Elevated high density lipoprotein cholesterol and low grade systemic inflammation is associated with increased gut permeability in normoglycemic men

Increased intestinal mucosal permeability and metabolic endotoxemia predict the risk of cardiovascular mortality

BACKGROUND AND AIMS

Low-grade chronic inflammation is a pathogenetic factor in atherosclerotic cardiovascular diseases (ASCVD), but the underlying mechanisms are not well understood. We aimed to explore the role of intestinal permeability and ensuing metabolic endotoxemia as risk factors for cardiovascular mortality.

METHODS

A random sub-cohort of home-living participants from the Helsinki Businessmen Study (HBS), born between 1919 and 1934 and followed since 1964, was recalled in 2003 (n = 632), 2011 (n = 316) and 2017 (n = 82). Six biomarkers representing intestinal permeability and endotoxemia were measured and the results were combined with extensive data on ASCVD prevalence, conventional risk factors, and mortality.

RESULTS

Correlation on the individual levels was observed for zonulin, lipopolysaccharide-binding protein (LBP), and intestinal fatty acid-binding protein (I-FABP) across the entire 15-year follow-up. These biomarkers are highly intercorrelated. Particularly zonulin, a marker of intestinal permeability, correlated with most of the conventional ASCVD risk factors. None of the biomarkers correlated with prevalent ASCVD, but higher levels of zonulin and LBP associated with 10-year risk of death from coronary artery disease (CAD, age-adjusted p < 0.001 and p = 0.006, respectively).

CONCLUSIONS

The results support metabolic endotoxemia as a contributing pathogenetic factor in atherosclerotic cardiovascular disease with an adverse outcome. Of the surrogate biomarkers studied, zonulin was the most robust predictor of mortality in CAD. Levels of zonulin, LBP, and I-FABP remained relatively stable in individuals over the 15-year follow up, suggesting a potential role for them as biomarkers for ASCVD risk.

A ginseng polysaccharide protects intestinal barrier integrity in high-fat diet-fed obese mice

A novel polysaccharide, GPH1, was extracted and isolated from ginseng. Structural analysis of GPH1 revealed a molecular weight of 7.321 × 105 Da and the presence of glucose and galactose components in a 30.2: 1 molar ratio. Results of methylation and NMR analyses indicated the GPH1 backbone consisted of →1)-α-Glc-(3→ and →1)-α-Glc-(6→. The anti-obesity activity of GPH1 was assessed by HFD-induced obesity mouse model. GPH1 was found to significantly reduced body weight, alleviated liver lipid accumulation and inflammatory damage. Meanwhile, GPH1 treatment increased the expression of tight junction proteins, including zonula occludens-1 (ZO-1) and claudin-1, while also regulating the intestinal microbiota of obese mice by promoting proliferation of beneficial bacteria with known anti-obesity effects, including s_Akkermansia muciniphila, s_Lactobacillus intestinalis, s_Lactobacillus reuteri, s_Streptococcus hyointestinalis, and s_Lactococcus garvieae. Our findings demonstrated that GPH1 is a practical natural dietary supplement with potential therapeutic effects on obesity.

Gastrointestinal Permeability After Bariatric Surgery: A Systematic Review

Gastrointestinal permeability refers to the movement of substances across the gut wall. This is mediated by endotoxemia (bacterial products entering the systemic circulation), and is associated with metabolic disease. The effect of bariatric surgery on permeability remains uncertain; the associated dietary, metabolic and weight changes are suggested to influence, or trigger, altered permeability. The primary aim of this study is to synthesize evidence and analyze the effect of bariatric surgery on permeability. A systematic review was performed, searching MEDLINE, EMBASE, and Scopus until February 2023, using MESH terms "intestinal permeability", "bariatric", for studies reporting in vivo assessment of permeability. Three cohort studies and two case series were identified (n=96). Data was heterogeneous; methodology and controls preclude meta-analysis. Gastroduodenal permeability reduced post-sleeve gastrectomy (SG). Two studies showed an increase in small intestinal permeability after biliopancreatic diversion. Two studies revealed a decrease in post-Roux-en-Y gastric bypass. One study identified increased colonic permeability six months post-SG. Evidence regarding permeability change after bariatric surgery is conflicting, notably for the small intestine. Impaired colonic permeability post-SG raises concerns regarding colonic protein fermentation and harmful dietary sequelae. There are multiple interacting variables confounding gastrointestinal permeability change; procedure type, altered microbiota and metabolic response to surgery. Further understanding of this important aspect of obesity is required, both before and after bariatric surgery.

