Ethnic and sex differences in circulating endotoxin levels: A novel marker of atherosclerotic and cardiovascular risk in a British multi-ethnic population

Obesity and polycystic ovary syndrome influence on intestinal permeability at fasting, and modify the effect of diverse macronutrients on the gut barrier

Women with the extremely prevalent polycystic ovary syndromegather multiple cardiovascular risk factors and chronic subclinical inflammation. Interactions between diet, adiposity, and gut microbiota modulate intestinal permeabilityand bacterial product translocation, and may contribute to the chronic inflammation process associated with the polycystic ovary syndrome. In the present study, we aimed to address the effects of obesity, functional hyperandrogenism, and diverse oral macronutrients on intestinal permeabilityby measuring circulating markers of gut barrier dysfunction and endotoxemia. Participants included 17 non-hyperandrogenic control women, 17 women with polycystic ovary syndrome, and 19 men that were submitted to glucose, lipid, and protein oral loads. Lipopolysaccharide-binding protein, plasma soluble CD14, succinate, zonulin family peptide, and glucagon-like peptide-2 were determined at fasting and after oral challenges. Macronutrient challenges induced diverse changes on circulating intestinal permeabilitybiomarkers in the acute postprancial period, with lipids and proteins showing the most unfavorable and favorable effects, respectively. Particularly, lipopolysaccharide-binding protein, zonulin family peptide, and glucagon-like peptide-2 responses were deregulated by the presence of obesity after glucose and lipid challenges. Obese subjects showed higher fasting intestinal permeabilitybiomarkers levels than non-obese individuals, except for plasma soluble CD14. The polycystic ovary syndromeexacerbated the effect of obesity further increasing fasting glucagon-like peptide-2, lipopolysaccharide-binding protein, and succinate concentrations. We observed specific interactions of the polycystic ovary syndromewith obesity in the postprandial response of succinate, zonulin family peptide, and glucagon-like peptide-2. In summary, obesity and polycystic ovary syndromemodify the effect of diverse macronutrients on the gut barrier, and alsoinfluence intestinal permeabilityat fasting,contributing to the morbidity of functional hyperandrogenism by inducing endotoxemia and subclinical chronic inflammation.

Molecular biomarker approaches to prevention of post-traumatic osteoarthritis

Up to 50% of individuals develop post-traumatic osteoarthritis (PTOA) within 10 years following knee-joint injuries such as anterior cruciate ligament rupture or acute meniscal tear. Lower-extremity PTOA prevalence is estimated to account for ≥12% of all symptomatic osteoarthritis (OA), or approximately 5.6 million cases in the USA. With knowledge of the inciting event, it might be possible to 'catch PTOA in the act' with sensitive imaging and soluble biomarkers and thereby prevent OA sequelae by early intervention. Existing biomarker data in the joint-injury literature can provide insights into the pathogenesis and early risk trajectory related to PTOA and can help to elucidate a research agenda for preventing or slowing the onset of PTOA. Non-traumatic OA and PTOA have many clinical, radiological and genetic similarities, and efforts to understand early risk trajectories in PTOA might therefore contribute to the identification and classification of early non-traumatic OA, which is the most prevalent form of OA.

Probiotics, gut microbiome, and cardiovascular diseases: An update

Cardiovascular diseases (CVD) are one of the most challenging diseases and many factors have been demonstrated to affect their pathogenesis. One of the major factors that affect CVDs, especially atherosclerosis, is the gut microbiota (GM). Genetics play a key role in linking CVDs with GM, in addition to some environmental factors which can be either beneficial or harmful. The interplay between GM and CVDs is complex due to the numerous mechanisms through which microbial components and their metabolites can influence CVDs. Within this interplay, the immune system plays a major role, mainly based on the immunomodulatory effects of microbial dysbiosis and its resulting metabolites. The resulting modulation of chronic inflammatory processes was found to reduce the severity of CVDs and to maintain cardiovascular health. To better understand the specific roles of GM-related metabolites in this interplay, this review presents an updated perspective on gut metabolites related effects on the cardiovascular system, highlighting the possible benefits of probiotics in therapeutic strategies.

South Asian ethnicity: What can we do to make this risk enhancer a risk equivalent?

South Asians account for around 25% of the global population and are the fastest-growing ethnicity in the US. This population has an increasing burden of atherosclerotic cardiovascular disease (ASCVD) which is also seen in the diaspora. Current risk prediction equations underestimate this risk and consider the South Asian ethnicity as a risk-enhancer among those with borderline-intermediate risk. In this review, we discuss why the South Asian population is at a higher risk of ASCVD and strategies to mitigate this increased risk.

Physiopathological mechanisms involved in the development of hypertension associated with gut dysbiosis and the effect of nutritional/pharmacological interventions

The gut microbiota dysbiosis represents a triggering factor for cardiovascular diseases, including hypertension. In addition to the harmful impact caused by hypertension on different target organs, gut dysbiosis is capable of causing direct damage to critical organs such as the brain, heart, blood vessels, and kidneys. In this sense, it should be noted that pharmacological and nutritional interventions may influence gut microbiota composition, either inducing or preventing the development of hypertension. Some of the most important nutritional interventions at this level are represented by pro-, pre-, post- and/or syn-biotics, as well as polysaccharides, polyunsaturated fatty acids ω-3, polyphenols and fiber contained in different foods. Meanwhile, certain natural and synthetic active pharmaceutical ingredients, including antibiotics, antihypertensive and immunosuppressive drugs, vegetable extracts and vitamins, may also have a key role in the modulation of both gut microbiota and cardiovascular health. Additionally, gut microbiota may influence drugs and food-derived bioactive compounds metabolism, positively or negatively affecting their biological behavior facing established hypertension. The understanding of the complex interactions between gut microbiome and drug/food response results of great importance to developing improved pharmacological therapies for hypertension prevention and treatment. The purpose of this review is to critically outline the most relevant and recent findings on cardiovascular, renal and brain physiopathological mechanisms involved in the development of hypertension associated with changes in gut microbiota, besides the nutritional and pharmacological interventions potentially valuable for the prevention and treatment of this prevalent pathology. Finally, harmful food/drug interventions on gut microbiota are also described.

Gut-Derived Endotoxin and Telomere Length Attrition in Adults with and without Type 2 Diabetes

Premature aging, as denoted by a reduced telomere length (TL), has been observed in several chronic inflammatory diseases, such as obesity and type 2 diabetes mellitus (T2DM). However, no study to date has addressed the potential inflammatory influence of the gut-derived Gram-negative bacterial fragments lipopolysaccharide, also referred to as endotoxin, and its influence on TL in low-grade inflammatory states such as type 2 diabetes mellitus (T2DM). The current study therefore investigated the influence of endotoxin and inflammatory factors on telomere length (TL) in adults with (T2DM: n = 387) and without (non-diabetic (ND) controls: n = 417) obesity and T2DM. Anthropometric characteristics were taken, and fasted blood samples were used to measure biomarkers, TL, and endotoxin. The findings from this study highlighted across all participants that circulating endotoxin (r = −0.17, p = 0.01) was inversely associated with TL, noting that endotoxin and triglycerides predicted 18% of the variance perceived in TL (p < 0.001). Further stratification of the participants according to T2DM status and sex highlighted that endotoxin significantly predicted 19% of the variance denoted in TL among male T2DM participants (p = 0.007), where TL was notably influenced. The influence on TL was not observed to be impacted by anti-T2DM medications, statins, or anti-hypertensive therapies. Taken together, these results show that TL attrition was inversely associated with circulating endotoxin levels independent of the presence of T2DM and other cardiometabolic factors, suggesting that low-grade chronic inflammation may trigger premature biological aging. The findings further highlight the clinical relevance of mitigating the levels of circulating endotoxin (e.g., manipulation of gut microbiome) not only for the prevention of chronic diseases but also to promote healthy aging.

