Markers Of Gut Permeability Research Articles

Multiwell Assay for the Analysis of Sugar Gut Permeability Markers: Discrimination of Sugar Alcohols with a Fluorescent Probe Array Based on Boronic Acid Appended Viologens.

With the aim of discerning between different sugar and sugar alcohols of biomedical relevance, such as gut permeability, arrays of 2-component probes were assembled with up to six boronic acid-appended viologens (BBVs): 4,4'-o-BBV, 3,3'-o-BBV, 3,4'-o-BBV, 4,4'-o,m-BBV, 4,7'-o-PBBV, and pBoB, each coupled to the fluorophore 8-hydroxypyrene, 1,3,6-trisulfonic acid trisodium salt (HPTS). These probes were screened for their ability to discriminate between lactulose, l-rhamnose, 3-O-methyl-d-glucose, and xylose. Binding studies of sugar alcohols mannitol, sorbitol, erythritol, adonitol, arabitol, galactitol, and xylitol revealed that diols containing threo-1,2-diol units have higher affinity for BBVs relative diols containing erythro-1,2 units. Those containing both threo-1,2- and 1,3-syn diol motifs showed high affinity for boronic acid binding. Fluorescence from the arrays were examined by principle component analysis (PCA) and linear discriminant analysis (LDA). Arrays with only three BBVs sufficed to discriminate between sugars (e.g., lactulose) and sugar alcohols (e.g., mannitol), establishing a differential probe. Compared with 4,4'-o-BBV, 2-fold reductions in lower limits of detection (LOD) and quantification (LOQ) were achieved for lactulose with 4,7-o-PBBV (LOD 41 μM, LOQ 72 μM). Using a combination of 4,4'-o-BBV, 4,7-o-PBBV, and pBoB, LDA statistically segregated lactulose/mannitol (L/M) ratios from 0.1 to 0.5, consistent with values encountered in small intestinal permeability tests. Another triad containing 3,3'-o-BBV, 4,4'-o-BBV, and 4,7-o-PBBV also discerned similar L/M ratios. This proof-of-concept demonstrates the potential for BBV arrays as an attractive alternate to HPLC to analyze mixtures of sugars and sugar alcohols in biomedical applications and sheds light on structural motifs that make this possible.

Abstract 11695: The Kinetics of Circulating Monocyte Subsets and Microbial Translocation in the Acute Phase of ST-Elevation Myocardial Infarction Reveals Prognostic Values for Cardiovascular Outcomes

Introduction: In experimental myocardial infarction (MI), a rise in cell counts of circulating monocyte subsets contributes to impaired myocardial healing, and to atherosclerotic plaque destabilization.The underlying pathophysiological mechanisms for the post-MI monocytosis and the prognostic role of monocyte subsets in patients suffering ST-elevation MI (STEMI) are still unclear. Hypothesis: The kinetics of the three monocyte subsets (classical CD14++CD16-, intermediate CD14++CD16+ and non-classical CD14+CD16++ monocytes) and gut microbial translocation are associated with cardiovascular outcomes after STEMI. Methods: In 100 STEMI patients treated with primary percutaneous coronary intervention (PCI), monocyte subsets and microbial translocation markers (lipopolysaccharide [LPS] and D-lactate) were measured on Days 1, 2, 3, 5 and 7 of STEMI onset, compared with 35 stable coronary heart disease patients and 35 healthy volunteers. All STEMI patients were prospectively followed for the first occurrence of an adverse cardiovascular event. Results: From Day 1 to Day 7, a parallel increase in CD14++CD16- cell counts, CD14++CD16+ cell counts, and gut permeability markers was observed, with peak levels on Day 2. During a median follow-up of 1.5 years, 25 events were recorded. Univariate Kaplan-Meier analysis revealed that Day 2 CD14++CD16- cell counts ( P =0.022), CD14++CD16+ cell counts ( P =0.024) and Δ LPS (Day 2 – Day 1; P =0.027) each predicted the primary endpoint when stratified by median values. After adjustment for confounders, Day 2 CD14++CD16+ monocyte counts showed the strongest predictive value (per SD increase: hazard ratio [HR]: 2.127; 95% CI 1.313 to 3.446; P =0.002) for cardiovascular events. Conclusions: The expansion of the CD14++CD16+ monocyte subset on Day 2, which is associated a transient increase in microbial translocation, independently predicts adverse cardiovascular outcome in STEMI patients treated with primary PCI.

