Impaired intestinal barrier function in type 2 diabetic patients measured by serum LPS, Zonulin, and IFABP

Markers of enterocyte damage, microbial translocation, and systemic inflammation following 9 h of heat exposure in young and older adults

Heat stress induced damage to the gastrointestinal barrier can induce local and systemic inflammatory reactions implicated in heat-stroke. Gastrointestinal barrier damage has been shown to be greater in older relative to young adults following hyperthermia. However, comparisons between young and older adults have been limited to brief exposures (3 h), which may not reflect the duration of heat stress experienced during heat waves. We therefore evaluated markers of intestinal epithelial damage (log transformed intestinal fatty acid binding protein, IFABPLOG), microbial translocation (soluble cluster of differentiation 14, sCD14LOG), and systemic inflammation (tumour necrosis factor alpha, TNF-αLOG; interleukin 6, IL-6LOG; C-reactive protein, CRP) in 19 young (interquartile range: 21-27 years; 10 females) and 37 older (68-73 years; 10 females) adults before and after 9 h of rest in 40 °C (9% relative humidity). The magnitude of the increase in IFABPLOG was 0.38 log pg/mL (95% CI, 0.10, 0.65 log pg/mL) greater in the older relative to young cohort (P = 0.049) after 9 h heat exposure. At baseline both IL-6LOG and CRP concentrations were higher in the older (IL-6: 2.67 (1.5) log pg/mL, CRP: 0.28 (1.5) mg/mL) relative to the young (IL-6: 1.59 log pg/mL, SD 1.2; CRP: 0.11 mg/mL, SD 1.7) group (both P ≤ 0.001). The change in IL-6 and CRP was similar between groups following 9 h heat exposure (IL-6: P = 0.053; CRP: P = 0.241). Neither sCD14LOG and TNF-αLOG were different between groups at baseline nor altered after 9 h heat exposure. Our data indicate that age may modify intestinal epithelial injury following 9 h of passive heat exposure.

Chemical detection and analysis of Astragalus-Cassia twig drug pair using UHPLC-Q-TOF-MS and HPLC-UV methods

The classic Astragalus-Cassia twig drug pair has a long history of proven efficacy. However, a fewer studies on material basis of the Astragalus and Cassia twig decoction (ACD) was researched at present. The method of UPLC-Q-TOF-MS for classifying and identifying the main chemical components of ACD was established and the differences in composition between single decoction and co-decoction were compared by using HPLC-UV. The therapeutic role of ACD on type 2 diabetes (T2D) rats was investigated. Thirty-five compounds were resolved from the ACD. Fifteen compounds were deduced from the decoction of Astragalus, whereas nine compounds were identified from Cassia twig. Pairing of herbs make a significant effect on the chemical composition of herbal decoction. ACD can play a more obvious role in alleviating the symptoms of T2D rats, compared to the application of single herb.

Hyperglycemic environments directly compromise intestinal epithelial barrier function in an organoid model and hyaluronan (∼35kDa) protects via a layilin dependent mechanism

BACKGROUND

Metabolic syndrome and diabetes in obese individuals are strong risk factors for development of inflammatory bowel disease (IBD) and colorectal cancer. The pathogenic mechanisms of low-grade metabolic inflammation, including chronic hyperglycemic stress, in disrupting gut homeostasis are poorly understood. In this study, we sought to understand the impact of a hyperglycemic environment on intestinal barrier integrity and the protective effects of small molecular weight (35 kDa) hyaluronan on epithelial barrier function.

METHODS

Intestinal organoids derived from mouse colon were grown in normal glucose media (5 mM) or high glucose media (25 mM) to study the impact of hyperglycemic stress on the intestinal barrier. Additionally, organoids were pretreated with 35 kDa hyaluronan (HA35) to investigate the effect of hyaluronan on epithelial barrier under high glucose stress. Immunoblotting as well as confocal imaging was used to understand changes in barrier proteins, quantitative as well as spatial distribution, respectively. Alterations in barrier function were measured using trans-epithelial electrical resistance and fluorescein isothiocyanate flux assays. Untargeted proteomics analysis was performed to elucidate mechanisms by which HA35 exerts a protective effect on the barrier. Intestinal organoids derived from receptor knockout mice specific to various HA receptors were utilized to understand the role of HA receptors in barrier protection under high glucose conditions.

RESULTS

We found that high glucose stress decreased the protein expression as well as spatial distribution of two key barrier proteins, zona occludens-1 (ZO-1) and occludin. HA35 prevented the degradation or loss of ZO-1 and maintained the spatial distribution of both ZO-1 and occludin under hyperglycemic stress. Functionally, we also observed a protective effect of HA35 on the epithelial barrier under high glucose conditions. We found that HA receptor, layilin, was involved in preventing barrier protein loss (ZO-1) as well as maintaining spatial distribution of ZO-1 and occludin. Additionally, proteomics analysis showed that cell death and survival was the primary pathway upregulated in organoids treated with HA35 under high glucose stress. We found that XIAP associated factor 1 (Xaf1) was modulated by HA35 thereby regulating apoptotic cell death in the intestinal organoid system. Finally, we observed that spatial organization of both focal adhesion kinase (FAK) as well as F-actin was mediated by HA35 via layilin.

CONCLUSION

Our results highlight the impact of hyperglycemic stress on the intestinal barrier function. This is of clinical relevance, as impaired barrier function has been observed in individuals with metabolic syndrome. Additionally, we demonstrate barrier protective effects of HA35 through its receptor layilin and modulation of cellular apoptosis under high glucose stress.