The Role of Gut Microbiota and Its Produced Metabolites in Obesity, Dyslipidemia, Adipocyte Dysfunction, and Its Interventions

Obesity is becoming an increasing problem worldwide and is often, but not invariably, associated with dyslipidemia. The gut microbiota is increasingly linked to cardiovascular disease, nonalcoholic fatty liver disease, and type 2 diabetes mellitus. However, relatively little focus has been attributed to the role of gut-microbiota-derived metabolites in the development of dyslipidemia and alterations in lipid metabolism. In this review, we discuss current data involved in these processes and point out the therapeutic potentials. We cover the ability of gut microbiota metabolites to alter lipoprotein lipase action, VLDL secretion, and plasma triglyceride levels, and its effects on reverse cholesterol transport, adipocyte dysfunction, and adipose tissue inflammation. Finally, the current intervention strategies for treatment of obesity and dyslipidemia is addressed with emphasis on the role of gut microbiota metabolites and its ability to predict treatment efficacies.

Role of Metabolic Endotoxemia in Systemic Inflammation and Potential Interventions

Diet-induced metabolic endotoxemia is an important factor in the development of many chronic diseases in animals and man. The gut epithelium is an efficient barrier that prevents the absorption of liposaccharide (LPS). Structural changes to the intestinal epithelium in response to dietary alterations allow LPS to enter the bloodstream, resulting in an increase in the plasma levels of LPS (termed metabolic endotoxemia). LPS activates Toll-like receptor-4 (TLR4) leading to the production of numerous pro-inflammatory cytokines and, hence, low-grade systemic inflammation. Thus, metabolic endotoxemia can lead to several chronic inflammatory conditions. Obesity, diabetes, and non-alcoholic fatty liver disease (NAFLD) can also cause an increase in gut permeability and potential pharmacological and dietary interventions could be used to reduce the chronic low-grade inflammation associated with endotoxemia.

Role of Gut Microbiota and Their Metabolites on Atherosclerosis, Hypertension and Human Blood Platelet Function: A Review

Emerging data have demonstrated a strong association between the gut microbiota and the development of cardiovascular disease (CVD) risk factors such as atherosclerosis, inflammation, obesity, insulin resistance, platelet hyperactivity, and plasma lipid abnormalities. Several studies in humans and animal models have demonstrated an association between gut microbial metabolites such as trimethylamine-N-oxide (TMAO), short-chain fatty acids, and bile acid metabolites (amino acid breakdown products) with CVD. Human blood platelets are a critical contributor to the hemostatic process. Besides, these blood cells play a crucial role in developing atherosclerosis and, finally, contribute to cardiac events. Since the TMAO, and other metabolites of the gut microbiota, are asociated with platelet hyperactivity, lipid disorders, and oxidative stress, the diet-gut microbiota interactions have become an important research area in the cardiovascular field. The gut microbiota and their metabolites may be targeted for the therapeutic benefit of CVD from a clinical perspective. This review's main aim is to highlight the complex interactions between microbiota, their metabolites, and several CVD risk factors.

PERIPHERAL BLOOD ENDOTOXIN LEVELS ARE NOT ASSOCIATED WITH SMALL INTESTINAL BACTERIAL OVERGROWTH IN NONALCOHOLIC FATTY LIVER DISEASE WITHOUT CIRRHOSIS

ABSTRACT BACKGROUND: Nonalcoholic fatty liver disease (NAFLD) is one of the most common forms of chronic liver disease worldwide. Approximately 20% of individuals with NAFLD develop nonalcoholic steatohepatitis (NASH), which is associated with increased risk of cirrhosis, portal hypertension, and hepatocellular carcinoma. Intestinal microflora, including small intestinal bacterial overgrowth (SIBO), appear to play an important role in the pathogenesis of the disease, as demonstrated in several clinical and experimental studies, by altering intestinal permeability and allowing bacterial endotoxins to enter the circulation. OBJECTIVE: To determine the relationship between SIBO and endotoxin serum levels with clinical, laboratory, and histopathological aspects of NAFLD and the relationship between SIBO and endotoxin serum levels before and after antibiotic therapy. METHODS: Adult patients with a histological diagnosis of NAFLD, without cirrhosis were included. A comprehensive biochemistry panel, lactulose breath test (for diagnosis of SIBO), and serum endotoxin measurement (chromogenic LAL assay) were performed. SIBO was treated with metronidazole 250 mg q8h for 10 days and refractory cases were given ciprofloxacin 500 mg q12h for 10 days. RESULTS: Overall, 42 patients with a histopathological diagnosis of NAFLD were examined. The prevalence of SIBO was 26.2%. Comparison of demographic and biochemical parameters between patients with SIBO and those without SIBO revealed no statistically significant differences, except for use of proton pump inhibitors, which was significantly more frequent in patients with positive breath testing. The presence of SIBO was also associated with greater severity of hepatocellular ballooning on liver biopsy. Although the sample, as a whole, have elevated circulating endotoxin levels, we found no significant differences in this parameter between the groups with and without SIBO. Endotoxin values before and after antibiotic treatment did not differ, even on paired analysis, suggesting absence of any relationship between these factors. Serum endotoxin levels were inversely correlated with HDL levels, and directly correlated with triglyceride levels. CONCLUSION: Serum endotoxin levels did not differ between patients with and without SIBO, nor did these levels change after antibacterial therapy, virtually ruling out the possibility that elevated endotoxinemia in non-cirrhotic patients with NAFLD is associated with SIBO. Presence of SIBO was associated with greater severity of ballooning degeneration on liver biopsy, but not with a significantly higher prevalence of NASH. Additional studies are needed to evaluate the reproducibility and importance of this finding in patients with NAFLD and SIBO.

Obesity and diabetes as comorbidities for COVID-19: Underlying mechanisms and the role of viral-bacterial interactions

Obesity and diabetes are established comorbidities for COVID-19. Adipose tissue demonstrates high expression of ACE2 which SARS- CoV-2 exploits to enter host cells. This makes adipose tissue a reservoir for SARS-CoV-2 viruses and thus increases the integral viral load. Acute viral infection results in ACE2 downregulation. This relative deficiency can lead to disturbances in other systems controlled by ACE2, including the renin-angiotensin system. This will be further increased in the case of pre-conditions with already compromised functioning of these systems, such as in patients with obesity and diabetes. Here, we propose that interactions of virally-induced ACE2 deficiency with obesity and/or diabetes leads to a synergistic further impairment of endothelial and gut barrier function. The appearance of bacteria and/or their products in the lungs of obese and diabetic patients promotes interactions between viral and bacterial pathogens, resulting in a more severe lung injury in COVID-19.

Anthocyanins As Modulators of Cell Redox-Dependent Pathways in Non-Communicable Diseases

Chronic Noncommunicable Diseases (NCDs), mostly represented by cardiovascular diseases, diabetes, chronic pulmonary diseases, cancers, and several chronic pathologies, are one of the main causes of morbidity and mortality, and are mainly related to the occurrence of metabolic risk factors. Anthocyanins (ACNs) possess a wide spectrum of biological activities, such as anti-inflammatory, antioxidant, cardioprotective and chemopreventive properties, which are able to promote human health. Although ACNs present an apparent low bioavailability, their metabolites may play an important role in the in vivo protective effects observed. This article directly addresses the scientific evidences supporting that ACNs could be useful to protect human population against several NCDs not only acting as antioxidant but through their capability to modulate cell redox-dependent signaling. In particular, ACNs interact with the NF-κB and AP-1 signal transduction pathways, which respond to oxidative signals and mediate a proinflammatory effect, and the Nrf2/ARE pathway and its regulated cytoprotective proteins (GST, NQO, HO-1, etc.), involved in both cellular antioxidant defenses and elimination/inactivation of toxic compounds, so countering the alterations caused by conditions of chemical/oxidative stress. In addition, supposed crosstalks could contribute to explain the protective effects of ACNs in different pathological conditions characterized by an altered balance among these pathways. Thus, this review underlines the importance of specific nutritional molecules for human health and focuses on the molecular targets and the underlying mechanisms of ACNs against various diseases.

