Altered Intestinal Permeability Research Articles

Link between gut microbiota dysbiosis and chronic kidney disease.

During chronic kidney disease (CKD), typical alterations in the gut microbiota are observed. The kidney no longer plays the role of the main excretory organ as this function is performed by the intestine. In CKD patients, an alteration of intestinal permeability and a degradation of the protective mucous layer are observed. These changes in the intestinal barrier allow the passage of bacterial material from the intestine to the bloodstream through the intestinal wall. This phenomenon contributes to the induction of the chronic inflammatory state, typical of CKD. In nephropathic patients, there is an increase in circulation of p-cresyl sulfate (p-CS), indoxyl sulphate (IS), indole-3 acetic acid (IAA) and trimethylamine-N-oxide (TMAO), all gut-derived uremic toxins. The changes in gut microbiota composition are related to CKD stage and this phenomenon is exacerbated in hemodialysis (HD) adult and pediatric patients. Interestingly, it is observed a positive shift in gut microbiota composition after renal transplantation and at the same time a reduction of circulating gut-derived uremic toxins. Either gut dysbiosis or uremic toxins accumulation contribute to the CKD onset and progression.

A15 GIARDIA DUODENALIS INDUCES REGIOSPECIFIC ALTERATIONS TO INTESTINAL MUCOSAL GLYCOSYLATION PATTERNS

BackgroundDisruption of intestinal barrier function is important in the pathogenesis of numerous intestinal diseases and can lead to increased intestinal permeability. During infection with the protozoan parasite Giardia duodenalis, intestinal permeability is increased in part due to disruption of the intestinal mucus barrier. Intestinal mucus is composed primarily of the heavily glycosylated MUC2 mucin. Glycosylation of mucins is important for maintaining the structure of the mucus gel, and glycans are key mediators of host-microbe interactions, as they provide binding sites to microbes and can be degraded as a nutrient source. Changes to mucin glycosylation patterns have been noted during intestinal inflammation and bacterial infection, and may contribute to altered intestinal permeability and dysbiosis. We hypothesized that intestinal mucosal glycosylation patterns may be disrupted during Giardia infection, and that this may contribute to Giardia-induced barrier dysfunction.AimsCharacterize changes to mucosal glycosylation patterns in the small and large intestines during in vivo Giardia infection.Methods3–4 week old C57BL/6 mice were infected with Giardia duodenalis strain GS/M for 7 days. Tissue sections from the jejunum and colon were collected and stained with various fluorescein-coupled lectins (CONA, DBA, PNA, WGA, SNA, UEA-1) and fluorescence was quantified and normalized to tissue area. Quantitative PCR (qPCR) was performed for glycosyltransferase genes in the jejunum and colon.ResultsIn the jejunum, abundance of N-acetylglucosamine increased upon infection, while sialic acid and fucose abundance were significantly decreased in infected mice compared to controls. Conversely, in the distal colon, mannose and sialic acid abundance increased significantly upon infection.Expression of mucin-associated glycosyltransferase genes was also altered in the small and large intestines of Giardia infected mice. In the jejunums of infected mice, expression of the sulfotransferase Chst4 decreased, while the fucosyltransferase Fut2 and the sialyltransferase St6GalNAc1 increased in comparison to controls. In both the jejunum and distal colon, expression of the core 2 synthase C2GnT1 increased, while expression of the core 1 synthase C1GalT1 was similar between control and infected mice.ConclusionsGlycosylation patterns and the expression of glycosyltransferase genes are altered in both the small and large intestines of Giardia-infected mice. Disruptions to mucin glycans appear to be regiospecific, suggesting that unique mechanisms are involved in the regulation of mucosal glycosylation during parasitic infection throughout different regions of the gut. These findings uncover a novel mechanism in the pathogenesis of Giardia infection, and may be important in understanding intestinal barrier dysfunction in a variety of different gastrointestinal diseases.Funding AgenciesCCC

Efficacy of a Product Containing Xyloglucan and Pea Protein on Intestinal Barrier Function in a Partial Restraint Stress Animal Model.

