with the induction of PPAR-alpha and PPAR-gamma expression

Charting Wellness in India: Piloting the iTHRIVE's Functional Nutrition Approach to Improve Glycaemic and Inflammatory Parameters in Prediabetes and Type 2 Diabetes Mellitus

Introduction Type 2 diabetes mellitus (T2DM) is characterized by elevation of blood glucose levels due to underlying insulin resistance and inflammation. Multiple modifiable risk factors such as unhealthy dietary habits, physical inactivity, obesity, smoking and psychological stress contribute to T2DM. We investigated the efficacy of a comprehensive functional nutrition approach aimed at mitigating T2DM using the iTHRIVE approach which encompassed anti-inflammatory and elimination diets, micronutrient supplements, physical activity, stress management and environmental modifications through a pre-post study design. The research assessed changes in blood glucose and inflammatory markers following the implementation of the functional nutrition program. Methods A prospective pre-post intervention pilot study was conducted at ThriveTribe Wellness Solutions Pvt Ltd. (iTHRIVE), where 50 study participants from urban areas of Pune city, India (n=25 each group) were recruited voluntarily in the age group of 20-60 years. The participants were subjected to 90 days of the iTHRIVE functional nutrition approach which consisted of eliminating certain inflammatory foods and adding a combination of nutritious organic foods, adding dietary supplements like magnesium, vitamin D, alpha lipoic acid, chromium picolinate, berberine and biogymnema, physical activities like resistance training, stress reduction techniques like meditation and deep breathing exercises along with environmental changes. The blood parameters like fasting blood glucose, postprandial blood glucose, glycated haemoglobin (HbA1C), fasting serum insulin, post-prandial serum insulin, high sensitivity C-reactive protein (hs-CRP), erythrocyte sedimentation rate (ESR), vitamin D, body weight and waist circumference were measured before and after the intervention. The changes were statistically analyzed using a paired t-test. Results The mean age of the participants was found to be 43.76±10.58 years. Around 68% of the participants were prediabetic (HbA1c: 5.7-6.4%) and 32% had T2DM (HbA1c ≥6.5%). A significant reduction was observed in the average HbA1c (13.75% reduction, p<0.0001), average post-prandial blood glucose levels (14.51% reduction, p<0.048), average post-prandial serum insulin (34.31% reduction, p<0.017) and average ESR levels (34.51% reduction, p<0.006). The hs-CRP levels were reduced by 6.6%, but not statistically significant. The average body weight of the participants dropped from 78.59±15.18 kg to 75.20±14.20 kg with a mean loss of 2.91 kg (p<0.05) whereas the waist circumference decreased from 37.54±5.09 to 35.97±4.74 inches with an average loss of 1.19 inches (p<0.0004). Conclusions Following the intervention, several health indicators indicated significant improvements. Particularly, there was a significant drop in HbA1c levels, suggesting better long-term blood glucose control. Blood glucose and serum insulin levels after a meal dropped significantly, indicating enhanced insulin sensitivity. There was a decrease in systemic inflammation as evidenced by the decrease in ESR levels. These results imply that the iTHRIVE functional nutrition approach used in this investigation might be beneficial for enhancing glycemic control and insulin sensitivity, along with reducing inflammatory markers in people with prediabetes and T2DM. Larger sample sizes and longer periods of monitoring would be useful in subsequent research to validate and build on these encouraging findings.

Gluten worsens non-alcoholic fatty liver disease by affecting lipogenesis and fatty acid oxidation in diet-induced obese apolipoprotein E-deficient mice

Obesity is closely associated with non-alcoholic fatty liver disease (NAFLD), characterized by hepatic fat accumulation and hepatocyte injury. Preclinical studies have shown exacerbated weight gain associated with an obesogenic gluten-containing diet. However, whether gluten affects obesity-induced hepatic lipid accumulation still remains unclear. We hypothesized that gluten intake could affect fatty liver development in high-fat diet (HFD)-induced obese mice. Thus, we aimed to investigate the impact of gluten intake on NAFLD in HFD-induced obese mice. Male apolipoprotein E-deficient (Apoe-/-) mice were fed with a HFD containing (GD) or not (GFD) vital wheat gluten (4.5%) for 10 weeks. Blood and liver were collected for further analysis. We found that gluten exacerbated weight gain, hepatic fat deposition, and hyperglycemia without affecting the serum lipid profile. Livers of the GD group showed a larger area of fibrosis, associated with the expression of collagen and MMP9, and higher expression of apoptosis-related factors, p53, p21, and caspase-3. The expression of lipogenic factors, such as PPARγ and Acc1, was more elevated and factors related to beta-oxidation, such as PPARα and Cpt1, were lower in the GD group compared to the GFD. Further, gluten intake induced a more significant expression of Cd36, suggesting higher uptake of free fatty acids. Finally, we found lower protein expression of PGC1α followed by lower activation of AMPK. Our data show that gluten-containing high-fat diet exacerbated NAFLD by affecting lipogenesis and fatty acid oxidation in obese Apoe-/- mice through a mechanism involving lower activation of AMPK.

High Fat Diet-Wheat Gliadin Interaction and its Implication for Obesity and Celiac Disease Onset: In Vivo Studies

The intestinal immune system plays a crucial role in obesity and insulin resistance. An altered intestinal immunity is associated with changes to the gut microbiota, barrier function, and tolerance to luminal antigens. Lipid metabolism and its unbalance can also contribute to acute and chronic inflammation in different conditions. In celiac disease (CD), the serum phospholipid profile in infants who developed CD is dramatically different when compared to that of infants at risk of CD not developing the disease. In a mouse model of gluten sensitivity, oral wheat gliadin challenge in connection with inhibition of the metabolism of arachidonic acid, an omega-6 polyunsaturated fatty acid, specifically induces the enteropathy. Recent evidence suggests that gluten may play a role also for development of life-style related diseases in populations on a high fat diet (HFD). However, the mechanisms behind these effects are not yet understood. Exploratory studies in mice feed HFD show that wheat gliadin consumption affects glucose and lipid metabolic homeostasis, alters the gut microbiota, and the immune cell profile in liver.

A Narrative Review of the Significance of Popular Diets in Diabetes Mellitus Management

Diabetes mellitus is a collection of metabolic disorders marked by elevated levels of glucose in the blood due to irregularities in the generation or functioning of insulin. Medical nutrition therapy and weight loss are crucial elements in the management of diabetes and the prevention of complications. Several diets have become popular over time for the goal of achieving weight loss, but their popularity has declined due to a lack of reliable scientific evidence. This study classifies popular diets into three categories: diets that manage the composition of macronutrients, diets that restrict specific foods or food groups, and diets that manipulate meal timing. The review includes research studies that investigated the effects of popular diets on the prevention, management, and complications of diabetes. It is clear that different popular diets can have positive effects on both preventing and treating diabetes and preventing and treating complications related to diabetes. However, it is not practical to determine which diet is the most effective option for preventing or controlling diabetes. Thus, the main focus should be on common underlying factors that support well-being, such as decreasing the intake of refined grains and added sugar, choosing non-starchy vegetables, and giving priority to whole foods over processed foods whenever possible, until there is stronger evidence supporting the specific benefits of different dietary patterns.

Dietary wheat gluten induces astro- and microgliosis in the hypothalamus of male mice

Gluten, which is found in cereals such as wheat, rye and barley, makes up a major dietary component in most western nations, and has been shown to promote body mass gain and peripheral inflammation in mice. In the current study, we investigated the impact of gluten on central inflammation that is typically associated with diet-induced obesity. While we found no effect of gluten when added to a low-fat diet (LFD), male mice fed high fat diet (HFD) enriched with gluten increased body mass and adiposity compared with mice fed HFD without gluten. We furthermore found that gluten, when added to the LFD, increases circulating C-reactive protein levels. Gluten regardless of whether it was added to LFD or HFD led to a profound increase in the number of microglia and astrocytes in the arcuate nucleus of the hypothalamus, as detected by immunohistochemistry for ionised calcium binding adaptor molecule 1 (Iba-1) and glial fibrillary acidic protein (GFAP), respectively. In mice fed LFD, gluten mimicked the immunogenic effects of HFD exposure and when added to HFD led to a further increase in the number of immunoreactive cells. Taken together, our results confirm a moderate obesogenic effect of gluten when fed to mice exposed to HFD and for the first-time report gluten-induced astro- and microgliosis suggesting the development of hypothalamic injury in rodents.