Association between C reactive protein and all-cause mortality in the ELSA-Brasil cohort

Background

High-sensitivity C reactive protein (hsCRP) has been proposed as a marker of incident cardiovascular disease and vascular mortality, and may also be a marker of non-vascular mortality. However, most evidence comes from either North American or European cohorts. The present proposal aims to investigate the association of hsCRP with the risk of all-cause mortality in a multiethnic Brazilian population.

Methods

Baseline data (2008–2010) of a cohort of 14 238 subjects participating in the Brazilian Longitudinal Study of Adult Health were used. hsCRP was assayed with immunochemistry. The association of baseline covariates with all-cause mortality was calculated by Cox regression for univariate model and adjusted for different confounders after a mean follow-up of 8.0±1.1 years. The final model was adjusted for age, sex, self-rated race/ethnicity, schooling, health behaviours and prevalent chronic disease.

Results

The risk of death increased steadily by quartiles of hsCRP, from 1.45 (95% CI 1.05 to 2.01) in quartile 2 to 1.95 (95% CI 1.42 to 2.69) in quartile 4, compared with quartile 1. Furthermore, the persistence of a significant graded association after the exclusion of deaths in the first year of follow-up suggests that these results are unlikely to be due to reverse causality. Finally, the HR was unaffected by the exclusion of participants who had self-reported medical history of diabetes, cancer and chronic obstructive pulmonary disease.

Conclusions

Our study shows that hsCRP level is associated with mortality in a highly admixed population, independent of a large set of lifestyle and clinical variables.

The Gut Microbiota and Its Implication in the Development of Atherosclerosis and Related Cardiovascular Diseases

The importance of gut microbiota in health and disease is being highlighted by numerous research groups worldwide. Atherosclerosis, the leading cause of heart disease and stroke, is responsible for about 50% of all cardiovascular deaths. Recently, gut dysbiosis has been identified as a remarkable factor to be considered in the pathogenesis of cardiovascular diseases (CVDs). In this review, we briefly discuss how external factors such as dietary and physical activity habits influence host-microbiota and atherogenesis, the potential mechanisms of the influence of gut microbiota in host blood pressure and the alterations in the prevalence of those bacterial genera affecting vascular tone and the development of hypertension. We will also be examining the microbiota as a therapeutic target in the prevention of CVDs and the beneficial mechanisms of probiotic administration related to cardiovascular risks. All these new insights might lead to novel analysis and CVD therapeutics based on the microbiota.

South Asian Health: Inflammation, Infection, Exposure, and the Human Microbiome

This paper presents the results of the literature review conducted for the working group topic on inflammation, infection, exposure, and the human microbiome. Infection and chronic inflammation can elevate risk for cardiovascular disease and cancer. Environmental exposures common among South Asian (SA) subgroups, such as arsenic exposure among Bangladeshis and particulate matter air pollution among taxi drivers, also pose risks. This review explores the effects of exposure to arsenic and particulate matter, as well as other infections common among SAs, including human papillomavirus (HPV) and hepatitis B/C infection. Emerging research on the human microbiome, and the effect of microbiome changes on obesity and diabetes risk among SAs are also explored.

Xian-Ling-Gu-Bao induced inflammatory stress rat liver injury: Inflammatory and oxidative stress playing important roles

ETHNOPHARMACOLOGICAL RELEVANCE

Xian-Ling-Gu-Bao (XLGB) Fufang is an herbal formula that has been used in clinical settings to treat osteoporosis, osteoarthritis, aseptic bone necrosis, and climacteric syndrome. Despite its uses, XLGB treatment has been linked to potential liver injury. To date, there is a lack of clear demonstration of such toxicity in animal models.

AIM OF THE STUDY

As animal models fail to reproduce the XLGB hepatotoxicity reported in humans, because human hepatocytes are clearly more sensitive to XLGB, this study was designed to investigate a more reliable animal model of such toxicity.

MATERIALS AND METHODS

We randomized rats into five groups, as follows: CON (control), XLGB, lipopolysaccharide (LPS), L-XLGB/LPS (XLGB, 0.125 g/kg; LPS, 0.1 mg/kg), and XLGB/LPS (XLGB, 1.25 g/kg; LPS, 0.1 mg/kg). These groups were treated with 0.5% sodium carboxymethyl cellulose (CMC-Na), XLGB suspension, normal saline, or LPS. The first administration of XLGB [0.125 g/kg or 1.25 g/kg, by mouth (PO)] or its solvent (0.5% CMC-Na) was delivered, and then food was removed. Twelve hours after the first administration of XLGB, rats received LPS [0.1 mg/kg, intravenously (IV)] or saline control. After 30 min, a second administration of XLGB (0.125 g/kg or 1.25 g/kg, PO) or solvent was administered. The rats were anesthetized at 12 h or 24 h following the second administration of XLGB. Liver function was evaluated by measuring liver weight, liver microscopy, serum biochemistry and plasma microRNA-122 (miR-122). The plasma levels of 27 cytokines were measured to evaluate inflammation. Moreover, the expression of cytochrome P450 2E1 (CYP2E1), nicotinic adenine dinucleotide phosphate (NADPH) oxidase and inducible nitric oxide synthase (iNOS) at protein levels were observed; immunofluorescence and immunohistochemistry were used to confirmed the hepatotoxicity of XLGB.

RESULTS

Hepatotoxicity in male rats with moderate inflammation induced by XLGB was indicated by liver histopathology, serum biochemical analysis, serum miR-122 levels, and immunofluorescent assessments. We observed significant increases in liver weight and liver indexes in male rats with moderate inflammation in response to XLGB. Histopathological assessment further showed that extensive hepatocellular necrosis and inflammatory infiltration were evident in rats co-treated with XLGB/LPS. The levels of serum transaminases [alanine aminotransferase (ALT), aspartate aminotransferase (AST), gamma-glutamyl transferase (GGT)], total bilirubin (TBIL) and triglyceride (TG), which are markers of liver function, were also significantly increased by XLGB/LPS treatment. Similarly, miR-122 was significantly elevated in XLGB/LPS treated rats relative to other groups. An immunofluorescent assessment showed extensive apoptosis in hepatocytes from these co-treated rats. What is more, XLGB can dose-dependently induce liver injury in male rats with moderate inflammation. Hepatic CYP2E1, neutrophil chemotactic factor (NCF-1), iNOS, and NOX-2 (an NADPH oxidase subunit) levels were increased in response to XLGB treatment, and staining for DMPO nitrone adducts further showed elevated oxidative stress level in XLGB/LPS-treated rats relative to the other experimental groups.

CONCLUSION

LPS and XLGB co-treatment in rats led to marked hepatotoxicity. This toxicity was associated with disrupted lipid metabolism, extensive liver necrosis and inflammatory infiltration, apoptosis, and expression of oxidative stress-related proteins. These results demonstrate a valuable model for the study of iDILI in the context of XLGB treatment, and further provide insights into the potential mechanisms by which XLGB may induce hepatotoxicity in humans.

