Complex links between dietary lipids, endogenous endotoxins and metabolic inflammation. Biochimie. 2011;93:39-45. [PMID: 20433893 DOI: 10.1016/j.biochi.2010.04.016]

Transcriptional profiles associated with coronary artery disease in type 2 diabetes mellitus

Background

Coronary artery disease (CAD) is a common complication of Type 2 diabetes mellitus (T2DM). Understanding the pathogenesis of this complication is essential in both diagnosis and management. Thus, this study aimed to characterize the presence of CAD in T2DM using molecular markers and pathway analyses.

Methods

The study is a sex- and age-frequency matched case-control design comparing 23 unrelated adult Filipinos with T2DM-CAD to 23 controls (DM with CAD). Healthy controls served as a reference. Total RNA from peripheral blood mononuclear cells (PBMCs) underwent whole transcriptomic profiling using the Illumina HumanHT-12 v4.0 expression beadchip. Differential gene expression with gene ontogeny analyses was performed, with supporting correlational analyses using weighted correlation network analysis (WGCNA).

Results

The study observed that 458 genes were differentially expressed between T2DM with and without CAD (FDR<0.05). The 5 top genes the transcription factor 3 (TCF3), allograft inflammatory factor 1 (AIF1), nuclear factor, interleukin 3 regulated (NFIL3), paired immunoglobulin-like type 2 receptor alpha (PILRA), and cytoskeleton-associated protein 4 (CKAP4) with AUCs >89%. Pathway analyses show differences in innate immunity activity, which centers on the myelocytic (neutrophilic/monocytic) theme. SNP-module analyses point to a possible causal dysfunction in innate immunity that triggers the CAD injury in T2DM.

Conclusion

The study findings indicate the involvement of innate immunity in the development of T2DM-CAD, and potential immunity markers can reflect the occurrence of this injury. Further studies can verify the mechanistic hypothesis and use of the markers.

The digestion and absorption characteristics of human milk phospholipid analogs: a combination study between in vitro and in vivo

Phospholipids play a crucial role in the growth and neurodevelopment of infants. Currently, soybean phospholipids (SPLs) are the common phospholipid component in most infant formulas (IFs), which, however, shows an obvious difference with the phospholipid (PL) composition of human milk fat. Therefore, in the present study, human milk phospholipid analogs (HMPAs) were prepared by mimicking the composition of PE, PC, PI, PS, and SM in breast milk phospholipids and the composition of the major fatty acids (C16:0, C18:0, C18:1, and C18:2), and their digestion and absorption characteristics were explored using in vitro and mice models. The prepared HMPA contained 26.48% PE, 24.64% PC, 36.19% SM, 6.35% PI, and 6.32% PS, with 40.51% C16:0, 17.02% C18:0, 29.19% C18:1, and 13.26% C18:2, showing different digestive properties relative to SPL. There was little effect on the physical and chemical properties of HMPA under in vitro gastric conditions. The hydrolysis degree, fatty acids release rate, and average particle size decreasing rate of HMPA was significantly higher than that of SPL during digestion in vitro intestine (P < 0.05), showing better digestive process relative to SPL. In terms of the mice model, HMPA had a higher hydrolysis degree in the intestinal tract. Based on the area under curve (AUC) analysis of serum fatty acids, it was found that despite HMPA being absorbed at a slower rate than SPL, it was absorbed more than SPL. In summary, the digestion and absorption of HMPA were preferred to SPL, and these obtained results might provide a theoretical basis for the development and utilization of HMPA in IF.

Lipid emulsion structure, digestion behavior, physiology, and health: a scoping review and future directions

Research investigating the effects of the food matrix on health is needed to untangle many unresolved questions in nutritional science. Emulsion structure plays a fundamental role in this inquiry; however, the effects of oil-in-water emulsion structure on broad metabolic, physiological, and health-related outcomes have not been comprehensively reviewed. This systematic scoping review targets this gap and examines methodological considerations for the field of relating food structure and health. MEDLINE, Web of Science, and CAB Direct were searched from inception to December 2022, returning 3106 articles, 52 of which were eligible for inclusion. Many investigated emulsion lipid droplet size and/or gastric colloidal stability and their relation to postprandial weight-loss-related outcomes. The present review also identifies numerous novel relationships between emulsion structures and health-related outcomes. "Omics" endpoints present an exciting avenue for more comprehensive analysis in this area, yet interpretation remains difficult. Identifying valid surrogate biomarkers for long-term outcomes and disease risk will be a turning point for food structure research, leading to breakthroughs in the pace and utility of research that generates advancements in health. The review's findings and recommendations aim to support new hypotheses, future trial design, and evidence-based emulsion design for improved health and well-being.

Endotoxemia in Acute Heart Failure and Cardiogenic Shock: Evidence, Mechanisms and Therapeutic Options

Acute heart failure and cardiogenic shock are frequently occurring and deadly conditions. In patients with those conditions, endotoxemia related to gut injury and gut barrier dysfunction is usually described as a driver of organ dysfunction. Because endotoxemia might reciprocally alter cardiac function, this phenomenon has been suggested as a potent vicious cycle that worsens organ perfusion and leading to adverse outcomes. Yet, evidence beyond this phenomenon might be overlooked, and mechanisms are not fully understood. Subsequently, even though therapeutics available to reduce endotoxin load, there are no indications to treat endotoxemia during acute heart failure and cardiogenic shock. In this review, we first explore the evidence regarding endotoxemia in acute heart failure and cardiogenic shock. Then, we describe the main treatments for endotoxemia in the acute setting, and we present the challenges that remain before personalized treatments against endotoxemia can be used in patients with acute heart failure and cardiogenic shock.

SERUM GLP-2 is Increased in Association with Excess Gestational Weight Gain

OBJECTIVE

Obesity in pregnancy bears unique maternal and fetal risks. Obesity has also been associated with chronic inflammation, including elevated serum levels of interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α). Higher serum lipopolysaccharide (LPS) levels have been implicated in driving this inflammation, a phenomenon called metabolic endotoxemia (ME). GLP-2, a proglucagon-derived peptide, is believed to be integral in maintaining the integrity of the intestine in the face of LPS-mediated endotoxemia. We hypothesized that obesity and/or excess weight gain in pregnancy would be associated with an increase in maternal and neonatal markers of ME, as well as GLP-2.

STUDY DESIGN

Paired maternal and neonatal (cord blood) serum samples (n = 159) were obtained from our pregnancy biobank repository. Serum levels of LPS, endotoxin core antibody-immunoglobulin M (EndoCAb-IgM), and GLP-2 were measured by ELISA. IL-6 and TNF-α were measured using a Milliplex assay. Results were stratified by maternal body mass index (BMI), maternal diabetes, and gestational weight gain (GWG).

RESULTS

Maternal IL-6 is significantly decreased in the obese, diabetic cohort compared with the nonobese, nondiabetic cohorts (95.28 vs. 99.48 pg/mL, p = 0.047), whereas GLP-2 is significantly increased (1.92 vs. 2.89 ng/mL, p = 0.026). Neonatal TNF-α is significantly decreased in the obese cohort compared with the nonobese cohort (12.43 vs. 13.93 pg/mL, p = 0.044). Maternal GLP-2 is significantly increased in women with excess GWG compared with those with normal GWG (2.27 vs. 1.48 ng/mL, p = 0.014). We further found that neonatal IL-6 and TNF-α are negatively correlated with maternal BMI (-0.186, p = 0.036 and -0.179, p = 0.044, respectively) and that maternal and neonatal IL-6 showed a positive correlation (0.348, p < 0.001).

CONCLUSION

Although we observed altered levels of markers of inflammation (IL-6 and TNF-α) with maternal obesity and diabetes, no changes in LPS or endoCAb-IgM were observed. We hypothesize that the increased GLP-2 levels in maternal serum in association with excess GWG may protect against ME in pregnancy.

KEY POINTS

· Maternal serum levels of GLP-2, a proglucagon-derived peptide, are increased in obese, diabetic gravidae.. · Maternal serum GLP-2 levels are also increased in association with excess gestational weight gain compared with normal gestational weight gain.. · GLP-2 may be increased in association with obesity and weight gain to protect against metabolic endotoxemia in pregnancy..

