Enterocyte Damage Research Articles

Effect of Two Forms of Tenofovir on Duodenal Enterocytes - a Hypothesis for Different Effect of TDF and TAF on Body Weight and Plasma Lipids.

Tenofovir disoproxil fumarate (TDF) compared to tenofovir alafenamide (TAF) leads to lower body weight and plasma lipids by an unknown mechanism. We hypothesize that TDF, when absorbed, may damage enterocytes of the proximal duodenum, leading to reduced absorption of nutrients. People living with HIV, without significant gastrointestinal symptoms, receiving TDF (n=12) or TAF (n=12) containing regimen underwent esophagogastroduodenoscopies with duodenal biopsies. Plasma/serum concentrations of nutrients absorbed from proximal duodenum and serum intestinal fatty-acid-binding protein (I-FABP), a marker of enterocyte damage, were measured. COX/SDH histochemical staining and electron microscopy (EM) were conducted to evaluate mitochondria. Five patients in TDF (celiac disease (excluded from further analyses), helicobacter gastritis, and three esophagitis) and two in TAF group (two esophagitis) had a pathological finding in esophagogastroduodenoscopy. Villi were flatter (337 (59) vs. 397 (42) μm, p=0.016), crypts non-significantly deeper (200 (46) vs. 176 (27) μm, p=0.2), and villus to crypt ratio lower (1.5 (0.42) vs. 2.5 (0.51), p=0.009) in TDF vs. TAF group. I-FABP concentration was higher in TDF vs. TAF group (3.0 (1.07) vs. 1.8 (0.53) ng/ml, p=0.003). TDF group had numerically but not statistically significantly lower concentrations of folate, vitamins A, B1, D, and E. COX/SDH staining showed signs of mitochondrial damage in 10 participants in TDF and 11 in TAF group. EM studies showed similar mitochondrial damage in both groups. Duodenal villous alterations may explain TDF-associated decrease in body weight and plasma lipids. Larger studies are needed to evaluate concentrations of nutrients absorbed from duodenum among TDF users.

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: 21-27years; 10 females) and 37 older (68-73years; 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: 0.11mg/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.

Stable iron (58Fe) isotopic measurements in Kenyan toddlers during 3 months of iron supplementation demonstrate that half of the iron absorbed is lost.

Increased iron loss may reduce the effectiveness of iron supplementation. The objective of this study was to determine if daily oral iron supplementation increases iron loss, measured using a stable isotope of iron (58Fe). We enrolled and dewormed 24 iron-depleted Kenyan children, 24-27 months of age, whose body iron was enriched and equilibrated with 58Fe given at least 1 year earlier. Over 3 months of supplementation (6 mg iron/kg body weight [BW]/day), mean (±SD) iron absorption was 1.10 (±0.28) mg/day. During supplementation, 0.55 (±0.36) mg iron/day was lost, equal to half of the amount of absorbed iron. Supplementation did not increase faecal haem/porphyrin or biomarkers of enterocyte damage and gut or systemic inflammation. Using individual patient data, we examined iron dose, absorption and loss among all available long-term iron isotopic studies of supplementation. Expressed in terms of body weight, daily iron loss was correlated significantly with iron absorption (Pearson's r = 0.66 [95% confidence interval 0.48-0.78]) but not with iron dose (r = 0.16 [95% CI -0.10-0.40]). The results of this study indicate that iron loss is increased with daily oral iron supplementation and may blunt the efficacy of iron supplements in children. This study was registered at ClinicalTrials.gov as NCT04721964.

Intestinal injury in paracetamol overdose (ATOM-8).