Imoxin attenuates LPS-induced inflammation and MuRF1 expression in mouse skeletal muscle

The double-stranded RNA-dependent protein kinase (PKR) contributes to inflammatory cytokine expression and disease pathogenesis in many conditions. Limited data are available on the efficacy of the PKR inhibitor imoxin to prevent lipopolysaccharide (LPS)-induced inflammation in skeletal muscle in vivo. The aim of this study was to evaluate the effect of imoxin, a PKR inhibitor, on inflammatory and atrophy signaling in skeletal muscle in response to an acute inflammatory insult with LPS. Six-week old C57BL/6J mice received vehicle (saline) or 0.5 mg/kg imoxin 24 and 2 h prior to induction of inflammation via 1 mg/kg LPS. Gastrocnemius muscles were collected 24 h post-LPS and mRNA and protein expression were assessed. LPS lead to a loss of body weight, which was similar in Imoxin+LPS. There were no differences in muscle weight among groups. LPS increased gastrocnemius mRNA expression of TNF-α and IL-1β, and protein levels of NLRP3, all of which were attenuated by imoxin. Similarly, IL-6 mRNA and IL-1β protein were suppressed in Imoxin+LPS compared to LPS alone. LPS increased mRNA of the atrogenes, MuRF1 and MAFbx, and imoxin attenuated the LPS-induced increase in MuRF1 mRNA, and lowered MuRF1 protein. Imoxin+LPS increased p-Akt compared to saline or LPS, whereas p-mTOR was unaltered. FoxO1 was upregulated and p-FoxO1/FoxO1 reduced by LPS, both of which were prevented by imoxin. Both LPS and Imoxin+LPS had diminished p-FoxO3/FoxO3 compared to control. These results demonstrate the potential anti-inflammatory and anti-atrophy effects of imoxin on skeletal muscle in vivo.

Inflammation, Immunity, and Infection in Atherothrombosis: JACC Review Topic of the Week

Observations on human and experimental atherosclerosis, biomarker studies, and now a large-scale clinical trial support the operation of immune and inflammatory pathways in this disease. The factors that incite innate and adaptive immune responses implicated in atherogenesis and in lesion complication include traditional risk factors such as protein and lipid components of native and modified low-density lipoprotein, angiotensin II, smoking, visceral adipose tissue, and dysmetabolism. Infectious processes and products of the endogenous microbiome might also modulate atherosclerosis and its complications either directly, or indirectly by eliciting local and systemic responses that potentiate disease expression. Trials with antibiotics have not reduced recurrent cardiovascular events, nor have vaccination strategies yet achieved clinical translation. However, anti-inflammatory interventions such as anticytokine therapy and colchicine have begun to show efficacy in this regard. Thus, inflammatory and immune mechanisms can link traditional and emerging risk factors to atherosclerosis, and offer novel avenues for therapeutic intervention.

The Role of Gut Microbiota in Atherosclerosis and Hypertension

In recent years, accumulating evidence has indicated the importance of gut microbiota in maintaining human health. Gut dysbiosis is associated with the pathogenesis of a number of metabolic diseases including obesity, type 2 diabetes mellitus (T2DM), non-alcoholic fatty liver disease (NAFLD), and cardiovascular diseases (CVDs). Indeed, CVD has become the leading cause of death worldwide, especially in developed countries. In this review, we mainly discuss the gut microbiota-involved mechanisms of CVD focusing on atherosclerosis and hypertension, two major risk factors for serious CVD. Then, we briefly discuss the prospects of gut microbiota-targeted therapeutic strategies for the treatment of CVD in the future.

The gut microbiota as a novel regulator of cardiovascular function and disease

The gut microbiome has emerged as a critical regulator of human physiology. Deleterious changes to the composition or number of gut bacteria, commonly referred to as gut dysbiosis, has been linked to the development and progression of numerous diet-related diseases, including cardiovascular disease (CVD). Most CVD risk factors, including aging, obesity, certain dietary patterns, and a sedentary lifestyle, have been shown to induce gut dysbiosis. Dysbiosis is associated with intestinal inflammation and reduced integrity of the gut barrier, which in turn increases circulating levels of bacterial structural components and microbial metabolites that may facilitate the development of CVD. The aim of the current review is to summarize the available data regarding the role of the gut microbiome in regulating CVD function and disease processes. Particular emphasis is placed on nutrition-related alterations in the microbiome, as well as the underlying cellular mechanisms by which the microbiome may alter CVD risk.

Lipopolysaccharide, a possible molecular mediator between periodontitis and coronary artery disease

AIM

We aimed to study how lipopolysaccharide (LPS) in saliva and serum associates with each other, periodontal microbial burden, periodontitis and coronary artery disease (CAD).

MATERIALS AND METHODS

The used Parogene cohort comprised N = 505 Finnish adults. Coronary diagnosis was acquired by coronary angiography, and the main outcomes were as follows: no significant CAD (n = 123), stable CAD (n = 184) and acute coronary syndrome (n = 169). Periodontitis was defined according to clinical and radiographic examinations. Levels for 75 strains of subgingival bacteria were determined by checkerboard DNA-DNA hybridization. Saliva and serum LPS activity was analysed by Limulus amebocyte lysate assay.

RESULTS

The level of 11 bacterial strains, which were mainly oral and respiratory Gram-negative species, associated with salivary LPS levels in an age- and gender-adjusted linear regression. A total of 4.9% of the serum LPS, that is endotoxemia, variation was explainable by saliva LPS among patients with periodontitis (n = 247, R²  = .049, Pearson's r = .222, p < .001). Endotoxemia associated with stable CAD in a confounder adjusted multinomial logistic regression model (OR 1.99, 95% CI 1.04-3.81, p = .039, 3rd tertile).

CONCLUSIONS

In particular in periodontitis patients, subgingival microbial burden contributes to endotoxemia. LPS is a possible molecular mediator between periodontitis and CAD.

Influence of Energy Balance and Glycemic Index on Metabolic Endotoxemia in Healthy Men

OBJECTIVE

Overfeeding with a high-fat and/or high-carbohydrate (CHO) diet is known to increase plasma concentrations of endotoxin (lipopolysaccharide [LPS]) that may lead to metabolic disturbances like insulin resistance. The impact of CHO quality (i.e., the glycemic index [GI]) independent of fat intake on metabolic endotoxemia remains unclear. In the present study, the effects of changes in energy balance and GI on plasma endotoxin were studied.

METHODS

Fifteen healthy young men overconsumed diets containing 65% CHO and 20% fat for 1 week (OF; +50% of energy requirement) followed by 3 weeks of caloric restriction (CR; -50% of energy requirement) and were then randomized to 2 weeks hypercaloric refeeding (RF, +50% of energy requirement) with either a low- or high-GI (40 vs 74) diet.

RESULTS

During OF, subjects gained 1.9 ± 0.7 kg body weight (+0.6 ± 0.8% fat mass) followed by a weight loss of 6.1 ± 0.8 kg (-2.0 ± 0.6% fat mass) and weight regain of 4.0 ± 0.6 kg (0.9 ± 0.8% fat mass). Fasting insulin and homeostasis model assessment-insulin resistance (HOMA_IR) increased with OF and RF and decreased with CR, Matsuda_ISI decreased by 37% after RF (all p < 0.05). Endotoxin significantly increased by 30.8% with OF and by 24.7% with RF (both p < 0.05), whereas CR normalized endotoxin levels. No difference in endotoxin levels was observed between refeeding a hypercaloric high- or low-GI diet. Changes in endotoxin levels with RF were not related to changes in insulin sensitivity.

CONCLUSION

A hypercaloric diet (OF and RF) increased plasma endotoxin irrespective of GI, whereas a negative energy balance did not reduce endotoxemia. Impaired insulin sensitivity with hypercaloric refeeding on a high-GI diet was not explained by metabolic endotoxemia.

Toxins, Toxicity, and Endotoxemia: A Historical and Clinical Perspective for Chiropractors

OBJECTIVE

The purpose of this commentary is to review the notion of toxicity in the context of chiropractic practice.

DISCUSSION

The belief that body toxicity is the cause of disease has been promoted for thousands of years. Prior to the emergence of the chiropractic profession, the medical profession embraced the notion that the body becomes "toxic," requiring detoxification interventions or surgery. The legacy of body toxicity within the chiropractic approach to patient care began with Daniel David Palmer. Today, some sectors within the medical and chiropractic professions continue to embrace the concept of body toxicity and the related need to engage in detoxifying treatments. The most common areas of focus for detoxification are the intestines and liver; however, the nature of the toxicity in these organs has yet to be defined or measured. In contrast, diet-induced systemic bacterial endotoxemia is a measureable state that is known to be promoted by a diet rich in sugar, flour, and refined oil. This suggests that bacterial endotoxin may be a candidate toxin to consider in the clinical context, as many common conditions, such as obesity, metabolic syndrome, diabetes, interstitial cystitis, depression, and migraine headache, are known to be promoted by endotoxemia.