OSA-starch stabilized EPA nanoliposomes: preparation, characterization, stability and digestion in vitro and in vivo

OSA-starch stabilized EPA nanoliposomes (OSA-EPA-NLs) were prepared by thin film rehydration/dispersion method. The physical properties and morphology of OSA-EPA-NLs were characterized. The best formulated sample was used to measure the storage stability and oxidative properties of EPA under different environmental stresses and to determine release and absorption of OSA-EPA-NLs in vitro and in vivo. The results showed that the encapsulation efficiency of OSA-EPA-NLs was 84.61%. All samples were relatively stable under different environmental stresses, and the release rate of EPA in simulated intestine stage (89.87%) was higher than that in the simulated gastric stage (5.86%). The areas under the EPA concentration-time curve of OSA-EPA-NLs group and EPA-NLs group through in vivo study were 0.42 and 0.32, respectively, which indicated that OSA-starch could improve the stability of EPA nanoliposomes and enhance EPA bioavailability in the form of ethyl esters.

Increased Weight Gain and Insulin Resistance in HF-Fed PLTP Deficient Mice Is Related to Altered Inflammatory Response and Plasma Transport of Gut-Derived LPS

Bacterial lipopolysaccharides (LPS, endotoxins) are found in high amounts in the gut lumen. LPS can cross the gut barrier and pass into the blood (endotoxemia), leading to low-grade inflammation, a common scheme in metabolic diseases. Phospholipid transfer protein (PLTP) can transfer circulating LPS to plasma lipoproteins, thereby promoting its detoxification. However, the impact of PLTP on the metabolic fate and biological effects of gut-derived LPS is unknown. This study aimed to investigate the influence of PLTP on low-grade inflammation, obesity and insulin resistance in relationship with LPS intestinal translocation and metabolic endotoxemia. Wild-type (WT) mice were compared with Pltp-deficient mice (Pltp-KO) after a 4-month high-fat (HF) diet or oral administration of labeled LPS. On a HF diet, Pltp-KO mice showed increased weight gain, adiposity, insulin resistance, lipid abnormalities and inflammation, together with a higher exposure to endotoxemia compared to WT mice. After oral administration of LPS, PLTP deficiency led to increased intestinal translocation and decreased association of LPS to lipoproteins, together with an altered catabolism of triglyceride-rich lipoproteins (TRL). Our results show that PLTP, by modulating the intestinal translocation of LPS and plasma processing of TRL-bound LPS, has a major impact on low-grade inflammation and the onset of diet-induced metabolic disorders.

Impact of internal aqueous phase gelation on in vitro lipid digestion of epigallocatechin gallate-loaded W1 /O/W2 double emulsions incorporated in alginate hydrogel beads

Our objective was to investigate if the internal aqueous phase gelation of Water-in-oil-in-water double emulsions encapsulated in alginate beads would affect their structural stability and lipid hydrolysis during in vitro digestion. Therefore, bioactive molecules such as (-)-epigallocatechin gallate were encapsulated into different types of delivery systems: original double emulsions (as control) and incorporated double emulsions (filled in alginate hydrogel beads), both with non-gelled or gelled internal aqueous phase by locust bean gum and κ-carrageenan. After 2 h of gastric digestion, the gelled original emulsions showed smaller mean droplet diameters and less coalescence during the in vitro simulated gastrointestinal digestion compared to the non-gelled original emulsions. For the incorporated emulsions, oil droplets released from beads aggregated under intestinal conditions, and the rate of lipolysis was delayed. Interestingly, the internal aqueous phase gelation also impacted the rate and cumulative amount of free fatty acids (FFA) released. PRACTICAL APPLICATION: The combination of incorporating (-)-epigallocatechin gallate-loaded double emulsions into the alginate hydrogel matrix and gelling the internal aqueous phase was a benefit to regulating the rate and extent of lipid digestion for specific applications in foods, such as to control blood lipid levels and appetite.

Palm Lipid Emulsion Droplet Crystallinity and Gastric Acid Stability in Relation to in vitro Bioaccessibility and in vivo Gastric Emptying

It is poorly understood how the physical state of emulsified triacylglycerol (TAG) alters colloidal behavior in the gastrointestinal tract to modulate lipid digestion and absorption. We, therefore, aimed to investigate the individual and combined effects on fatty acid (FA) bioaccessibility using the dynamic TIM-1 in vitro digestion model and integrate the results with those from a human clinical study. Four 20% oil-in-water emulsions with overlapping particle size distributions contained either partially crystalline solid (palm stearin) or liquid (palm olein) lipid droplets at 37°C and either the colloidally acid-stable Tween 80 (2.2%) or acid-unstable Span 60 (2.5%) emulsifier. Experimental meals were fed to the TIM-1, and jejunal and ileal dialysates were analyzed over 6 h to measure free FA concentration. Cumulative FA bioaccessibility was significantly higher for the liquid stable emulsion compared to all others (p < 0.05), which did not differ (p > 0.05). Emulsified TAG physical state was associated with differences in overall bioaccessibility (higher for liquid state TAG) in the colloidally stable emulsions, but this difference was blunted in droplets susceptible to acidic flocculation. In contrast, human postprandial TAG concentrations did not differ significantly between the emulsions. The discrepancy may relate to differences in in vivo gastric emptying (GE) as evidenced by ultrasonography. When the in vivo differences in GE were accounted for in follow-up TIM-1 experiments, the findings aligned more closely. Cumulative FA bioaccessibility for the liquid stable emulsion no longer differed significantly from the other emulsions, and SU’s bioaccessibility was the lowest, consistent with the in vivo observations. This work highlights the potential for TAG physical state and colloidal stability to interactively alter behavior in the gastrointestinal tract with implications for FA absorption, and the importance of establishing and improving in vitro–in vivo correlations in food-nutrition research.

Intestinal barrier disorders and metabolic endotoxemia in obesity: Current knowledge

The World Health Organization reports that the prevalent problem of excessive weight and obesity currently affects about 1.9 billion people worldwide and is the fifth most common death factor among patients. In view of the growing number of patients with obesity, attention is drawn to the insufficient effectiveness of behavioral treatment methods. In addition to genetic and environmental factors leading to the consumption of excess energy in the diet and the accumulation of adipose tissue, attention is paid to the role of intestinal microbiota in maintaining a normal body weight. Dysbiosis – a disorder in the composition of the gut microbiota – is mentioned as one of the contributing factors to the development of metabolic diseases, including obesity, type 2 diabetes, and cardiovascular disorders. The human gastrointestinal tract is colonized largely by a group of Gram-negative bacteria that are indicated to be a source of lipopolysaccharide (LPS), associated with inducing systemic inflammation and endotoxemia. Research suggests that disturbances in the gut microbiota, leading to damage to the intestinal barrier and an increase in circulating LPS, are implicated in obesity and other metabolic disorders. Plasma LPS and lipopolysaccharide-binding protein (LBP) levels have been shown to be elevated in individuals with excess body weight. Bariatric surgery has become a popular treatment option, leading to stable weight loss and an improvement in obesity-related conditions. The aim of this study was to characterize the factors that promote the induction of metabolic endotoxemia and its associated health consequences, along with the presentation of their changes after bariatric surgery.

Partial Replacement of Dietary Fat with Krill Oil or Coconut Oil Alleviates Dyslipidemia by Partly Modulating Lipid Metabolism in Lipopolysaccharide-Injected Rats on a High-Fat Diet

This study investigated the effects of partial replacement of dietary fat with krill oil (KO) or coconut oil (CO) on dyslipidemia and lipid metabolism in rats fed with a high-fat diet (HFD). Sprague Dawley rats were divided into three groups as follows: HFD, HFD + KO, and HFD + CO. The rats were fed each diet for 10 weeks and then intraperitoneally injected with phosphate-buffered saline (PBS) or lipopolysaccharide (LPS) (1 mg/kg). The KO- and CO-fed rats exhibited lower levels of serum lipids and aspartate aminotransferases than those of the HFD-fed rats. Rats fed with HFD + KO displayed significantly lower hepatic histological scores and hepatic triglyceride (TG) content than rats fed with HFD. The KO supplementation also downregulated the adipogenic gene expression in the liver. When treated with LPS, the HFD + KO and HFD + CO groups reduced the adipocyte size in the epididymal white adipose tissues (EAT) relative to the HFD group. These results suggest that KO and CO could improve lipid metabolism dysfunction.