Paracetamol, a widely used medication, is known for its delayed hepatotoxicity in cases of overdose. However, the potential for intestinal toxicity resulting from very high paracetamol concentrations during absorption is not well explored. This study aims to investigate the presence of intestinal toxicity and its correlation with observations in early and late paracetamol toxicity. Serial samples of 30 patients with acute paracetamol overdose (>10g or 200mg/kg) were prospectively tested. Markers of enterocyte damage, including plasma intestinal fatty acid binding protein (IFABP) and selected gut-related microRNAs (miR-21, miR-122, miR-194, and miR-215), were analyzed. Sub-analysis was performed on patients presenting with hyperlactatemia defined as a lactate greater than 2mmol/L within 12h post ingestion. In paracetamol overdose patients, median plasma IFABP was significantly elevated compared with healthy controls (720μg/L [interquartile range, IQR, 533-1644] vs 270μg/L [IQR 153-558], P<0.001). Four patients had early hyperlactatemia and had significantly higher median plasma IFABP compared with those without early hyperlactatemia (3028μg/L [IQR 1399-3556] vs 574μg/L [IQR 526-943], P=0.007). Furthermore, two microRNAs (miR-122 and miR-215) were downregulated in early hyperlactatemia (P=0.019 and P=0.006, respectively). Plasma IFABP concentrations correlated with paracetamol concentration (Spearman's r=0.55) and lactate (r=0.60). Paracetamol overdose causes concentration-related intestinal toxicity, and this is a possible explanation for the early hyperlactatemia syndrome. Intestinal toxicity has potential impacts on pharmacokinetics of other agents ingested and on the evolution of hepatotoxicity. Further studies are required to explore the mechanisms and prognostic implications of intestinal toxicity.

Measurement of an intestinal biomarker during poisonings from select toxicants and toxins

Introduction Intestinal toxicity can occur following ingestion of various drugs, chemicals, and toxins. Intestinal fatty acid binding protein is a cytosolic protein specific to intestinal epithelial cells released into the systemic circulation following intestinal injury. Understanding intestinal toxicity in poisoning has the potential to explain mechanisms of toxicity and gastrointestinal symptoms. Methods Plasma samples were retrospectively analysed for intestinal fatty acid binding protein in 25 healthy controls and in those poisoned with Gloriosa superba (n = 18), Thevetia peruviana (n = 26), organophosphates (in various solvents) (n = 17), paracetamol (n = 14), glyphosate (n = 20), 2-methyl-4-chlorophenoxyacetic acid (n = 18) and propanil (n = 19). Results Median peak plasma intestinal fatty acid binding protein concentrations were significantly higher in patients poisoned with Gloriosa superba (2,994.1 µg/L; interquartile range 600.0–5,158.2, P < 0.001), Thevetia peruviana (1,292.5 µg/L; interquartile range 760.3 − 2,076.2; P < 0.001), glyphosate (1,803.6 µg/L; interquartile range 225.7–8,927.7; P < 0.001), 2-methyl-4-chlorophenoxyacetic acid (1,236.2 µg/L; interquartile range 192.6 − 1,709.7; P = 0.010), paracetamol (1,066.5 µg/L; interquartile range 512.9 − 1,336.9; P = 0.035), and organophosphate poisoning (729.8 µg/L; interquartile range 431.5 − 1,588.2; P = 0.046) than in healthy controls (221.6 µg/L; interquartile range 134.8 − 460.1). Median intestinal fatty acid binding protein was not statistically significantly increased compared to controls after propanil poisoning (630.0 µg/L; interquartile range 23.5 − 1,390.3; P = 0.423). Conclusions Our pilot study describes intestinal injury assessed by elevated plasma intestinal fatty acid binding protein concentrations following the ingestion of several poisons. This serves as a foundation for further exploration into enterocyte damage in toxicology.

Impaired intestinal permeability in patients with multiple sclerosis.

A number of recent studies have shown that the intestinal microbiome, part of the brain-gut axis, is implicated in the pathophysiology of multiple sclerosis. An essential part of this axis, is the intestinal barrier and gastrointestinal disorders with intestinal barrier dysregulation appear to be linked to CNS demyelination, and hence involved in the etiopathogenesis of multiple sclerosis (MS). The aim of this study was to evaluate the integrity of the intestinal barrier in patients with clinically definite multiple sclerosis (CDMS) and clinically isolated syndrome (CIS) using two serum biomarkers, claudin-3 (CLDN3), a component of tight epithelial junctions, and intestinal fatty acid binding protein (I-FABP), a cytosolic protein in enterocytes. Serum levels of CLDN3 in 37 MS patients and 22 controls, and serum levels of I-FABP in 46 MS patients and 51 controls were measured using commercial ELISA kits. Complete laboratory tests excluded the presence of gluten-related disorders in all subjects. Thirty MS patients received either disease-modifying drugs (DMD), immunosuppression (IS) or corticosteroid treatment. CLDN3 levels were only significantly higher in the MS patients treated with DMD or IS compared to the control group (P=0.006). There were no differences in I-FABP serum levels between the groups. Serum CLDN3 levels did not correlate with serum I-FABP levels in CDMS, in CIS patients or controls. In multiple sclerosis patients, the intestinal epithelium may be impaired with increased permeability, but without significant enterocyte damage characterized by intracellular protein leakage. Based on our data, CLDN3 serum levels appear to assess intestinal dysfunction in MS patients but mainly in treated ones.