CONCLUSION

A diet rich in refined sugar, flour, and oils may induce proinflammatory changes within intestinal microbiota that lead to systemic, low-grade endotoxemia, which is a common variety of "toxicity" that is measurable and worthy of research consideration. Introducing a diet to reduce endotoxemia, rather than attempting to target a specific organ, appears to be a rational clinical approach for addressing the issue of toxicity.

Maternal vitamin D beneficially programs metabolic, gut and bone health of mouse male offspring in an obesogenic environment

BACKGROUND/OBJECTIVES

Vitamin D is an anti-inflammatory nutrient and a determinant of bone health. Some prospective studies suggest that maternal vitamin D status is positively associated with offspring bone mass. We found that serum concentrations of lipopolysaccharide (LPS), an inflammatory molecule related to adiposity, insulin resistance and bone resorption, is lower in healthy mouse offspring exposed to high dietary vitamin D during pregnancy and lactation. LPS reaches the circulation via the gut. This study investigated whether maternal vitamin D programs metabolic, gut and bone health of male offspring in an obesogenic environment.

METHODS

C57BL/6J dams received an AIN-93G diet with high (H) or low (L) vitamin D during pregnancy and lactation. At weaning, offspring remained on their dam's vitamin D level (LL or HH) or were switched (LH or HL) and fed a high fat (44.2%) and sucrose (19.8%) diet. Glucose response, adiposity, systemic inflammation (LPS, cytokines), intestinal permeability and mass, strength and microarchitecture of trabecular and cortical bone were assessed in 7-month-old male offsprings.

RESULTS

Higher maternal dietary vitamin D resulted in lower intestinal permeability (fecal albumin, P=0.010) and benefited trabecular but not cortical bone structure at the distal femur (higher trabecular number, P=0.022; less trabecular separation, P=0.015) and lumbar vertebra 2 (bone volume/total volume%, P=0.049). Higher maternal and offspring vitamin D resulted in lower fasting glucose (HH versus LL, P=0.039) and serum LPS concentrations (dam diet, P=0.011; pup diet, P=0.002). Higher offspring vitamin D resulted in lower epididymal fat pad relative weight (P=0.006). The serum concentrations of IL-6 and TNF-α did not differ among groups.

CONCLUSIONS

Maternal dietary vitamin D beneficially programs intestinal permeability and systemic LPS concentration, which is accompanied by stronger trabecular bone in an obesogenic environment. Thus, the gut may mediate vitamin D effects. Moreover, optimizing vitamin D in early life may be critical for later health.

Both systemic and local lipopolysaccharide (LPS) burden are associated with knee OA severity and inflammation

OBJECTIVE

The microbiome is recognized as a new frontier in medicine with connections to a variety of diseases. We aimed to evaluate the association of lipopolysaccharide (LPS), a key pro-inflammatory product of the microbiome, with severity of inflammation, symptoms and radiographic abnormalities of knee osteoarthritis (OA).

DESIGN

LPS was measured using a recombinant Factor C (rFC) assay, carefully optimized for systemic and synovial fluid (SF) analyses. LPS binding protein (LBP) was tested in both serum and SF of 25 patients (31 knees) from the Etarfolatide cohort for association with OA phenotypic outcomes. Models were adjusted for age, gender and body mass index.

RESULTS

Based on LPS spike-and-recovery, both serum and SF dilutions of 0.1% were required to achieve recovery rates of at least 75% in all test specimens. Low coefficients of variation (CVs) (<10%) were achieved with both serum and SF dilutions <0.2%. Serum LPS and LBP were associated with the abundance of activated macrophages in the knee joint capsule and synovium. SF LPS and LBP were associated with the abundance of activated macrophages in the synovium. Serum LPS, LBP and SF LPS were associated with knee osteophyte severity. SF LPS was positively associated with knee joint space narrowing (JSN) severity and total WOMAC score. SF LBP was positively associated with self-reported knee pain score.

CONCLUSION

These data strongly support a role for LPS in the pathogenesis and severity of structural abnormalities and symptoms of knee OA.

Impact of Gut Microbiota on Obesity, Diabetes, and Cardiovascular Disease Risk

Gut microbiota has been recently established to have a contributory role in the development of cardiometabolic disorders, such as atherosclerosis, obesity, and type 2 diabetes. Growing interest has focused on the modulation of gut microbiota as a therapeutic strategy in cardiovascular diseases and metabolic disorders. In this paper, we have reviewed the impact of gut microbiota on metabolic disorders and cardiovascular disease risk, focusing on the newest findings in this field.

Multiple-unit tablet of probiotic bacteria for improved storage stability, acid tolerability, and in vivo intestinal protective effect

The aim of this study was to formulate probiotics-loaded pellets in a tablet form to improve storage stability, acid tolerability, and in vivo intestinal protective effect. Bacteria-loaded pellets primarily prepared with hydroxypropyl methylcellulose acetate succinate were compressed into tablets with highly compressible excipients and optimized for flow properties, hardness, and disintegration time. The optimized probiotic tablet consisted of enteric-coated pellets (335 mg), microcrystalline cellulose (Avicel PH102, 37.5 mg), and porous calcium silicate (25 mg) and allowed whole survival of living bacteria during the compaction process with sufficient tablet hardness (13 kp) and disintegration time (14 minutes). The multiple-unit tablet showed remarkably higher storage stability under ambient conditions (25°C/60% relative humidity) over 6 months and resistance to acidic medium compared to uncoated strains or pellets. Repeated intake of this multiple-unit tablet significantly lowered plasma level of endotoxin, a pathogenic material, compared to repeated intake of bare probiotics or marketed products in rats. These results, therefore, suggest that the multiple-unit tablet is advantageous to better bacterial viability and gain the beneficial effects on the gut flora, including the improvement of intestinal barrier function.

Lipopolysaccharide-binding protein cannot independently predict type 2 diabetes mellitus: A nested case-control study

BACKGROUND

Cross-sectional studies have reported a close association between serum lipopolysaccharide-binding protein (LBP) and many metabolic disorders. However, no longitudinal study has explored the relationship between LBP and type 2 diabetes mellitus (T2DM). The aim of the present study was to investigate the association between serum LBP levels and the risk of developing T2DM.

METHODS

A 5-year nested case-control study of 3510 individuals was performed as part of the Environment, Inflammation and Metabolic Diseases Study (EIMDS). Clinical data were collected at baseline. Serum levels of LBP and other biochemical factors, such as insulin and high-sensitivity C-reactive protein, were detected 5 years later. Subjects were diagnosed as having T2DM on the basis of results of an oral glucose tolerance test (OGTT) and 1998 World Health Organization criteria. Controls were randomly selected to match cases according to age, gender, and body mass index (BMI) in a 1:1 ratio. Odds ratios (OR) for T2DM were calculated using conditional logistic regression analysis.

RESULTS

Over a 5-year follow-up period, 255 subjects developed T2DM. There was no significant difference in serum LBP levels between the T2DM and control groups at baseline (19.78 ± 6.40 versus 20.53 ± 6.99 μg/mL; P = 0.207). Subjects were divided into three groups based on tertiles of LBP concentrations (n = 170 in each group; T1 = 1.31-17.16 μg/mL LBP; T2 = 17.21-22.37 μg/mL LBP; T3 = 22.49-40.08 μg/mL LBP). There was no significant association between the risk of developing T2DM and any of the LBP tertiles in either a simple model or after adjusting for general status and biochemical factors.

CONCLUSION

After matching for gender, age, and BMI, LBP does not improve prediction of the development of T2DM independently.

Does lipopolysaccharide-mediated inflammation have a role in OA?