Predictive Value of Serum Lipid for Intravenous Immunoglobulin Resistance and Coronary Artery Lesion in Kawasaki Disease

CONTEXT

Intravenous immunoglobulin (IVIG) resistance and coronary artery lesions (CALs) prediction are pivotal topic of interests in Kawasaki disease (KD). However, data on the predictive value of lipid profile for both IVIG resistance and CALs are limited.

PURPOSE

To investigate the predictive validity of lipid profile for IVIG resistance and CALs in KD.

DESIGN

Prospective cohort study.

SETTING

West China Second University Hospital.

PATIENTS

363 KD patients were divided into the initial IVIG-resistant group and initial IVIG-responsive group; repeated IVIG-resistant group and repeated IVIG-responsive group; CAL+ group and CAL- group.

MAIN OUTCOME MEASURES

Validity of lipid profile in predicting IVIG resistance and CALs.

RESULTS

Triglycerides were significantly higher whereas total cholesterol (TC), high-densisty lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), and apolipoprotein A (Apo A) were significantly lower in initial IVIG-resistant subjects, with cut-off values of 1.625 mmol/L, 3.255 mmol/L, 0.475 mmol/L, 1.965 mmol/L, and 0.665 g/L, yielding sensitivities of 52%, 70%, 52%, 61%, and 50% and specificities of 68%, 53%, 78%, 71%, and 81%, respectively. TC, LDL-C, and Apo A levels were significantly lower in repeated IVIG-resistant subjects, with cut-off values of 3.20 mmol/L, 1.78 mmol/L, and 0.605 g/L, producing sensitivities of 91%, 70%, and 57% and specificities of 55%, 67%, and 70%, respectively. Apo A level was significantly lower in the CAL+ group, with cut-off value of 0.805 g/L, yielding sensitivity of 66% and specificity of 54%.

CONCLUSIONS

Lipid profiles were significantly dysregulated in KD patients suffering IVIG resistance and CALs. Some of them, such as LDL-C and Apo A, could serve as complementary laboratory markers for predicting both IVIG resistance and CALs.

Roux-en-Y gastric bypass potentially improved intestinal permeability by regulating gut innate immunity in diet-induced obese mice

Roux-en-Y gastric bypass (RYGB) has been demonstrated to be the most effective treatment for morbid obesity, yet the impact of RYGB on intestinal permeability is not fully known. In this work, we subjected obese mice to RYGB and sham operation procedures. Serum lipopolysaccharide (LPS) level, inflammatory cytokines and intestinal permeability were measured at 8 weeks post surgery. In contrast to sham surgery, RYGB reduced body weight, improved glucose tolerance and insulin resistance, and decreased serum levels of LPS, IL6 and TNFα. Intestinal permeability of the common limb and colon was significantly improved in the RYGB group compared to the sham group. The mRNA levels of IL1β, IL6, and TLR4 in the intestine were significantly decreased in the RYGB group compared with the sham group. The expression levels of intestinal islet-derived 3β (REG3β), islet-derived 3γ (REG3γ) and intestinal alkaline phosphatase (IAP) were higher in the RYGB group than in the sham group. In conclusion, in a diet-induced obesity (DIO) mouse model, both decreased intestinal permeability and attenuated systemic inflammation after RYGB surgery were associated with improved innate immunity, which might result from enhanced production of IAP and antimicrobial peptides.

Sepsis and the evolution of human increased sensitivity to lipopolysaccharide

Among mammals, humans are exquisitely sensitive to lipopolysaccharide (LPS), an environmentally pervasive bacterial cell membrane component. Very small doses of LPS trigger powerful immune responses in humans and can even initiate symptoms of sepsis. Close evolutionary relatives such as African and Asian monkeys require doses that are an order of magnitude higher to do the same. Why humans have evolved such an energetically expensive antimicrobial strategy is a question that biological anthropologists are positioned to help address. Here we compare LPS sensitivity in primate/mammalian models and propose that human high sensitivity to LPS is adaptive, linked to multiple immune tactics against pathogens, and part of multi-faceted anti-microbial strategy that strongly overlaps with that of other mammals. We support a notion that LPS sensitivity in humans has been driven by microorganisms that constitutively live on us, and has been informed by human behavioral changes over our species' evolution (e.g., meat eating, agricultural practices, and smoking).