Functional abdominal bloating and distension (FABD) are common and frequent symptoms in patients with pre-existing gastrointestinal (GI) disorders. FABD is characterized by recurrent abdominal fullness and bloating. The pathophysiology of FABD is still unclear. However, the plausible mechanisms involved are small intestinal bacterial overgrowth (SIBO), imbalance of gut microbiota, visceral hypersensitivity, intestinal permeability alteration, and disruption of intestinal barrier function. Thus, the creation of a barrier on the wall of the intestine could represent an alternative therapeutic strategy to prevent FABD. This study aimed to investigate the effect of two natural substances, Xyloglucan (XG) and Pea-protein (PP), known for their mucosal-protective properties, in an in vivo model of Partial restraint-stress (PRS). Our results showed that the pre-treatment with a product containing XG and PP in stressed-rats was able to reduce the number of abdominal contractions and visceral hypersensitivity. Moreover, XG and PP were able to reduce intestinal permeability alteration, restoring tight-junctions (TJs) expression and decreased the lactulose–mannitol ratio, a quantitative marker used to measure intestinal permeability, compared to PRS-group. In conclusion, the data obtained revealed that the product containing XG and PP was able to restore the normal intestinal-barrier function; therefore, it could be considered a therapeutic strategy to manage FABD.

Demonstration of Gut-Barrier Dysfunction in Early Stages of Non-alcoholic Fatty Liver Disease: A Proof-Of-Concept Study

Gut-barrier dysfunction is well recognized in pathogenesis of both non-alcoholic fatty liver disease (NAFLD) and alcoholic liver disease (ALD). However, comparison of components of this dysfunction between the two etiologies remains unexplored especially in early stages of NAFLD. Components of gut-barrier dysfunction like alterations in intestinal permeability (IP) by lactulose mannitol ratio (LMR) in urine, systemic endotoxemia (IgG and IgM anti-endotoxin antibodies), systemic inflammation (serum tumor necrosis factor alpha [TNF-α] and interleukin-1 [IL-1] levels), tight junction (TJ) proteins expression in duodenal biopsy and stool microbiota composition using Oxford Nanopore MinION device were prospectively evaluated in patients with NAFLD (n= 34) with no cirrhosis, ALD (n= 28) and were compared with disease free controls (n= 20). Patients with ALD had more advanced disease than those with NAFLD (median liver stiffness -NAFLD:7.1kPa [5.9-8.9] vs. ALD:14.3kPa [9.6-24], P < 0.001]. Median LMR was significantly higher in NAFLD and ALD group when compared to controls (NAFLD 0.054 [0.037-0.17] vs. controls 0.027 [0.021-0.045] (P= 0.001)) and ALD 0.043 [0.03-0.068] vs. controls 0.027 [0.021-0.045] (P= 0.019)]. Anti-endotoxin antibody titer (IgM) (MMU/mL) was lowest in NAFLD 72.9 [3.2-1089.5] compared to ALD 120.6 [20.1-728]) (P= 0.042) and controls 155.3 [23.8-442.9]) (P= 0.021). Median TNF-α (pg/mL) levels were elevated in patients with NAFLD (53.3 [24.5-115]) compared to controls (16.1 [10.8-33.3]) (P < 0.001) and ALD (12.3 [10.1-42.7]) (P < 0.001). Expression of zonulin-1 and claudin-3 in duodenal mucosa was lowest in NAFLD. On principal co-ordinate analysis (PCoA), the global bacterial composition was significantly different across the three groups (PERMANOVA test, P < 0.001). While remaining activated in both etiologies, gut-barrier dysfunction abnormalities were more pronounced in NAFLD at early stages compared to ALD despite more advanced disease in the latter.

Alterations of the Intestinal Permeability are Reflected by Changes in the Urine Metabolome of Young Autistic Children: Preliminary Results.

Several metabolomics-based studies have provided evidence that autistic subjects might share metabolic abnormalities with gut microbiota dysbiosis and alterations in gut mucosal permeability. Our aims were to explore the most relevant metabolic perturbations in a group of autistic children, compared with their healthy siblings, and to investigate whether the increased intestinal permeability may be mirrored by specific metabolic perturbations. We enrolled 13 autistic children and 14 unaffected siblings aged 2–12 years; the evaluation of the intestinal permeability was estimated by the lactulose:mannitol test. The urine metabolome was investigated by proton nuclear magnetic resonance (1H-NMR) spectroscopy. The lactulose:mannitol test unveiled two autistic children with altered intestinal permeability. Nine metabolites significantly discriminated the urine metabolome of autistic children from that of their unaffected siblings; however, in the autistic children with increased permeability, four additional metabolites—namely, fucose, phenylacetylglycine, nicotinurate, and 1-methyl-nicotinamide, strongly discriminated their urine metabolome from that of the remaining autistic children. Our preliminary data suggest the presence of a specific urine metabolic profile associated with the increase in intestinal permeability.