Markers of Intestinal Permeability and Inflammation in Enterally Fed Children with Cerebral Palsy

Cerebral palsy (CP) results in non-progressive damage to the central nervous system, leading to functional disorders of the gastrointestinal tract and requiring enteral nutrition via gastrostomy in some patients. The aim of the study was to assess the impact of enteral nutrition on intestinal inflammation expressed by stool calprotectin and intestinal permeability determined by fecal zonulin and IFABP, and to determine whether CP affects these parameters. The study group consisted of 30 children with CP, fed enterally (Cerebral Palsy Enteral Nutrition-CPEN), and two reference groups: 24 children with CP, fed orally with a standard diet (CPC-Cerebral Palsy Controls) and 24 healthy children (HC-healthy controls). The differences between these groups and between the combined CP groups (CPG and CPEN + CPC) and HC were analyzed. Fecal zonulin, calprotectin, and intestinal fatty acid-binding protein 2 (IFABP2) levels were determined by ELISA. The concentrations of fecal calprotectin and zonulin were significantly higher in the CPEN group than in the CPC group (p = 0.012, p = 0.025). When comparing the CPG (n = 53) with the HC group (n = 24), statistically significant differences were observed for calprotectin (p = 0.000018, higher in the CPG) and IFABP (p = 0.021, higher in HC). Enteral nutrition was associated in our cohort with increased fecal calprotectin and zonulin. Children with cerebral palsy presented with increased fecal calprotectin but not increased intestinal permeability expressed by stool zonulin.

Gut permeability is associated with lower insulin sensitivity in youth with perinatally acquired HIV

The relationships between alterations in the intestinal barrier, and bacterial translocation with the development of metabolic complications in youth with perinatally acquired HIV (YPHIV) have not been investigated. The PHACS Adolescent Master Protocol enrolled YPHIV across 15 U.S. sites, including Puerto Rico, from 2007 to 2009. For this analysis, we included YPHIV with HIV viral load 1000 c/ml or less, with at least one measurement of homeostatic assessment of insulin resistance (HOMA-IR) or nonhigh density lipoprotein (non-HDLc) between baseline and year 3 and plasma levels of intestinal fatty-acid binding protein (I-FABP), lipopolysaccharide-binding protein (LBP), and zonulin levels at baseline. We fit linear regression models using generalized estimating equations to assess the association of baseline log 10 gut markers with log 10 HOMA-IR and non-HDLc at all timepoints. HOMA-IR or non-HDLc was measured in 237, 189, and 170 PHIV at baseline, Yr2, and Yr3, respectively. At baseline, median age (Q1, Q3) was 12 years (10, 14), CD4 + cell count was 762 cells/μl (574, 984); 90% had HIV RNA less than 400 c/ml. For every 10-fold higher baseline I-FABP, HOMA-IR dropped 0.85-fold at baseline and Yr2. For a 10-fold higher baseline zonulin, there was a 1.35-fold increase in HOMA-IR at baseline, 1.23-fold increase in HOMA-IR at Yr2, and 1.20-fold increase in HOMA-IR at Yr3 in adjusted models. For a 10-fold higher baseline LBP, there was a 1.23-fold increase in HOMA-IR at baseline in the unadjusted model, but this was slightly attenuated in the adjusted model. Zonulin was associated with non-HDLc at baseline, but not for the other time points. Despite viral suppression, intestinal damage may influence downstream insulin sensitivity in YPHIV.

Enteric neuropathy in diabetes: Implications for gastrointestinal function

Diabetes, commonly known for its metabolic effects, also critically affects the enteric nervous system (ENS), which is essential in regulating gastrointestinal (GI) motility, secretion, and absorption. The development of diabetes-induced enteric neuropathy can lead to various GI dysfunctions, such as gastroparesis and irregular bowel habits, primarily due to disruptions in the function of neuronal and glial cells within the ENS, as well as oxidative stress and inflammation. This editorial explores the pathophysiological mechanisms underlying the development of enteric neuropathy in diabetic patients. Additionally, it discusses the latest advances in diagnostic approaches, emphasizing the need for early detection and intervention to mitigate GI complications in diabetic individuals. The editorial also reviews current and emerging therapeutic strategies, focusing on pharmacological treatments, dietary management, and potential neuromodulatory interventions. Ultimately, this editorial highlights the necessity of a multidisciplinary approach in managing enteric neuropathy in diabetes, aiming to enhance patient quality of life and address a frequently overlooked complication of this widespread disease.

Gut Permeability and Immune-Mediated Inflammation in Heart Failure

Heart failure (HF) is characterized by low-grade immune-mediated inflammation due to increased Toll-like receptor (TLR) expression as response to endotoxin increase and dysregulated gut barrier permeability. We investigated TLR expression and possible gut dysbiosis in HF patients compared to a control group. We enrolled 80 Caucasian HF patients and 20 controls. Low-grade immune-mediated inflammation was evaluated by TLR expression, while gut dysbiosis by the detection of zonulin and bacterial endotoxin activity in a semi-quantitative (endotoxin activity assay [EAA]) and quantitative (limulus amebocyte lysate [LAL] test) way. Compared to controls, patients with HF showed significantly higher age and blood pressure values, worse metabolic profile and kidney function, higher inflammatory biomarkers levels, and lower levels of zonulin and endotoxin activity. When dividing failing patients in those with reduced ejection fraction (HF-rEF) and those with preserved ejection fraction (HF-pEF), HF-rEF patients showed significantly higher values of inflammatory biomarkers and TLR expression than HF-pEF patients. Gut permeability biomarkers inversely correlated with the severity of HF and positively with renal function. eGFR was retained as an independent predictor of zonulin variation in all the three groups of failing patients. Present data work to extend current knowledge about the role of gut microbiota in immune-mediated inflammation in HF.