Transgenerational effects on intestinal inflammation status in mice perinatally exposed to bisphenol S

Increasing evidence has highlighted the critical role of early life environment in shaping the future health outcomes of individuals in subsequent generations. Bisphenol S (BPS) has been widely used as a substitute for various plastic materials due to the limited application of Bisphenol A (BPA) which is an endocrine disruptor. However, the lack of efficient evaluation of BPS leaves doubts about the relevant substitute of BPA. Few studies of transgenerational inheritance have examined the effects of environmental exposures to endocrine disruptors on the immune system. In this study, we analyzed the transgenerational effects of BPS on intestinal inflammation and its consequence in metabolism. In this study, only F0 pregnant mice were exposed to BPS (1.5 μg/kg bw/day) from gestational day 0 until weaning of offspring. In this work, both F1 and F2 male offspring developed an inflammatory response in the ileum and colon at adulthood after F0 mothers were exposed to BPS; this phenomenon disappeared in F3. This inflammatory response in F1 male offspring is associated with a significant decrease of blood cholesterol without modification of metabolic status. Further, in F3 offspring male, the decrease of gut inflammatory response is associated with a decrease of fat weight and with an increase of blood glucose and cholesterol level. A sex-specific profile is observed in female offspring. We also observed that early life exposure to BPS was associated with strong abnormal intestinal immune status. The study presented here demonstrates that the immune system, like other organ systems, is vulnerable to transgenerational effects caused by environmental exposures.

Oridonin Attenuates TNBS-induced Post-inflammatory Irritable Bowel Syndrome via PXR/NF-κB Signaling

To investigate the beneficial effects of oridonin, a diterpenoid compound isolated from Rabdosia rubescens, on the inflammatory response in TNBS-induced post-inflammatory irritable bowel syndrome (PI-IBS) model and the underlying mechanism. Using the PI-IBS rat model and Caco-2 cell lines, we found that intestinal barrier function reflected by lactulose/mannitol (L/M) ratio and tight junction protein level was significantly ameliorated by oridonin. We also demonstrated that oridonin abrogated inflammation through inhibiting the phosphorylation of NF-κBp65 as well as its downstream gene (iNOS, COX-2, IL-1β, and IL-6) level. Molecular docking studies confirmed the good binding activity between oridonin and PXR. In Caco-2 cell lines, oridonin markedly inhibited LPS-induced NF-κB activation in a PXR-dependent manner. Meanwhile, PXR and its target genes CYP3A4 and P-gp were induced by oridonin, which was associated with the decreased expression of NF-κB and the recovery of intestinal barrier. This study indicated that the therapeutic effect of oridonin on experimental PI-IBS through repairing intestinal barrier function may be closely associated with the regulatory role of PXR/NF-κB signaling pathway. Oridonin may serve as a PXR ligand for the development of drugs in the therapy for PI-IBS.

Polysaccharide fraction from greens of Raphanus sativus alleviates high fat diet-induced obesity

Radish (Raphanus sativus) greens are commonly used as a vegetable in Korea; however, their anti-obesity effect has not been reported yet. We prepared the polysaccharide fraction of radish greens (PRG) and assessed its anti-obesity activity in high fat diet (HFD)-induced obese C57BL/6J mice. Supplementation with 4 mg/kg PRG reduced weight gain and body fat percentage, and regulated serum biomarkers against HFD-induced obesity. Moreover, PRG treatment improved gut permeability by increasing tight junction protein expression and colon length shortening. HFD intake increased the proportion of Firmicutes and decreased the proportion of Bacteroidetes and Verrucomicrobia; however, PRG supplementation maintained gut microbial composition to normal diet condition. Moreover, PRG reduced HFD-induced increase of lipid metabolism-related protein expression, along with adipocyte size in white adipose tissue. These results indicated that PRG as a potential prebiotic, has anti-obesity properties by improving gut barrier function, modulating gut microbiota and regulating lipid metabolism.

H. pylori Eradication Treatment Causes Alterations in the Gut Microbiota and Blood Lipid Levels

Background: The gut microbiome plays an important role in the lipid metabolism. Antibiotic treatment causes changes in the intestinal microbiota. Our objective was to explore the relationship between changes in the intestinal microbiota and the level of plasma high density lipoprotein cholesterol (HDL) and low density lipoprotein cholesterol (LDL).

