Markers Of Gut Permeability Research Articles

A triad of gut dysbiosis, dysregulated immunity, and ‘leaky’ gut characterize HCMV associated neonatal cholestasis

BackgroundGut microbiome dysbiosis and related immune dysfunction have been associated with the pathogenesis of Human Cytomegalovirus (HCMV) infection in infants with neonatal cholestasis (NC) as previously reported by us. However, the interaction of a perturbed microbiome, HCMV infection, and dysregulated immunity leading to exacerbation of disease severity has not been investigated so far. In this study, we examined the association of gut microbiome, host inflammatory and homeostatic markers that are likely to govern increased pathogenesis of NC in HCMV infected IgM positive infants (N = 15) compared to IgM negative (N = 15) individuals. Stool samples of HCMV infected infants and age-matched healthy controls (N = 10) were assessed for gut bacteria-derived metabolites like short-chain fatty acids (SCFAs), Lipopolysaccharide (LPS), cytokines and markers of gut barrier integrity. Data were correlated with previously determined gut microbiome composition and frequency of immune cell subsets. Finally, validation of clinical potential was undertaken by principal component analysis (PCA) of integrated data to delineate the spectrum of clinical pathology. ResultsSignificantly lower levels of SCFAs and elevated fecal levels of soluble inflammatory mediators were observed in IgM positive HCMV infected infants. Further, increased plasma LPS levels and markers of gut permeability, suggestive of microbial translocation due to a ‘leaky gut’ were observed in HCMV infected IgM positive group. PCA of integrated data revealed clearly disparate profiles representative of IgM positive, IgM negative, and uninfected healthy states. ConclusionOur results suggest the utility of an integrated approach involving dysregulated microbiome-immune axis for gaining a better understanding of pathogenesis associated with HCMV infection in NC.Graphical

Novel factors affecting fibrin clot formation and their clinical implications.

Fibrin formation is pivotal in hemostasis, serving as a temporary barrier to blood loss following vascular injury, while in thrombosis this process is involved in thrombus progression, stability, and recurrence. Growing evidence shows an exceptional complexity of processes that determine fibrin clot structure and function, especially lysability, both in health and disease, which might be relevant in the pathogenesis of arterial and venous thromboembolic diseases. In this overview we summarized available data on novel factors that in recent years have been suggested to contribute to prothrombotic fibrin clot properties, involving formation of compact fibrin networks (reduced clot permeability) displaying impaired susceptibility to lysis (prolonged clot lysis time). The factors discussed in this review encompass elevated levels of factor (F)XI, and its activated form (FXIa), protein carbonylation as the most common type of post-translational modification, neutrophil extracellular traps (NETs) formation, increased levels of circulating lipopolysaccharide (LPS) and zonulin, a marker of gut permeability, along with antithrombin deficiency. These factors have been shown to be not only associated with ischemic stroke, myocardial infarction, pulmonary embolism, and cardiovascular death, but also with unfavorably altered fibrin clot characteristics, which underscores clinical relevance of fibrin clot properties. Given preclinical or ongoing studies aimed at modifying some of these factors, in particular FXI / FXIa inhibitors, recent findings might expand our knowledge on fibrin-related mechanisms of emerging therapeutic agents tested and stimulate further research into new targets for future therapeutic interventions to prevent thromboembolic events.