Dietary gluten worsens hepatic steatosis by increasing inflammation and oxidative stress in ApoE-/- mice fed a high-fat diet

Non-alcoholic fatty liver disease (NAFLD) is the most prevalent chronic liver disorder in the world. We have seen that gluten intake exacerbated obesity and atherosclerosis in apolipoprotein E knockout (ApoE-/-) mice. In this study, we investigated the effect of gluten consumption on inflammation and oxidative stress in the liver of mice with NAFLD. Male ApoE-/- mice were fed a gluten-free (GF-HFD) or gluten-containing (G-HFD) high-fat diet for 10 weeks. Blood, liver, and spleen were collected to perform the analyses. The animals of the gluten group had increased hepatic steatosis, followed by increased serum AST and ALT. Gluten intake increased hepatic infiltration of neutrophils, macrophages, and eosinophils, as well as the levels of chemotaxis-related factors CCL2, Cxcl2, and Cxcr3. The production of the TNF, IL-1β, IFNγ, and IL-4 cytokines in the liver was also increased by gluten intake. Furthermore, gluten exacerbated the hepatic lipid peroxidation and nitrotyrosine deposition, which were associated with increased production of ROS and nitric oxide. These effects were related to increased expression of NADPH oxidase and iNOS, as well as decreased activity of superoxide dismutase and catalase enzymes. There was an increased hepatic expression of the NF-κB and AP1 transcription factors, corroborating the worsening effect of gluten on inflammation and oxidative stress. Finally, we found an increased frequency of CD4+FOXP3+ lymphocytes in the spleen and increased gene expression of Foxp3 in the livers of the G-HFD group. In conclusion, dietary gluten aggravates NAFLD, exacerbating hepatic inflammation and oxidative stress in obese ApoE-deficient mice.

Exercise training restores weight gain and attenuates hepatic inflammation in a rat model of non-celiac gluten sensitivity

Gluten intolerance is associated with several disorders in the body. Although research has grown in recent years, the understanding of its impact on different tissues and the effects of physical exercise in mitigating health problems in the condition of gluten intolerance are still limited. Therefore, our objective was to test whether gliadin would affect metabolism and inflammation in liver tissue and whether aerobic physical exercise would mitigate the negative impacts of gliadin administration in rodents. Wistar rats were divided into exercised gliadin, gliadin, and control groups. Gliadin was administered by gavage from birth to 60 days of age. The rats in the exercised gliadin group performed an aerobic running exercise training protocol for 15 days. At the end of the experiments, physiological, histological, and molecular analyzes were performed in the study. Compared to the control group, the gliadin group had impaired weight gain and increased gluconeogenesis, lipogenesis, and inflammatory biomarkers in the liver. On the other hand, compared to the gliadin group, animals in the exercise-gliadin group had a recovery in body weight, improved insulin sensitivity, and a reduction in some gluconeogenesis, lipogenesis, and inflammatory biomarkers in the liver. In conclusion, our results revealed that the administration of gliadin from birth impaired weight gain and induced an increase in hepatic inflammatory cytokines, which was associated with an impairment of glycemic homeostasis in the liver, all of which were attenuated by adding aerobic exercise training in the gliadin group.

Gluten-Free Diet and Metabolic Syndrome: Could Be a Not Benevolent Encounter?

Celiac disease is a rising disorder and is becoming frequently diagnosed in recent years. To date, the only available treatment is the gluten-free diet (GFD). The role of gluten on components of metabolic syndrome and on related inflammatory response is still unclear due to controversial results. In recent years, scientific focus on this topic has been growing up, in particular regarding the role of the GFD on glycometabolic parameters and diabetes. In addition, studies on the remaining components showed discordant results, which was likely due to heterogeneous and large celiac disease populations and to the lack of prospective studies. Furthermore, knowledge about the role of the GFD on inflammatory cytokines and the relationship among vitamin D and celiac disease, metabolic syndrome (MS) and GFD is needed. In this narrative review, we provided evidence regarding the role of the GFD on glycometabolic parameters, cholesterol, triglycerides, waist circumference, blood pressure and inflammatory cascade, also evaluating the role of vitamin D, trying to summarize whether this nutritional pattern may be a value-added for subjects with dysmetabolic conditions. Finally, due to the limited findings and very low-certainty evidence, predominantly based on observational studies, the real effects of a GFD on different components of MS, however, are unclear; nevertheless, an improvement in HDL levels has been reported, although data on glycemic levels are discordant.

Nutritional Quality of Gluten-Free Bakery Products Labeled Ketogenic and/or Low-Carb Sold in the Global Market

Gluten-free and ketogenic bakery products are gaining momentum. This study aims to develop a better understanding of the nutritional quality of gluten-free bakery products labeled ketogenic and/or low-carb. For this reason, the products available on the global market that were labeled ketogenic and/or low-carb (n = 757) were retrieved and compared to standard gluten-free products (n = 509). Overall, nutritionally, no significant differences were found among ketogenic and/or low-carb products due the high intra-variability of each type, but they differed from standard products. Compared to standard products, all ketogenic and/or low carb, irrespective of categories, showed lower carbohydrates that derived chiefly from fibers and, to a lesser extent, from sugars. They also had higher protein contents (p < 0.05) compared to standard products. Fats was higher (p < 0.05) in ketogenic and/or low-carb baking mixes, savory biscuits, and sweet biscuits than in their standard counterparts. Saturated fats were higher (p < 0.05) in low-carb savory biscuits and breads, as well as in ketogenic sweet biscuits than in the same standard products. Overall, median values of the nutrients align with the definition of the ketogenic diet. Nevertheless, several products did not align with any of the ketogenic definitions. Therefore, consumers need to carefully read the nutritional facts and not rely on mentions such as low-cab and ketogenic to make their decision of purchase/consumption.

Orphan receptor GPR50 attenuates inflammation and insulin signaling in 3T3-L1 preadipocytes

Type 2 diabetes (T2DM) is characterized by insulin secretion deficiencies and systemic insulin resistance (IR) in adipose tissue, skeletal muscle, and the liver. Although the mechanism of T2DM is not yet fully known, inflammation and insulin resistance play a central role in the pathogenesis of T2DM. G protein-coupled receptors (GPCRs) are involved in endocrine and metabolic processes as well as many other physiological processes. GPR50 (G protein-coupled receptor 50) is an orphan GPCR that shares the highest sequence homology with melatonin receptors. The aim of this study was to investigate the effect of GPR50 on inflammation and insulin resistance in 3T3-L1 preadipocytes. GPR50 expression was observed to be significantly increased in the adipose tissue of obese T2DM mice, while GPR50 deficiency increased inflammation in 3T3-L1 cells and induced the phosphorylation of AKT and insulin receptor substrate (IRS) 1. Furthermore, GPR50 knockout in the 3T3-L1 cell line suppressed PPAR-γ expression. These data suggest that GPR50 can attenuate inflammatory levels and regulate insulin signaling in adipocytes. Furthermore, the effects are mediated through the regulation of the IRS1/AKT signaling pathway and PPAR-γ expression.