Lowering glycemic levels via gastrointestinal tract factors: the roles of dietary fiber, polyphenols, and their combination

Dietary fiber (DF) and polyphenols (DP) are typical blood sugar-lowering components, and both play distinct yet interconnected roles in exerting their blood sugar-lowering effects. We comprehensively summarized the single and combined effects of DF and DP on blood glucose homeostasis through regulating the relevant factors in the upper gastrointestinal tract (UGT) and lower gastrointestinal tract (LGT). In the UGT, DF slowed down glucose metabolism by enhancing digesta viscosity and hindering enzyme-substrate interaction. DP primarily targeted enzymes and substrates. When combined, DP enhanced the adsorption capacity of DF for glucose. DF weakened DP's inhibitory effect on enzymes. Both DF and DP disrupted glucose intestinal uptake via physical or genomic modulation, but the co-consumption of DF and DP demonstrated a lower inhibitory effect on glucose uptake than DP alone. In the LGT, DF and DP showed synergistic or antagonistic effects on gut microbiota. Remarkably, whole foods exhibited potent prebiotic effects due to their compound-rich matrix, potentially enhancing glucose homeostasis and expanding dietary options for glucose regulation research.

The Role of the Adrenal-Gut-Brain Axis on Comorbid Depressive Disorder Development in Diabetes

Diabetic patients are more affected by depression than non-diabetics, and this is related to greater treatment resistance and associated with poorer outcomes. This increase in the prevalence of depression in diabetics is also related to hyperglycemia and hypercortisolism. In diabetics, the hyperactivity of the HPA axis occurs in parallel to gut dysbiosis, weakness of the intestinal permeability barrier, and high bacterial-product translocation into the bloodstream. Diabetes also induces an increase in the permeability of the blood-brain barrier (BBB) and Toll-like receptor 4 (TLR4) expression in the hippocampus. Furthermore, lipopolysaccharide (LPS)-induced depression behaviors and neuroinflammation are exacerbated in diabetic mice. In this context, we propose here that hypercortisolism, in association with gut dysbiosis, leads to an exacerbation of hippocampal neuroinflammation, glutamatergic transmission, and neuronal apoptosis, leading to the development and aggravation of depression and to resistance to treatment of this mood disorder in diabetic patients.

Dietary Supplementation with a Cocoa-Carob Blend Modulates Gut Microbiota and Prevents Intestinal Oxidative Stress and Barrier Dysfunction in Zucker Diabetic Rats

We have recently developed a cocoa-carob blend (CCB) rich in polyphenols with antidiabetic properties. In this study, we investigated whether its benefits could be related to gut health and gut microbiota (GM) composition and the likely phenolic metabolites involved. Zucker diabetic fatty rats were fed on a standard or a CCB-rich diet for 12 weeks. Intestinal barrier structure and oxidative and inflammatory biomarkers were analyzed in colonic samples. GM composition and phenolic metabolites were evaluated from feces. The results show that CCB improved mucin and tight-junction proteins and counteracted gut oxidative stress and inflammation by regulating sirtuin-1 and nuclear factor erythroid 2-related factor 2 (Nrf2) levels. CCB also modulated the composition of the GM, showing increases in Akkermansia and Bacteroides and decreases in Ruminococcus genera. Correlation analysis strengthened the associations between these genera and improved pathological variables in diabetic animals. Moreover, 12 phenolic metabolites were identified in CCB feces, being2,3-dihydroxybenzoic and 3,4,5-trihydroxybenzoic acids significantly associated with increased levels of Akkermansia and Oscillospira genera. Our findings support the potential use of CCB to prevent intestinal damage and dysbiosis in T2D, which would help to delay the progression of this pathology.

Zonulin as a Potential Therapeutic Target in Microbiota-Gut-Brain Axis Disorders: Encouraging Results and Emerging Questions

The relationship between dysbiosis and central nervous diseases has been proved in the last 10 years. Microbial alterations cause increased intestinal permeability, and the penetration of bacterial fragment and toxins induces local and systemic inflammatory processes, affecting distant organs, including the brain. Therefore, the integrity of the intestinal epithelial barrier plays a central role in the microbiota-gut-brain axis. In this review, we discuss recent findings on zonulin, an important tight junction regulator of intestinal epithelial cells, which is assumed to play a key role in maintaining of the blood-brain barrier function. In addition to focusing on the effect of microbiome on intestinal zonulin release, we also summarize potential pharmaceutical approaches to modulate zonulin-associated pathways with larazotide acetate and other zonulin receptor agonists or antagonists. The present review also addresses the emerging issues, including the use of misleading nomenclature or the unsolved questions about the exact protein sequence of zonulin.

Intestinal barrier functions in hematologic and oncologic diseases

The intestinal barrier is a complex structure that not only regulates the influx of luminal contents into the systemic circulation but is also involved in immune, microbial, and metabolic homeostasis. Evidence implicating disruption in intestinal barrier functions in the development of many systemic diseases, ranging from non-alcoholic steatohepatitis to autism, or systemic complications of intestinal disorders has increased rapidly in recent years, raising the possibility of the intestinal barrier as a potential target for therapeutic intervention to alter the course and mitigate the complications associated with these diseases. In addition to the disease process being associated with a breach in the intestinal barrier functions, patients with hematologic and oncologic diseases are particularly at high risks for the development of increased intestinal permeability, due to the frequent use of broad-spectrum antibiotics and chemoradiation. They also face a distinct challenge of being intermittently severely neutropenic due to treatment of the underlying conditions. In this review, we will discuss how hematologic and oncologic diseases are associated with disruption in the intestinal barrier and highlight the complications associated with an increase in the intestinal permeability. We will explore methods to modulate the complication. To provide a background for our discussion, we will first examine the structure and appraise the methods of evaluation of the intestinal barrier.