476 Induced hindgut acidosis in sheep affected gut permeability and ruminal fermentation

Abstract Leaky gut may be caused by acidotic conditions in the hindgut and lead to systemic inflammation and negative effects on the gastrointestinal tract. The objective was to determine the effects of induced hindgut acidosis in sheep on cecal pH, ruminal fermentation, and gut permeability. Ruminally and cecally cannulated ewes [n = 11; body weight (BW) = 49 ± 4 kg] were assigned to one of two treatments: control (CON; n = 5) or induced hindgut acidosis (HGA; n = 6). To induce hindgut acidosis, 3 g wheat starch/kg BW per 24 h was continuously infused via the cecal cannula for 4 d. Control ewes received a constant infusion of deionized water. The diet contained 40% grass hay pellets, 35% whole shelled corn, 15% dried distillers grains, and 10% alfalfa cubes. Chromium EDTA was dosed once daily via the cecal cannula as a marker of gut permeability. Rumen, cecal, and fecal samples were collected to determine pH and volatile fatty acids (VFA). Rumen fluid was collected on d 4 for an ex vivo fermentation. Flasks were incubated for 24 h to determine pH, VFA, ammonia and in vitro dry matter digestibility. Tissue samples from the ileum, cecum, and colon were mounted in Ussing chambers to measure transepithelial electrical resistance (TEER). There was a treatment × time effect (P = 0.05) for cecal pH with HGA ewes having lesser cecal pH after d 1. By d 4, cecal pH had declined to 5.07 for HGA ewes compared with CON ewes which remained above 6.40 throughout the experiment. A treatment × time interaction was also observed (P < 0.01) for fecal pH and followed the same trend as cecal pH. Rumen pH was not affected (P = 0.87) by the interaction of treatment and time but was affected (P < 0.01) by treatment as ewes on the HGA treatment had a lesser rumen pH than CON ewes. Control ewes had lesser ruminal VFA and ammonia concentrations than HGA ewes (P < 0.01). Urinary Cr recovery was not affected by the interaction of treatment and time, or treatment (P ≥ 0.13). In vitro dry matter disappearance was not affected by cecal infusion treatment (P = 0.60). There was no effect (P = 0.78) of treatment on ex vivo pH. There were no effects (P ≥ 0.11) of treatment, time, or their interaction on ex vivo ammonia or total VFA concentration. In cecal tissue, TEER tended (P = 0.09) to be greater in CON ewes than HGA ewes. In contrast, TEER was not different (P ≥ 0.83) in ileal or colonic tissues between treatments. Induced hindgut acidosis in sheep altered rumen fermentation and tended to increase ex vivo measures of cecal permeability, but did not affect ex vivo rumen fermentation.

The administration route of indigestible gut permeability markers modulates urinary marker recovery in calves

Indigestible gut permeability markers are used to assess gut integrity and can be administered to calves via a milk meal (MM) or orally pulsed (OP). This study investigated how marker administration route (ADM_R) affects the estimation of gut permeability in relation to MR fat inclusion. Thirty-two male Holstein calves were blocked based on their arrival sequence at the facility. Within each block of 4 calves, calves were randomly assigned to one of 2 treatments (n = 16/ treatment): a MR high in lactose (HL) and a MR high in fat (HF). During the first 5 d, calves were fed 6.0 L/d followed by 7.0 L/d offered in 2 meals per day at 15% solids. To evaluate gut permeability, indigestible markers (lactulose, D-mannitol, and chromium (Cr)-EDTA) were administered in 2 periods, on Tuesday and Thursday in the third week after arrival. Within each block, calves with different MR treatments were randomly assigned to a different marker ADM_R order: MM in the first period and OP in the second (n = 16) or the opposite order (n = 16). Thus, one block of 4 calves included all combinations of MR and ADM_R. Following marker administration, urine was collected over 2 sampling periods: the first from 0 to 6 h and the second from 6 to 24 h. Measurements included weekly BW and daily MR intake and fecal scoring. Intake, growth, and fecal consistency were not affected by dietary treatments nor by ADM_R. The urinary recovery of lactulose was greater in calves fed HF during the 6–24 h and the overall 24-h collection period. Consistently, D-mannitol recovery tended to be greater in calves fed HF during the 24-h collection. With OP administration, the urinary recovery of all markers was greater between 0 and 6 h, whereas in the 6–24 h period, the recovery of lactose and D-mannitol were lower. Over 24-h of collection, Cr-EDTA recovery was greater with OP. No interaction between ADM_R and MR composition was detected. This suggests that both ADM_R were equivalent in assessing the effects of dietary interventions on gut permeability. However, different ADM_R affected the trajectory and time spent by the markers in each section of the gut.

Elevated lipopolysaccharide level is largely driven by time since symptom onset in acute ischemic stroke: the impact on clinical outcomes

BackgroundGut dysbiosis leading to increased intestinal barrier permeability and translocation of lipopolysaccharide (LPS) in the circulation has been demonstrated in patients with acute myocardial infarction and pulmonary embolism. ObjectivesWe investigated changes in circulating LPS concentrations in acute ischemic stroke (AIS) and their consequences, including prognosis. MethodsWe studied 98 AIS patients, aged 74 ± 12 years, including 74 (75.5%) thrombolysed individuals. We determined serum LPS and zonulin, a marker of gut permeability, along with protein carbonyl (PC), fibrin clot properties, and thrombin generation on admission, at 24 hours and 3 months. Stroke severity was assessed using the National Institutes of Health Stroke Scale. Stroke functional outcome using modified Rankin scale and stroke-related mortality were evaluated at 3 months. ResultsSerum LPS and zonulin levels on admission were associated with time since symptom onset (r = 0.57; P < .0001; and r = 0.40; P < .0001). Baseline LPS levels correlated with PC (r = 0.51; P < .0001) but not with coagulation and fibrinolysis markers. LPS levels increased at 24 hours in thrombolysed patients (P < .001) and correlated with the National Institutes of Health Stroke Scale score (r = 0.31; P = .002) and PC (r = 0.32; P = .0057). Both LPS and zonulin levels measured at 24 hours increased the odds of having unfavorable modified Rankin scale scores (odds ratio [OR], 1.22; 95% CI, 1.04-1.42; and OR, 2.36; 95% CI, 1.24-4.49 per unit). Elevated LPS level, but not zonulin, was associated with stroke-related mortality (OR, 1.26; 95% CI, 1.02-1.55 per unit). ConclusionIn AIS patients intestinal permeability is mainly driven by increasing time since the symptom onset. Our findings suggest that LPS, with a trend toward its further rise following thrombolysis, adversely affects neurologic functional outcomes and 3-month mortality.