Muscle-to-tumor crosstalk: The effect of exercise-induced myokine on cancer progression

Physical exercise has gradually become a focus in cancer treatment due to its pronounced role in reducing cancer risk, enhancing therapeutic efficacy, and improving prognosis. In recent decades, skeletal muscles have been considered endocrine organs, exerting their biological functions via the endocrine, autocrine, and paracrine systems by secreting various types of myokines. The amount of myokines secreted varies depending on the intensity, type, and duration of exercise. Recent studies have shown that muscle-derived myokines are highly involved the effects of exercise on cancer. Multiple myokines, such as interleukin-6 (IL-6), oncostatin M (OSM), secreted protein acidic and rich in cysteine (SPARC), and irisin, directly mediate cancer progression by influencing the proliferation, apoptosis, stemness, drug resistance, metabolic reprogramming, and epithelial-mesenchymal transformation (EMT) of cancer cells. In addition, IL-6, interleukin-8 (IL-8), interleukin-15 (IL-15), brain-derived neurotrophic factor (BDNF), and irisin can improve obesity-induced inflammation by stimulating lipolysis of adipose tissues, promoting glucose uptake, and accelerating the browning of white fat. Furthermore, some myokines could regulate the tumor microenvironment, such as angiogenesis and the immune microenvironment. Cancer cachexia occurs in up to 80% of cancer patients and is responsible for 22%-30% of patient deaths. It is characterized by systemic inflammation and decreased muscle mass. Exercise-induced myokine production is important in regulating cancer cachexia. This review summarizes the roles and underlying mechanisms of myokines, such as IL-6, myostatin, IL-15, irisin, fibroblast growth factor 21 (FGF21) and musclin, in cancer cachexia. Through comprehensive analysis, we conclude that myokines are potential targets for inhibiting cancer progression and the associated cachexia.

Transcriptome-wide analysis reveals gluten-induced suppression of small intestine development in young chickens

Wheat gluten is an increasingly common ingredient in poultry diets but its impact on the small intestine in chicken is not fully understood. This study aimed to identify effects of high-gluten diets on chicken small intestines and the variation of their associated transcriptional responses by age. A total of 120 broilers (Ross Strain) were used to perform two animal experiments consisting of two gluten inclusion levels (0% or 25%) by bird’s age (1 week or 4 weeks). Transcriptomics and histochemical techniques were employed to study the effect of gluten on their duodenal mucosa using randomly selected 12 broilers (3 chicks per group). A reduction in feed intake and body weight gain was found in the broilers fed a high-gluten containing diet at both ages. Histochemical photomicrographs showed a reduced villus height to crypt depth ratio in the duodenum of gluten-fed broilers at 1 week. We found mainly a significant effect on the gene expression of duodenal mucosa in gluten-fed broilers at 1 week (289 differentially expressed genes [DEGs]). Pathway analyses revealed that the significant DEGs were mainly involved in ribosome, oxidative phosphorylation, and peroxisome proliferator-activated receptor (PPAR) signaling pathways. These pathways are involved in ribosome protein biogenesis, oxidative phosphorylation and fatty acid metabolism, respectively. Our results suggest a pattern of differential gene expression in these pathways that can be linked to chronic inflammation, suppression of cell proliferation, cell cycle arrest and apoptosis. And via such a mode of action, high-gluten inclusion levels in poultry diets could lead to the observed retardation of villi development in the duodenal mucosa of young broiler chicken.

Differential Association of Wheat and Rice Consumption With Overweight/Obesity in Chinese Adults: China Health and Nutrition Survey 1991–2015

Wheat and rice are the main staple foods in China and likely have a major influence on health. This analysis examined the potential association between wheat and rice consumption and the risk of overweight/obesity in Chinese adults. We used data collected in the China Health and Nutrition Survey (CHNS) from 1991 to 2015. Adults aged 18–80 years old (n = 11,503) were included in the present analysis, for whom questionnaires and anthropometric data were collected during at least two waves. We constructed three-level mixed-effect linear regression models to estimate body mass index (BMI) in relation to wheat and rice intakes and performed three-level mixed-effect logistic regression models to assess the risk of overweight/obesity. Women showed significant BMI increases of 0.14 (95% CI: 0.04, 0.24) from a higher intake of wheat but not from a higher intake of rice when adjusted for all potential confounders. Comparing the highest quartiles of intake of wheat with non-consumers in men and women, odds ratios (ORs; 95% CI) of overweight/obesity were 1.45 (1.15, 1.85) and 1.26 (1.00, 1.60), respectively. In men, there was an inverse association with the risk of overweight/obesity in the comparison of the highest quartiles of intake of rice (OR: 0.73; 95% CI: 0.55, 0.96) and non-consumers when adjusted for all potential confounders. Higher intake of wheat was positively associated with the risk of overweight/obesity among Chinese adults. Further, there was an inverse association between rice intake with overweight/obesity in Chinese men but not in women.

Do gluten peptides stimulate weight gain in humans?

Observations from animal and in vitro laboratory research, and anecdotal evidence, have led to the suggestion that gluten consumption stimulates weight gain by the presence of peptides expressing opioid activity. Another proposed mechanism is that gluten peptides decrease resting energy expenditure resulting in a positive energy balance. In order to induce such effects in vivo, intact food peptides must be absorbed in sufficient quantities, remain intact in the blood for sufficient time to have long-lasting biological activity and bind to receptors involved in appetite, satiety and energy regulation. However, although peptides from food may pass from the intestine into the blood in extremely low quantities, they are generally rapidly degraded by plasma and vasculum-bound aminopeptidases, resulting in very short half-lives and loss of bioactivity. At present, gluten peptide sequences that influence regulators of energy metabolism have not been identified. Furthermore, data on the quantitative absorption of gluten peptides in the blood stream, their stability and lasting bioactivity are also lacking. Therefore, there is no evidence for proposed effects on driving appetite by the brain, nor on energy expenditure and weight gain. Furthermore, the level of overweight observed in various countries appears to be independent of the level of wheat consumption, and abundant observational evidence in humans shows that the levels of gluten consumption are neither related to daily calorie intake nor to BMI. This narrative review therefore discusses the proposed effects of gluten on bodyweight (BW) and putative biological mechanisms in the light of the current evidence.

Dietary Protein Source Matters for Changes in Inflammation Measured by Urinary C-Reactive Protein in Rural Polish Women

Objectives

Multiple macronutrients have been shown to affect systemic inflammation, a well-known predictor of chronic disease. Less often, varying sources of these macronutrients are examined. Different subsistence environments lead to varying access to protein sources which, combined with physical activity patterns, may lead to different relationships than among more typically studied sedentary, industrialized populations. This study hypothesizes an association between dietary protein intake and urinary C-Reactive Protein (CRP) concentration in women from a rural, agrarian Polish community.

Materials and Methods

We assessed protein intake and their sources for 80 nonsmoking, premenopausal Polish women who were not pregnant, nursing, or on hormonal birth control during the study or within the previous six months. Each participant completed multiple 24-hour dietary recalls during one menstrual cycle. Participants collected morning void urinary samples daily over one menstrual cycle for urinary CRP analysis. We analyzed relationships between plant and animal protein intake and CRP over the menstrual cycle by multiple linear regression.

Results

Plant protein in cereal foods was significantly positively associated with cycle-average urinary CRP concentrations (p<0.05) after controlling for body fat percent, total energy intake, and dietary fiber. Foods containing animal protein were not significantly associated with CRP.

Discussion

Contents of this population's main plant and animal protein sources differ from those of more commonly studied industrialized populations. Within the context of a population's typical diet, more emphasis may need to be placed on particular source of protein consumed, beyond plant versus animal, in order to understand relationships with CRP.

Effects of a gluten-reduced or gluten-free diet for the primary prevention of cardiovascular disease

BACKGROUND

Cardiovascular diseases (CVD) are a major cause of disability and the leading cause of death worldwide. To reduce mortality and morbidity, prevention strategies such as following an optimal diet are crucial. In recent years, low-gluten and gluten-free diets have gained strong popularity in the general population. However, study results on the benefits of a gluten-reduced or gluten-free diet are conflicting, and it is unclear whether a gluten-reduced diet has an effect on the primary prevention of CVD.

OBJECTIVES

To determine the effects of a gluten-reduced or gluten-free diet for the primary prevention of CVD in the general population.

SEARCH METHODS

We systematically searched CENTRAL, MEDLINE, Embase, CINAHL and Web of Science up to June 2021 without language restrictions or restrictions regarding publication status. Additionally, we searched ClinicalTrials.gov for ongoing or unpublished trials and checked reference lists of included studies as well as relevant systematic reviews for additional studies.