The nature of the gastrointestinal microbiome determines the reservoir of lipopolysaccharide, which can migrate from the gut into the circulation, where it contributes to low-grade inflammation. Osteoarthritis (OA) is a low-grade inflammatory condition, and the elevation of levels of lipopolysaccharide in association with obesity and metabolic syndrome could contribute to OA. A 'two- hit' model of OA susceptibility and potentiation suggests that lipopolysaccharide primes the proinflammatory innate immune response via Toll-like receptor 4 and that progression to a full-blown inflammatory response and structural damage of the joint results from coexisting complementary mechanisms, such as inflammasome activation or assembly by damage-associated molecular patterns in the form of fragmented cartilage-matrix molecules. Lipopolysaccharide could be considered a major hidden risk factor that provides a unifying mechanism to explain the association between obesity, metabolic syndrome and OA.

Metabolic endotoxaemia in childhood obesity

Background

Childhood obesity is associated with chronic low-grade inflammation considered as a precursor to metabolic disease; however, the underlying mechanisms for this remain unclear. Studies in adults have implicated gut derived gram-negative bacterial fragments known as lipopolysaccharide or endotoxin, activating the inflammatory response, whilst the importance in childhood obesity is unclear. The aim of this research is to understand the relationship between circulating endotoxin in childhood obesity, and its’ association with inflammatory and cardiovascular (CV) injury biomarkers.

Methods

Fasted blood was obtained from children with varying degrees of obesity (age: 13.9 ± 2.3Yr; BMI: 35.1 ± 5.2 Kg/m²; n = 60). Multiplex CVD biomarker immunoassays were used to determine systemic levels of inflammatory and vascular injury biomarkers, such as tumour necrosis factor-α (TNF-α), interleukin (IL-) 1β, 6, 8 and 10, plasminogen activator inhibitor-1 (PAI-1), soluble intercellular adhesion molecule type-1 (sICAM-1), matrix metalloproteinase-9 (MMP-9), myeloperoxidase (MPO) and vascular endothelial growth factor (VEGF) as well as endotoxin levels.

Results

Endotoxin levels demonstrated a significant and positive correlation with the markers for inflammation, vascular injury and atherogenesis (TNF-α: r² = 0.077, p < 0.05; PAI-1: r² = 0.215, p < 0.01; sICAM-1: r² = 0.159, p < 0.01; MMP-9: r² = 0.159, p < 0.01; MPO: r² = 0.07, p < 0.05; VEGF: r² = 0.161, p < 0.01). Males demonstrated significantly higher circulating endotoxin than females (Males: 9.63 ± 5.34 EU/ml; p = 0.004; Females: 5.56 ± 4.06 EU/ml; n = 60) in these BMI and age-matched cohorts.

Conclusion

The present study demonstrates for the first time a significant association between circulating endotoxin and biomarkers of metabolic risk in children as young as 11 years. Thus, endotoxin-mediated sub-clinical inflammation during childhood obesity may be a key contributor to T2DM and CVD development later in life.

Chasing a ghost?--Issues with the determination of circulating levels of endotoxin in human blood

Reliable quantification of bacterial products such as endotoxin is important for the diagnosis of Gram-negative infection and for the monitoring of its treatment. Further, it is important to identify patients with persistent subclinical level of bacterial products in their systemic circulation as data from animal studies also suggest this may be correlated with the onset of metabolic syndrome. In this review, we first aim to describe the principles of the Limulus amoebocyte lysate (LAL) test, an assay that is used to quantify endotoxin, and the various shortcomings that must be addressed before it can become a reliable means of quantifying endotoxin in samples derived from blood. We then review published data regarding endotoxin levels in healthy subjects and those with sepsis, inflammatory bowel disease, liver disorders and metabolic disorders such as obesity and diabetes. We also review the evidence regarding influence of macronutrients in augmenting the levels of systemic endotoxin. The results of this review show that reported mean levels of endotoxin in the systemic circulation of healthy humans and of those with various clinical disorders vary over a wide range. Further, this review shows that a significant proportion of this variation can be related to the method that was used to prepare plasma and serum samples prior to assay and its ability to reduce the effect of various blood borne factors that interfere with the LAL assay.

The effect of prebiotic supplementation with inulin on cardiometabolic health: Rationale, design, and methods of a controlled feeding efficacy trial in adults at risk of type 2 diabetes

Prediabetes is associated with low-grade chronic inflammation that increases the risk for developing type 2 diabetes (T2D) and cardiovascular disease (CVD). An elevated lipopolysaccharide concentration, associated with dysbiosis of the intestinal microbiota, has been implicated in the development of both T2D and CVD. Selective modulation of the intestinal microbiota with prebiotics reduces intestinal permeability and endotoxin concentrations, inflammation, and metabolic dysfunction in rodents. The effect of prebiotic supplementation on cardio-metabolic function in humans at risk for T2D is not known. The primary aim of this trial is to determine the influence of prebiotic supplementation with inulin on insulin sensitivity and skeletal muscle metabolic flexibility in adults at risk for T2D. We hypothesize that prebiotic supplementation with inulin will improve insulin sensitivity and skeletal muscle metabolic flexibility. We will randomize 48 adults (40-75 yrs) with prediabetes or a score ≥ 5 on the American Diabetes Association (ADA) risk screener to 6 weeks of prebiotic supplementation with inulin (10 g/day) or placebo. Subjects will be provided with all food for the duration of the study, to avoid potential confounding through differences in dietary intake between individuals. Intestinal permeability, serum endotoxin concentrations, insulin sensitivity, skeletal muscle metabolic flexibility, endothelial function, arterial stiffness, and fecal bacterial composition will be measured at baseline and following treatment. The identification of prebiotic supplementation with inulin as an efficacious strategy for reducing cardio-metabolic risk in individuals at risk of T2D could impact clinical practice by informing dietary recommendations and increasing acceptance of prebiotics by the scientific and medical community.

Postprandial Effect of a High-Fat Meal on Endotoxemia in Arab Women with and without Insulin-Resistance-Related Diseases

This study determined the effects of a high-fat meal on circulating endotoxin and cardiometabolic indices in adult Arab women. The cohort consisted of 92 consenting Saudi women (18 non-diabetic (ND)) control subjects; Age 24.4 ± 7.9 year; body mass index (BMI) 22.2 ± 2.2 Kg/m2), 24 overweight/obese (referred to as overweight-plus (overweight+)) subjects (Age 32.0 ± 7.8 year; BMI 28.5 ± 1.5 Kg/m2) and 50 type 2 diabetes mellitus (T2DM) patients (Age 41.5 ± 6.2 year; BMI 35.2 ± 7.7 Kg/m2). All were given a high-fat meal (standardized meal: 75 g fat, 5 g carbohydrate, 6 g protein) after an overnight fast of 12-14 h. Anthropometrics were obtained and fasting blood glucose, lipids, and endotoxin were serially measured for four consecutive postprandial hours. Endotoxin levels were significantly elevated prior to a high-fat meal in the overweight+ and T2DM than the controls (p < 0.05). Furthermore, the postprandial cardiometabolic changes led to a more detrimental risk profile in T2DM subjects than other groups, with serial changes most notable in glucose, triglycerides, high density lipoprotein-cholesterol (HDL-cholesterol), and insulin levels (p-values < 0.05). The same single meal given to subjects with different metabolic states had varying impacts on cardiometabolic health. Endotoxemia is exacerbated by a high-fat meal in Arab subjects with T2DM, accompanied by a parallel increase in cardiometabolic risk profile, suggesting disparity in disease pathogenesis of those with or without T2DM through the altered cardiometabolic risk profile rather than variance in metabolic endotoxinaemia with a high-fat meal.