Sex Modifies the Effect of COVID-19 on Arterial Elasticity.

There is limited long-term evidence on the effects of COVID-19 on vascular injury between male and female sex. An adult cohort of COVID-19 survivors (COVID+) and confirmed SARS-CoV-2 antibody-negative participants (COVID-) were prospectively enrolled. COVID+ participants who have documented the presence of persistent symptoms four weeks following infection were considered to have post-acute sequelae of COVID-19 (PASC). Non-invasive, FDA-approved EndoPAT (Endo-PAT2000) was used for endothelial assessment. COVID-(n = 94) were 1:1 propensity score matched to COVID+ (n = 151) on baseline covariates including sex. Among COVID+, 66.2% (n = 100) had PASC. Higher levels of coagulation marker, D-dimer (p = 0.001), and gut permeability marker, zonulin (p = 0.001), were associated with female sex. Estimated differences in augmentation index (AI) between COVID- (0.9 ± 17.2) and COVID+ (8.4 ± 15.7; p = 0.001) and between female and male sex (12.9 ± 1.9; p < .0001) were observed. Among COVID+ with PASC, the average AI (10.5 ± 1.6) was 9.7 units higher than COVID- (p < .0001) and 6.2 units higher compared to COVID+ with no PASC (p = 0.03). COVID+ PASC+ female sex had the highest AI (14.3 ± 1.9). The effects of SARS-CoV-2 infection on vascular function varies across strata of sex and female sex in the post-acute phase of COVID-19 have the worse arterial elasticity (highest AI).

Gut microbiota associations with chronic kidney disease: insights into nutritional and inflammatory parameters.

The gut barrier, comprising gut microbiota, plays a pivotal role in chronic kidney disease (CKD) progression and nutritional status. This study aimed to explore gut barrier alterations in hemodialyzed (HD) patients, non-HD (NHD) CKD patients, and healthy volunteers. Our cross-sectional study enrolled 22 HD patients, 11 NHD patients, and 11 healthy volunteers. We evaluated fecal microbiota composition (assessed via bacterial 16S rRNA gene sequencing), fecal IgA levels, surrogate markers of gut permeability, serum cytokines, appetite mediators, nutritional status, physical activity, and quality of life. HD patients exhibited significant alterations in fecal microbiota composition compared to healthy volunteers, with observed shifts in taxa known to be associated with dietary patterns or producing metabolites acting on human host. In comparison to healthy volunteers, individuals with HD patients exhibited elevated levels of inflammatory markers (CRP, IL-6 and TNF-α), glucagon-like peptide-2, and potential anorexigenic markers (including leptin and peptide YY). NHD patients had increased levels of CRP and peptide YY. Overall fecal microbiota composition was associated with height, soft lean mass, resting energy expenditure, handgrip strength, bone mineral content and plasma albumin and TNF-α. Compared to healthy volunteers, HD patients have an altered fecal microbiota composition, a higher systemic inflammation, and a modification in plasma levels of appetite mediators. While some differences align with previous findings, heterogeneity exists likely due to various factors including lifestyle and comorbidities. Despite limitations such as sample size, our study underscores the multifaceted interplay between gut microbiota, physiological markers, and kidney function, warranting further investigation in larger cohorts.