SELECTION CRITERIA

We planned to include randomised controlled trials (RCTs) and non-randomised studies of interventions (NRSIs), such as prospective cohort studies, comparing a low-gluten or gluten-free diet or providing advice to decrease gluten consumption with no intervention, diet as usual, or a reference gluten-intake category. The population of interest comprised adults from the general population, including those at increased risk for CVD (primary prevention). We excluded cluster-RCTs, case-control studies, studies focusing on participants with a previous myocardial infarction and/or stroke, participants who have undergone a revascularisation procedure as well as participants with angina or angiographically-defined coronary heart disease, with a confirmed diagnosis of coeliac disease or with type 1 diabetes.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed eligibility of studies in a two-step procedure following Cochrane methods. Risk of bias (RoB) was assessed using the Cochrane risk of bias tool (RoB2) and the 'Risk Of Bias In Non-randomised Studies - of Interventions' (ROBINS-I) tool, and the certainty of evidence was rated using the GRADE approach.

MAIN RESULTS

One RCT and three NRSIs (with an observational design reporting data on four cohorts: Health Professionals Follow-up Study (HPFS), Nurses' Health Study (NHS-I), NHS-II, UK Biobank) met the inclusion criteria. The RCT was conducted in Italy (60 participants, mean age 41 ± 12.1 years), two NRSIs (three cohorts, HPFS, NHS-I, NHS II) were conducted across the USA (269,282 health professionals aged 24 to 75 years) and one NRSI (Biobank cohort) was conducted across the UK (159,265 participants aged 49 to 62 years). Two NRSIs reported that the lowest gluten intake ranged between 0.0 g/day and 3.4 g/day and the highest gluten intake between 6.2 g/day and 38.4 g/day. The NRSI reporting data from the UK Biobank referred to a median gluten intake of 8.5 g/day with an interquartile range from 5.1 g/day to 12.4 g/day without providing low- and high-intake categories. Cardiovascular mortality From a total of 269,282 participants, 3364 (1.3%) died due to cardiovascular events during 26 years of follow-up. Low-certainty evidence may show no association between gluten intake and cardiovascular mortality (adjusted hazard ratio (HR) for low- versus high-gluten intake 1.00, 95% confidence interval (CI) 0.95 to 1.06; 2 NRSIs (3 cohorts)). All-cause mortality From a total of 159,265 participants, 6259 (3.9%) died during 11.1 years of follow-up. Very low-certainty evidence suggested that it is unclear whether gluten intake is associated with all-cause mortality (adjusted HR for low vs high gluten intake 1.00, 95% CI 0.99 to 1.01; 1 NRSI (1 cohort)). Myocardial infarction  From a total of 110,017 participants, 4243 (3.9%) participants developed non-fatal myocardial infarction within 26 years. Low-certainty evidence suggested that gluten intake may not be associated with the development of non-fatal myocardial infarction (adjusted HR for low versus high gluten intake 0.99, 95% CI 0.89 to 1.10; 1 NRSI (2 cohorts)). Lowering gluten intake by 5 g/day also showed no association on the primary prevention of non-fatal and fatal myocardial infarction (composite endpoint) in linear dose-response meta-analyses (adjusted HR 1.02, 95% CI 0.98 to 1.06; 1 NRSI (2 cohorts)). Coronary risk factors  Type 2 diabetes From a total of 202,114 participants, 15,947 (8.0%) developed type 2 diabetes after a follow-up between 22 and 28 years. There was low-certainty evidence that a lower compared with a higher gluten intake may be associated with a slightly increased risk to develop type 2 diabetes (adjusted HR 1.14, 95% CI 1.07 to 1.22; 1 NRSI (3 cohorts)). Furthermore, lowering gluten intake by 5 g/day may be associated with a slightly increased risk to develop type 2 diabetes in linear dose-response meta-analyses (adjusted HR 1.12, 95% CI 1.08 to 1.16; 1 NRSI (3 cohorts)). Blood pressure, low-density lipoprotein level, body mass index (BMI) After six months of follow-up, very low-certainty evidence suggested that it is unclear whether gluten intake affects systolic blood pressure (mean difference (MD) -6.9, 95% CI -17.1 to 3.3 mmHg). There was also no difference between the interventions for diastolic blood pressure (MD -0.8, 95% CI -5.9 to 4.3 mmHg), low-density lipoprotein levels (MD -0.1, 95% CI -0.5 to 0.3 mmol/L) and BMI (MD -0.1, 95% CI -3.3 to 3.1 kg/m²).  No study reported data on adverse events or on other outcomes. Funding sources did not appear to have distorted the results in any of the studies.

AUTHORS' CONCLUSIONS

Very low-certainty evidence suggested that it is unclear whether gluten intake is associated with all-cause mortality. Our findings also indicate that low-certainty evidence may show little or no association between gluten intake and cardiovascular mortality and non-fatal myocardial infarction. Low-certainty evidence suggested that a lower compared with a higher gluten intake may be associated with a slightly increased risk to develop type 2 diabetes - a major cardiovascular risk factor. For other cardiovascular risk factors it is unclear whether there is a difference between a gluten-free and normal diet. Given the limited findings from this review predominantly based on observational studies, no recommendations for practice can be made.

Gluten, Inflammation, and Neurodegeneration

Growing evidence supports a potential link between dietary gluten intake and neurodegenerative disease in susceptible populations. Observational data supporting this link are described along with interventional study data evaluating the effects of restricting gluten from the diet in patients with neurologic disorders. Suggested underlying mechanisms between gluten intake and neurodegeneration are discussed.

Gluten-Free Diet Reduces Diet Quality and Increases Inflammatory Potential in Non-Celiac Healthy Women

AIM

Gluten-free diets (GFDs) have gained popularity in the general population. Nonetheless, controlled studies are necessary before decisions can be made to promote GFDs. We aimed to evaluate the effects of gluten intake on body weight, body composition, and resting energy expenditure and observe the changes in nutrient intake caused by GFDs.

METHODS

Twenty-three women were kept on a GFD for six weeks and received muffins with 20 g of gluten isolate (gluten period) or muffins without gluten (gluten-free period) in a crossover, single-blind, non-randomized trial. Gastrointestinal symptoms, food frequency questionnaires, body composition, and resting energy expenditure were assessed before the study (habitual or usual diet) and in the third and sixth weeks. Food intake was recorded daily for six weeks.

RESULTS

Gastrointestinal symptoms, resting energy expenditure, and body weight and composition were similar during the gluten period and gluten-free period. When the diet of the gluten-free period was compared with the habitual diet, we found an increase in the intake of fat and sodium and a reduction in the intake of fiber and vitamins B1, B6, B12, and folate. The nutrient imbalance caused by a GFD led to an increase in the dietary inflammatory index, thus suggesting that this type of diet has high inflammatory potential.

CONCLUSION

Gluten intake (20 g/day) did not alter body composition and resting energy expenditure in healthy women without caloric restriction in the diet for a short period (three weeks). However, a GFD led to changes in the composition of the diet, which worsened the quality of the diet and increased its inflammatory potential.

Gluten and FODMAPs Relationship with Mental Disorders: Systematic Review

Nowadays, gluten and FODMAP food components (fermentable oligosaccharides, disaccharides, monosaccharides and polyols) are increasingly studied due to their possible relation with extraintestinal-associated conditions. In recent years, gluten-free diets (GFD) and low-FODMAP diets (LFD) are becoming more popular not only in order to avoid the food components that cause intolerances or allergies in some people, but also due to the direct influence of marketing movements or diet trends on feeding habits. Likewise, neurological and psychiatric diseases are currently of increasing importance in developed countries. For this reason, a bibliographic systematic review has been carried out to analyse whether there is a pathophysiological relationship between the dietary intake of gluten or FODMAPs with mental disorders. This review collects 13 clinical and randomized controlled trials, based on the PRISMA statement, which have been published in the last ten years. Based on these results, limiting or ruling out gluten or FODMAPs in the diet might be beneficial for symptoms such as depression, anxiety (7 out of 7 articles found any positive effect), or cognition deficiency (improvements in several cognition test measurements in one trial), and to a lesser extent for schizophrenia and the autism spectrum. Nevertheless, further studies are needed to obtain completely reliable conclusions.