Abstract 938: Circulating biomarkers of gut barrier function: Correlates and responses to calcium supplementation among sporadic colorectal adenoma patients in a dose-response randomized controlled trial

Abstract Gut barrier dysfunction contributes to several gastrointestinal disorders, including inflammatory bowel diseases and colorectal cancer, but factors associated with intestinal hyperpermeability have rarely been assessed in human populations, and there is very limited clinical trial evidence on whether gut barrier function may be modified by dietary factors. To address these gaps, we 1) evaluated factors associated with baseline circulating biomarkers of gut barrier function, and 2) tested the effect of calcium on these biomarkers over a 4-month treatment period among patients with previous colorectal adenoma in a randomized, double-blinded, placebo-controlled clinical trial (n = 193). Patients were randomized to placebo (n = 66), 1.0 g calcium (n = 64), or 2.0 g calcium (n = 63) daily. Circulating levels of anti-flagellin and anti-lipopolysaccharide (LPS) immunoglobulins (Igs) as markers of colonic hyperpermeability were measured at baseline and at 4-month follow-up via ELISA. At baseline, mean levels of anti-flagellin and anti-LPS IgA but not IgG were higher among men and those with a larger body mass index (BMI), a larger waist circumference, and higher levels of plasma C-reactive protein. Mean anti-flagellin IgG levels were higher among those with higher proinflammatory cytokine scores. We did not observe effects of calcium on anti-flagellin or anti-LPS Igs: the relative change of a combined permeability score (defined as the sum of the optical densities of all biomarkers) from baseline to follow-up was 0.07 (95% confidence interval [CI] -0.13, 0.27) for each treatment group relative to the placebo group (p-values ≥ 0.5). Our results suggest that 1) men and those with a larger BMI or waist circumference may have greater gut permeability, 2) markers of gut permeability and systemic inflammation may be directly associated with one another, and 3) supplemental calcium administered for 4 months may not modify circulating levels of biomarkers of gut barrier function. Citation Format: Baiyu Yang, Roberd M. Bostick, Andrew T. Gewirtz, Hao Quang Tran, Veronika Fedirko. Circulating biomarkers of gut barrier function: Correlates and responses to calcium supplementation among sporadic colorectal adenoma patients in a dose-response randomized controlled trial. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 938. doi:10.1158/1538-7445.AM2015-938

Immunoglobulin A and immunoglobulin G antibodies against β-lactoglobulin and gliadin at age 1 associate with immunoglobulin E sensitization at age 6.

Serum immunoglobulin A (IgA) and immunoglobulin G (IgG) antibodies against wheat gliadin and cow's milk β-lactoglobulin (BLG) are considered markers of gut permeability and inflammation which modulate the development of mucosal tolerance. Living on a farm has been shown to decrease allergies in children. Our aim was to study whether farm environment affected mucosal tolerance, immunoglobulin E (IgE) sensitization, or allergic diseases. The PASTURE birth cohort study was conducted in Finland, France, Germany, Austria, and Switzerland. At age 1, we measured serum IgA and IgG against wheat gliadin (N = 636) and cow's milk BLG (N = 639) using ELISA. Serum-specific IgE was measured at ages 1 and 6 (N = 459). Data on environmental factors and allergic diseases were collected by questionnaires. Discrete time hazard and multivariate logistic regression models were used for analyses. Increased IgA or IgG antibodies against BLG at age 1 increased the risk of sensitization to at least one of the measured allergens or food allergens at age 6. Increased IgG against gliadin at age 1 increased the risk of sensitization to any, at least one inhalant, or at least one food allergen at age 6. Early exposure to cow's milk formula associated with increased IgA or IgG against BLG. No association with farming or clinical allergy was found. Increased IgA or IgG against BLG or gliadin at age 1 was associated with IgE sensitization at age 6. We suggest that an enhanced antibody response to food antigens reflects mucosal tolerance aberrancies, e.g., altered microbiota and/or increased gut permeability, which is later seen as sensitization to allergens.

Toll-like Receptor Status in Obesity and Metabolic Syndrome: A Translational Perspective

The prevalence of both obesity and metabolic syndrome (MetS) is increasing at alarming rates globally. Both predispose to diabetes, cardiovascular disease, fatty liver disease, obstructive sleep apnea, and certain cancers. Understanding the mechanisms contributing to increased cardiometabolic risk in obesity and MetS is of utmost importance. For this review, we performed a detailed literature search on PubMed of all publications related to Toll-like receptors (TLRs) and obesity and MetS for the last 20 years. The TLRs are well-characterized immune receptors that enhance inflammation. The recognition of pathogen-associated molecular patterns and endogenous (host-derived) ligands released by various cell types triggers activation and expression of TLRs. TLRs, especially TLR2 and TLR4, induce insulin resistance, which is pivotal in the pathogenesis of obesity and MetS. Both obesity and MetS are characterized by low-grade chronic inflammation, possibly triggered by activation of TLR2 and TLR4. TLRs, especially TLR4, are activated by fatty acids and endotoxinemia (a marker of gut permeability), features of both obesity and MetS, resulting in activation of nuclear factor-κB and increased release of inflammatory biomediators such as IL-6, IL-1β, TNF-α, and monocyte chemotactic protein-1, which play a role in the pathophysiology of obesity and MetS. Reduction of calories, exercise, and nutraceutical and pharmacological agents can modulate TLRs. In this review, we present evidence for a pivotal role of TLR-induced inflammation in both obesity and MetS and speculate that targeting these TLRs can forestall their adverse sequelae of diabetes and cardiovascular disease.