Aging Increases Enterocyte Damage during a 3-Hour Exposure to Very Hot and Dry Heat: A Preliminary Study.

Profound heat stress can damage the gastrointestinal barrier, leading to microbial translocation from the gut and subsequent systemic inflammation. Despite the greater vulnerability of older people to heat wave-related morbidity and mortality, it is unknown if age modulates gastrointestinal barrier damage and inflammation during heat stress. Therefore, the aim of this study was to determine if aging impacted enterocyte damage and systemic inflammatory responses to a 3-h exposure to very hot and dry (47 °C, 15% humidity) heat with accompanying activities of daily living (intermittent activity at 3 METS). Data from 16 young (age 21 to 39 years) and 16 older (age 65 to 76 years) humans were used to address this aim. In each group, log-transformed plasma concentrations of intestinal fatty acid binding protein (I-FABPlog), interleukin-8 (IL-8log), and tissue factor (TFlog) were assessed as indices of enterocyte damage, systemic inflammation, and blood coagulation, respectively, before and after the 3-h heat exposure. In the younger cohort, I-FABPlog concentration did not increase from pre to post heat exposure (p = 0.264, d = 0.20), although it was elevated in the older group (p = 0.014, d = 0.67). The magnitude of the increase in I-FABPlog was greater in the older participants (p = 0.084, d = 0.55). Across all participants, there was no correlation between the change in core temperature and the change in IFABPlog. There was no change in IL-8log in the younger group (p = 0.193, d = 0.23) following heat exposure, but we observed a decrease in IL-8log in the older group (p = 0.047, d = 0.48). TFlog decreased in the younger group (p = 0.071, d = 0.41), but did not change in the older group (p = 0.193, d = 0.15). Our data indicate that I-FABPlog concentration (an index of enterocyte damage) is increased in older humans during a 3-h extreme heat exposure. Future studies should determine whether this marker reflects increased gastrointestinal barrier permeability in older individuals during heat exposure.

Intestinal fatty acid binding protein is associated with cardiac function and gut dysbiosis in chronic heart failure.

The gut microbiota in patients with chronic heart failure (HF) is characterized by low bacterial diversity and reduced ability to synthesize beneficial metabolites. These changes may facilitate leakage of whole bacteria or bacterial products from the gut into the bloodstream, which may activate the innate immune system and contribute to the low-grade inflammation seen in HF. In this exploratory cross-sectional study, we aimed to investigate relationships between gut microbiota diversity, markers of gut barrier dysfunction, inflammatory markers, and cardiac function in chronic HF patients. In total, 151 adult patients with stable HF and left ventricular ejection fraction (LVEF) < 40% were enrolled. We measured lipopolysaccharide (LPS), LPS-binding protein (LBP), intestinal fatty acid binding protein (I-FABP), and soluble cluster of differentiation 14 (sCD14) as markers of gut barrier dysfunction. N-terminal pro-B-type natriuretic peptide (NT-proBNP) level above median was used as a marker of severe HF. LVEF was measured by 2D-echocardiography. Stool samples were sequenced using 16S ribosomal RNA gene amplification. Shannon diversity index was used as a measure of microbiota diversity. Patients with severe HF (NT-proBNP > 895 pg/ml) had increased I-FABP (p < 0.001) and LBP (p = 0.03) levels. ROC analysis for I-FABP yielded an AUC of 0.70 (95% CI 0.61-0.79, p < 0.001) for predicting severe HF. A multivariate logistic regression model showed increasing I-FABP levels across quartiles of NT-proBNP (OR 2.09, 95% CI 1.28-3.41, p = 0.003). I-FABP was negatively correlated with Shannon diversity index (rho = -0.30, p = <0.001), and the bacterial genera Ruminococcus gauvreauii group, Bifidobacterium, Clostridium sensu stricto, and Parasutterella, which were depleted in patients with severe HF. In patients with HF, I-FABP, a marker of enterocyte damage, is associated with HF severity and low microbial diversity as part of an altered gut microbiota composition. I-FABP may reflect dysbiosis and may be a marker of gut involvement in patients with HF.

Pyroptotic MAITs link microbial translocation with severity of alcohol-associated liver disease.