Gluten intake and metabolic health: conflicting findings from the UK Biobank

PURPOSE

The impact of gluten intake on metabolic health in subjects without celiac disease is unclear. The present study aimed to assess the association between gluten intake and body fat percentage (primary objective), as well as a broad set of metabolic health markers.

METHODS

Gluten intake was estimated in 39,927 participants of the UK Biobank who completed a dietary questionnaire for assessment of previous 24-h dietary intakes. Multiple linear regression analyses were performed between gluten intake and markers of metabolic health with Holm adjustment for multiple comparisons.

RESULTS

Median gluten intake was 9.7 g/day (male: 11.7 g/day; female: 8.2 g/day; p < 0.0001). In multiple linear regression analysis, association between gluten intake and percentage body fat was negative in males (β = - 0.028, p = 0.0020) and positive in females (β = 0.025, p = 0.0028). Furthermore, gluten intake was a negative predictor of total cholesterol (male: β = - 0.031, p = 0.0154; female: β = - 0.050, p < 0.0001), high-density lipoprotein cholesterol (male: β = - 0.052, p < 0.0001; female: β = - 0.068, p < 0.0001), and glomerular filtration rate (sexes combined: β = - 0.031, p < 0.0001) in both sexes. In females only, gluten intake was positively associated with waist circumference (β = 0.041, p < 0.0001), waist-to-height ratio (β = 0.040, p < 0.0001), as well as body mass index (β = 0.043, p < 0.0001), and negatively related to low-density lipoprotein cholesterol (β = - 0.035, p = 0.0011). A positive association between gluten intake and triglycerides was observed in males only (β = 0.043, p = 0.0001).

CONCLUSION

This study indicates that gluten intake is associated with markers of metabolic health. However, all associations are weak and not clinically meaningful. Limiting gluten intake is unlikely to provide metabolic health benefits for a population in total.

Gluten Intake and All-Cause and Cause-Specific Mortality: Prospective Findings from the UK Biobank

BACKGROUND

Gluten has been linked to adverse effects on metabolic and vascular health.

OBJECTIVES

The present study determines the association between dietary gluten intake and all-cause (primary objective), as well as cause-specific, mortality in people without celiac disease.

METHODS

Gluten intake was estimated in 159,265 participants of the UK Biobank which is a large multicenter, prospective cohort study initiated in 2006. Cox proportional hazard regression models were used and HRs were determined for all-cause and cause-specific mortality. All models were adjusted for confounders and multiple testing.

RESULTS

Median (IQR) age was 57 (49-62) y with 52.1% of participants being female. Gluten intake was 8.5 (5.1-12.4) g/d with significantly higher consumption in males [10.0 (6.3-14.1) g/d] than in females [7.2 (4.6-10.7) g/d] (P < 0.0001). During a median follow-up of 11.1 (10.6-11.9) y and 1.8 million person-years, 6259 deaths occurred. Gluten intake was not significantly associated with all-cause mortality after adjusting for confounders (HR: 1.00; 95% CI: 1.00, 1.01; P = 0.59). Dietary gluten was not significantly associated with cancer (HR: 1.00; 95% CI: 1.00, 1.01; raw P = 0.24) or noncancer (HR: 1.00; 95% CI: 0.99, 1.01; raw P = 0.56) mortality. However, gluten intake was positively associated with ischemic heart disease mortality (HR: 1.02; 95% CI: 1.01, 1.04; raw P = 0.003, Holm-adjusted P = 0.04).

CONCLUSIONS

Gluten intake is not significantly associated with all-cause and cancer mortality in adults without celiac disease. The findings support the hypothesis that limiting gluten intake is unlikely to provide significant overall survival benefits on a population level. The positive association between gluten intake and ischemic heart disease mortality requires further study.

Association of Adipose Tissue and Adipokines with Development of Obesity-Induced Liver Cancer

Obesity is rapidly dispersing all around the world and is closely associated with a high risk of metabolic diseases such as insulin resistance, dyslipidemia, and nonalcoholic fatty liver disease (NAFLD), leading to carcinogenesis, especially hepatocellular carcinoma (HCC). It results from an imbalance between food intake and energy expenditure, leading to an excessive accumulation of adipose tissue (AT). Adipocytes play a substantial role in the tumor microenvironment through the secretion of several adipokines, affecting cancer progression, metastasis, and chemoresistance via diverse signaling pathways. AT is considered an endocrine organ owing to its ability to secrete adipokines, such as leptin, adiponectin, resistin, and a plethora of inflammatory cytokines, which modulate insulin sensitivity and trigger chronic low-grade inflammation in different organs. Even though the precise mechanisms are still unfolding, it is now established that the dysregulated secretion of adipokines by AT contributes to the development of obesity-related metabolic disorders. This review focuses on several obesity-associated adipokines and their impact on obesity-related metabolic diseases, subsequent metabolic complications, and progression to HCC, as well as their role as potential therapeutic targets. The field is rapidly developing, and further research is still required to fully understand the underlying mechanisms for the metabolic actions of adipokines and their role in obesity-associated HCC.

Marein ameliorates Ang II/hypoxia-induced abnormal glucolipid metabolism by modulating the HIF-1α/PPARα/γ pathway in H9c2 cells

The objectives of this study were to investigate the effects of marein, a major bioactive compound in functional food Coreopsis tinctoria, in hypertrophic H9c2 cells. Treating angiotensin II/hypoxia-stimulated H9c2 cells with marein led to decreasing cell surface area, intracellular total protein, atrial natriuretic peptide, and free fatty acids levels, but increasing glucose level. Marein treatment decreased hypoxia inducible factor-1α (HIF-1α), peroxisome proliferator activated receptor γ (PPARγ), medium chain acyl-coenzyme A dehydrogenase, glucose transporter-4, and glycerol-3-phosphate acyltransferase protein expressions, and increased PPARα, fatty acid transport protein-1, carnitine palmitoyltransferase-1, and pyruvate dehydrogenase kinase-4 protein expressions. Similar results were observed in HIF-1α-overexpressing H9c2 cells, whereas these effects were abolished in siRNA-HIF-1α-transfected H9c2 cells. It was concluded that marein could ameliorate abnormal glucolipid metabolism in hypertrophic H9c2 cells, and the effects could be attributable to reduction of HIF-1α expression and subsequent regulation PPARα/γ-mediated lipogenic gene expressions.

Inconsistent effects of gluten on obesity: is there a role for the haptoglobin isoforms?

BACKGROUND AND AIMS

There is no clear evidence about the effects of gluten intake on obesity. It is known that gluten's effects on gut permeability are mediated by zonulin, a protein identified as pre-haptoglobin 2, a physiological regulator of the intestinal barrier. We investigated the obesogenic and inflammatory effects of gluten and its association with the haptoglobin genotype.

METHODS

This was a single blinded, crossover study, including 40 overweight or obesity women free of celiac disease. Participants adopted a gluten-free diet (GFD) for 8 weeks and consumed a gluten-free muffin (GF-M) or a gluten-containing muffin (GLU-M, 24 g gluten) for 4 weeks, switching muffin type during the subsequent 4 weeks. During a follow-up period of 4 weeks we evaluated the usual diet (UD). Food diaries were collected to estimate the macronutrient intake and dietary inflammatory index (DII®). Bodyweight and composition, resting energy expenditure (REE), and cytokines were assessed. Haptoglobin alleles (Hp1 and Hp2) were genotyped to characterize zonulin expression.

RESULTS

Energy and macronutrient intakes were similar during both periods, except for protein intake, which was higher during GLU-M. DII scores indicated a more inflammatory profile during the GF-M and GLU-M periods compared to UD. No differences were observed in body composition or REE between interventions when the Hp genotype was not considered. Nonetheless, those carrying the Hp2-2 genotype (overexpressing zonulin) presented lower REE and higher levels of IL6 and IL1beta only during gluten intake (GLU-M and UD) compared to age- and body mass index-matched Hp1-1 carrier. These results suggest an obesogenic and inflammatory action of gluten only in those overexpressing zonulin (Hp2-2).