Cardiovascular Health and The Intestinal Microbial Ecosystem: The Impact of Cardiovascular Therapies on The Gut Microbiota

It has become evident over the past several years that the intestinal microbial ecosystem plays a critical role in the development and prevention of cardiovascular diseases (CVDs) and other metabolic disorders, such as hypertension, obesity, diabetes mellitus, and metabolic syndrome. The intestinal microbiota ecosystem functions as a major virtual endocrine organ that interacts and responds to molecules' signals within the host. Several meta-organismal pathways are involved in the gut-host interaction, including trimethylamine-N-oxide (TMAO) and short-chain fatty acids (SCFA). Host phenotype and cardiovascular diseases (CVDs) varying from hypertension, insulin resistance, and obesity to more specific inflammatory processes, such as atherosclerosis and hypercoagulability, have shown to be affected by the gut-host interaction. Additionally, several studies that involved animals and humans demonstrated a striking connection between the development of new CVDs and an imbalance in the gut microbiota composition along with the presence of their derived metabolites. Through this review article, we aim to evaluate the role of the normal gut microbiota ecosystem, its association with CVDs, effects of the therapies used to control and manage CVDs in the gut microbiota environment and explore potential therapeutic interventions to amplify disease outcomes in patients with CVDs.

Meal-induced inflammation: postprandial insights from the Personalised REsponses to DIetary Composition Trial (PREDICT) study in 1000 participants

BACKGROUND

Meal-induced metabolic changes trigger an acute inflammatory response, contributing to chronic inflammation and associated diseases.

OBJECTIVES

We aimed to characterize variability in postprandial inflammatory responses using traditional (IL-6) and novel [glycoprotein acetylation (GlycA)] biomarkers of inflammation and dissect their biological determinants with a focus on postprandial glycemia and lipemia.

METHODS

Postprandial (0-6 h) glucose, triglyceride (TG), IL-6, and GlycA responses were measured at multiple intervals after sequential mixed-nutrient meals (0 h and 4 h) in 1002 healthy adults aged 18-65 y from the PREDICT (Personalised REsponses to DIetary Composition Trial) 1 study, a single-arm dietary intervention study. Measures of habitual diet, blood biochemistry, gut microbiome composition, and visceral fat mass (VFM) were also collected.

RESULTS

The postprandial changes in GlycA and IL-6 concentrations were highly variable between individuals. Participants eliciting an increase in GlycA and IL-6 (60% and 94% of the total participants, respectively) had mean 6-h increases of 11% and 190%, respectively. Peak postprandial TG and glucose concentrations were significantly associated with 6-h GlycA (r = 0.83 and r = 0.24, respectively; both P < 0.001) but not with 6-h IL-6 (both P > 0.26). A random forest model revealed the maximum TG concentration was the strongest postprandial TG predictor of postprandial GlycA and structural equation modeling revealed that VFM and fasting TG were most strongly associated with fasting and postprandial GlycA. Network Mendelian randomization demonstrated a causal link between VFM and fasting GlycA, mediated (28%) by fasting TG. Individuals eliciting enhanced GlycA responses had higher predicted cardiovascular disease risk (using the atherosclerotic disease risk score) than the rest of the cohort.

CONCLUSIONS

The variable postprandial increases in GlycA and their associations with TG metabolism highlight the importance of modulating TG in concert with obesity to reduce GlycA and associated low-grade inflammation-related diseases.This trial was registered at clinicaltrials.gov as NCT03479866.

High-fat diet promotes hypothalamic inflammation in animal models: a systematic review

CONTEXT

Hypothalamic inflammation and dysfunction may be induced by high-fat diets. However, the mechanisms involved in this process have not been fully elucidated.

OBJECTIVE

To evidence, in animal models, of how a high-fat diet influence the mechanisms involved in hypothalamic inflammation.

DATA SOURCES

Scopus, PubMed/Medline, Web of Science, Science Direct, and Embase databases were searched.

DATA EXTRACTION

The exclusion criteria were human studies, studies with medicinal products or other substances not related to food, paper reviews, studies that used a surgical intervention or an intervention with food to reverse hypothalamic inflammation, and studies with genetically modified animals. The identified studies were evaluated according to the following inclusion criteria: animal studies, studies in which a control group was included in the experimental design, and studies in which markers of inflammation in the hypothalamus were evaluated.

DATA ANALYSIS

A total of 322 studies were found, of which 9 met the inclusion criteria for a systematic review, conducted in accordance with the PRISMA guidelines, and were included in this review.

CONCLUSION

The exposure of rodents to high-fat diets promoted an increase in levels of several pro-inflammatory cytokines and other proteins involved in the inflammatory process in the hypothalamus. This process was associated with increased glial cell activity.

The association of dietary patterns with dietary inflammatory index, systemic inflammation, and insulin resistance, in apparently healthy individuals with obesity

Inflammation is considered a key mechanism leading to obesity. Dietary patterns and certain food items influence inflammation. Few studies have investigated the contribution of major dietary patterns to biological measures of inflammation. Therefore, the present study aimed to examine the associations of different dietary patterns with dietary inflammatory index (DII), systemic inflammation, and insulin resistance (IR) in the apparently healthy obese. In this cross-sectional study, 151 abdominally obese subjects were recruited from the Northwest of Iran. Dietary intake, demographic data, anthropometric indices, and physical activity (PA) was assessed. DII scores were calculated based on a validated 168-item food frequency questionnaire (FFQ). Three dietary patterns were identified, using principal component analysis. Basal blood samples were collected to determine biochemical parameters. Linear regression test with adjusted beta estimates was applied for data analysis. Three dietary patterns were extracted as Healthy, Western, and Traditional. Body mass index (BMI) (p < 0.01) and fat mass (p < 0.001) were directly associated with the Western dietary pattern. Conversely, serum lipopolysaccharide-binding protein (LBP) (b = - 0.1, p < 0.04) was negatively associated with Healthy dietary pattern, after controlling for confounders. The Traditional pattern was found to be inversely related to DII (b = - 0.3, p < 0.001). The association was also reveresed between Traditional pattern and IR (Odds Ratio: 0.3 (95% Confidence Interval 0.1-0.9)). The results suggested that the Western dietary pattern was related to higher BMI and fat mass. In addition, the Healthy pattern was associated with decreased levels of LBP. Adherence to the Traditional dietary pattern was inversely related to DII as well as IR.

Mediterranean Diet for the Prevention of Gestational Diabetes in the Covid-19 Era: Implications of Il-6 In Diabesity

The aim of this review is to highlight the influence of the Mediterranean Diet (MedDiet) on Gestational Diabetes Mellitus (GDM) and Gestational Weight Gain (GWG) during the COVID-19 pandemic era and the specific role of interleukin (IL)-6 in diabesity. It is known that diabetes, high body mass index, high glycated hemoglobin and raised serum IL-6 levels are predictive of poor outcomes in coronavirus disease 2019 (COVID-19). The immunopathological mechanisms of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection include rising levels of several cytokines and in particular IL-6. The latter is associated with hyperglycemia and insulin resistance and could be useful for predicting the development of GDM. Rich in omega-3 polyunsaturated fatty acids, vitamins, and minerals, MedDiet improves the immune system and could modulate IL-6, C reactive protein and Nuclear Factor (NF)-κB. Moreover, polyphenols could modulate microbiota composition, inhibit the NF-κB pathway, lower IL-6, and upregulate antioxidant enzymes. Finally, adhering to the MedDiet prior to and during pregnancy could have a protective effect, reducing GWG and the risk of GDM, as well as improving the immune response to viral infections such as COVID-19.