Biomarkers of Coronary Artery Disease Differ Between Asians and Caucasians in the General Population

Coronary artery disease (CAD) markers have not been thoroughly investigated among Asians. The incidence of CAD, however, is rising rapidly in Asia. In this review, we systematically discuss publications that compare CAD biomarkers between Asians and Caucasians in the general population. A PubMed search yielded 5,570 hits, containing 59 articles describing 47 unique cohorts that directly compare Asians with Caucasians. Ten biomarkers were taken into account for this review: total cholesterol; triglycerides; high-density lipoprotein cholesterol; low-density lipoprotein cholesterol; C-reactive protein; glucose; insulin; glycated hemoglobin; fibrinogen; and plasminogen activator inhibitor-1. Triglycerides were 1.13-fold higher in South Asians than in Caucasians, and insulin levels were 1.33-fold higher. In Japanese and Chinese subjects, lower C-reactive protein levels were reported: 0.52 and 0.36-fold, respectively. Ethnicity-specific prognostic measures of CAD biomarkers were rarely reported. CAD biomarker levels differ between Asians and Caucasians and among Asian ethnic groups in population-based cohorts. The ethnicity-specific prognostic value of CAD biomarkers is yet to be determined.

Higher plasma lipopolysaccharide concentrations are associated with less favorable phenotype in overweight/obese men

PURPOSE

Lipopolysaccharide (LPS) from the outer membrane of gram-negative bacteria might be an inflammation trigger in adipose tissue. It has recently been proposed that there is a link between adipose tissue distribution and blood LPS. However, the number of studies on this topic is scarce, and further investigation in humans is required. In this study, we explored the association between plasma LPS concentrations and body fat distribution, as well as the biochemical parameters that may indicate the presence of metabolic disorders.

METHODS

Sixty-seven young adult men with body mass index of 26-35 kg/m(2) were evaluated. Anthropometry, body composition and body fat distribution, blood pressure, energy expenditure, physical activity level, dietary intake, and biochemical parameters were assessed.

RESULTS

Men with median plasma LPS ≥ 0.9 EU/mL presented higher sagittal abdominal diameter, trunk fat percentage, and android fat percentage, and mass, insulin and alanine aminotransferase concentrations, homeostasis model assessment of insulin resistance (HOMA-IR), and beta cell dysfunction (HOMA-B) than those with lower plasma LPS. LPS correlated positively with the trunk fat percentage, and android fat percentage, and mass, insulin, aspartate aminotransferase, alanine aminotransferase, and alkaline phosphatase concentrations, as well as HOMA-IR and HOMA-B.

CONCLUSION

Our results suggest that a higher plasma LPS concentration is associated with a less favorable phenotype as characterized by higher central adiposity, higher values of HOMA-IR, and beta cell function impairment in overweight/obese men.

Aspirin-induced increase in intestinal paracellular permeability does not affect the levels of LPS in venous blood of healthy women

The presence of subclinical levels of LPS from Gram-negative bacteria, also referred to as endotoxin, in the circulation may induce a pro-inflammatory immune response that leads to the development of obesity and insulin resistance. Recent data indicate that high-fat meals may elevate circulating levels of LPS. However, it is currently unclear how the LPS transits from the gut lumen to the general circulation. We determined whether aspirin-induced damage of the small intestinal mucosa, evidenced by an increase in the paracellular permeability, allows greater transit of LPS into the systemic circulation. The 3-h cumulative excretion of lactulose was significantly increased after the consumption of aspirin solution relative to that after the consumption of an equal volume of water in 15 healthy women (median after aspirin 0.09% of dose vs. median after water 0.03% of dose; P = 0.004). Dosage with aspirin also significantly increased the lactulose : mannitol ratio (median after aspirin 0.014 vs. median after water 0.005; P = 0.017). However, serum LPS levels after the consumption of the aspirin solution were not significantly different from those after consumption of the control (plain water). Further, there was no correlation between body fat content and circulating levels of LPS.

Vitamin D receptor gene polymorphisms are associated with obesity and inflammosome activity

To explore the mechanisms underlying the suggested role of the vitamin D/vitamin D receptor (VDR) complex in the pathogenesis of obesity we performed genetic and immunologic analyses in obese and non-obese Saudi individuals without other concomitant chronic diseases. Genomic DNA was genotyped for gene single nucleotide polymorphisms (SNPs) of VDR by allelic discrimination in 402 obese (body mass index –BMI≥30 kg/m2) and 489 non-obese (BMI<30 kg/m2) Saudis. Q-PCR analyses were performed using an ABI Prism 7000 Sequence Detection System. The inflammosome pathway was analysed by PCR, cytokines and plasma lipopolysaccaride (LPS) concentrations with ELISA assays. Results showed that the VDR SNPs rs731236 (G) (TaqI) and rs1544410 (T) (Bsm-I) minor allele polymorphisms are significantly more frequent in obese individuals (p = 0.009, β = 0.086 and p = 0.028, β = 0.072, respectively). VDR haplotypes identified are positively (GTA) (p = 0.008, β = 1.560); or negatively (ACC) (p = 0.044, β = 0.766) associated with obesity and higher BMI scores. The GTA "risk" haplotype was characterized by an up-regulation of inflammosome components, a higher production of proinflammatory cytokines (p<0.05) and a lower VDR expression. Plasma LPS concentration was also increased in GTA obese individuals (p<0.05), suggesting an alteration of gut permeability leading to microbial translocation. Data herein indicate that polymorphisms affecting the vitamin D/VDR axis play a role in obesity that is associated with an ongoing degree of inflammation, possibly resulting from alterations of gut permeability and microbial translocation. These results could help the definition of VDR fingerprints that predict an increased risk of developing obesity and might contribute to the identification of novel therapeutic strategies for this metabolic condition.

Microencapsulated Bifidobacterium longum subsp. infantis ATCC 15697 favorably modulates gut microbiota and reduces circulating endotoxins in F344 rats

The gut microbiota is a bacterial bioreactor whose composition is an asset for human health. However, circulating gut microbiota derived endotoxins cause metabolic endotoxemia, promoting metabolic and liver diseases. This study investigates the potential of orally delivered microencapsulated Bifidobacterium infantis ATCC 15697 to modulate the gut microbiota and reduce endotoxemia in F344 rats. The rats were gavaged daily with saline or microencapsulated B. infantis ATCC 15697. Following 38 days of supplementation, the treated rats showed a significant (P < 0.05) increase in fecal Bifidobacteria (4.34 ± 0.46 versus 2.45 ± 0.25% of total) and B. infantis (0.28 ± 0.21 versus 0.52 ± 0.12 % of total) and a significant (P < 0.05) decrease in fecal Enterobacteriaceae (0.80 ± 0.45 versus 2.83 ± 0.63% of total) compared to the saline control. In addition, supplementation with the probiotic formulation reduced fecal (10.52 ± 0.18 versus 11.29 ± 0.16 EU/mg; P = 0.01) and serum (0.33 ± 0.015 versus 0.30 ± 0.015 EU/mL; P = 0.25) endotoxins. Thus, microencapsulated B. infantis ATCC 15697 modulates the gut microbiota and reduces colonic and serum endotoxins. Future preclinical studies should investigate the potential of the novel probiotic formulation in metabolic and liver diseases.

The SLE transcriptome exhibits evidence of chronic endotoxin exposure and has widespread dysregulation of non-coding and coding RNAs

BACKGROUND

Gene expression studies of peripheral blood mononuclear cells from patients with systemic lupus erythematosus (SLE) have demonstrated a type I interferon signature and increased expression of inflammatory cytokine genes. Studies of patients with Aicardi Goutières syndrome, commonly cited as a single gene model for SLE, have suggested that accumulation of non-coding RNAs may drive some of the pathologic gene expression, however, no RNA sequencing studies of SLE patients have been performed. This study was designed to define altered expression of coding and non-coding RNAs and to detect globally altered RNA processing in SLE.

METHODS

Purified monocytes from eight healthy age/gender matched controls and nine SLE patients (with low-moderate disease activity and lack of biologic drug use or immune suppressive treatment) were studied using RNA-seq. Quantitative RT-PCR was used to validate findings. Serum levels of endotoxin were measured by ELISA.