CONCLUSION

These results highlight the importance of zonulin as the mediator of gluten obesogenic and inflammatory effects. Our data suggest that in the presence of gluten, zonulin release is associated with a reduction of REE and an increase of inflammatory markers that are not seen in zonulin low producers.

Gluten consumption may contribute to worldwide obesity prevalence

Gluten consumption has been controversially associated with obesity in previous studies. We sought to examine this association at the worldwide level.

Country specific data were obtained from 168 countries. Scatter plots, bivariate, partial correlation and multiple linear regression models were used to explore and compare the coincidence between obesity prevalence and consumption of gluten, non-gluten cereal protein and total cereal protein respectively. The established risk factors of obesity: caloric intake, sedentary lifestyle, urbanization, socioeconomic status, meat protein intake and sugar consumption were included in analyses as potential confounders. The 168 countries were also stratified into developing and developed country groupings for further examination of the relationships.

Worldwide, bivariate correlation analyses revealed that the strength and direction of correlations between all variables (independent, dependent and potential confounders) were at similar levels. Obesity prevalence was positively correlated to gluten consumption but was negatively correlated to consumption of non-gluten cereal protein, and was in almost nil correlation to total cereal protein consumption. These relationships were similar across all countries (n= 168), developed country grouping (N=44) and developing country grouping (n=124). When caloric intake, Gross Domestic Product at Purchasing Power Parity, sedentary lifestyle and urbanization were kept statistically constant in the partial correlation analysis, obesity was significantly correlated to gluten consumption in all countries, developed country grouping and developing country grouping, and was significantly but inversely and weakly correlated to non-gluten cereal protein in all countries and developing countries, and was in almost nil correlation to total cereal protein in all country groupings. Globally, stepwise multiple regression analysis, when all the independent variables and potential confounding factors were included, selected consumption of sugar as the variable having the greatest influence on obesity with R2 = 0.510, while gluten was placed second increasing R2 to 0.596. Gluten consumption may have been emerging as an inconspicuous, but significant cause of obesity. While Westernization has driven the diet patterns worldwide to incorporate more gluten crops, obesity prevalence projection methods may estimate future obesity rates poorly if gluten consumption is not considered.

Dietary Gluten and Neurodegeneration: A Case for Preclinical Studies

Although celiac disease (CD) is an autoimmune disease that primarily involves the intestinal tract, mounting evidence suggests that a sizeable number of patients exhibit neurological deficits. About 40% of the celiac patients with neurological manifestations have circulating antibodies against neural tissue transglutaminase-6 (tTG6). While early diagnosis and strict adherence to a gluten-free diet (GFD) have been recommended to prevent neurological dysfunction, better therapeutic strategies are needed to improve the overall quality of life. Dysregulation of the microbiota-gut-brain axis, presence of anti-tTG6 antibodies, and epigenetic mechanisms have been implicated in the pathogenesis. It is also possible that circulating or gut-derived extracellular structures and including biomolecular condensates and extracellular vesicles contribute to disease pathogenesis. There are several avenues for shaping the dysregulated gut homeostasis in individuals with CD, non-celiac gluten sensitivity (NCGS) and/or neurodegeneration. In addition to GFD and probiotics, nutraceuticals, such as phyto and synthetic cannabinoids, represent a new approach that could shape the host microbiome towards better prognostic outcomes. Finally, we provide a data-driven rationale for potential future pre-clinical research involving non-human primates (NHPs) to investigate the effect of nutraceuticals, such as phyto and synthetic cannabinoids, either alone or in combination with GFD to prevent/mitigate dietary gluten-induced neurodegeneration.

Exit Gluten-Free and Enter Low FODMAPs: A Novel Dietary Strategy to Reduce Gastrointestinal Symptoms in Athletes

Exercise-associated physiological disturbances alter gastrointestinal function and integrity. These alterations may increase susceptibility to dietary triggers, namely gluten and a family of short-chain carbohydrates known as FODMAPs (fermentable oligo-, di-, monosaccharides and polyols). A recent surge in the popularity of gluten-free diets (GFDs) among athletes without celiac disease has been exacerbated by unsubstantiated commercial health claims and high-profile athletes citing this diet to be the secret to their success. Up to 41% of athletes at least partially adhere to a GFD diet, with the belief that gluten avoidance improves exercise performance and parameters influencing performance, particularly gastrointestinal symptoms (GIS). In contrast to these beliefs, seminal work investigating the effects of a GFD in athletes without celiac disease has demonstrated no beneficial effect of a GFD versus a gluten-containing diet on performance, gastrointestinal health, inflammation, or perceptual wellbeing. Interestingly, the subsequent reduction in FODMAPs concurrent with the elimination of gluten-containing grains may actually be the factors affecting GIS improvement, not gluten. Pre-existent in the gastrointestinal tract or ingested during exercise, the osmotic and gas-producing effects of variably absorbed FODMAPs may trigger or increase the magnitude of exercise-associated GIS. Research using FODMAP reduction to address gastrointestinal issues in clinically healthy athletes is emerging as a promising strategy to reduce exercise-associated GIS. Applied research and practitioners merging clinical and sports nutrition methods will be essential for the effective use of a low FODMAP approach to tackle the multifactorial nature of gastrointestinal disturbances in athletes.

PPARs and the Development of Type 1 Diabetes

Peroxisome proliferator-activated receptors (PPARs) are a family of transcription factors with a key role in glucose and lipid metabolism. PPARs are expressed in many cell types including pancreatic beta cells and immune cells, where they regulate insulin secretion and T cell differentiation, respectively. Moreover, various PPAR agonists prevent diabetes in the non-obese diabetic (NOD) mouse model of type 1 diabetes. PPARs are thus of interest in type 1 diabetes (T1D) as they represent a novel approach targeting both the pancreas and the immune system. In this review, we examine the role of PPARs in immune responses and beta cell biology and their potential as targets for treatment of T1D.

Wheat gluten intake increases the severity of experimental colitis and bacterial translocation by weakening of the proteins of the junctional complex

Gluten is only partially digested by intestinal enzymes and can generate peptides that can alter intestinal permeability, facilitating bacterial translocation, thus affecting the immune system. Few studies addressed the role of diet with gluten in the development of colitis. Therefore, we investigate the effects of wheat gluten-containing diet on the evolution of sodium dextran sulphate (DSS)-induced colitis. Mice were fed a standard diet without (colitis group) or with 4·5 % wheat gluten (colitis + gluten) for 15 d and received DSS solution (1·5 %, w/v) instead of water during the last 7 d. Compared with the colitis group, colitis + gluten mice presented a worse clinical score, a larger extension of colonic injury area, and increased mucosal inflammation. Both intestinal permeability and bacterial translocation were increased, propitiating bacteria migration for peripheral organs. The mechanism by which diet with gluten exacerbates colitis appears to be related to changes in protein production and organisation in adhesion junctions and desmosomes. The protein α-E-catenin was especially reduced in mice fed gluten, which compromised the localisation of E-cadherin and β-catenin proteins, weakening the structure of desmosomes. The epithelial damage caused by gluten included shortening of microvilli, a high number of digestive vacuoles, and changes in the endosome/lysosome system. In conclusion, our results show that wheat gluten-containing diet exacerbates the mucosal damage caused by colitis, reducing intestinal barrier function and increasing bacterial translocation. These effects are related to the induction of weakness and disorganisation of adhesion junctions and desmosomes as well as shortening of microvilli and modification of the endocytic vesicle route.

The Janus Face of Cereals: Wheat-Derived Prebiotics Counteract the Detrimental Effect of Gluten on Metabolic Homeostasis in Mice Fed a High-Fat/High-Sucrose Diet

SCOPE

Cereals are important sources of carbohydrates, but also contain nutrients that could impact adiposity. The contribution of gluten to obesity and the effects of prebiotics-arabinoxylo-oligosaccharides (AXOS) and fructo-oligosaccharides (FOS)-that can be extracted from gluten-containing cereals are analyzed.