P701 Compositional and functional alterations of the gut microbiome are associated with impaired intestinal permeability in healthy relatives of patients with Crohn’s disease

Abstract Background The gut microbiome may play a role in gut barrier homeostasis including epithelial barrier integrity and function. However, data are scarce and limited to animal studies. We aimed to assess if alterations in the gut microbiome are associated with altered intestinal permeability. Methods We utilized the Genetic Environmental Microbial (CCC GEM) cohort of healthy first-degree relatives of patients with Crohn’s disease. Gut barrier function was assessed using the ratio of urinary fractional excretion of lactulose to mannitol (LMR). Stool bacterial DNA was extracted and sequenced for the V4 hypervariable region of the 16S rDNA gene using MiSeq and processed using QIIME2. PICRUSt2 was used to impute Microbial functions. In order to identify robust associations, the overall cohort was divided based on geographic region into a North American discovery cohort (n=2,472) and non-North American external validation cohort (n=655). LMR&amp;gt;0.025 was defined as abnormal. LMR-microbiome associations were assessed using generalized estimating equation multivariable regression model and Random Forest (RF) classifier algorithm. q&amp;lt;0.05 was considered significant when multiple tests were performed. Results The median age of the entire cohort was 17.0 years [IQR 12.0; 24.0], 52.6% were females and 25.4% had LMR&amp;gt;0.025. In the discovery cohort, subjects with LMR&amp;gt;0.025 had markedly reduced alpha diversity (Chao1 index, estimate= -0.0037, p=4.0e-04) and altered beta diversity (Bray-Curtis dissimilarity index, PERMANOVA: pseudo-F statistic = 2.99, p=1.0e-03). Eight bacterial genera and 52 microbial pathways were identified to be associated with LMR&amp;gt;0.025 (q&amp;lt;0.05). The compositional associations were replicated in four genera (Adlercreutzia [odds ratio(OR)=0.74, 95% confidence interval (CI) 0.6–0.91], Clostridia-UCG-014 [OR=0.71, 95%CI 0.59–0.86], Clostridium-sensu-stricto-1 [OR=0.75, 95%CI 0.61–0.92] and Colidextribacter [OR=1.65, 95%CI 1.2–2.26]). The pathway associations were replicated in eight pathways (biosynthesis of glutamate [OR=0.4, 95%CI 0.21–0.74], tryptophan [OR=0.06, 95%CI 0.01–0.27] and threonine [OR=0.038, 95%CI 0.003–0.41], among others). Bacterial community composition was associated with gut barrier homeostasis as defined by the RF analysis (p= 1.4e-6). Conclusion Gut microbiome community composition and microbial pathways are associated with gut barrier function. These findings may identify microbial targets that enhance barrier function.

Питание как способ контроля хронического воспаления низкой интенсивности через коррекцию кишечной микробиоты

This review focuses on the interaction between the microbiota and macroorganism in conditions of biological equilibrium, which is the basis of maintaining human homeostasis in general. Low-grade chronic inflammation (LGCI) is realized within this interaction in dysbiosis of various genesis. Bacterial endotoxins are normally the final effectors of LGCI, which are involved in the maturation of the immune system’s components, further determining its ability to neutralize and eliminate pathogens. However, altered intestinal permeability with subsequent microbial translocation to unrelated epitopes may cause LGCI. The review presents several possible options for affecting the gut microbiota and thus LGCI: through the use of probiotics, prebiotics, restrictive diets, and fermented probiotic food products. Key words: diet, probiotics, prebiotics, gut microbiota, low-grade chronic inflammation

Hypothesis and Preliminary Results on the Role of MUC1 and MUC2 in Relationship to Autism Etiology

Background: Autism is a neurological disorder with either genetic or environmental component. Autism generally presents changes of intestinal permeability to produce alteration of metabolism in the gastrointestinal tract. The intestinal macrobiota produces metabolites, opioid-like peptides, that show properties experimentally associated with autism. The aim of this study is to understand the cause of intestinal permeability's alteration. Materials and Methods: We determined intestinal MUC2 on stool samples of 12 patients and healthy controls with Fecal Mucin Assay and analyzed the results with Mann–Whitney U-test calculator. Results: The results of the dosage of MUC2's concentration in autistic people decrease when compared with those of healthy control groups: this result is statistically significant: the p-value is 0.00124. Discussion: The results show an increase of MUC2, perhaps due to genetic origin. We hypnotize a probable over expression on highly hypoglycosylated MUC1. All this prevents a regular linkage of MUC2 to MUC1, so as to form many channels in mucosa. The free MUC2 relies on themselves and joins together with hydrogen bridge bonds, leaving the highly glycosylated end parts to become the starting point for abnormal growth of the bacteria, which in turn produce opioid such as peptides, that pass into the channels of the mucosa layer.