Melatonin-mediated corrective changes in gut microbiota of experimentally chronodisrupted C57BL/6J mice

ABSTRACT Chronic consumption of a high-calorie diet coupled with an altered sleep-wake cycle causes disruption of circadian clock that can impact the gut microbiome leading to metabolic syndrome and associated diseases. Herein, we investigate the effects of a high fat high fructose diet (H) alone or in combination with photoperiodic shifts induced chronodisruption (CD) on gut microbiota of C57BL/6J male mice. Further, the merits of daily evening intraperitoneal administration of melatonin in restoring gut microbiota are studied herein. Experimental groups viz. H, CD and HCD mice recorded higher levels of serum pro-inflammatory cytokines (TNF-α and IL-6) and lower levels of the anti-inflammatory cytokine, IL-10. These findings correlate with a concomitant increase in the transcripts of TLR4, TNF-α, and IL-6 in small intestine of the said groups. A decrement in mRNA levels of Ocln, ZO-1 and Vdr in these groups implied towards an altered gut permeability. These results were in agreement with the observed decrement in percentage abundance of total gut microflora and Firmicutes: Bacteroidetes (F/B) ratio. Melatonin administration accounted for lower-level inflammation (serum and gut) along with an improvement in gut permeability markers. The total abundance of gut microflora and F/B ratio showed an improvement in all the melatonin-treated groups and the same is the highlight of this study. Taken together, our study is the first to report perturbations in gut microbiota resulting due to a combination of photoperiodic shifts induced CD and a high fat high calorie diet-induced lifestyle disorder. Further, melatonin-mediated rejuvenation of gut microbiome provides prima facie evidence of its role in improving gut dysbiosis that needs a detailed scrutiny.

Gut permeability, circulating bacterial fragments and measures of congestion in peritoneal dialysis.

Limited data exist on the association between gut permeability, circulating bacterial fragment and volume overload in peritoneal dialysis (PD) patients. We measured circulating bacterial fragments, N-terminal pro B-type natriuretic peptide (NT-proBNP), calprotectin and zonulin levels, and evaluate their association with the clinical outcomes in PD patients. This was a single-center prospective study on 108 consecutive incident PD patients. Plasma endotoxin and bacterial DNA, and serum NT-proBNP, calprotectin and zonulin levels were measured. Primary outcomes were technique and patient survival, secondary outcomes were hospitalization data. There was no significant correlation between plasma endotoxin and bacterial DNA, and serum NT-proBNP, calprotectin and zonulin levels. The Homeostatic Model Assessment for Insulin Resistance (HOMA)-2β index, which represents insulin resistance, positively correlated with plasma bacterial DNA (r=0.421, P<.001) and calprotectin levels (r=0.362, P=.003), while serum NT-proBNP level correlated with the severity of volume overload and residual renal function. Serum NT-proBNP level was associated with technique survival even after adjusting for confounding factors [adjusted hazard ratio (aHR) 1.030, 95% confidence interval 1.009-1.051]. NT-proBNP level was also associated with patient survival by univariate analysis, but the association became insignificant after adjusting for confounding factors (aHR 1.010, P=.073). Similarly, NT-proBNP correlated with the number of hospitalizations and duration of hospitalization by univariate analysis, but the association became insignificant after adjusting for confounding factors. There was no correlation between markers of gut permeability, circulating bacterial fragments and measures of congestion in PD patients. Bacterial fragments levels and gut permeability are both associated with insulin resistance. Serum NT-proBNP level is associated with the severity of volume overload and technique survival. Further studies are required to delineate the mechanism of high circulating bacterial fragment levels in PD patients.

Safety and efficacy of a probiotic cocktail containing P. acidilactici and L. plantarum for gastrointestinal discomfort in endurance runners: randomized double-blinded crossover clinical trial.

Probiotics are increasingly used to treat conditions associated with gastrointestinal injury and permeability, including exercise-induced gastrointestinal discomfort. This study assessed safety and efficacy of a probiotic in altering the intestinal milieu and mitigating gastrointestinal symptoms (GIS) in endurance runners. In a double blind, crossover study, 16 runners were randomized to 4 weeks of daily supplementation with a probiotic cocktail containing Pediococcus acidilactici bacteria and Lactobacillus plantarum or placebo. Fasting blood and stool samples were collected for measurement of gut permeability markers, immune parameters, and microbiome analyses. Treadmill run tests were performed before and after treatment; participants ran at 65%-70% of VO2max at 27°C for a maximum of 90 min or until fatigue/GIS developed. A blood sample was collected after the treadmill run test. In healthy individuals, 4 weeks of probiotic supplementation did not alter health parameters, although a marginal reduction in aspartate aminotransferase levels was observed with probiotic treatment only (p=0.05). GIS, gut permeability-associated parameters (intestinal fatty acid binding protein, lipopolysaccharide binding protein, zonulin, and cytokines), and intestinal microbial content were not altered by the probiotic supplementation. Post-run measurements of GIS and gut-associated parameters did not differ between groups; however, the observed lack of differences is confounded by an absence of measurable functional outcome as GIS was not sufficiently induced during the run. Under the current study conditions, the probiotic was safe to use, and did not affect gut- or immune-associated parameters, or intestinal symptoms in a healthy population. The probiotic might reduce tissue damage, but more studies are warranted.