Mucosal-associated invariant T cells (MAITs) are markedly reduced in patients with alcohol-associated liver disease (ALD); however, the potential mechanism underlying MAITs' loss remains elusive. Hence, we aimed to explore what induced MAITs' loss and its clinical significance. The characteristics of pyroptotic MAITs were evaluated in a cohort of patients with ALD, including 41 patients with alcohol-associated liver cirrhosis (ALC) and 21 patients with ALC complicated with severe alcoholic hepatitis (ALC + SAH). In patients with ALD, blood MAITs were significantly decreased, hyperactivated, and displayed enhanced cell death through pyroptosis. The frequencies of pyroptotic MAITs increased with disease severity in patients with ALC and patients with ALC + SAH. These frequencies were negatively associated with the frequencies of MAITs and positively correlated with the levels of MAITs' activation, plasma levels of intestinal fatty acid-binding protein (a marker of intestinal enterocyte damage), soluble CD14, lipopolysaccharide-binding protein, and peptidoglycan recognition proteins (surrogate markers of microbial translocation). Pyroptotic MAITs were also found in the liver of patients with ALD. Interestingly, MAITs underwent further activation and pyroptosis in vitro under stimulation by Escherichia coli or direct bilirubin. Notably, blocking IL-18 signaling reduced the activation and frequencies of pyroptotic MAITs. The loss of MAITs in patients with ALD is, at least in part, due to cell death from pyroptosis and is associated with the severity of ALD. Such increased pyroptosis may be affected by dysregulated inflammatory responses to intestinal microbial translocation or direct bilirubin.

Citrulline, Intestinal Fatty Acid-Binding Protein and the Acute Gastrointestinal Injury Score as Predictors of Gastrointestinal Failure in Patients with Sepsis and Septic Shock.

Gastrointestinal (GI) failure can be both a cause of sepsis and a consequence of the systemic pro-inflammatory response in sepsis. Changes in biomarkers of enterocyte damage, citrulline and I-FABP (intestinal fatty acid binding protein), may indicate altered intestinal permeability and damage. The study group consisted of patients with sepsis (N = 28) and septic shock (N = 30); the control group included patients without infection (N = 10). Blood samples were collected for citrulline and I-FABP and a 4-point AGI score (acute GI injury score) was calculated to monitor GI function on days 1, 3, 5, 7, and 10. Citrulline concentrations in the study group were lower than in the control. Lower values were also noted in septic patients with shock when compared to the non-shock group throughout the study period. I-FABP was higher in the septic shock group than in the sepsis group only on days 1 and 3. Citrulline was lower in patients with GI failure (AGI III) when compared to AGI I/II, reaching significance on days 7 (p = 0.034) and 10 (p = 0.015); moreover, a higher AGI score was associated with an increased 28 day mortality (p = 0.038). The results indicate that citrulline measurements, along with the AGI assessment, have clinical potential in monitoring GI function and integrity in sepsis.

Intestinal Fatty Acid-binding Protein in Patients with Psoriasis: A Marker of Impaired Intestinal Permeability Barrier and its Relation to Demographic Data and Clinical Characteristics

Abstract Background: Alterations of intestinal microbiota may play a role in the pathogenesis of psoriasis. Dysbiosis may cause disruption of the intestinal barrier, which contributes to immune activation by translocation of microbial antigens and metabolites. Intestinal fatty acid-binding protein (I-FABP) serves as a biomarker of enterocyte damage. Purpose: The aim of this study was to investigate serum concentration of I-FABP in patients with psoriasis. Methods: A cross-sectional hospital-based study on fifty psoriatic patients and thirty-five age and sex-matched healthy volunteers as a control group were enrolled in the study, serum I-FABP concentration was measured using an enzyme-linked immunosorbent assay. Results: Concentration of serum I-FABP was higher in patients compared to controls (P = 0.04). The serum level of I-FABP was higher in patients with skin phototype IV than in those with skin phototype III (P = 0.040). There were significant positive statistical correlations between I-FABP with age and disease duration. Conclusion: I-FABP, a biomarker for gut permeability, is increased in psoriasis and correlates with disease duration and age. Further investigations are needed to determine whether reinforcing intestinal barrier may be a new therapeutic target in psoriasis.

Intestinal Fatty Acid Binding Protein (I-FABP) as a Prognostic Marker in Critically Ill COVID-19 Patients.