Methods: Prospective case-control study with Helicobacter pylori-positive patients undergoing eradication therapy with omeprazole, clarithromycin, and amoxicillin. Stool and blood samples were obtained from 20 controls (H. pylori negative) and 40 patients before and 2 months after antibiotic treatment. Gut microbiota was determined through 16S rRNA amplicon sequencing (Illumina MiSeq).

Results: Eradication treatment for H. pylori increased the HDL levels, and caused changes in gut microbiota profiles. An unfavorable lipid profiles (high LDL and low HDL levels) was associated with a low microbial richness and an increase of the Bacteroidetes phylum. Prevotella copri, Lachonobacterium, and Delsufovibrio were positively associated with HDL while Rikenellaceae was negatively associated with HDL after completing antibiotic treatment.

Conclusions:Helicobacter pylori eradication treatment could improve lipid metabolism in relation with an increase in the HDL. Changes in the abundance of specific bacteria, such as P. copri, Lachonobacterium, Delsufovibrio, and Rikenellaceae could be associated with change in the plasma HDL levels.

Short-term High-fat Overfeeding Does Not Induce NF-κB Inflammatory Signaling in Subcutaneous White Adipose Tissue

CONTEXT

It is unclear how white adipose tissue (WAT) inflammatory signaling proteins respond during the early stages of overnutrition.

OBJECTIVE

To investigate the effect of short-term, high-fat overfeeding on fasting abdominal subcutaneous WAT total content and phosphorylation of proteins involved in nuclear factor-κB (NF-κB) inflammatory signaling, systemic metabolic and inflammatory biomarkers.

DESIGN

Individuals consumed a high-fat (65% total energy from total fat), high-energy (50% above estimated energy requirements) diet for 7 days.

RESULTS

Fifteen participants (aged 27 ± 1 years; body mass index 24.4 ± 0.6 kg/m2) completed the study. Body mass increased following high-fat overfeeding (+1.2 ± 0.2 kg; P < 0.0001). However, total content and phosphorylation of proteins involved in NF-κB inflammatory signaling were unchanged following the intervention. Fasting serum glucose (+0.2 ± 0.0 mmol/L), total cholesterol (+0.4 ± 0.1 mmol/L), low-density lipoprotein cholesterol (+0.3 ± 0.1 mmol/L), high-density lipoprotein cholesterol (+0.2 ± 0.0 mmol/L), and lipopolysaccharide-binding protein (LBP; +4.7 ± 2.1 µg/mL) increased, whereas triacylglycerol concentrations (-0.2 ± 0.1 mmol/L) decreased following overfeeding (all P < 0.05). Systemic biomarkers (insulin, soluble cluster of differentiation 14 [CD14], C-reactive protein, interleukin-6, tumor necrosis factor-α and monocyte chemoattractant protein-1) and the proportion and concentration of circulating CD14+ monocytes were unaffected by overfeeding.

CONCLUSION

Acute lipid oversupply did not impact on total content or phosphorylation of proteins involved in WAT NF-κB inflammatory signaling, despite modest weight gain and metabolic alterations. Systemic LBP, which is implicated in the progression of low-grade inflammation during the development of obesity, increased in response to a 7-day high-fat overfeeding period.

Low-grade inflammation causes gap junction-coupled cell dysfunction throughout the body, which can lead to the spread of systemic inflammation

BACKGROUND AND AIMS

Gap junction-coupled cells form networks in different organs in the body. These networks can be affected by inflammatory stimuli and become dysregulated. Cell signaling is also changed through connexin-linked gap junctions. This alteration affects the surrounding cells and extracellular matrix in organs. These changes can cause the spread of inflammatory substances, thus affecting other network-linked cells in other organs in the body, which can give rise to systemic inflammation, which in turn can lead to pain that can turn into chronic.

METHODS

This is a review based on literature search and our own research data of inflammatory stimuli that can affect different organs and particularly gap-junction-coupled cells throughout the body.

CONCLUSIONS

A remaining question is which cell type or tissue is first affected by inflammatory stimuli. Can endotoxin exposure through the air, water and body start the process and are mast cells the first target cells that have the capacity to alter the physiological status of gap junction-coupled cells, thereby causing breakdown of different barrier systems?

IMPLICATIONS

Is it possible to address the right cellular and biochemical parameters and restore inflammatory systems to a normal physiological level by therapeutic strategies?