METHODS AND RESULTS

Mice are fed a control diet, Western diet (WD, consisting of high fat/high sucrose), or WD with 5% gluten. Prebiotics are tested in the WD with gluten. Gluten does not increase body weight and has a minor effect on ileal inflammation. Gluten decreases the expression of browning markers in the fat and increases the triglycerides synthesis in the muscle. AXOS decreases body weight and adiposity in fat pads muscle and liver. AXOS promotes gluten cleavage by the induction of prolyl endopeptidase that is translated into a reduction of gluten immunogenic peptides. Gluten has minor effects on cecal microbiota composition, whereas prebiotics increased Bifidobacterium, Butyricicoccus, Prevotella, and Parasutterella, which are all negatively correlated to the cecal content of gluten peptides.

CONCLUSION

While gluten may affect metabolic homeostasis, these effects are lessened when gluten is consumed along with cereal-derived fibers. If confirmed in humans, the authors bring new arguments to eat fiber-rich cereals to promote a healthy diet.

Gluten exacerbates atherosclerotic plaque formation in ApoE-/- mice with diet-induced obesity

OBJECTIVES

Atherosclerosis is an underlying cause of cardiovascular disease, and obesity is one of the risk factors for atherogenesis. Although a gluten-free diet (GFD) has gained popularity as a strategy for weight loss, little is known about the effects of gluten on obesity. We have previously shown a negative effect of gluten on obesity in mice. However, its effects on atherogenesis are still unknown. Therefore, the aim of this study was to determine the effects of gluten on atherosclerosis progression during obesity.

METHODS

Atherosclerosis-susceptible ApoE knockout mice were subjected to an obesogenic GFD or a diet with 4.5% gluten (GD) for 10 wk.

RESULTS

Results from the study found that food intake and lipid profile were similar between the groups. However, GD promoted an increase in weight gain, adiposity, and plasma glucose. Pro-inflammatory factors such as tumor necrosis factor, interleukin-6, chemokine ligand-2, and matrix metalloproteinase-2 and -9 also were increased in the adipose tissue of gluten-fed mice. This inflammatory profile was associated with reduced phosphorylation of Akt, and consequently with the intensification of insulin resistance. The GD-enhanced vascular inflammation contributed to the worsening of atherosclerosis in the aorta and aortic root. Inflammatory cells, such as monocyte/macrophage and natural killer cells, and oxidative stress markers, such as superoxide and nitrotyrosine, were increased in atherosclerotic lesions of the GD group. Furthermore, the lesions presented higher necrotic core and lower collagen content, characterizing the less stable plaques.

CONCLUSION

The gluten-containing high-fat diet was associated with a more severe proatherogenic profile than the gluten-free high-fat diet owing to increased inflammatory and oxidative status at atherosclerotic lesions in obese mice.

A sea cucumber (Holothuria leucospilota) polysaccharide improves the gut microbiome to alleviate the symptoms of type 2 diabetes mellitus in Goto-Kakizaki rats

Diabetes mellitus has become a worldwide concern in recent years. In this study, the effect of Holothuria leucospilota polysaccharide (HLP) on type 2 diabetes mellitus (T2DM) was investigated in Goto-Kakizaki (GK) rats. The results showed that HLP significantly improved glucose intolerance and regulated blood lipid and hormone levels (p < 0.05). Pathological analysis showed that HLP repaired the impairments of the pancreas and colon in diabetic rats. In addition, a high dose of HLP (200 mg/kg) significantly upregulated the gene expression of peroxisome proliferator-activated receptor-α (PPAR-α), peroxisome proliferator-activated receptor-γ (PPAR-γ), phosphoinositide 3-kinase (PI3K), protein kinase B (PKB/AKT), glucose transporter-4 (GLUT4) and anti-apoptotic (Bcl-2), and downregulated the mRNA levels of pro-apoptotic (Bax) and cluster of differentiation 36 (CD36) in diabetic rats (p < 0.05). Furthermore, HLP treatment increased the short-chain fatty acid-producing bacteria and decreased the opportunistic bacterial pathogen in the feces of diabetic rats. These results demonstrated that HLP has the potential to ameliorate T2DM in GK rats.

Scientific evidence of diets for weight loss: Different macronutrient composition, intermittent fasting, and popular diets

New dietary strategies have been created to treat overweight and obesity and have become popular and widely adopted. Nonetheless, they are mainly based on personal impressions and reports published in books and magazines, rather than on scientific evidence. Animal models and human clinical trials have been employed to study changes in body composition and metabolic outcomes to determine the most effective diet. However, the studies present many limitations and should be carefully analyzed. The aim of this review was to discuss the scientific evidence of three categories of diets for weight loss. There is no one most effective diet to promote weight loss. In the short term, high-protein, low-carbohydrate diets and intermittent fasting are suggested to promote greater weight loss and could be adopted as a jumpstart. However, owing to adverse effects, caution is required. In the long term, current evidence indicates that different diets promoted similar weight loss and adherence to diets will predict their success. Finally, it is fundamental to adopt a diet that creates a negative energy balance and focuses on good food quality to promote health.

Possible Prevention of Diabetes with a Gluten-Free Diet

Gluten seems a potentially important determinant in type 1 diabetes (T1D) and type 2 diabetes (T2D). Intake of gluten, a major component of wheat, rye, and barley, affects the microbiota and increases the intestinal permeability. Moreover, studies have demonstrated that gluten peptides, after crossing the intestinal barrier, lead to a more inflammatory milieu. Gluten peptides enter the pancreas where they affect the morphology and might induce beta-cell stress by enhancing glucose- and palmitate-stimulated insulin secretion. Interestingly, animal studies and a human study have demonstrated that a gluten-free (GF) diet during pregnancy reduces the risk of T1D. Evidence regarding the role of a GF diet in T2D is less clear. Some studies have linked intake of a GF diet to reduced obesity and T2D and suggested a role in reducing leptin- and insulin-resistance and increasing beta-cell volume. The current knowledge indicates that gluten, among many environmental factors, may be an aetiopathogenic factors for development of T1D and T2D. However, human intervention trials are needed to confirm this and the proposed mechanisms.

A low-gluten diet induces changes in the intestinal microbiome of healthy Danish adults

Adherence to a low-gluten diet has become increasingly common in parts of the general population. However, the effects of reducing gluten-rich food items including wheat, barley and rye cereals in healthy adults are unclear. Here, we undertook a randomised, controlled, cross-over trial involving 60 middle-aged Danish adults without known disorders with two 8-week interventions comparing a low-gluten diet (2 g gluten per day) and a high-gluten diet (18 g gluten per day), separated by a washout period of at least six weeks with habitual diet (12 g gluten per day). We find that, in comparison with a high-gluten diet, a low-gluten diet induces moderate changes in the intestinal microbiome, reduces fasting and postprandial hydrogen exhalation, and leads to improvements in self-reported bloating. These observations suggest that most of the effects of a low-gluten diet in non-coeliac adults may be driven by qualitative changes in dietary fibres.

Gluten-free diets are increasingly common in the general population. Here, the authors report the results of a randomised cross-over trial involving middle-aged, healthy Danish adults, showing evidence that a low-gluten diet leads to gut microbiome changes, possibly due to variations in dietary fibres.

Mood Disorders and Gluten: It's Not All in Your Mind! A Systematic Review with Meta-Analysis

Gluten elimination may represent an effective treatment strategy for mood disorders in individuals with gluten-related disorders. However, the directionality of the relationship remains unclear. We performed a systematic review of prospective studies for effects of gluten on mood symptoms in patients with or without gluten-related disorders. Six electronic databases (CINAHL, PsycINFO, Medline, Web of Science, Scopus and Cochrane Library) were searched, from inception to 8 August 2018, for prospective studies published in English. Meta-analyses with random-effects were performed. Three randomised-controlled trials and 10 longitudinal studies comprising 1139 participants fit the inclusion criteria. A gluten-free diet (GFD) significantly improved pooled depressive symptom scores in GFD-treated patients (Standardised Mean Difference (SMD) -0.37, 95% confidence interval (CI) -0.55 to -0.20; p < 0.0001), with no difference in mean scores between patients and healthy controls after one year (SMD 0.01, 95% CI -0.18 to 0.20, p = 0.94). There was a tendency towards worsening symptoms for non-coeliac gluten sensitive patients during a blinded gluten challenge vs. placebo (SMD 0.21, 95% CI -0.58 to 0.15; p = 0.25). Our review supports the association between mood disorders and gluten intake in susceptible individuals. The effects of a GFD on mood in subjects without gluten-related disorders should be considered in future research.