Abstract WP321: Novel Therapeutic Potential of Intestinal Organoids Secretomes for Cerebrovascular Stroke

Background: Our recent studies show that transplants of intestine epithelial stem cells (IESCs) promote acute and long term recovery after stroke in middle-aged rats. To improve the translational potential of this therapy, we investigated whether injections of the IESC conditioned media (CM) would be similarly effective in improving acute and chronic stroke outcomes. Methods: Conditioned media was collected intestinal organoids culture from young animals and processed for proteomic and tropic factors analysis. CM efficacy was tested in middle-aged male and female rats assigned to the following groups: Control (sham), stroke+vehicle injection, or stroke+IESC-CM treatment. Middle cerebral artery occlusion (MCAo) was induced by Endothelin-1 (vasoconstrictor). Conditioned media was injected ip (CMip) 4h/24h/48h after stroke. In the acute phase, infarct volume, sensorimotor function and serum levels of the gut permeability markers were measured 4d post stroke. Long term (4 weeks after stroke) depressive-like behavior was assessed by the Social Interaction test, and cognitive performance by the Novel object Recognition test and Barnes maze test. Results: Proteomic analysis of CM showed elevated levels of small peptide growth factors ad large matrix molecules. IESC-CMip treatment significantly improved acute stroke outcomes and reduced gut permeability in middle-aged hosts of either sex. In long term study, vehicle-treated MCAo animals showed depressive-like behaviors compared to their pre-stroke behaviors. In contrast, stroke animals that received IESC secretome were no different from their pre stroke performance and were similar sham (no-stroke) animals. In cognition assesments. MCAo+vehicle animals showed poor ability to discriminate the novel object and displayed impaired learning and recall on the Barnes maze. MCAo animals that received IESC secretome did not show significant improved during the Barnes learning trials, but retrieval (memory recall) performance was improved and significantly different from the vehicle group. Conclusion: Overall, these data show that IESC secretome derived from a healthy young animal can significantly improve acute stroke outcomes and specific aspects of cognitive performance.

Gut Microbiota Ecological and Functional Modulation in Post-Stroke Recovery Patients: An Italian Study.

Ischemic stroke (IS) can be caused by perturbations of the gut-brain axis. An imbalance in the gut microbiota (GM), or dysbiosis, may be linked to several IS risk factors and can influence the brain through the production of different metabolites, such as short-chain fatty acids (SCFAs), indole and derivatives. This study examines ecological changes in the GM and its metabolic activities after stroke. Fecal samples of 10 IS patients were compared to 21 healthy controls (CTRLs). GM ecological profiles were generated via 16S rRNA taxonomy as functional profiles using metabolomics analysis performed with a gas chromatograph coupled to a mass spectrometer (GC-MS). Additionally fecal zonulin, a marker of gut permeability, was measured using an enzyme-linked immuno assay (ELISA). Data were analyzed using univariate and multivariate statistical analyses and correlated with clinical features and biochemical variables using correlation and nonparametric tests. Metabolomic analyses, carried out on a subject subgroup, revealed a high concentration of fecal metabolites, such as SCFAs, in the GM of IS patients, which was corroborated by the enrichment of SCFA-producing bacterial genera such as Bacteroides, Christensellaceae, Alistipes and Akkermansia. Conversely, indole and 3-methyl indole (skatole) decreased compared to a subset of six CTRLs. This study illustrates how IS might affect the gut microbial milieu and may suggest potential microbial and metabolic biomarkers of IS. Expanded populations of Akkermansia and enrichment of acetic acid could be considered potential disease phenotype signatures.

Zonulin as a Biomarker for the Development of Celiac Disease.