Gastrointestinal symptoms are common in critically ill COVID-19 patients. There is currently no generally recognized method of assessing gastrointestinal injury in unconscious or sedated intensive care unit (ICU) patients. I-FABP (intestinal fatty acid binding protein) and citrulline have previously been studied as potential biomarkers of enterocyte damage in various gastrointestinal tract diseases, and changes in the levels of these markers may reflect intestinal wall damage in COVID-19. Patients with critical COVID-19, with diagnosed sepsis, or septic shock requiring ICU treatment were included in the study. Blood samples for citrulline and I-FABP were taken daily from day 1 to 5. I-FABP levels were significantly higher in patients who eventually died from COVID-19 than in survivors, and the optimal I-FABP cut-off point for predicting 28-day mortality was 668.57 pg/mL (sensitivity 0.739, specificity 0.765). Plasma levels of I-FABP, but not citrulline, were associated with significantly higher mortality and appeared to be a predictor of poor outcome in multivariate logistic regression analysis. In conclusion, I-FABP seems to be an effective prognostic marker in critically ill COVID-19 patients. Assessing mortality risk based on intestinal markers may be helpful in making clinical decisions regarding the management of intestinal injury, imaging diagnostics, and potential surgical interventions.

Virological and histological evaluation of intestinal samples in COVID-19 patients.

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is the pathogen responsible for pandemic coronavirus disease 2019 (COVID-19). It is a highly contagious virus which primarily affects the respiratory tract, nevertheless, the lungs are not the only target organs of the virus. The intestinal tract could represent an additional tropism site for SARS-CoV-2. Several observations have collectively suggested that enteric infections can occur in COVID-19 patients. However, the detection of viral RNA in gastrointestinal (GI) tissue samples has not been adequately investigated and results are conflicting. To detect the presence of SARS-CoV-2 RNA in intestinal mucosa samples and to evaluate histological features. The COVID-19 patients hospitalized at an Italian tertiary hospital from April 2020 to March 2021 were evaluated for enrollment in an observational, monocentric trial. The study population was composed of two groups of adult patients. In the first group (biopsy group, 30 patients), patients were eligible for inclusion if they had mild to moderate disease and if they agreed to have a rectal biopsy; in the second group (surgical specimen group, 6 patients), patients were eligible for inclusion if they underwent intestinal resection during index hospitalization. Fifty-nine intestinal mucosal samples were analyzed. Viral RNA was not detectable in any of the rectal biopsies performed (0/53). Histological examination showed no enterocyte damage, but slight edema of the lamina propria with mild inflammatory lymphoplasmacytic infiltration. There was no difference in inflammatory infiltrates in patients with and without GI symptoms. SARS-CoV-2 RNA was detected in fecal samples in 6 cases out of 14 cases examined (42.9%). In the surgical specimen group, all patients underwent emergency intestinal resection. Viral RNA was detected in 2 surgical specimens of the 6 examined, both of which were from patients with active neoplastic disease. Histological examination also pointed out abundant macrophages, granulocytes and plasma cells infiltrating the muscular layer and adipose tissue, and focal vasculitis. Mild-moderate COVID-19 may not be associated with rectal infection by the virus. More comprehensive autopsies or surgical specimens are needed to provide histological evidence of intestinal infection.

Effects of lutein on jejunal mucosal barrier function and inflammatory responses in lipopolysaccharide-challenged yellow-feather broilers

Broilers are frequently exposed to various immunological stresses, which lead to intestinal damage, weakened immunity, and even growth retardation. Lutein, as a kind of carotenoid, possesses antioxidant and immunomodulatory functions. Therefore, this study was conducted to investigate the effects of lutein on jejunal mucosal barrier function and inflammatory responses of yellow-feather broilers challenged with lipopolysaccharide (LPS). A total of two hundred eight-eight 1-day-old yellow-feather broilers were randomly allocated to 3 groups with 8 replicate cages containing 12 birds each. Birds were fed broken-rice-soybean basal diet containing 0, 20 and 40 mg/kg lutein (CON, LU20 and LU40) for 26 d. On days 21, 23, and 25 of the trial, broilers were intraperitoneally injected with LPS (1 mg/kg body weight). The results showed that, compared with CON group, LU40 supplementations significantly increased the average daily gain (ADG) of broilers at 1 to 21 and 22 to 26 d of age (P < 0.05), significantly decreased the ratio of feed to gain (F/G) of broilers at 22 to 26 d of age (P < 0.05). LU20 and LU40 supplementations increased goblet cell density in jejunum of broilers under LPS challenge, and LU20 supplementation elevated the villus area (P < 0.05). Scanning electron microscopy of jejunal mucosa revealed significant villi damage, while transmission electron microscopy demonstrated severe enterocyte damage and loss of cellular integrity in CON group. In particular, mitochondria were morphologically altered, appearing irregular or swollen. Apical junctional complexes between adjacent enterocytes were obviously shorter and saccular in CON group. LU20 and LU40 supplementations increased the mRNA expressions of Occludin, Claudin-1, and ZO-1 in the jejunal mucosa of broilers under LPS challenge (P < 0.05), restrained TLR4/MyD88/NF-κB pathway activation in the jejunal mucosa, decreased the mRNA expressions of IL-1β and IL-6, and strengthened the mRNA expressions of IL-4 and IL-10 (P < 0.05). Meanwhile, the protein expressions of p38 and JNK in LU40 group were lower than CON group (P < 0.05). It can be concluded that 40 mg/kg lutein supplementation improved LPS-induced jejunal mucosal barrier function and tamed inflammation of yellow-feather broilers.