Endotoxins and Non-Alcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease worldwide. It occurs with a prevalence of up to 25%, of which 10-20% cases progress to nonalcoholic steatohepatitis (NASH), cirrhosis, and liver cancer. The histopathology of NASH is characterized by neutrophilic infiltration, and endotoxins from gram-negative rods have been postulated as a contributing factor. Elevations in endotoxin levels in the blood can be classified as intestinal and hepatic factors. In recent years, leaky gut syndrome, which is characterized by impaired intestinal barrier function, has become a significant issue. A leaky gut may prompt intestinal bacteria dysbiosis and increase the amount of endotoxin that enters the liver from the portal vein. These contribute to persistent chronic inflammation and progressive liver damage. In addition, hepatic factors suggest that liver damage can be induced by low-dose endotoxins, which does not occur in healthy individuals. In particular, increased expression of CD14, an endotoxin co-receptor in the liver, may result in leptin-induced endotoxin hyper-responsiveness in obese individuals. Thus, elevated blood endotoxin levels contribute to the progression of NASH. The current therapeutic targets for NASH treat steatosis and liver inflammation and fibrosis. While many clinical trials are underway, no studies have been performed on therapeutic agents that target the intestinal barrier. Recently, a randomized placebo-controlled trial examined the role of the intestinal barrier in patients with NAFLD. To our knowledge, this study was the first of its kind and study suggested that the intestinal barrier may be a novel target in the future treatment of NAFLD.

New Insights into the Pathogenesis of Non-Alcoholic Fatty Liver Disease: Gut-Derived Lipopolysaccharides and Oxidative Stress

Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disease worldwide. The intricate NAFLD pathogenesis is summarized by the multiple-hits hypothesis, which combines all the environmental and genetic factors that promote the development of NAFLD into a single scenario. Among these, bacterial lipopolysaccharides (LPS) are derived from the overgrowth of Gram-negative bacteria and translocated mainly as a consequence of enhanced intestinal permeability. Furthermore, oxidative stress is increased in NAFLD as a consequence of reactive oxygen species (ROS) overproduction and a shortage of endogenous antioxidant molecules, and it is promoted by the interaction between LPS and the Toll-like receptor 4 system. Interestingly, oxidative stress, which has previously been described as being overexpressed in cardiovascular disease, could represent the link between LPS and the increased cardiovascular risk in NAFLD subjects. To date, the only effective strategy for the treatment of NAFLD and non-alcoholic steatohepatitis (NASH) is the loss of at least 5% body weight in overweight and/or obese subjects. However, the dose-dependent effects of multispecies probiotic supplementation on the serum LPS level and cardiometabolic profile in obese postmenopausal women were demonstrated. In addition, many antibiotics have regulatory effects on intestinal microbiota and were able to reduce serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), and tumor necrosis factor alpha (TNF-α) in NASH animal models. Regarding the oxidant status, a Mediterranean diet has been reported to reduce oxidant stress, while vitamin E at high daily dosages induced the resolution of NASH in 36% of treated patients. Silymarin had the positive effect of reducing transaminase levels in NAFLD patients and long-term treatment may also decrease fibrosis and slow liver disease progression in NASH. Finally, the influence of nutraceuticals on gut microbiota and oxidant stress in NAFLD patients has not yet been well elucidated and there are insufficient data either to support or refuse their use in these subjects.

Alterations of Gut Microbiome in Tibetan Patients With Coronary Heart Disease

Coronary heart disease (CHD) is closely related to gut microbiota, which may be significantly affected by ethnicity and the environment. Knowledge regarding the gut microbiome of Tibetan CHD patients living in the Qinghai–Tibet Plateau is very limited. In this study, we characterized the physiological parameters and gut microbiota from 23 healthy Tibetans (HT), 18 CHD patients, and 12 patients with non-stenosis coronary heart disease (NCHD). We analyzed the alterations of the gut microbiome in CHD patients and investigated the relationship between these alterations and the pathological indicators. We found no changes in trimethylamine N-oxide, however, a significant increase in lipopolysaccharides and white blood cells, and a decrease in high-density lipoprotein were observed in the blood of CHD patients, compared to that in the HT group. The gut microbiota of the NCHD group had a significantly higher Shannon index than that of the HT group. Adonis analysis showed that both microbial compositions and functions of the three groups were significantly separated. The Dialister genus was significantly lower and Blautia, Desulfovibrio, and Succinivibrio were significantly higher in abundance in CHD patients compared with the HT group, and the changes were significantly correlated with physiological indexes, such as increased lipopolysaccharides. Moreover, enrichment of genes decreased in four pathways of amino acid metabolism, such as arginine biosynthesis and histidine metabolism, although two lipid metabolism pathways, including fatty acid degradation and arachidonic acid metabolism, increased in the CHD group. Additionally, occupation and a family history of CHD were shown to be risk factors and affected the gut microbiota in Tibetans. Our study will provide insights into the understanding of CHD, leading to better diagnosis and treatment of Tibetan patients.

Dietary fiber and its associations with depression and inflammation

Dietary fiber is a crucial component of a healthy diet, with benefits that can be attributed to processes in the gut microbiota and the resulting by-products. Observational studies support associations between dietary fiber intake and depression and inflammation, but the potential mechanisms are poorly understood. This review examines evidence of the effects of dietary fiber on depression and inflammation and considers plausible mechanisms linking dietary fiber and depression, including microbiota-driven modification of gene expression and increased production of neurotransmitters. Additionally, inflammation may mediate the relationship between dietary fiber intake and depression. A high-fiber diet potentially lowers inflammation by modifying both the pH and the permeability of the gut. The resultant reduction in inflammatory compounds may alter neurotransmitter concentrations to reduce symptoms of depression. Further research into the link between dietary fiber intake and inflammation and depression is essential, as findings could potentially provide guidance for improvement in or prevention of inflammatory and depressive disorders.

Comparative study on the digestion and absorption characteristics of n-3 LCPUFA-enriched phospholipids in the form of liposomes and emulsions

Previous studies have reported that phospholipids rich in n-3 long-chain polyunsaturated fatty acids (n-3 LCPUFA) in the form of liposome exhibited superior bioactivities than other formulation. However, the digestion and absorption characteristics of n-3 LCPUFA-enriched phospholipids were still unclear, restricting the molecular mechanism analysis related to their distinctive activities. The aim of the present study was to compare the digestion and absorption characteristics of DHA/EPA-PC in the forms of liposome and emulsion. The fatty acid composition and lipid species in serum, intestinal wall and content of healthy mice were determined after oral administration with DHA/EPA-PC. Results showed that the peak value of serum DHA/EPA level in the liposome group was significantly higher than that of the emulsion group (p < 0.05), although the peak in the liposome group appeared at 3 h and the peak time was 2 h in the emulsion group. Lipidomics analysis indicated that the high levels of total PL and PL-DHA could be retained in serum for a substantial period after administration of the DHA/EPA-PC liposome, which might be attributed to that the DHA/EPA-PC in the form of liposomes was hydrolyzed slower by pancreatic phospholipase A2 than the emulsion form in small intestinal content. The obtained results might provide theoretical basis for the development and utilization of marine-derived phospholipids.

Developmental programming of insulin resistance: are androgens the culprits?

Insulin resistance is a common feature of many metabolic disorders. The dramatic rise in the incidence of insulin resistance over the past decade has enhanced focus on its developmental origins. Since various developmental insults ranging from maternal disease, stress, over/undernutrition, and exposure to environmental chemicals can all program the development of insulin resistance, common mechanisms may be involved. This review discusses the possibility that increases in maternal androgens associated with these various insults are key mediators in programming insulin resistance. Additionally, the intermediaries through which androgens misprogram tissue insulin sensitivity, such as changes in inflammatory, oxidative, and lipotoxic states, epigenetic, gut microbiome and insulin, as well as data gaps to be filled are also discussed.

Role of gut microbiota in cardiovascular diseases

The human gut is colonized by a community of microbiota, primarily bacteria, that exist in a symbiotic relationship with the host. Intestinal microbiota-host interactions play a critical role in the regulation of human physiology. Deleterious changes to the composition of gut microbiota, referred to as gut dysbiosis, has been linked to the development and progression of numerous diseases, including cardiovascular disease (CVD). Imbalances in host-microbial interaction impair homeostatic mechanisms that regulate health and can activate multiple pathways leading to CVD risk factor progression. Most CVD risk factors, including aging, obesity, 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, including trimethylamine-N-oxide and short-chain fatty acids, that may facilitate the development of CVD. This article reviews the normal function and composition of the gut microbiome, mechanisms leading to the leaky gut syndrome, its mechanistic link to CVD and potential novel therapeutic approaches aimed towards restoring gut microbiome and CVD prevention. As CVD is the leading cause of deaths globally, investigating the gut microbiota as a locus of intervention presents a novel and clinically relevant avenue for future research.