Increased intestinal permeability seems to be a key factor in the pathogenesis of autoimmune diseases, including celiac disease (CeD). However, it is unknown whether increased permeability precedes CeD onset. This study's objective was to determine whether intestinal permeability is altered before celiac disease autoimmunity (CDA) in at-risk children. We also examined whether environmental factors impacted zonulin, a widely used marker of gut permeability. We evaluated 102 children in the CDGEMM study from 2014-2022. We included 51 CDA cases and matched controls, who were enrolled for 12 months or more and consumed gluten. We measured serum zonulin from age 12 months to time of CDA onset, and the corresponding time point in controls, and examined clinical factors of interest. We ran a mixed-effects longitudinal model with dependent variable zonulin. Children who developed CDA had a significant increase in zonulin in the 18.3 months (range 6-78) preceding CDA compared to those without CDA (slope differential = β = 0.1277, 95% CI: 0.001, 0.255). Among metadata considered, zonulin trajectory was only influenced by increasing number of antibiotic courses, which increased the slope of trajectory of zonulin over time in CDA subjects (P = .04). Zonulin levels significantly rise in the months that precede CDA diagnosis. Exposure to a greater number of antibiotic courses was associated with an increase in zonulin levels in CDA subjects. This suggests zonulin may be used as a biomarker for preclinical CeD screening in at-risk children, and multiple antibiotic courses may increase their risk of CDA by increasing zonulin levels.

Low-grade endotoxemia is associated with cardiovascular events in community-acquired pneumonia

Community-acquired pneumonia (CAP) is associated with low-grade endotoxemia but its relationship with cardiovascular events (CVE) has not been investigated. We evaluated the incidence of CVE including myocardial infarction, stroke, and cardiovascular death in 523 adult patients hospitalized for CAP. Serum lipopolysaccharide (LPS) and zonulin, a marker of gut permeability, were analyzed in the cohort, that was followed-up during hospitalization and up to 43 months thereafter. During the hospital-stay, 55 patients experienced CVE with a progressive increase from the lowest (0.6%) to highest LPS tertile (23.6%, p<0.001). Logistic regression analyses showed that higher LPS tertile was independently associated with CVE; LPS significantly correlated with age, hs-CRP and zonulin. In a sub-group of 23 CAP patients, blood E. coli DNA was higher in patients compared to 24 controls and correlated with LPS. During the long-term follow-up, 102 new CVE were registered; the highest tertile of LPS levels was associated with incident CVE; Cox regression analysis showed that LPS tertiles, age, history of CHD, and diabetes independently predicted CVE. In CAP low-grade endotoxemia is associated to short- and long-term risk of CVE. Further study is necessary to assess if lowering LPS by non-absorbable antibiotics may result in improved outcomes.

223 Impacts of Active Dry Yeast (Saccharomyces cerevisiae) on Gut Permeability in Finishing Beef Cattle

Abstract The objectives of this study were to examine the impacts of active live yeast (Saccharomyces cerevisiae) as a dietary feed additive on dry matter intake, feed sorting, gut permeability, ruminal pH and volatile fatty acids (VFA) concentration, as well as fecal pH and VFA concentration in cattle fed a high-grain finishing diet and subjected to a ruminal acidotic challenge. Fifteen Hereford X Charolais heifers were blocked by BW into three blocks. Heifers were randomly assigned within block to one of two dietary treatments; CON (no additive), or YST (3 g· animal-1· day-1 of active live S. cerevisiae) added to a steam-flaked corn diet (83% steam-flaked corn, 8% wheat straw, 5% soybean meal protein mix, 4% vitamin and minerals on a DM basis). The experimental timeline was as follows: 30 d adaptation (ADPT), 5 d baseline (BASE), 5 d ruminal acidosis challenge (CHAL), and three subsequent 5 d recovery phases (REC1, REC2, and REC3). On day 2 of each phase and days 2 and 4 of CHAL, 179 mM Cr-EDTA and 360 mM Co-EDTA were infused into the omasum and rumen, respectively, as gut permeability markers. Within each phase, in-dwelling pH probes were used to capture reticulo-ruminal pH every 5min for 96 consecutive hours, rumen fluid and fecal grab samples were collected once for every 3 h in a 24 h period, and blood was collected at 2, 4, 12, and 24 h after each Co and Cr infusion. Dry matter intake and feed sorting were measured daily for each animal. Statistical analysis was conducted using PROC GLIMMIX in SAS as a randomized complete block design with block, treatment, and phase as fixed effects and animal as a random effect. Ruminal acidosis was successfully induced using this method, as suggested by the statistically significant reduction in minimum pH and increase in pH range in the CHAL phase compared with other phases of the experiment (P ≤ 0.02). Recovery from the ruminal acidosis challenge was detected within the REC1 phase when comparing minimum pH (CHAL 5.25 vs. REC1 5.54; P = 0.001). Additionally, the sorting behavior of some particle sizes was significantly impacted by phase (P ≤ 0.01). Overall, the addition of yeast to the diet did not impact feed intake, sorting behavior, spot ruminal and fecal pH, volatile fatty acid concentrations in ruminal fluid or feces, or the uptake of Cr-EDTA and Co-EDTA. These results suggest that adding live S. cerevisiae yeast at this dose in a high-grain finishing diet does not impact feed intake, gut permeability, or the production of VFA when ruminal acidosis is induced.