Enteric Permeability, Systemic Inflammation, and Post-Discharge Growth Among a Cohort of Hospitalized Children in Kenya and Pakistan.

To determine whether gut permeability is associated with post-discharge growth and systemic inflammation among hospitalized children in low- and middle-income countries. Children aged 2-23 months being discharged from Civil Hospital Karachi (Pakistan) and Migori County Referral Hospital (Kenya) underwent lactulose-rhamnose ratio (LRR) permeability testing and were compared to age-matched children from their home communities. Linear mixed effect models estimated the associations between LRR among discharged children with change in length-for-age (LAZ) and weight-for-age z score (WAZ) at 45, 90, and 180 days after discharge. Linear regression tested if relationships between LRR, systemic inflammation [C-reative protein (CRP), Cluster of Differentiation 14 (CD14), Tumour Necrosis Factor Alpha (TNFα), Interleukin-6 (IL-6)], and enterocyte damage [Intestinal Fatty-Acid Binding protein (I-FABP)] differed between the hospitalized and community groups. One hundred thirty-seven hospitalized and 84 community participants were included. The hospitalized group had higher log-LRR [0.43, 95% confidence interval (CI): 0.15-0.71, P = 0.003] than the community children. Adjustment for weight-for-length z score at discharge attenuated this association (0.31, 95% CI: 0.00-0.62, P = 0.049). LRR was not associated with changes in WAZ or LAZ in the post-discharge period. Associations between LRR and CRP (interaction P = 0.036), TNFα ( P = 0.017), CD14 ( P = 0.078), and IL-6 ( P = 0.243) differed between community and hospitalized groups. LRR was associated with TNFα ( P = 0.004) and approached significance with CD14 ( P = 0.078) and IL-6 ( P = 0.062) in community children, but there was no evidence of these associations among hospitalized children. Although increased enteric permeability is more prevalent among children being discharged from hospital compared to children in the community, it does not appear to be an important determinant of systemic inflammation or post-discharge growth among hospitalized children.

INTESTINAL DAMAGE AND IMMUNE RESPONSE AFTER EXPERIMENTAL BLUNT ABDOMINAL TRAUMA

Abdominal trauma (AT) is of major global importance, particularly because the civil, terroristic, and military traumatic potential of blast injuries has increased. The consequences of blunt abdominal injuries are highly variable and frequently underestimated or even overlooked. However, the underlying path mechanisms and subsequent innate immune response remain poorly understood. Therefore, we investigated the spatiotemporal local and systemic effects of a standardized blast-induced blunt AT on the intestine and innate immune response. In an established AT model, 66 male C57Bl6 mice were anesthetized and exposed to either a single blast wave centered on the epigastrium or control treatment (sham). At 2, 6, or 24 hours after trauma induction, animals were sacrificed. In 16 of 44 (36%) AT animals, one or more macroscopically visible injuries of the intestine were observed. Epithelial damage was detected by histological analysis of jejunum and ileum tissue samples, quantified by the Chiu score and by increased plasma concentrations of the intestinal fatty acid-binding protein, an enterocyte damage marker. Moreover, in the early posttraumatic period, elevated syndecan-1, claudin-5, and mucin-2 plasma levels also indicated alterations in the gut-blood barrier. Increased levels of pro-inflammatory cytokines such as TNF and macrophage inflammatory protein 2 in tissue homogenates and plasma indicate a systemic immune activation after blunt AT. In conclusion, we detected early morphological intestinal damage associated with high, early detectable intestinal fatty acid-binding protein plasma levels, and a considerable time- and dose-dependent impairment of the gut-blood barrier in a newly established mouse model of blunt AT. It appears to be a sufficient model for further studies of the intestinal immunopathophysiological consequences of AT and the evaluation of novel therapeutic approaches.