Cordyceps militaris polysaccharide alleviates diabetic symptoms by regulating gut microbiota against TLR4/NF-κB pathway

The relationship between gut microbiota and type 2 diabetes mellitus (T2DM) has attracted increasing attention. In our work, one purified fraction a (AEPSa) was obtained from Cordyceps militaris polysaccharides, and its hypoglycemic activity and underlying mechanisms were investigated in high-fat diet (HFD)- and streptozotocin (STZ)-induced T2DM mice. The results revealed that AEPSa reshaped gut microbiota by increasing Allobaculum, Alistipes, Lachnospiraceae_NK4A136_group and norank_f_Muribaculaceae and decreasing Enterococcus and Ruminococcus_torques_group to inhibit the colonic toll-like receptor 4 (TLR4)/nuclear factor kappa-B (NF-κB) pathway and upregulate intestinal tight junction protein expression, thereby improving glucose and serum lipid metabolism, hormone secretion and complications. Fecal microbiota transplantation (FMT) also confirmed these findings. These results indicated that symptomatic relief of T2DM might be related to AEPSa regulating the gut microbiota against the TLR4/NF-κB pathway to protect the intestinal barrier. Therefore, AEPSa might be developed as a prebiotic agent against T2DM by regulating gut microbiota.

Effects of hemicellulose on intestinal mucosal barrier integrity, gut microbiota, and metabolomics in a mouse model of type 2 diabetes mellitus

Background and objective

Impaired gut barrier contributes to the progression of type 2 diabetes mellitus (T2DM), and the gut microbiota and metabolome play an important role in it. Hemicellulose, a potential prebiotics, how its supplementation impacted the glucose level, the impaired gut barrier, and the gut microbiota and metabolome in T2DM remained unclear.

Methods

In this study, some mice were arranged randomly into four groups: db/db mice fed by a compositionally defined diet (CDD), db/db mice fed by a CDD with 10% and 20% hemicellulose supplementation, and control mice fed by a CDD. Body weight and fasting blood glucose levels were monitored weekly. The gut barrier was evaluated. Fresh stool samples were analyzed using metagenomic sequencing and liquid chromatography-mass spectrometry to detect gut microbiota and metabolome changes. Systemic and colonic inflammation were evaluated.

Results

Better glycemic control, restoration of the impaired gut barrier, and lowered systemic inflammation levels were observed in db/db mice with the supplementation of 10 or 20% hemicellulose. The gut microbiota showed significant differences in beta diversity among the four groups. Fifteen genera with differential relative abundances and 59 significantly different metabolites were found. In the db/db group, hemicellulose eliminated the redundant Faecalibaculum and Enterorhabdus. The increased succinate and ursodeoxycholic acid (UDCA) after hemicellulose treatment were negatively correlated with Bifidobacterium, Erysipelatoclostridium, and Faecalibaculum. In addition, hemicellulose reduced the colonic expressions of TLR2/4 and TNF-α in db/db mice.

Conclusion

Hemicellulose may serve as a potential therapeutic intervention for T2DM by improving impaired intestinal mucosal barrier integrity, modulating gut microbiota composition, and altering the metabolic profile.

Lacticaseibacillus rhamnosus Hao9 exerts antidiabetic effects by regulating gut microbiome, glucagon metabolism, and insulin levels in type 2 diabetic mice

Introduction

Type 2 diabetes mellitus (T2DM) is a metabolic disease that has led to a significant global public health burden.

Methods

In this work, we investigated the effects of Lacticaseibacillus rhamnosus Hao9 on T2DM in mice with high-fat diet- and streptozotocin (STZ)-induced diabetes (diabetic mice) and explored the underlying mechanisms.

Results

We found that 10⁹ colony forming units (CFUs) of Hao9 per day significantly reduced fasting blood glucose and insulin levels (p < 0.001) in diabetic mice. Moreover, Hao9 enhanced liver antioxidant capacity and significantly decreased glucose-6-phosphatase and phosphoenolpyruvate carboxykinase expression in the livers of diabetic mice (p < 0.001). Hao9 also reduced the serum concentrations of pro-inflammatory cytokines such as tumor necrosis factor alpha (TNFα), interleukin-1β (IL1β), and IL6 (p < 0.05) and improved intestinal barrier function in diabetic mice. The composition of the gut microbiome was modulated by Hao9, with an increased abundance of Roseburia, Eubacterium, and Lacticaseibacillus, and decreased abundance of Escherichia/Shigella. Notably, Lacticaseibacillus was detected at both weeks 5 and 12 post-treatment, suggesting sustained colonization of the gut by Hao9.

Discussion

The supplementation of Hao9 improved gut microbiota, glucose metabolism, and insulin levels significantly in T2DM mice. That means Hao9 contributes to improving T2DM symptoms with its potential beneficial effects. Therefore, Hao9 is a promising dietary supplement for the treatment of T2DM.

A water-soluble tomato extract rich in secondary plant metabolites lowers trimethylamine-n-oxide and modulates gut microbiota: a randomized, double-blind, placebo-controlled cross-over study in overweight and obese adults

BACKGROUND

Natural products rich in polyphenols have been shown to lower plasma trimethylamine-n-oxide (TMAO) known for its proatherogenic effects by modulating the intestinal microbiota.

OBJECTIVES

We aimed to determine the impact of Fruitflow, a water-soluble tomato extract, on TMAO, fecal microbiota, and plasma and fecal metabolites.