RESULTS

We found that SLE patients had diminished expression of most endogenous retroviruses and small nucleolar RNAs, but exhibited increased expression of pri-miRNAs. Splicing patterns and polyadenylation were significantly altered. In addition, SLE monocytes expressed novel transcripts, an effect that was replicated by LPS treatment of control monocytes. We further identified increased circulating endotoxin in SLE patients.

CONCLUSIONS

Monocytes from SLE patients exhibit globally dysregulated gene expression. The transcriptome is not simply altered by the transcriptional activation of a set of genes, but is qualitatively different in SLE. The identification of novel loci, inducible by LPS, suggests that chronic microbial translocation could contribute to the immunologic dysregulation in SLE, a new potential disease mechanism.

Metabolic endotoxemia: a molecular link between obesity and cardiovascular risk

Obesity is associated with significantly increased cardiovascular (CV) risk and mortality. Several molecular mechanisms underlying this association have been implied, among which the intestinal barrier has gained a growing interest. In experimental models of obesity, significant alterations in the intestinal barrier lead to increased intestinal permeability, favoring translocation of microbiome-derived lipopolysaccharide to the bloodstream. This has been shown to result in a two- to threefold increase in its serum concentrations, a threshold named 'metabolic endotoxemia' (ME). ME may trigger toll-like receptor 4-mediated inflammatory activation, eliciting a chronic low-grade proinflammatory and pro-oxidative stress status, which may result in high CV risk and target-organ damage. In this review, we discuss the potential molecular implications of ME on several CV risk factors, such as obesity, insulin resistance, dyslipidemia, and oxidative stress, as well as its potential impact on the development of CV target-organ disease.

Effects of probiotics in patients with diabetes mellitus type 2: study protocol for a randomized, double-blind, placebo-controlled trial

BACKGROUND

Low grade chronic inflammation is observed in patients with type 2 diabetes mellitus (T2DM). Endotoxin derived from gut bacteria may act as a potent inflammatory stimulant. Probiotics, which are believed to contain health promoting live microorganisms, may influence circulating endotoxin levels. Ingestion of live probiotic cultures may alter gut microbiota in a beneficial manner to reduce inflammation; no information is available whether or not they do so in patients with T2DM. Therefore, the aim of this study is to characterize the beneficial effects of probiotics on circulating endotoxin levels and other biomarkers related to systemic low-grade inflammation in patients with T2DM.

METHODS

One hundred and twenty consenting adult Saudi T2DM patients (naïve or newly diagnosed and without co-morbidities) will be enrolled in this clinical trial and randomized to receive daily placebo or probiotics (Ecologic®Barrier) for 26 weeks in a double-blind manner. Inflammatory and metabolic markers will be measured and fecal samples analyzed. Measurements/samples will be obtained at baseline and after 4, 8, 12/13 and 26 weeks of treatment.

DISCUSSION

It is expected that the probiotic product will induce beneficial changes in gut microbiota, reduce the systemic inflammatory state through altering systemic endotoxin levels and, as such, reduce the systemic inflammatory response observed in T2DM subjects.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT01765517.

Effects of probiotics in patients with diabetes mellitus type 2: study protocol for a randomized, double-blind, placebo-controlled trial

Background

Low grade chronic inflammation is observed in patients with type 2 diabetes mellitus (T2DM). Endotoxin derived from gut bacteria may act as a potent inflammatory stimulant. Probiotics, which are believed to contain health promoting live microorganisms, may influence circulating endotoxin levels. Ingestion of live probiotic cultures may alter gut microbiota in a beneficial manner to reduce inflammation; no information is available whether or not they do so in patients with T2DM. Therefore, the aim of this study is to characterize the beneficial effects of probiotics on circulating endotoxin levels and other biomarkers related to systemic low-grade inflammation in patients with T2DM.

Methods

One hundred and twenty consenting adult Saudi T2DM patients (naïve or newly diagnosed and without co-morbidities) will be enrolled in this clinical trial and randomized to receive daily placebo or probiotics (Ecologic®Barrier) for 26 weeks in a double-blind manner. Inflammatory and metabolic markers will be measured and fecal samples analyzed. Measurements/samples will be obtained at baseline and after 4, 8, 12/13 and 26 weeks of treatment.

Discussion

It is expected that the probiotic product will induce beneficial changes in gut microbiota, reduce the systemic inflammatory state through altering systemic endotoxin levels and, as such, reduce the systemic inflammatory response observed in T2DM subjects.

Trial registration

ClinicalTrials.gov Identifier: NCT01765517

Effect of acute and chronic red wine consumption on lipopolysaccharide concentrations

BACKGROUND

Chronic red wine (RW) consumption has been associated with decreased cardiovascular disease risk, mainly attributed to an improvement in lipid profile. RW intake is also able to change the composition of gut microbiota. High fat intake has recently been reported to increase metabolic endotoxemia. The gut microbiota has been proposed as the main resource of plasma lipopolysaccharides (LPSs) in metabolic endotoxemia.

OBJECTIVE

We analyzed the effect on LPS concentrations of chronic RW consumption and acute RW intake in relation to high fat intake in middle-aged men.

DESIGN

For the chronic study, 10 middle-aged male volunteers were randomly assigned in a crossover trial, and after a washout period, all subjects received RW, dealcoholized red wine (DRW), or gin for 20 d. Serum endotoxin and LPS-binding protein (LBP) concentrations were determined after the washout period and after each of the treatments, and changes in fecal microbiota were quantified. For the acute study, 5 adult men underwent a fat overload or a fat overload together with the consumption of RW, DRW, or gin. Baseline and postprandial serum LPS and LBP concentrations and postprandial chylomicron LPS concentrations were measured.

RESULTS

There were no significant differences in the change in LPS or LBP concentrations between chronic RW, DRW, and gin consumption. Bifidobacterium and Prevotella amounts were significantly increased by RW and correlated negatively with LPS concentrations. There were no differences in postprandial serum LPS, LBP, or chylomicron LPS concentrations between acute RW, DRW, or gin intake together with a fatty meal.

CONCLUSION

Chronic RW consumption increases Bifidobacterium and Prevotella amounts, which may have beneficial effects by leading to lower LPS concentrations. This trial was registered at controlled-trials.com as ISRCTN88720134.

mRNA-binding protein ZFP36 is expressed in atherosclerotic lesions and reduces inflammation in aortic endothelial cells

OBJECTIVE

We studied the expression and function of an mRNA-binding protein, zinc finger protein-36 (ZFP36), in vascular endothelial cells in vivo and in vitro. We tested the hypotheses that ZFP36 regulates inflammation in vascular endothelial cells and that it functions through direct binding to target cytokine mRNAs. We also tested whether ZFP36 inhibits nuclear factor-κB-mediated transcriptional responses in vascular endothelial cells.

APPROACH AND RESULTS

ZFP36 was minimally expressed in healthy aorta but was expressed in endothelial cells overlying atherosclerotic lesions in mice and humans. The protein was also expressed in macrophage foam cells of atherosclerosis. ZFP36 was expressed in human aortic endothelial cells in response to bacterial lipopolysaccharide, glucocorticoid, and forskolin, but not oxidized low-density lipoproteins or angiotensin II. Functional studies demonstrated that ZFP36 reduces the expression of inflammatory cytokines in target cells by 2 distinct mechanisms: ZFP36 inhibits nuclear factor-κB transcriptional activation and also binds to cytokine mRNAs, leading to reduced transcript stability.

CONCLUSIONS

ZFP36 is expressed in vascular endothelial cells and macrophage foam cells where it inhibits the expression of proinflammatory mRNA transcripts. The anti-inflammatory effects of ZFP36 in endothelial cells occur via both transcriptional and posttranscriptional mechanisms. Our data suggest that enhancing vascular ZFP36 expression might reduce vascular inflammation.