Intestinal plasticity in response to nutrition and gastrointestinal surgery

The plasticity of a material corresponds to its capacity to change its feature under the effect of an external action. Intestinal plasticity could be defined as the ability of the intestine to modify its size or thickness and intestinal cells to modulate their absorption and secretion functions in response to external or internal cues/signals. This review will focus on intestinal adaptation mechanisms in response to diet and nutritional status. These physiological mechanisms allow a fine and rapid adaptation of the gut to promote absorption of ingested food, but they can also lead to obesity in response to overnutrition. This plasticity could thus become a therapeutic target to treat not only undernutrition but also obesity. How the intestine adapts in response to 2 types of surgical remodeling of the digestive tract-extensive bowel resection leading to intestinal failure and surgical treatment of pathological obesity (ie, bariatric surgeries)-will also be reviewed.

The effect of quantity and quality of dietary fat intake on subcutaneous white adipose tissue inflammatory responses

The global prevalence of obesity and obesity-associated cardiometabolic diseases is a significant public health burden. Chronic low-grade inflammation in metabolic tissues such as white adipose tissue (WAT) is linked to obesity and may play a role in disease progression. The overconsumption of dietary fat has been suggested to modulate the WAT inflammatory environment. It is also recognised that fats varying in degree of fatty acid saturation may elicit differential WAT inflammatory responses. This information has originated predominantly from animal or cell models and translation into human participants in vivo remains limited. This review will summarise human intervention studies investigating the effect of dietary fat quantity and quality on subcutaneous WAT inflammation, with a specific focus on the toll-like receptor 4 (TLR4)/NF-κB and nucleotide-binding and oligomerisation domain-like receptor, leucine-rich repeat and pyrin domain-containing 3 (NLRP3) inflammasome molecular signalling pathways. Overall, firm conclusions are hard to draw regarding the effect of dietary fat quantity and quality on WAT inflammatory responses due to the heterogeneity of study designs, diet composition and participant cohorts recruited. Previous studies have predominantly focused on measures of WAT gene expression. It is suggested that future work includes measures of WAT total content and phosphorylation of proteins involved in TLR4/NF-κB and NLRP3 signalling as this is more representative of alterations in WAT physiological function. Understanding pathways linking the intake of total fat and specific fatty acids with WAT metabolic-inflammatory responses may have important implications for public health by informing dietary guidelines aimed at cardiometabolic risk reduction.

Emulsion Droplet Crystallinity Attenuates Postprandial Plasma Triacylglycerol Responses in Healthy Men: A Randomized Double-Blind Crossover Acute Meal Study

BACKGROUND

The presence of triacylglycerol (TAG) cystallinity is assumed to influence digestibility and postprandial lipemia (PPL), although studies to date are limited.

OBJECTIVE

This study aimed to investigate whether the presence of solid fat compared with undercooled liquid oil, specifically, plays a role in determining PPL by comparing emulsion droplets differing only in terms of physical state.

METHODS

Ten percent palm stearin and 0.4% sorbitan monostearate emulsions were tempered to contain identically sized, charged, and shaped (spherical) undercooled liquid (LE) compared with partially crystalline solid (SE; mean ± SEM: 33.2% ± 0.03% solid fat at 37°C) droplets. Fifteen healthy fasting adult men (mean ± SD age: 27.5 ± 5.7 y; BMI: 24.1 ± 2.5 kg/m2) consumed 500 mL of each emulsion on separate occasions and plasma TAG concentrations, particle size of the plasma chylomicron-rich fraction (CMRF), and fatty acid (FA) composition of the CMRF-TAG were serially determined in a 6-h postprandial randomized double-blind crossover acute meal study. Changes from baseline values were analyzed by repeated-measures ANOVA.

RESULTS

An earlier (2 compared with 3 h, P < 0.05) significant rise, a 39.9% higher mean postprandial TAG change from baseline (P = 0.08), and higher peak concentration (mean ± SEM: 1.47 ± 0.19 compared with 1.20 ± 0.15 mmol/L, P = 0.04) and iAUC (1.95 ± 0.39 compared with 1.45 ± 0.31 mmol/L × h, P = 0.03) values were observed for LE compared with SE. The compositions of the CMRF-TAG FAs shifted toward those of the ingested palm stearin by 4 h but did not differ between SE and LE (P = 0.90). Nor were there differences in postprandial changes in CMRF particle size (P = 0.79) or nonesterified FAs (P = 0.72) based on lipid physical state.

CONCLUSIONS

Despite their identical compositions and colloidal properties, differences in lipid absorption were observed between SE and LE in healthy adult men. This is direct evidence that TAG physical state contributes to PPL, with the presence of solid fat having an attenuating influence.This trial was registered at clinicaltrials.gov as NCT03515590.

Effect of proinflammatory diet before pregnancy on gestational age and birthweight: The Japan Environment and Children's Study

The daily diet plays a role in systematic inflammation and may be one of the causes of preterm birth. We aimed to examine the effect of a daily proinflammatory diet before pregnancy on gestational age and birthweight using a large birth cohort in Japan. We used data of singleton pregnancies in the Japan Environment and Children's Study involving live birth from 2011 to 2014 to calculate the dietary inflammatory index. We used individual meals with 30 food parameters from a semiquantitative food frequency questionnaire, which assessed diet intake before pregnancy. Participants were categorized according to the quartile of dietary inflammatory index. A multiple logistic regression model was used to estimate the risk of a proinflammatory diet on preterm birth (PTB) before 37 or 34 weeks and low birthweight (LBW) less than 2,500 or 1,500 g, accounting for maternal age, body mass index before pregnancy, smoking status, education, and household income. After applying our inclusion criteria, 89,329 participants were eligible for the present study. Multiple regression analysis showed that the proinflammatory diet had an increased risk of PTB < 34 weeks (adjusted odds ratio: 1.29, 95% confidence interval [1.07, 1.55]) and <2,500‐g LBW (adjusted odds ratio: 1.08, 95% confidence interval [1.01, 1.16]) compared with the control. In conclusion, a proinflammatory diet before pregnancy was a risk factor for PTB < 34 weeks and LBW < 2,500 g. Therefore, proinflammatory diet needs to be controlled to improve perinatal prognosis.

Digestion, Absorption, and Metabolism Characteristics of EPA-Enriched Phosphoethanolamine Plasmalogens Based on Gastrointestinal Functions in Healthy Mice

EPA-enriched phosphoethanolamine plasmalogens (EPA-pPE), widely present in marine creatures, is a unique glycerophospholipid with EPA at the sn-2 position of the glycerol backbone. EPA-pPE has been reported to exhibit numerous distinctive bioactivities. However, the digestion, absorption, and metabolism characteristics of EPA-pPE in vivo are not clear, which restrict the molecular mechanism analysis related to its distinctive activities. The aim of the present study was to illustrate the digestion, absorption, and metabolism characteristics of EPA-pPE by lipid analysis in serum, intestinal wall, and content after oral administration of EPA-pPE emulsion. Results showed the EPA percentage of total fatty acids in serum was increasing over time, with two peaks at 5 and 10 h by 1.89 ± 0.2 and 2.58 ± 0.27, respectively, and then fell from 1.89 ± 0.17 at 10 h to 1.35 ± 0.16 at 16 h. In small intestinal content, EPA-pPE was hydrolyzed to lyso-phospholipids and EPA by phospholipases A2 and the vinyl ether bond was retained at the sn-1 position. The released EPA could be quickly taken up into the enterocytes and enter circulation. The comparison of simulated digestion in vitro showed that the distinct digestion and absorption process of EPA-pPE was a unique phenomenon. EPA could be retained in serum at a high level for a substantial period of time, which suggested that EPA-pPE was not just a short-lived circulating molecule.