METHODS

Overweight and obese adults (n = 22, BMI 28-35 kg/m²) were included in a double-blind, placebo-controlled, cross-over study receiving 2×150 mg Fruitflow per day or placebo (maltodextrin) for 4 wk with a 6-week wash-out between interventions. Stool, blood, and urine samples were collected to assess changes in plasma TMAO (primary outcome) as well as fecal microbiota, fecal and plasma metabolites, and urine TMAO (secondary outcomes). In a subgroup (n = 9), postprandial TMAO was evaluated following a choline-rich breakfast (∼450 mg). Statistical methods included paired t-tests or Wilcoxon signed rank tests and permutational multivariate analysis of variance.

RESULTS

Fruitflow, but not placebo, reduced fasting levels of plasma (-1.5 μM, P ≤ 0.05) and urine (-19.1 μM, P ≤ 0.01) TMAO as well as plasma lipopolysaccharides (-5.3 ng/mL, P ≤ 0.05) from baseline to the end of intervention. However, these changes were significant only for urine TMAO levels when comparing between the groups (P ≤ 0.05). Changes in microbial beta, but not alpha, diversity paralleled this with a significant difference in Jaccard distance-based Principal Component (P ≤ 0.05) as well as decreases in Bacteroides, Ruminococccus, and Hungatella and increases in Alistipes when comparing between and within groups (P ≤ 0.05, respectively). There were no between-group differences in SCFAs and bile acids (BAs) in both faces and plasma but several changes within groups such as an increase in fecal cholic acid or plasma pyruvate with Fruitflow (P ≤ 0.05, respectively). An untargeted metabolomic analysis revealed TMAO as the most discriminant plasma metabolite between groups (P ≤ 0.05).

CONCLUSIONS

Our results support earlier findings that polyphenol-rich extracts can lower plasma TMAO in overweight and obese adults related to gut microbiota modulation. This trial was registered at clinicaltrials.gov as NCT04160481 (https://clinicaltrials.gov/ct2/show/NCT04160481?term= Fruitflow&draw= 2&rank= 2).

Inflammation in Children with CKD Linked to Gut Dysbiosis and Metabolite Imbalance

BACKGROUND

CKD is characterized by a sustained proinflammatory response of the immune system, promoting hypertension and cardiovascular disease. The underlying mechanisms are incompletely understood but may be linked to gut dysbiosis. Dysbiosis has been described in adults with CKD; however, comorbidities limit CKD-specific conclusions.

METHODS

We analyzed the fecal microbiome, metabolites, and immune phenotypes in 48 children (with normal kidney function, CKD stage G3-G4, G5 treated by hemodialysis [HD], or kidney transplantation) with a mean±SD age of 10.6±3.8 years.

RESULTS

Serum TNF-α and sCD14 were stage-dependently elevated, indicating inflammation, gut barrier dysfunction, and endotoxemia. We observed compositional and functional alterations of the microbiome, including diminished production of short-chain fatty acids. Plasma metabolite analysis revealed a stage-dependent increase of tryptophan metabolites of bacterial origin. Serum from patients on HD activated the aryl hydrocarbon receptor and stimulated TNF-α production in monocytes, corresponding to a proinflammatory shift from classic to nonclassic and intermediate monocytes. Unsupervised analysis of T cells revealed a loss of mucosa-associated invariant T (MAIT) cells and regulatory T cell subtypes in patients on HD.

CONCLUSIONS

Gut barrier dysfunction and microbial metabolite imbalance apparently mediate the proinflammatory immune phenotype, thereby driving the susceptibility to cardiovascular disease. The data highlight the importance of the microbiota-immune axis in CKD, irrespective of confounding comorbidities.

Is compromised intestinal barrier integrity responsible for the poor prognosis in critically ill patients with pre-existing hyperglycemia?

BACKGROUND

Compromised intestinal barrier integrity can be independently driven by hyperglycemia, and both hyperglycemia and intestinal barrier injury are associated with poor prognosis in critical illness. This study investigated the intestinal barrier biomarkers in critically ill patients, to explore the role of compromised intestinal barrier integrity on the prognosis of critically ill patients with pre-existing hyperglycemia.

METHODS

This was a retrospective observational study. The relationships between intestinal barrier biomarkers and glycated hemoglobin A1c (HbA1c), fasting blood glucose (FBG), indicators of clinical characteristics, disease severity, and prognosis in critically ill patients were investigated. Then the metrics mentioned above were compared between survivors and non-survivors, the risk factors of 90-day mortality were investigated by logistic regression analysis. Further, patients were divided into HbA1c < 6.5% Group and HbA1c ≥ 6.5% Group, metrics mentioned above were compared between these two groups.

RESULTS

A total of 109 patients with critical illness were included in the study. D-lactate and lipopolysaccharide (LPS) were associated with sequential organ failure assessment (SOFA) score and 90-day mortality. LPS was an independent risk factor of 90-day mortality. DAO, NEU (neutrophil) proportion, temperature, lactate were lower in HbA1c ≥ 6.5% Group while D-lactate, LPS, indicators of disease severity and prognosis showed no statistical difference between HbA1c < 6.5% Group and HbA1c ≥ 6.5% Group.

CONCLUSIONS

Intestinal barrier integrity is associated with the disease severity and prognosis in critical illness. Compromised intestinal barrier integrity might be responsible for the poor prognosis in critically ill patients with pre-existing hyperglycemia.