The Effect of Gluten Free Diet on Components of Metabolic Syndrome: A Randomized Clinical Trial

Background:

This study aimed to assess the effects of Gluten free diet (GFD) on components of metabolic syndrome (MES).

Materials and Methods:

In this randomized clinical trial, 50 subjects diagnosed with MES were randomly divided into two groups (n=25). The first group received a GFD and the second group continued their regular diet. Biochemical markers of MES and blood pressure were measured before and after 8-week intervention.

Results:

Forty five subjects completed the study. A post-hoc comparison of the groups showed no effects of the GFD and control diet on LDL cholesterol, total cholesterol, fasting insulin, HOMA-IR, systolic and diastolic blood pressure levels. The GFD reduced fasting blood glucose, waist circumference (WC) and serum triglyceride concentration significantly compared with the control diet (p<0.05).

Conclusion:

Short-term GFD reduced WC and improved glycemic control and Triglyceride level in subjects with the metabolic syndrome.

Glycemic control and microvascular complications in adults with type 1 diabetes and long-lasting treated celiac disease: A case-control study

AIMS

To investigate whether in type 1 diabetes (T1DM) patients the concomitance of long-lasting celiac disease (CD) treated with a gluten free diet (GFD) impacts glycaemic control and the prevalence/severity of microvascular complications.

METHODS

A case-control, observational study was performed in 34 patients with T1DM and GFD-treated CD and 66 patients with T1DM alone matched for age, gender, and T1DM duration. Anthropometric parameters, glucose control (HbA1_c), status of chronic complications and concomitant autoimmune diseases were evaluated.

RESULTS

HbA1_c level was similar in T1DM + CD and T1DM alone (7.8 ± 1.0 vs 7.7 ± 1.1%, P = 0.57); insulin requirement was significantly higher in T1DM + CD compared with T1DM (P = 0.04). There were no differences in systolic blood pressure while diastolic blood pressure was significantly lower in T1DM + CD (P = 0.003). The prevalence/severity of microvascular complications was similar between the two groups. Glomerular filtration rate (eGFR) was significantly lower in T1DM + CD (100 ± 20 vs 110 ± 16 ml/min/1.73 m², P = 0.007).

CONCLUSIONS

In patients with T1DM, the co-occurrence of long-term GFD-treated CD neither worsens glycemic control nor negatively impacts chronic microvascular complications. However, patients with T1DM + CD have lower eGFR values than those with T1DM alone.

Comparison of the effect of the Dietary Approaches to Stop Hypertension diet with usual dietary advice on expression of peroxisome proliferators-activated receptor gamma gene in women: A randomized controlled clinical trial

BACKGROUND

Peroxisome proliferator-activated receptor gamma (PPAR-γ) which controls body weight, glucose homeostasis, and adipocyte differentiation is a valuable candidate gene for insulin resistance (IR). The present study aimed to compare the effects of the Dietary Approaches to Stop Hypertension (DASH) diet and usual dietary advice (UDA) on PPAR-γ gene expression in women at risk for cardiovascular disease (CVD).

METHODS

This randomized controlled trial was performed on 44 women aged 20-50 years at risk for CVD (BMI > 25 kg/m2 and low physical activity). Participants were randomly assigned to the UDA (n = 22) or DASH (n = 22) diets for 12 weeks. The DASH diet was rich in fruits, vegetables, whole grains and low-fat dairy products and low in saturated fat, total fat, cholesterol, refined grains and sweets, with a total of 2400 mg/day sodium. The UDA diet was a regular diet with healthy dietary advice. Anthropometric indices and PPAR-γ gene expression were measured and compared between the two groups at the end of the study.

RESULTS

After the intervention, body mass index (BMI) and waist circumference (WC) significantly decreased in the DASH group (P < 0.050) but the results showed no significant differences between the two groups. At the end of the trial, PPAR-γ gene expression was significantly different between the UDA and the DASH diet groups (P = 0.040) and this difference remained significant after adjustment for BMI, and physical activity (P = 0.030).

CONCLUSION

The result of the study showed that the DASH diet significantly decreased the expression of PPAR-γ. This finding was unexpected and future studies on the current topic are therefore recommended.

Review: Shaping a sustainable food future by rediscovering long-forgotten ancient grains

Genetic erosion of crops has been determined way back in the 1940s and accelerated some twenty years later by the inception of the Green Revolution. Claims that the revolution was a complete triumph remain specious, especially since the massive production boost in the global big three grain crops; wheat, maize, and rice that happened back then is unlikely to recur under current climate irregularities. Presently, one of the leading strategies for sustainable agriculture is by unlocking the genetic potential of underutilized crops. The primary focus has been on a suite of ancient cereals and pseudo-cereals which are riding on the gluten-free trend, including, among others, grain amaranth, buckwheat, quinoa, teff, and millets. Each of these crops has demonstrated tolerance to various stress factors such as drought and heat. Apart from being the centuries-old staple in their native homes, these crops have also been traditionally used as forage for livestock. This review summarizes what lies in the past and present for these underutilized cereals, particularly concerning their potential role and significance in a rapidly changing world, and provides compelling insights into how they could one day be on par with the current big three in feeding a booming population.

Adipocyte-Derived Exosomal MiR-27a Induces Insulin Resistance in Skeletal Muscle Through Repression of PPARγ

The mechanism by which adipocyte-derived endocrine factors promote insulin resistance in skeletal muscle are not fully understood. MiR-27a is highly expressed in sera of obese individuals with prediabetes and T2DM, and mainly derived by adipose tissues. Thus, miR-27a secreted into circulation by adipose tissue may regulate insulin resistance in skeletal muscle.

Methods: The association between miR-27a and insulin resistance in skeletal muscle was determined in obese children, high-fat diet-induced miR-27a knockdown obese mice, db/db mice and C2C12 cells overexpressing miR-27a. The crosstalk mediated by exosomal miR-27a between adipose tissue and skeletal muscle was determined in C2C12 cells incubated with conditioned medium prepared from palmitate-treated 3T3-L1 adipocytes.

Results: We showed that serum miR-27a level correlated positively with obesity and insulin resistance in obese children, and that elevated serum miR-27a levels correlated with insulin resistance in leptin receptor-deficient db/db mice, and with obesity and insulin resistance in high-fat diet-fed C57BL/6J mice. MiR-27a released from adipocytes of high-fat diet-fed C57BL/6J mice was associated with triglyceride accumulation. MiR-27a derived from these adipocytes induced insulin resistance in C2C12 skeletal muscle cells through miR-27a-mediated repression of PPARγ and its downstream genes involved in the development of obesity.

Conclusions: These results identify a novel crosstalk signaling pathway between adipose tissue and skeletal muscle in the development of insulin resistance, and indicate that adipose tissue-derived miR-27a may play a key role in the development of obesity-triggered insulin resistance in skeletal muscle.

Nutritional Consideration in Celiac Disease and Nonceliac Gluten Sensitivity

Celiac disease is an autoimmune disorder due to the inflammatory response to gluten in genetically predisposed individuals. It causes an enteropathy associated with several nutritional complications. Strict compliance to a gluten-free diet (GFD) is the current primary therapy. Nonceliac gluten sensitivity (NCGS) is a condition in which gluten ingestion leads to systemic symptoms but is not associated with small bowel atrophy or abnormal celiac serologies. A GFD heals celiac disease enteropathy and improves symptoms in NCGS. However, a long-term GFD can be associated with nutritional deficiencies and requires monitoring and guidance.