Intestinal basolateral lipid substrate transport is linked to chylomicron secretion and is regulated by apoC-III

Chylomicron metabolism is critical for determining plasma levels of triacylglycerols (TAGs) and cholesterol, both of which are risk factors for CVD. The rates of chylomicron secretion and remnant clearance are controlled by intracellular and extracellular factors, including apoC-III. We have previously shown that human apoC-III overexpression in mice (apoC-IIITg mice) decreases the rate of chylomicron secretion into lymph, as well as the TAG composition in chylomicrons. We now find that this decrease in chylomicron secretion is not due to the intracellular effects of apoC-III, but instead that primary murine enteroids are capable of taking up TAG from TAG-rich lipoproteins (TRLs) on their basolateral surface; and via Seahorse analyses, we find that mitochondrial respiration is induced by basolateral TRLs. Furthermore, TAG uptake into the enterocyte is inhibited when excess apoC-III is present on TRLs. In vivo, we find that dietary TAG is diverted from the cytosolic lipid droplets and driven toward mitochondrial FA oxidation when plasma apoC-III is high (or when basolateral substrates are absent). We propose that this pathway of basolateral lipid substrate transport (BLST) plays a physiologically relevant role in the maintenance of dietary lipid absorption and chylomicron secretion. Further, when apoC-III is in excess, it inhibits BLST and chylomicron secretion.

Age-dependent association of gut bacteria with coronary atherosclerosis: Tampere Sudden Death Study

Background

The gut microbiome is thought to remain stable into old age. Gut bacteria and their translocation may play a role in the development of coronary heart disease (CHD) by modulating cholesterol levels and immune responses, as well as by producing toxic metabolites and bacterial endotoxins. The association of changes in the gut microbiome with the severity of coronary atherosclerosis and the ability of gut bacteria themselves to translocate into coronary plaques has not been studied.

Materials and methods

As a part of the Tampere Sudden Death Study, we measured age-dependent changes in the relative ratios of major intestinal bacterial communities (Bacteroides species [spp.], the Clostridium leptum group, the Clostridium coccoides group, Bifidobacterium spp., Enterobactericeae, Lactobacillus spp.) and Streptococcus spp. in both feces and coronary plaques of the same male autopsy cases (n = 67, age range 44–95) using real-time quantitative PCR (qPCR). The area of coronary atherosclerotic lesions were measured by computer-assisted morphometry. Fecal bacterial DNA measurements from healthy volunteers served as a control for gut bacterial analyses of autopsy cases. The relative amount of bacterial DNA in a sample was determined with the comparative Cq method.

Results

The relative ratios of fecal Lactobacillus spp., Bifidobacterium spp., the Clostridium coccoides group, and Bacteroides spp. did not differ between controls and autopsy cases and showed no age-dependence. In contrast, the ratios of the Clostridium leptum group, Enterobactericeae, and Streptococcus spp. increased with age. Elevated relative ratios of fecal Enterobactericeae associated with a larger coronary plaque fibrotic area (p = 0.001), and the Clostridium leptum group with a larger calcification area (p = 0.015). Intestinal bacterial DNA could be amplified in 67.6% of the coronary plaques, the most common being Streptococcus spp. (41.0%), followed by Enterobactericeae (12.1%), Clostridium leptum (2.4%), and Lactobacillus spp. (2.4%). The percentages of Streptococcus spp. DNA decreased, and those of Enterobactericeae increased in coronary plaques along with age.

Conclusions

DNA of the Clostridium leptum group and pathogenic Enterobactericeae increase in the gut microbiome with age and can be detected in the same individual’s coronary plaques along with pathogenic Streptococcus spp., associating with more severe coronary atherosclerosis.

Metabolic Endotoxemia: A Potential Underlying Mechanism of the Relationship between Dietary Fat Intake and Risk for Cognitive Impairments in Humans?

(1) Background: Nutrition is a major lifestyle factor that can prevent the risk of cognitive impairment and dementia. Diet-induced metabolic endotoxemia has been proposed as a major root cause of inflammation and these pathways emerge as detrimental factors of healthy ageing. The aim of this paper was to update research focusing on the relationship between a fat-rich diet and endotoxemia, and to discuss the potential role of endotoxemia in cognitive performances. (2) Methods: We conducted a non-systematic literature review based on the PubMed database related to fat-rich meals, metabolic endotoxemia and cognitive disorders including dementia in humans. A total of 40 articles out of 942 in the first screening met the inclusion criteria. (3) Results: Evidence suggested that a fat-rich diet, depending on its quality, quantity and concomitant healthy food components, could influence metabolic endotoxemia. Since only heterogeneous cross-sectional studies are available, it remains unclear to what extent endotoxemia could be associated or not with cognitive disorders and dementia. (4) Conclusions: A fat-rich diet has the capability to provide significant increases in circulating endotoxins, which highlights nutritional strategies as a promising area for future research on inflammatory-associated diseases. The role of endotoxemia in cognitive disorders and dementia remains unclear and deserves further investigation.

Immune tolerance attenuates gut dysbiosis, dysregulated uterine gene expression and high-fat diet potentiated preterm birth in mice

BACKGROUND

Preterm delivery accounts for 85% of perinatal morbidity and mortality. Although the consumption of a high-fat diet leads to exaggerated proinflammatory responses and, in pregnant women, increased rates of spontaneous preterm birth, the underlying mechanisms remain unclear.

OBJECTIVE

We sought to elucidate the mechanisms by which maternal consumption of a high-fat diet leads to a dysregulated immune response and, subsequently, spontaneous preterm birth.

STUDY DESIGN

We performed 16S ribosomal RNA sequencing of DNA extracted and amplified from stool samples and compared the gut microbiomes of lipopolysaccharide-induced pregnant mice that were maintained on a high-fat diet compared to a normal control diet. Next, we sequenced the uterine transcriptomes of the mice. To test the effect of dampening of the immune response on the microbiome, transcriptome, and risk of spontaneous preterm birth, we induced immune tolerance with repetitive subclinical doses (0.2 mg/kg/week for 8 weeks) of endotoxin and performed 16S ribosomal RNA and uterine transcriptome sequencing on these immunotolerized mice.

RESULTS

High-fat diet potentiates lipopolysaccharide-induced preterm birth by affecting the maternal gut microbiome and uterine transcriptome and reduces antioxidant capacity in a murine model. High-fat diet consumption also increases the colonization of the gut by 5 immunogenic bacteria and decreases colonization by Lachnospiraceae_NK4A136_group. Uteri from high-fat diet mice had increased expression of genes that stimulate the inflammatory-oxidative stress axis, autophagy/apoptosis, and smooth muscle contraction. Repetitive endotoxin priming protects high-fat diet dams from spontaneous preterm birth, increases colonization of the gut by Lachnospiraceae_NK4A136_group, decreases levels of immunogenic bacteria in the gut microbiome, and reduces the number of dysregulated genes after high-fat diet consumption from 994 to 74.

CONCLUSION

High-fat diet-potentiated spontaneous preterm birth is mediated by increased inflammation, oxidative stress, and gut dysbiosis. The induction of immune tolerance via endotoxin priming reverses these effects and protects high-fat diet dams from spontaneous preterm birth. Based on this work, the role of immunomodulation as a novel therapeutic approach to prevent preterm birth among women who consume high-fat diets should be explored.

Role of gut microbiota in chronic low-grade inflammation as potential driver for atherosclerotic cardiovascular disease: a systematic review of human studies

A hallmark of obesity is chronic low-grade inflammation, which plays a major role in the process of atherosclerotic cardiovascular disease (ACVD). Gut microbiota is one of the factors influencing systemic immune responses, and profound changes have been found in its composition and metabolic function in individuals with obesity. This systematic review assesses the association between the gut microbiota and markers of low-grade inflammation in humans. We identified 14 studies which were mostly observational and relatively small (n = 10 to 471). The way in which the microbiome is analysed differed extensively between these studies. Lower gut microbial diversity was associated with higher white blood cell counts and high sensitivity C-reactive protein (hsCRP) levels. The abundance of Bifidobacterium, Faecalibacterium, Ruminococcus and Prevotella were inversely related to different markers of low-grade inflammation such as hsCRP and interleukin (IL)-6. In addition, this review speculates on possible mechanisms through which the gut microbiota can affect low-grade inflammation and thereby ACVD. We discuss the associations between the microbiome and the inflammasome, the innate immune system, bile acids, gut permeability, the endocannabinoid system and TMAO. These data reinforce the importance of human research into the gut microbiota as potential diagnostic and therapeutic strategy to prevent ACVD.