Increased circulatory levels of lipopolysaccharide (LPS) and zonulin signify novel biomarkers of proinflammation in patients with type 2 diabetes

Emerging data indicate that gut-derived endotoxin (metabolic endotoxemia) may contribute to low-grade systemic inflammation in insulin-resistant states. Specific gut bacteria seem to serve as lipopolysaccharide (LPS) sources and several reports claim a role for increased intestinal permeability in the genesis of metabolic disorders. Therefore, we investigated the serum levels of LPS and zonulin (ZO-1, a marker of gut permeability) along with systemic levels of tumor necrosis factor-α (TNF-α) and Interleukin-6 (IL-6) in patients with type 2 diabetes mellitus (T2DM) compared to control subjects. Study subjects were recruited from the Chennai Urban Rural Epidemiology Study [CURES], Chennai, India. Study group (n=45 each) comprised of a) subjects with normal glucose tolerance (NGT) and (b) patients with T2DM. LPS, ZO-1, TNF-α, and IL-6 levels were measured by ELISA. Serum levels of LPS [p<0.05], LPS activity [p<0.001], ZO-1 [p<0.001], TNFα [p<0.001], and IL-6 [p<0.001] were significantly increased in patients with T2DM compared to control subjects. Pearson correlation analysis revealed that LPS activity was significantly and positively correlated with ZO-1, fasting plasma glucose, 2h post glucose, HbA1c, serum triglycerides, TNF-α, IL-6, and negatively correlated with HDL cholesterol. Regression analysis showed that increased LPS levels were significantly associated with type 2 diabetes [odds ratio (OR) 13.43, 95% CI 1.998-18.9; p=0.003]. In Asian Indians who are considered highly insulin resistant, the circulatory LPS levels, LPS activity, and ZO-1 were significantly increased in patients with type 2 diabetes and showed positive correlation with inflammatory markers and poor glycemic/lipid control.

Oral administration of fermented red ginseng suppressed ovalbumin-induced allergic responses in female BALB/c mice

Anti-allergic efficacy of red ginseng (RG) and fermented red ginseng (FRG) was evaluated. RG or FRG were administered to ovalbumin (OVA)-sensitized mice for 8 weeks. Immunoglobulins (Igs), Th1/Th2 type cytokines, and β-lactoglobulin (BLG) in serum, and intestinal barrier-related molecules in jejunum were measured using enzyme-linked immunosorbent assay or reverse transcription-polymerase chain reaction. Mice sensitized with OVA increased serum IgG1, IgE, OVA-IgG1, and OVA-IgE. Both RG and FRG decreased serum IgE, OVA-IgE, and pro-inflammatory cytokines. Serum BLG, a marker of gut permeability, was significantly higher in sensitized animals and was decreased in mice fed RG or FRG. In addition, intestinal barrier-related markers such as MMCP-1, IL-4, TNF-α, COX-2, and iNOS mRNA expressions were decreased by RG or FRG. Our results suggest in vivo anti-allergic activities of RG or FRG, which are associated with the regulation of Th1/Th2 balance, intestinal inflammation and subsequent the suppression of IgE.

Changes of Gut Microbiota and Immune Markers During the Complementary Feeding Period in Healthy Breast‐fed Infants

Little is known about changes in intestinal microbiota during the important period of complementary feeding (weaning). This descriptive study investigated changes of selected gut microbiota and markers of gut permeability and the immune system in breast fed infants during the complementary feeding period. 22 healthy, exclusively breast fed infants (from birth to 4 months) with no antibiotic intake during the month prior to the study, were followed from 4 to 9 months of age. Faecal and saliva samples were collected at the start of the study (V0) and at monthly intervals (V1-V5) for measurement of selective gut microbiota (bifidobacteria, lactobacilli, vancomycin-insensitive lactobacilli, enterobacteria, enterococci, Clostridium perfringens) using semi-selective media. Immune markers (alpha-1-antitrypsin, eosinophil cationic protein (ECP), secretory IgA and TNF-alpha were measured in saliva and secretory IgA and TNF-alpha in faecal samples. High stool bifidobacteria counts at the start of the study (7.99 1 1.95 log10 CFU/g faeces) remained stable throughout the 5 months of complementary feeding while counts of enterobacteria and enterococci increased with age (P < 0.05 and P = 0.02 respectively). Vancomycin-insensitive lactobacilli increased significantly during weaning for V0 to V3 (P < 0.01), and then decreased slightly (V4). Faecal Clostridium perfringens remained below the detection limit during the study and parameters measured in saliva did not change. Faecal ECP decreased significantly from 1.011.4 (V0) to 0.510.9 mg/mg protein (V5) P = 0.03. Age and/or diet modifications during complementary feeding had no impact on faecal bifidobacteria counts but increased those of enterobacteria and enterococci. Transient increases in faecal lactobacilli and vancomycin-insensitive lactobacilli counts were observed. The reduction in faecal ECP may indicate a decrease in gut permeability (reinforcement of gut mucosa integrity) during the weaning period with age [corrected]