Low-grade endotoxemia in acute pulmonary embolism: Links with prothrombotic plasma fibrin clot phenotype

BackgroundLipopolysaccharide (LPS) can traverse the intestinal barrier and enter bloodstream, causing endotoxemia and triggering inflammation. Increased circulating LPS was reported in arterial thromboembolism. We investigated whether increased LPS levels occur in acute pulmonary embolism (PE) and if it is associated with a prothrombotic state. MethodsWe studied 120 normotensive PE patients (aged 59 [48–68] years) on admission, after 5–7 days, and after a 3-month anticoagulation. Serum LPS levels, along with zonulin, a marker of gut permeability, endogenous thrombin potential (ETP), fibrin clot permeability (Ks), clot lysis time (CLT), fibrinolysis proteins, and platelet markers were assessed. ResultsMedian LPS concentration on admission was 70.5 (61.5–82) pg/mL (min-max, 34–134 pg/mL), in association with C-reactive protein (r = 0.22, p = 0.018), but not with fibrinogen, D-dimer or platelet markers. Patients with more severe PE had higher LPS levels compared with the remainder. Median zonulin level was 3.26 (2.74–4.08) ng/mL and correlated with LPS (r = 0.66, p < 0.0001). Patients with baseline LPS levels in the top quartile (≥82 pg/mL; n = 29) compared to lower quartiles had 18.6 % increased ETP, 14.5 % reduced Ks, and 25.3 % prolonged CLT, related to higher plasminogen activator inhibitor type 1 (PAI-1) levels. LPS decreased by 23.4 % after 5–7 days and by 40.4 % after 3-month anticoagulation together with reduced zonulin by 18.4 % and 22.3 %, respectively, compared to baseline (all p < 0.001). LPS levels were not related with fibrin characteristics and other variables assessed at 3 months. ConclusionsLow-grade endotoxemia is detectable in patients with acute PE and may contribute to increased thrombin generation and PAI-1-mediated hypofibrinolysis.

Adverse childhood experiences and obesity linked to indicators of gut permeability and inflammation in adult women

Gut permeability may increase cardiovascular disease risk by allowing bacterial components (e.g., lipopolysaccharide or LPS) to enter the bloodstream, leading to low-grade inflammation. People with adverse childhood experiences (ACEs) consistently display evidence of chronic inflammation, but the source of this inflammation, and whether gut permeability may contribute, is unknown. Moreover, whether ACE status may further perturb obesity-associated gut permeability and inflammation is unknown. Women (N = 79, aged 18–84y) free of cardiometabolic diseases and inflammatory conditions and not regularly taking anti-inflammatory medications were included in a 2 × 2 factorial design with low or high ACE status (either 0 ACEs or 3+ ACEs) and body mass index (BMI) (either normal-weight [18.5–24.9 kg/m2; NW] or obesity [>30 kg/m2; OB]) as factors (n = 15–27/group). Serum LPS binding protein (LBP), soluble CD14 (sCD14), fatty-acid binding protein-2 (FABP2), LPS core IgM, and the ratio of LBP:sCD14 were used as indicators of gut permeability. Inflammatory markers C-reactive protein (CRP), tumor necrosis factor (TNF)-α, and interleukin (IL)-6 were also measured. Data were analyzed using 2-way ANCOVA (age-adjusted). LBP, LBP:sCD14 and FABP2 were higher in OB versus NW, regardless of ACE status (PBMI < 0.05). Higher ACE status was associated with increased circulating LBP:sCD14 and LPS core IgM (PACE < 0.05). sCD14 was unrelated to BMI or ACEs. CRP was elevated in OB versus NW (PBMI < 0.001) and tended to be higher with 3+ ACEs compared to 0 ACEs (PACE = 0.06). Moreover, TNF-α was greater in 3+ ACEs relative to 0 ACEs (PACE = 0.03). IL-6 was unrelated to BMI or ACE status. No interaction effects were observed for any marker of gut permeability or inflammation. In sum, ACE status and obesity were independently associated with evidence of gut permeability and systemic inflammation but did not interact in relation to indicators of gut permeability.