Glucose but Not Fructose Alters the Intestinal Paracellular Permeability in Association With Gut Inflammation and Dysbiosis in Mice.

A causal correlation between the metabolic disorders associated with sugar intake and disruption of the gastrointestinal (GI) homeostasis has been suggested, but the underlying mechanisms remain unclear. To unravel these mechanisms, we investigated the effect of physiological amounts of fructose and glucose on barrier functions and inflammatory status in various regions of the GI tract and on the cecal microbiota composition. C57BL/6 mice were fed chow diet and given 15% glucose or 15% fructose in drinking water for 9 weeks. We monitored caloric intake, body weight, glucose intolerance, and adiposity. The intestinal paracellular permeability, cytokine, and tight junction protein expression were assessed in the jejunum, cecum, and colon. In the cecum, the microbiota composition was determined. Glucose-fed mice developed a marked increase in total adiposity, glucose intolerance, and paracellular permeability in the jejunum and cecum while fructose absorption did not affect any of these parameters. Fructose-fed mice displayed increased circulation levels of IL6. In the cecum, both glucose and fructose intake were associated with an increase in Il13, Ifnγ, and Tnfα mRNA and MLCK protein levels. To clarify the relationships between monosaccharides and barrier function, we measured the permeability of Caco-2 cell monolayers in response to IFNγ+TNFα in the presence of glucose or fructose. In vitro, IFNγ+TNFα-induced intestinal permeability increase was less pronounced in response to fructose than glucose. Mice treated with glucose showed an enrichment of Lachnospiracae and Desulfovibrionaceae while the fructose increased relative abundance of Lactobacillaceae. Correlations between pro-inflammatory cytokine gene expression and bacterial abundance highlighted the potential role of members of Desulfovibrio and Lachnospiraceae NK4A136 group genera in the inflammation observed in response to glucose intake. The increase in intestinal inflammation and circulating levels of IL6 in response to fructose was observed in the absence of intestinal permeability modification, suggesting that the intestinal permeability alteration does not precede the onset of metabolic outcome (low-grade inflammation, hyperglycemia) associated with chronic fructose consumption. The data also highlight the deleterious effects of glucose on gut barrier function along the GI tract and suggest that Desulfovibrionaceae and Lachnospiraceae play a key role in the onset of GI inflammation in response to glucose.

Dietary Fish Hydrolysate Improves Memory Performance Through Microglial Signature Remodeling During Aging.

Brain aging is characterized by a chronic low-grade inflammation, which significantly impairs cognitive function. Microglial cells, the immunocompetent cells of the brain, present a different phenotype, switching from a homeostatic signature (M0) to a more reactive phenotype called “MGnD” (microglial neurodegenerative phenotype), leading to a high production of pro-inflammatory cytokines. Furthermore, microglial cells can be activated by age-induced gut dysbiosis through the vagus nerve or the modulation of the peripheral immune system. Nutrients, in particular n-3 long chain polyunsaturated fatty acids (LC-PUFAs) and low molecular weight peptides, display powerful immunomodulatory properties, and can thus prevent age-related cognitive decline. The objective of this study was to investigate the effects of n-3 LC-PUFAs and low molecular weight peptides contained in a marine by-product-derived hydrolysate on microglial phenotypes and intestinal permeability and their consequences on cognition in mice. We demonstrated that the hydrolysate supplementation for 8 weeks prevented short- and long-term memory decline during aging. These observations were linked to the modulation of microglial signature. Indeed, the hydrolysate supplementation promoted homeostatic microglial phenotype by increasing TGF-β1 expression and stimulated phagocytosis by increasing Clec7a expression. Moreover, the hydrolysate supplementation promoted anti-inflammatory intestinal pathway and tended to prevent intestinal permeability alteration occurring during aging. Therefore, the fish hydrolysate appears as an interesting candidate to prevent cognitive decline during aging.