Anthocyanin-Rich Blackcurrant Extract Preserves Gastrointestinal Barrier Permeability and Reduces Enterocyte Damage but Has No Effect on Microbial Translocation and Inflammation After Exertional Heat Stress.

This study investigated the effects of 7days of 600mg/day anthocyanin-rich blackcurrant extract intake on small intestinal permeability, enterocyte damage, microbial translocation, and inflammation following exertional heat stress. Twelve recreationally active men (maximal aerobic capacity = 55.6 ± 6.0ml·kg-1·min-1) ran (70% VO2max) for 60min in an environmental chamber (34°C, 40% relative humidity) on two occasions (placebo/blackcurrant, randomized double-blind crossover). Permeability was assessed from a 4-hr urinary excretion of lactulose and rhamnose and expressed as a ratio of lactulose/rhamnose. Venous blood samples were taken at rest and 20, 60, and 240min after exercise to measure enterocyte damage (intestinal fatty acid-binding protein); microbial translocation (soluble CD14, lipopolysaccharide-binding protein); and interleukins 6, interleukins 10, and interleukins 1 receptor antagonist. Exercise increased rectal temperature (by ∼2.8°C) and heart rate (by ∼123 beats/min) in each condition. Blackcurrant supplementation led to a ∼12% reduction in lactulose/rhamnose ratio (p < .0034) and enterocyte damage (∼40% reduction in intestinal fatty acid-binding protein area under the curve; p < .0001) relative to placebo. No between-condition differences were observed immediately after exercise for lipopolysaccharide-binding protein (mean, 95% confidence interval [CI]; +80%, 95% CI [+61%, +99%]); soluble CD14 (+37%, 95% CI [+22%, +51%]); interleukins 6 (+494%, 95% CI [+394%, +690%]); interleukins 10 (+288%, 95% CI [+105%, +470%]); or interleukins 1 receptor antagonist (+47%, 95% CI [+13%, +80%]; all time main effects). No between-condition differences for these markers were observed after 60 or 240min of recovery. Blackcurrant extract preserves the GI barrier; however, at subclinical levels, this had no effect on microbial translocation and downstream inflammatory processes.

Serological biomarkers for management of primary sclerosing cholangitis.

Clinical manifestations and progression of primary sclerosing cholangitis (PSC) are heterogeneous, and its pathogenesis is poorly understood. The importance of gut-liver interactions in the pathogenesis has been clinically confirmed and highlighted in different theories. Recent advances regarding biomarkers of biliary-gut crosstalk may help to identify clinically relevant PSC subgroups assisting everyday clinical work-up (e.g., diagnosis, disease stratification, or surveillance) and the exploration of potential therapeutic targets. Alkaline phosphatase produced by the biliary epithelium is consistently associated with prognosis. However, its level shows natural fluctuation limiting its use in individual patients. Inflammatory, cell activation, and tissue remodeling markers have been reported to predict clinical outcome. Elevated immunoglobulin (Ig) G4 level is associated with a shorter transplantation-free survival. IgG type atypical perinuclear anti-neutrophil cytoplasmic antibodies (P-ANCAs) are non-specific markers of various autoimmune liver diseases and may reflect an abnormal B-cell response to gut microbial antigens. IgG type atypical P-ANCA identifies PSC patients with particular clinical and genetic (for human leukocyte antigens) characteristics. The presence of IgA type anti-F-actin antibody (AAA) may predict a progressive disease course, and it is associated with enhanced mucosal immune response to various microbial antigens and enterocyte damage. IgA type anti-glycoprotein 2 (GP2) antibodies identify patients with a severe disease phenotype and poor survival due to enhanced fibrogenesis or development of cholangiocarcinoma. Elevated soluble vascular adhesion protein-1 (sVAP-1) level is associated with adverse disease outcomes in PSC. High sVAP-1 levels correlate with mucosal addressin cell adhesion molecule-1 (MAdCAM-1) expression in the liver that contributes to gut activated T-cell homing to the hepatobiliary tract. In the present paper, we review the evidence on these possible serological markers that could potentially help address the unmet clinical needs in PSC.