Research Progress on the Therapeutic Effect of Polysaccharides on Non-Alcoholic Fatty Liver Disease through the Regulation of the Gut–Liver Axis

Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disease affecting global public health at present, which can induce cirrhosis and liver cancer in serious cases. However, NAFLD is a multifactorial disease, and there is still a lack of research on its mechanism and therapeutic strategy. With the development of the gut–liver axis theory, the association between the gut–liver axis and the pathogenesis of NAFLD has been gradually disclosed. Polysaccharides, as a kind of natural product, have the advantages of low toxicity, multi-target and multi-pathway action. It has been reported that polysaccharides can affect the gut–liver axis at multiple interrelated levels, such as maintaining the ecological balance of gut microbiota (GM), regulating the metabolites of GM and improving the intestinal barrier function, which thereby plays a protective role in NAFLD. These studies have great scientific significance in understanding NAFLD based on the gut–liver axis and developing safe and effective medical treatments. Herein, we reviewed the recent progress of polysaccharides in improving nonalcoholic fatty liver disease (NAFLD) through the gut–liver axis.

Bifidobacterium longum 070103 Fermented Milk Improve Glucose and Lipid Metabolism Disorders by Regulating Gut Microbiota in Mice

Background: Fermented milk is beneficial for metabolic disorders, while the underlying mechanisms of action remain unclear. This study explored the benefits and underlying mechanisms of Bifidobacterium longum 070103 fermented milk (BLFM) in thirteen-week high-fat and high-sugar (HFHS) fed mice using omics techniques. Methods and results: BLFM with activated glucokinase (GK) was screened by a double-enzyme coupling method. After supplementing BLFM with 10 mL/kg BW per day, fasting blood glucose, total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), and leptin were significantly reduced compared with the HFHS group. Among them, the final body weight (BW), epididymal fat, perirenal fat, and brown fat in BLFM group had better change trends than Lacticaseibacillus rhamnosus GG fermented milk (LGGFM) group. The amplicon and metabolomic data analysis identified Bifibacterium as a key gut microbiota at regulating glycolipid metabolism. BLFM reverses HFHS-induced reduction in bifidobacteria abundance. Further studies showed that BLFM significantly reduces the content of 3-indoxyl sulofphate associated with intestinal barrier damage. In addition, mice treated with BLFM improved BW, glucose tolerance, insulin resistance, and hepatic steatosis. Conclusion: BLFM consumption attenuates obesity and related symptoms in HFHS-fed mice probably via the modulation of gut microbes and metabolites.

Differential expression of MSTN, IGF2BP1, and FABP2 across different embryonic ages and sexes in white Muscovy ducks

To explore the effects of growth-related genes in both sexes and at different growth and development stages, male and female white Muscovy ducks at embryonic day E13, E17, E21, E25 and E29 were assessed in this study. RT-qPCR was used to determine the mRNA transcription levels of selected growth-related genes in the leg muscles of Muscovy ducks of both sexes and at different growth and developmental stages. MSTN, IGF2BP1 and FABP2 mRNAs were expressed in the leg muscles of male and female Muscovy ducks, but with different expression patterns. The MSTN and IGF2BP1 mRNA expression patterns were wavelike. MSTN mRNA expression was elevated at E13, increased at E17, decreased rapidly to the lowest level at E21, increased again at E25, and then decreased. IGF2BP1 mRNA expression was elevated at E13, increased at E17, decreased rapidly at E21, decreased rapidly to the lowest level at E25, and increased at E29. The expression trend of FABP2 mRNA was approximately "⊥" shape; the expression was the lowest at E13, increased slowly from E17 to E25, and increased extremely significantly at E29. In addition, the expression of MSTN in male Muscovy ducks was significantly higher than that in female ducks at E25 (P < 0.05). The expression of IGF2BP1 in male Muscovy ducks was extremely significantly higher than that in female ducks at E17 (P < 0.01). However, the expression of FABP2 in female Muscovy ducks was extremely significantly higher than that in male Muscovy ducks at E21 and E29 (P < 0.01). In conclusion, the mRNA expression of MSTN, IGF2BP1 and FABP2 in white Muscovy ducks is gestational age specific and sex specific. The differential gene expression patterns observed in this study provide a basis for understanding the physiological changes in white Muscovy ducks at different embryonic ages and in both sexes, supplementing the existing research on duck embryo muscle development. In addition, the findings provide a new framework for further discussion of poultry breeding.

Is type 2 diabetes mellitus another intercellular junction-related disorder?

Type 2 diabetes mellitus (T2D) is nowadays a worldwide epidemic and has become a major challenge for health systems around the world. It is a multifactorial disorder, characterized by a chronic state of hyperglycemia caused by defects in the production as well as in the peripheral action of insulin. This minireview highlights the experimental and clinical evidence that supports the novel idea that intercellular junctions (IJs)-mediated cell-cell contacts play a role in the pathogenesis of T2D. It focuses on IJs repercussion for endocrine pancreas, intestinal barrier, and kidney dysfunctions that contribute to the onset and evolution of this metabolic disorder.