Inflammatory Potential of Diet: Association With Chemerin, Omentin, Lipopolysaccharide-Binding Protein, and Insulin Resistance in the Apparently Healthy Obese

OBJECTIVE

Low-grade inflammation is a characteristic of various conditions, including obesity. Diet is regarded as a strong modifier of inflammation. The potential links between inflammatory properties of diet and adipokines as well as insulin resistance (IR) warrant further investigation. Therefore, this study aimed to examine the associations of the dietary inflammatory index (DII) with serum chemerin, omentin, and lipopolysaccharide-binding protein (LBP) as well as IR among apparently healthy obese adults.

DESIGN

In this cross-sectional study, 171 abdominally obese subjects were recruited in the northwest of Iran. Demographic data, dietary intake, anthropometric indices, and physical activity (PA) were assessed. DII scores were calculated based on dietary intake, using a validated 168-item food frequency questionnaire (FFQ). Basal blood samples were collected to determine the biochemical parameters. A linear regression test with adjusted beta estimates was applied for data analysis.

RESULT

Compared to those with higher DII score, the group with lower DII score (anti-inflammatory diet) had higher protein (83.62 ± 36.42 g vs. 71.61 ± 25.94 g) and lower carbohydrate (325.00 ± 125.76 g vs. 378.19 ± 137.69 g) intake. Participants with higher DII score had lower consumption of polyunsaturated and monounsaturated fats as well as fiber and higher saturated fats (p < .001). Those with elevated DII score had higher levels of chemerin (p = .034) and LBP (p = .040), compared to those with lower DII. Omentin showed no significant differences between groups with different DII scores. Additionally, people with a more proinflammatory diet had higher FBS (p = .005); however, other markers of IR did not differ by DII scores.

CONCLUSIONS

The results suggest that increased inflammatory potential of diet, as indicated by higher DII score, is associated with elevated levels of chemerin and LBP. While DII was positively associated with FBS, no significant correlation was found for insulin and other indices of IR.

Diet-induced inflammation: From gut to metabolic organs and the consequences for the health and longevity of ruminants

Dietary shifts play an important role in decreased longevity in ruminant livestock. Ruminants evolved as cellulose fermenters adapt to fiber-rich diets. Instead, high-producing ruminants nowadays are commonly fed with grain-based diets to increase intake and productivity. Such diets, however, trade off the health of the animal. One negative aspect of such feeding is related to elevated levels of bacterial endotoxin (lipopolysaccharide, LPS) in the gut lumen and the likelihood of LPS translocation across the gut causing systemic and local (tissue) inflammation with consequences for production and longevity. However, the view for toxicity of gut LPS is oversimplified, overlooking the physicochemistry of LPS and the translocation route that determine the fate and immune reactive activity of LPS within the host. The barrier and defensive mechanisms of rumen morphology and intestinal mucus are understated. LPS cross the epithelial barrier paracellularly through impaired tight-junction and transcellularly through receptor-mediated transcytosis and the lipoprotein pathway transporting lipids. The lipoprotein pathway delivers LPS to the circulation before reaching the liver for detoxification and is believed to be the major natural route of gut LPS translocation at least in non-ruminants. Ruminant research has focused on endotoxemia and systemic inflammation but with little success and conflicting results, not to mention that low-grade inflammation is not easy to detect. In fact, LPS in the circulation must be effectively removed to avoid an adverse effect of rising level of LPS in the circulation. Circulating LPS could be transported towards target tissues in various organs, leading to local inflammation and altered metabolic activity in the tissues. Therefore, it might be feasible to capture tissue inflammation, especially in the metabolic organs including the liver, adipose tissues, and mammary gland. The present review gathers research updates and presents a comprehensive view of the physicochemical properties and bioactivity of LPS and the possibilities of translocation as well as other possible fate of LPS at each gut site in ruminants. Furthermore, we describe the involvement of three key metabolic organs including the liver, adipose tissue, and mammary gland in response to gut-derived LPS that lead to inflammation in the tissue posing consequences for the health and longevity of dairy cows.

Lipopolysaccharides in Food, Food Supplements, and Probiotics: Should We be Worried?

The fever-inducing effect of lipopolysaccharides (LPS) is well known, and human blood is extremely responsive to this pyrogen. Recently, the safety of LPS-containing food supplements and probiotic drugs as immune-stimulants has been questioned, although these products are orally taken and do not reach the bloodstream undigested. The concerns are understandable, as endotoxaemia is a pathological condition, but the oral uptake of probiotic products containing LPS or Gram-negative bacteria does not pose a health risk, based on the available scientific evidence, as is reviewed here. The available methods developed to detect LPS and other pyrogens are mostly used for quality control of parentally applied therapeuticals. Their outcome varies considerably when applied to food supplements, as demonstrated in a simple comparative experiment. Products containing different Escherichia coli strains can result in vastly different results on their LPS content, depending on the method of testing. This is an inherent complication to pyrogen testing, which hampers the communication that the LPS content of food supplements is not a safety concern.

Metabolic and inflammatory postprandial effect of a highly saturated fat meal and its relationship to abdominal obesity

Introduction: The postprandial stage is associated with the increase of markers related to cardiovascular risk, and its intensity depends on the metabolic state. Objective: To determine the impact of a high-fat meal intake on the metabolic and inflammatory profile, and its relationship to abdominal obesity. Materials and methods: This clinical trial included 42 individuals (21 with abdominal obesity). We measured glucose, insulin, lipid profile, reactive C protein, lipopolysaccharides, and interleukin 6 in fasting blood, and four hours after eating. Results: Besides obesity, we found insulin resistance and higher levels of fasting triacylglycerides and C-reactive protein. There were higher postprandial responses to glucose, insulin, and triacylglycerides. Interleukin 6 decreased in the non-obese group, and lipopolysaccharides increased in both groups. Conclusions: A saturated high-fat food intake produced a greater impact on the glycemic variables in the group with obesity, while it affected the lipids in both groups. However, the increase of triacylglycerides was higher in the presence of a high basal concentration, and it promoted the increase of lipopolysaccharides. The basal and postprandial inflammatory state affected the group with obesity more. The postprandial moment reflected the most frequent state of the individuals on a normal day and evidenced the capacity of the metabolic response to food intake, as well as early metabolic risk states.

Toll-like receptor signaling and serum levels of interferon β and lipopolysaccharide binding protein are related to abdominal obesity: a case-control study between metabolically healthy and metabolically unhealthy obese individuals

It is still unclear whether toll-like receptor (TLR) signaling and serum levels of inflammatory markers in metabolically unhealthy abdominally obese (MUAO) are due to their obesity and/or their metabolic state. We hypothesized that abdominal obesity is an important mediator of the association of metabolic state with TLR signaling and serum inflammatory markers. Therefore, in this case-control study, we compared the expression levels of TLR4 and Toll/interleukin-1 receptor domain containing adaptor protein-inducing interferon β (TRIF) and serum concentrations of interferon β and lipoprotein-binding protein (LBP) in metabolically healthy abdominally obese (MHAO) and MUAO individuals. Basal blood samples from 65 abdominally obese subjects with waist circumference (WC) of at least 95 cm were collected to determine serum metabolic parameters, IFNβ, and LBP. Those with 3 or more metabolic alterations were defined as MUAO (n = 34), and those having 2 or less were classified as MHAO (n = 31). Furthermore, messenger RNA (mRNA) was isolated from peripheral blood mononuclear cells. TLR4 and TRIF gene expression assay was performed using quantitative real-time polymerase chain reaction. There were significant differences in serum fasting blood sugar (P = .017), triglyceride (P < .001), cholesterol (P = .002), and low-density lipoprotein cholesterol (P = .034) between the MUAO and MHAO groups, whereas no significant difference was observed in the expression ratio of TLR4 and TRIF mRNA and serum levels of IFNβ and LBP. However, a significant correlation was noticed between mRNA expression levels of TLR4 and TRIF (r = 0.50, P < .001) and serum IFNβ and LBP (r = 0.70, P < .001). It is concluded that the expression levels of TLR4 and TRIF as well as serum IFNβ and LBP are more related to abdominal obesity than to metabolic health.