The deficit subtype of schizophrenia is associated with a pro-inflammatory phenotype but not with altered levels of zonulin: Findings from a case-control study

There is evidence that subclinical inflammation and increased gut permeability might be involved in the pathophysiology of schizophrenia. Less is known about these phenomena in patients with the deficit subtype of schizophrenia (D-SCZ) characterized by primary and enduring negative symptoms. Therefore, in the present study we aimed to compare the levels of zonulin (the marker of gut permeability) and immune-inflammatory markers in patients with D-SCZ, those with non-deficit schizophrenia (ND-SCZ) and healthy controls (HCs). A total of 119 outpatients with schizophrenia and 120 HCs were enrolled. The levels of 26 immune-inflammatory markers and zonulin were determined in serum samples. The following between-group differences were significant after adjustment for multiple testing and the effects of potential confounding factors: 1) higher levels of interleukin(IL)− 1β and C-reactive protein (CRP) in patients with D-SCZ compared to those with ND-SCZ and HCs; 2) higher levels of tumor necrosis factor-α and RANTES in both groups of patients with schizophrenia compared to HCs and 3) higher levels of IL-17 in patients with D-SCZ compared to HCs. No significant between-group differences in zonulin levels were found. Higher levels of IL-1β and CRP were associated with worse performance of attention after adjustment for age, education and chlorpromazine equivalents. Also, higher levels of IL-1β were correlated with greater severity of negative symptoms after adjustment for potential confounding factors. In conclusion, individuals with D-SCZ are more likely to show subclinical inflammation. However, findings from the present study do not support the hypothesis that this phenomenon is secondary to increased gut permeability.

Iohexol is an intestinal permeability marker in broilers under coccidiosis challenge

Intestinal integrity losses have been identified as a main driver for poor performance in broilers. The oral administration of markers such as iohexol is a major asset for measuring intestinal permeability (IP) alterations. The aim of the current study was to evaluate oral iohexol administration and serum levels as a quantitative measure for IP in Ross 308 broilers and to identify possible associations with histologic measurements. A total of 40, day-old broiler chickens were randomly divided into 4 groups of 10 broilers and a coccidiosis model was used to induce IP. Three challenge groups received a mixture of different field strains and concentrations of Eimeria acervulina and Eimeria maxima at d 16, and 1 group operated as an uninfected control group. On d 20, 5 birds per group were orally administered the permeability marker iohexol at a dose of 64.7 mg/kg body weight and blood was taken 60 min after the oral gavage. On d 21 these 5 birds per group were euthanized. On d 21, 5 other birds per group were given iohexol where after blood was taken. These birds were euthanized on d 22. During necropsy, birds were scored for coccidiosis lesions and a duodenal segment was taken for histology. The Eimeria challenge had a significant impact on the villus length, crypt depth, villus-to-crypt ratio and CD3+ T-lymphocytes area percentage. Challenged birds had a significant higher concentration of serum iohexol on both sampling days, as compared to the uninfected controls. A significant correlation could be found between the serum iohexol concentration and the histologic parameters (villus length, crypt depth and villus-to-crypt ratio) on the first sampling day. This suggests that iohexol may be used as a gut permeability marker in broilers under Eimeria challenge.

Prospective Placebo-Controlled Assessment of Spore-Based Probiotic Supplementation on Sebum Production, Skin Barrier Function, and Acne.

Probiotic supplementation has been shown to modulate the gut-skin axis. The goal of this study was to investigate whether oral spore-based probiotic ingestion modulates the gut microbiome, plasma short-chain fatty acids (SCFAs), and skin biophysical properties. This was a single-blinded, 8-week study (NCT03605108) in which 25 participants, 7 with noncystic acne, were assigned to take placebo capsules for the first 4 weeks, followed by 4 weeks of probiotic supplementation. Blood and stool collection, facial photography, sebum production, transepidermal water loss (TEWL), skin hydration measurements, and acne assessments were performed at baseline, 4, and 8 weeks. Probiotic supplementation resulted in a decreasing trend for the facial sebum excretion rate and increased TEWL overall. Subanalysis of the participants with acne showed improvement in total, noninflammatory, and inflammatory lesion counts, along with improvements in markers of gut permeability. The gut microbiome of the nonacne population had an increase in the relative abundance of Akkermansia, while the subpopulation of those with acne had an increase in the relative abundance of Lachnospiraceae and Ruminococcus gnavus. Probiotic supplementation augmented the circulating acetate/propionate ratio. There is preliminary evidence for the use of spore-based probiotic supplementation to shift the gut microbiome and augment short-chain fatty acids in those with and without acne. Further spore-based supplementation studies in those with noncystic acne are warranted.