Clinical Interest of Serum Alpha-2 Macroglobulin, Apolipoprotein A1, and Haptoglobin in Patients with Non-Alcoholic Fatty Liver Disease, with and without Type 2 Diabetes, before or during COVID-19

In patients with non-alcoholic fatty liver disease (NAFLD) with or without type 2 diabetes mellitus (T2DM), alpha-2 macroglobulin (A2M), apolipoprotein A1 (ApoA1), and haptoglobin are associated with the risk of liver fibrosis, inflammation (NASH), and COVID-19. We assessed if these associations were worsened by T2DM after adjustment by age, sex, obesity, and COVID-19. Three datasets were used: the “Control Population”, which enabled standardization of protein serum levels according to age and sex (N = 27,382); the “NAFLD-Biopsy” cohort for associations with liver features (N = 926); and the USA “NAFLD-Serum” cohort for protein kinetics before and during COVID-19 (N = 421,021). The impact of T2DM was assessed by comparing regression curves adjusted by age, sex, and obesity for the liver features in “NAFLD-Biopsy”, and before and during COVID-19 pandemic peaks in “NAFLD-Serum”. Patients with NAFLD without T2DM, compared with the values of controls, had increased A2M, decreased ApoA1, and increased haptoglobin serum levels. In patients with both NAFLD and T2DM, these significant mean differences were magnified, and even more during the COVID-19 pandemic in comparison with the year 2019 (all p < 0.001), with a maximum ApoA1 decrease of 0.21 g/L in women, and a maximum haptoglobin increase of 0.17 g/L in men. In conclusion, T2DM is associated with abnormal levels of A2M, ApoA1, and haptoglobin independently of NAFLD, age, sex, obesity, and COVID-19.

Clinical investigation of lipopolysaccharide in the persistence of metabolic syndrome (MS) through the activation of GRP78-IRE1α-ASK1 signaling pathway

OBJECTIVE

Endoplasmic reticulum stress (ERS) might play a pivotal role in the persistence of metabolic syndrome (MS). Lipopolysaccharide (LPS) derived from various gram-negative bacteria could result in the ERS. Therefore, we aimed to investigate the association between LPS and ERS in MS.

METHOD

We enrolled 86 patients with MS and 42 healthy people aged 35-65 years. Body weight, waist circumference, blood pressure were measured. LPS, LBP and inflammation factors, fasting plasma glucose (FPG), insulin, total cholesterol (TC), triglyceride, high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C), free fatty acid (FFA) were analyzed in blood plasma of patient's cohort. Body mass index (BMI) and HOMA-IR were calculated. The mRNA and protein expression of ERS GRP78, IRE1α, ASK1 and IKKβ, JNK1 were measured in blood plasma of patient's cohort by RT-PCR and Elisa. MS was defined by the updated National Cholesterol Education Program Adult Treatment Panel III criterion for Asian Americans.

RESULTS

BMI, waist circumference, blood pressure, FPG, insulin, HOMA-IR, TC, triglyceride, HDL-C, LDL-C, FFA and LPS, LBP, TNF-α, CRP, IL-1, IL-6, MCP-1 were significantly higher in patients with MS than healthy people (P < 0.001). The correlation analysis suggested that LPS were associated with TNF-α, IL-1, IL-6, MCP-1, LBP, FFA, HOMA-IR potently (P < 0.05). The marker gene and protein expressions of ERS (GRP78, IRE1α, ASK1, IKKβ and JNK) were significantly overexpressed in patients with MS and were positive correlation with LPS (P < 0.05).

CONCLUSION

LPS may play an important role in mediating chronic low-grade inflammation by activating the ERS GRP78-IRE1α-ASK1 signaling pathway, contributing to the persistence of MS.

A narrative review of the role of gastrointestinal dysbiosis in the pathogenesis of polycystic ovary syndrome

Diet-induced gastrointestinal dysbiosis has been hypothesized to play a significant role in stimulating an increase in gastrointestinal permeability and activating systemic inflammation in women with polycystic ovary syndrome (PCOS). We reviewed the current proof-of-concept studies on the proposed mechanism of dysbiosis in the pathogenesis of PCOS. A literature search was performed to identify articles on changes in the intestinal microbiome (dysbiosis) and increased intestinal mucosal permeability involving lipopolysaccharide (LPS), LPS-binding protein (LPS-BP), and zonulin. We also searched for systematic reviews and meta-analyses that synthesized the results of studies on the therapeutic effects of prebiotics, probiotics, or synbiotics in women with PCOS. Our search was confined to human studies between 2012 and 2021 using the PubMed, Scopus, and Cochrane databases. Thirty-one studies met the inclusion criteria (14 microbiota, 1 LPS, 1 LPS-BP, 1 LPS and LPS-BP, 5 zonulin, 9 systematic reviews). Our analysis revealed that most studies reported reduced alpha diversity and dysbiosis in women with PCOS. Preliminary studies suggest that LPS, LPS-BP, and zonulin may be involved in the pathophysiology of increased intestinal permeability. Treatment of PCOS with prebiotics, probiotics, and synbiotics appears to have a range of beneficial effects on metabolic and biochemical profiles. This review highlights the need for continued research into the pathophysiological mechanisms of dysbiosis and the clinical efficacy of prebiotics, probiotics, and synbiotics in women with PCOS.

Transcriptome analysis provides insights into the anti-diabetic mechanism of theaflavins in high-fat diet and streptozotocin-induced mice

Black tea exhibits potential to improve hyperglycemia and insulin resistance, and theaflavins (TFs) are one of its characteristic components. The aim of this study was to explore the anti-diabetic mechanism...

Electroacupuncture at Lower He-Sea and Front-Mu Acupoints Ameliorates Insulin Resistance in Type 2 Diabetes Mellitus by Regulating the Intestinal Flora and Gut Barrier

INTRODUCTION

The study objective was to investigate the effects of electroacupuncture performed at the he-sea and front-mu acupoints on the intestinal microflora and intestinal barrier in db/db mice and to explore the related mechanism in type 2 diabetes mellitus.

METHODS

Db/m mice in the normal control group (NOC), electroacupuncture group (EA), metformin group (MET) and T2DM group (T2DM) were used as model controls, and db/db mice were used in all three groups, with 8 mice in each group. The treatment period was 2 weeks. Fasting blood glucose (FBG) and triglyceride (TG) levels were measured. Lipopolysaccharide (LPS) and tumor necrosis factor-α (TNF-α) levels were detected by enzyme-linked immune sorbent assay (ELISA). The ileal tissue was stained with hematoxylin-eosin staining (H&E), and histopathological changes were observed under a light microscope. Illumina sequencing was used to analyze the V4 region of the 16S rRNA gene to evaluate the effect of EA on the intestinal flora.