Possible mechanisms for probiotics to reduce cholesterol and improve lipid metabolism

Probiotics can not only reduce the level of cholesterol but also improve abnormal lipid metabolism and reduce the levels of inflammatory factors, which are closely related to cardio-cerebrovascular diseases. Although "coprecipitation with bile salts" is considered to play a critical role in the cholesterol-lowering effect of probiotics, the mechanisms for probiotics to lower cholesterol and improve lipid metabolism have not been established yet. This article summarizes various hypotheses proposed by Chinese scholars to explain why the use of probiotics can improve abnormal lipid metabolism and lower cholesterol.

Targeted inhibition of STATs and IRFs as a potential treatment strategy in cardiovascular disease

Key factors contributing to early stages of atherosclerosis and plaque development include the pro-inflammatory cytokines Interferon (IFN)α, IFNγ and Interleukin (IL)-6 and Toll-like receptor 4 (TLR4) stimuli. Together, they trigger activation of Signal Transducer and Activator of Transcription (STAT) and Interferon Regulatory Factor (IRF) families. In particular, STAT1, 2 and 3; IRF1 and 8 have recently been recognized as prominent modulators of inflammation, especially in immune and vascular cells during atherosclerosis. Moreover, inflammation-mediated activation of these STATs and IRFs coordinates a platform for synergistic amplification leading to pro-atherogenic responses.

Searches for STAT3-targeting compounds, exploring the pTyr-SH2 interaction area of STAT3, yielded many small molecules including natural products. Only a few inhibitors for other STATs, but none for IRFs, are described. Promising results for several STAT3 inhibitors in recent clinical trials predicts STAT3-inhibiting strategies may find their way to the clinic. However, many of these inhibitors do not seem STAT-specific, display toxicity and are not very potent. This illustrates the need for better models, and screening and validation tools for novel STAT and IRF inhibitors.

This review presents a summary of these findings. It postulates STAT1, STAT2 and STAT3 and IRF1 and IRF8 as interesting therapeutic targets and targeted inhibition could be a potential treatment strategy in CVDs. In addition, it proposes a pipeline approach that combines comparative in silico docking of STAT-SH2 and IRF-DBD models with in vitro STAT and IRF activation inhibition validation, as a novel tool to screen multi-million compound libraries and identify specific inhibitors for STATs and IRFs.

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.

Chronic maternal inflammation or high-fat-feeding programs offspring obesity in a sex-dependent manner

BACKGROUND/OBJECTIVES

The current world-wide obesity epidemic partially results from a vicious circle whereby maternal obesity during pregnancy predisposes the offspring for accelerated weight gain and development of metabolic syndrome. Here we investigate whether low-grade inflammation, characteristic of the obese state, provides a causal role for this disastrous fetal programming in mice.

METHODS

We exposed pregnant and lactating C57BL/6JBom female mice to either high-fat diet (HFD), or continuous infusion of lipopolysaccharide (LPS), a potent trigger of innate immunity, and studied offspring phenotypes.

RESULTS

Both maternal LPS or HFD treatments rendered the offspring hyperphagic and inept of coping with a HFD challenge during adulthood, increasing their adiposity and weight gain. The metabolic effects were more pronounced in female offspring, while exposed male offspring mounted a larger inflammatory response to HFD at adulthood.

CONCLUSIONS

This supports our hypothesis and highlights the programming potential of inflammation in obese pregnancies.

Association of endotoxaemia with serum free fatty acids in metabolically healthy and unhealthy abdominally obese individuals: a case-control study in northwest of Iran

OBJECTIVES

This study aimed to compare serum free fatty acids (FFAs) and lipopolysaccharide-binding protein (LBP) between metabolically healthy abdominally obese (MHAO) and metabolically unhealthy abdominally obese (MUAO) individuals. We also examined the association between serum FFAs and LBP in the participants.

METHODS

In this age-matched and gender-matched case-control study, 164 abdominally obese subjects were recruited from June to November 2015 in the northwest of Iran. Demographic data, dietary intake, body composition, anthropometric indices and physical activity (PA) were assessed. Basal blood samples were collected to determine serum metabolic parameters, FFAs and LBP. Abdominal obesity was defined as having waist circumference ≥95 cm. Those with three or more metabolic alterations were defined as MUAO and those having two or less were classified as MHAO. Data were analysed using SPSS V.17.0.

RESULTS

There were no significant differences in dietary intake, anthropometric indices, body composition and PA between the two groups. The odds of MUAO significantly increased by increments in serum fasting blood sugar (OR 3.79, 95% CI 2.25 to 6.40), triglycerides (OR 1.10, 95% CI 1.05 to 1.15), systolic blood pressure (OR 1.02, 95% CI 1.00 to 1.04) and diastolic blood pressure (OR 1.03, 95% CI 1.01 to 1.06) and decreased by increase in serum high-density lipoprotein cholesterol (OR 0.32, 95% CI 0.20 to 0.52). The levels of LBP and FFAs showed no significant differences between the two groups. However, significant correlations were found between LBP and FFAs in pooled population (r=0.712; p<0.001) as well as in cases (r=0.717; p<0.001) and controls (r=0.704; p<0.001). Neither FFAs nor LBP were significantly correlated with dietary intake or metabolic parameters (p>0.05).

CONCLUSION

The results indicated that serum LBP and FFAs are highly correlated both in MHAO and MUAO states. In addition, the levels of LBP and FFAs seem to be more related to abdominal obesity than to the presence or absence of metabolic health.

Comparisons of the Postprandial Inflammatory and Endotoxaemic Responses to Mixed Meals in Young and Older Individuals: A Randomised Trial

Postprandial inflammation and endotoxaemia are determinants of cardiovascular and metabolic disease risk which are amplified by high fat meals. We aimed to examine the determinants of postprandial inflammation and endotoxaemia in older and younger adults following a high fat mixed meal. In a randomised cross-over trial, healthy participants aged 20-25 and 60-75 years (n = 15/group) consumed a high-fat breakfast and a low-fat breakfast. Plasma taken at baseline and post-meal for 5 h was analysed for circulating endotoxin, cytokines (monocyte chemotactic protein-1 (MCP-1), interleukin (IL)-1β, IL-6, and tumour necrosis factor-alpha (TNF-α)), lipopolysaccharide binding protein (LBP), and inflammatory gene expression in peripheral blood mononuclear cells (PBMC). Older subjects had lower baseline PBMC expression of Glutathione peroxidase 1 (GPX-1) but greater insulin-like growth factor-binding protein 3 (IGFBP3) and circulating MCP-1 compared to younger subjects. After either meal, there were no age differences in plasma, chylomicron endotoxin, or plasma LBP concentrations, nor in inflammatory cytokine gene and protein expression (MCP-1, IL-1β, and TNF-α). Unlike younger participants, the older group had decreased superoxide dismutase (SOD)-2 expression after the meals. After a high-fat meal, older adults have no increased inflammatory or endotoxin response, but an altered oxidative stress gene response compared with younger adults. Healthy older adults, without apparent metabolic dysfunction, have a comparable postprandial inflammatory and endotoxaemia response to younger adults.

Probiotics may delay the progression of nonalcoholic fatty liver disease by restoring the gut microbiota structure and improving intestinal endotoxemia

Gut-derived bacterial lipopolysaccharide (LPS) and subsequent hepatic toll-like receptor 4 (TLR4) activation have been recognized to be involved in the onset of diet-induced nonalcoholic fatty liver disease (NAFLD), but little is known about the variation of LPS and TLR4 during the progression of NAFLD. Probiotics were able to inhibit proliferation of harmful bacteria and improve gastrointestinal barrier function. However, it's unclear whether LPS/TLR4 is involved in the protection effect of probiotics on NAFLD. In this study, we described characteristic of gut microbiota structure in the progression of NAFLD, and we also analyzed the relationship between gut microbiota and LPS/TLR4 in this process. Furthermore, we applied probiotics intervention to investigate the effect of probiotics on gut flora structure, intestinal integrity, serum LPS, liver TLR4 and liver pathology. Our results showed that serum LPS and liver TLR4 were highly increased during progression of NAFLD, with gut flora diversity and gut mircobiological colonization resistance (B/E) declining. Furthermore, probiotics could improve gut microbiota structure and liver pathology. Probiotics could also downregulate serum LPS and liver TLR4. Our results suggested that both gut flora alteration and endotoxemia may be involved in the progression of NAFLD. Probiotics may delay the progression of NAFLD via LPS/TLR4 signaling.