Zonulin and I-FABP are markers of enterocyte damage in celiac disease

To evaluate the level of serum I-FABP (Fatty-Acid-Binding Protein a protein that binds fatty acids) and fecal zonulin as markers of the permeability of the mucous membrane of the small intestine in celiac patients. A total of 151 celiac patients (25 men and 126 women) were examined. The median age was 42 years. Group I included 58 patients with newly diagnosed celiac disease; in group 2 38 patients, knowingly or unknowingly violating the gluten-free diet; group 3 consisted of 55 patients strictly observing gluten-free diet. The control group consisted of 20 healthy volunteers: 4 men and 16 women. All patients underwent esophagogastroduodenoscopy by biopsy of the mucous membrane of the small intestine and assessment of duodenobioptates according to Marsh. In the blood serum, the level of antibodies to tissue transglutaminase IgA and IgG was determined by the enzyme-linked immunosorbent assay using kits manufactured by Orgentec Diagnostics GmbH (Germany), the concentration of I-FABP in blood serum was determined using Hycult Biotech kits (Netherlands). The content of zonulin in feces was investigated by enzyme-linked immunosorbent assay using kits from Immundiagnostik AG (Germany). Statistical analysis was performed using the Statistica 13.3 software (StatSoft Inc., USA). There was a significant increase in the level of antibodies to tissue transglutaminase IgA [120.0 (41.1200)] IU/ml and IgG [31.4 (5.578.9)] IU/ml in patients of group 1 compared with group 2 [IgA 9.1 (2.987.6)] and IgG [3.8 (2.219.7)] IU/ml and group 3 [IgA 1.6 (1.03.2)] and IgG [2.2 (1.152.53)] (p0.01). The level of I-FABP in blood serum in patients of group 1 averaged 2045 pg/ml, in patients in group 2 1406 pg/ml, in patients in group 3 1000 pg/ml. All patients showed a significant increase in the mean I-FABP values compared to controls (1, 2 and control p0.01, 3 and control p=0.016). In patients with Marsh grade III AC atrophy, the I-FABP level depended on the degree of damage to the mucosa and significantly differed from the control: March IIIA (median: 1310 pg/ml, interquartile range: 12121461 pg/ml), March IIIB (median: 2090 pg/ml, interquartile range: 18122322 pg/ml) as well as Marsh IIIC (median: 2058 pg/ml, interquartile range 18582678 pg/ml). The concentration of zonulin in feces in patients of group 1 averaged 111.6 pg/mg, in patients of group 2 90.5 pg/mg. In patients of group 3 50 IU/ml. The concentration of zonulin in feces increased as the degree of mucosa atrophy increased (r=0.585, p0.01). However, despite the fact that both of these markers may indicate impaired permeability, each of them indicates damage to a certain level of the intestinal barrier, which is not always associated with the degree of mucosa atrophy. Determination of serum I-FABP and fecal zonulin levels in celiac patients allows for the assessment of intestinal permeability and can serve as non-invasive markers for monitoring ongoing structural changes in the mucosa without the need for endoscopy.

Augmented Enterocyte Damage During Candida albicans and Proteus mirabilis Coinfection.

The human gut acts as the main reservoir of microbes and a relevant source of life-threatening infections, especially in immunocompromised patients. There, the opportunistic fungal pathogen Candida albicans adapts to the host environment and additionally interacts with residing bacteria. We investigated fungal-bacterial interactions by coinfecting enterocytes with the yeast Candida albicans and the Gram-negative bacterium Proteus mirabilis resulting in enhanced host cell damage. This synergistic effect was conserved across different P. mirabilis isolates and occurred also with non-albicans Candida species and C. albicans mutants defective in filamentation or candidalysin production. Using bacterial deletion mutants, we identified the P. mirabilis hemolysin HpmA to be the key effector for host cell destruction. Spatially separated coinfections demonstrated that synergism between Candida and Proteus is induced by contact, but also by soluble factors. Specifically, we identified Candida-mediated glucose consumption and farnesol production as potential triggers for Proteus virulence. In summary, our study demonstrates that coinfection of enterocytes with C. albicans and P. mirabilis can result in increased host cell damage which is mediated by bacterial virulence factors as a result of fungal niche modification via nutrient consumption and production of soluble factors. This supports the notion that certain fungal-bacterial combinations have the potential to result in enhanced virulence in niches such as the gut and might therefore promote translocation and dissemination.