RESULTS

Our results suggest that EA treatment can reduce the expression of diabetes-related markers, with an effect similar to that of metformin. After EA intervention, the abundance of Firmicutes and the ratio of Firmicutes to Bacteroidetes increased, while the abundances of Bacteroidetes and Eubacterium decreased. In addition, the serum levels of LPS and TNF-α in the electroacupuncture group were downregulated, and ileal tissue damage was alleviated under an electron microscope.

CONCLUSION

EA combined with acupoints can restore the intestinal flora structure, decrease the blood LPS level, reduce levels of inflammation, maintain the integrity of the intestinal barrier, and play a therapeutic role in the treatment of T2DM, mainly by increasing the abundance of Firmicutes and the ratio of Firmicutes to Bacteroidetes and decreasing the abundances of Bacteroidetes and Eubacterium.

Exploring the Link between Leaky-Gut-Related Markers and Metabolic Health in a Large Dutch Adult Population

A leaky gut can trigger chronic inflammation and poses a primary risk for metabolic diseases. This study established a relationship between intestinal integrity (leaky gut) and metabolic health in a general population. Leaky-gut markers (LGMs) were studied in a large population of Dutch adults with a broad spectrum of metabolic health. This study enrolled 500 individuals selected within the NQplus cohort study (n = 2048) by stratified randomization, based on waist circumference, fasting glucose, and high-density lipoprotein (HDL) cholesterol to obtain a representative and balanced population in terms of metabolic health parameters, sex (male/female), and age (<54/≥54 years). LGMs-zonulin, lipopolysaccharide-binding protein (LBP), and soluble CD14 (sCD14)-were measured in EDTA plasma or serum. Zonulin was most strongly associated with metabolic health. Zonulin and LBP were most strongly associated with the inflammatory marker C-reactive protein (CRP). The quartile analysis for zonulin and LBP showed that most metabolic health parameters and CRP levels increased from Q1 to Q4, with significant differences between quartiles, except for markers related to glucose homeostasis (glucose and glycated hemoglobin A1c (HbA1c)). Associations between LGMs and metabolic health parameters in this large Dutch adult population indicate that LGMs are valuable markers for identifying people at risk of a leaky gut and subsequent chronic inflammation linked to metabolic disorders.

Lactobacillus casei LC89 exerts antidiabetic effects through regulating hepatic glucagon response and gut microbiota in type 2 diabetic mice

Previous study suggests that Lactobacillus casei exhibits antihyperglycemic activity, however, the molecular mechanism of this has yet to be elucidated. Here, the anti-diabetic effects and underlying mechanisms of Lactobacillus casei LC89 are investigated in type 2 diabetes mellitus (T2DM) mice, which was induced by a high-fat diet (HFD) with streptozotocin (100 mg per kg BW). The results show that LC89 at a dose of 109 CFU day-1 decreases fasting blood glucose (FBG) and insulin levels by 35.12% and 28.37%, respectively, compared to the diabetes control (DC) group. Moreover, LC89 treatment improved the insulin resistance index (HOMA-IR), serum lipid profiles and inflammation cytokines. The real-time polymerase chain reaction indicated that LC89 markedly downregulates the mRNA expression of hepatic glucagon (GCG), glucagon receptor (GCGR), phosphoenolpyruvate carboxykinase (PEPCK) and glucose-6-phosphatase (G6Pase). Meanwhile, LC89 significantly decreases the abundance of Odoribacter, but increases the Alloprevotella, Bacteroides, Parabacteroides and Ruminococcus content. Therefore, LC89 plays a positive role in alleviating T2DM by regulating gut microbiota and glucagon signal pathway-related genes, and it may be a beneficial dietary supplement to regulate glucose metabolism in T2DM.

Chlorogenic Acid-Induced Gut Microbiota Improves Metabolic Endotoxemia

BACKGROUND

Coffee can regulate glucose homeostasis but the underlying mechanism is unclear. This study investigated the preventive and therapeutic effects of chlorogenic acid (CGA), a polyphenol that is found in coffee, on obesity and obesity-related metabolic endotoxemia.

METHOD

Male 4-week-old C57BL/6 mice were fed either normal chow or a high-fat diet or 20 weeks and half the mice in each group were gavaged with CGA. Oral glucose tolerance tests (OGTTs) and insulin tolerance tests (ITTs) were performed. Markers of inflammation and intestinal barrier function were assayed. The composition of the gut microbiota was analyzed by 16S rRNA high-throughput pyrosequencing. The role of CGA-altered microbiota in metabolic endotoxemia was verified by fecal microbiota transplantation.

RESULTS

CGA protected against HFD-induced weight gain, decreased the relative weight of subcutaneous and visceral adipose, improved intestinal barrier integrity, and prevented glucose metabolic disorders and endotoxemia (P <0.05). CGA significantly changed the composition of the gut microbiota and increased the abundance of short chain fatty acid (SCFA)-producers (e.g., Dubosiella, Romboutsia, Mucispirillum, and Faecalibaculum) and Akkermansia, which can protect the intestinal barrier. In addition, mice with the CGA-altered microbiota had decreased body weight and fat content and inhibited metabolic endotoxemia.

CONCLUSION

CGA-induced changes in the gut microbiota played an important role in the inhibition of metabolic endotoxemia in HFD-fed mice.