Altered Intestinal Permeability and Drug Repositioning in a Post-operative Ileus Guinea Pig Model.

Background/AimsThe aim of this study is to identify the alteration in intestinal permeability with regard to the development of post-operative ileus (POI). Moreover, we investigated drug repositioning in the treatment of POI.MethodsAn experimental POI model was developed using guinea pigs. To measure intestinal permeability, harvested intestinal membranes of the ileum and proximal colon was used in an Ussing chamber. To identify the mechanisms associated with altered permeability, we measured leukocyte count and expression of calprotectin, claudin-1, claudin-2, and mast cell tryptase. We compared control, POI, and drug groups (mosapride [0.3 mg/kg and 1 mg/kg, orally], glutamine [500 mg/kg, orally], or ketotifen [1 mg/kg, orally] with regard to these parameters.ResultsIncreased permeability after surgery significantly decreased after administration of mosapride, glutamine, or ketotifen. Leukocyte counts increased in the POI group and decreased significantly after administration of mosapride (0.3 mg/kg) in the ileum, and mosapride (0.3 mg/kg and 1 mg/kg), glutamine, or ketotifen in the proximal colon. Increased expression of calprotectin after surgery decreased after administration of mosapride (0.3 mg/kg), glutamine, or ketotifen in the ileum and proximal colon, and mosapride (1 mg/kg) in the ileum. The expression of claudin-1 decreased significantly and that of claudin-2 increased after operation. After administration of glutamine, the expression of both proteins was restored. Finally, mast cell tryptase levels increased in the POI group and decreased significantly after administration of ketotifen.ConclusionsThe alteration in intestinal permeability is one of the factors involved in the pathogenesis of POI. We repositioned 3 drugs (mosapride, glutamine, and ketotifen) as novel therapeutic agents for POI.

Impacts of Fructose on Intestinal Barrier Function, Inflammation and Microbiota in a Piglet Model.

The metabolic disorder caused by excessive fructose intake was reported extensively and often accompanied by intestinal barrier dysfunction. And the rising dietary fructose was consumed at an early age of human. However, related researches were almost conducted in rodent models, while in the anatomy and physiology of gastrointestinal tract, pig is more similar to human beings than rodents. Hence, weaned piglets were chosen as the model animals in our study to investigate the fructose’s impacts on intestinal tight junction, inflammation response and microbiota structure of piglets. Herein, growth performance, inflammatory response, oxidation resistance and ileal and colonic microbiota of piglet were detected after 35-day fructose supplementation. Our results showed decreased tight junction gene expressions in piglets after fructose addition, with no obvious changes in the growth performance, antioxidant resistance and inflammatory response. Moreover, fructose supplementation differently modified the microbiota structures in ileum and colon. In ileum, the proportions of Streptococcus and Faecalibacterium were higher in Fru group (fructose supplementation). In colon, the proportions of Blautia and Clostridium sensu stricto 1 were higher in Fru group. All the results suggested that tight junction dysfunction might be an earlier fructose-induced event than inflammatory response and oxidant stress and that altered microbes in ileum and colon might be the potential candidates to alleviate fructose-induced intestinal permeability alteration.

Assessment of serum zonulin as a marker of altered intestinal permeability in patients with multiple sclerosis

Abstract Background Here we enrolled patients into 3 groups: Relapsing remittent MS in relapse (RRMS) [N = 26], progressive MS (progressive) [N = 19] and relapsing remittent MS in remission (remission) [N = 18] Control group matching age and sex [N = 20] P-Value was &amp;lt;0.001, which is significant in RRMS group in relation to progressive, remission and control groups. P-Value was 0.849, which is insignificant in progressive group in relation to remission group. P-Value was 0.584, which is insignificant in progressive group in relation to control group. P-Value was 0.973, which is insignificant in remission group in relation to control group. Aim of the Work To investigate the possible association between IP changes and MS through measurement serum zonulin in different population of MS for possible implication on treatment. Patients and Methods A. Subjects Type of the Study A case control observational cross sectional study Study Setting The Neurology department of Ain Shams University hospitals. Study Period 6 months to 1 year Study Population This study will enroll 92 subjects who will be divided into 4 groups; group 1 including 24patients with the diagnosis of relapsing remittent MS (RRMS) who are in relapse phase within one week from the time of sample withdrawal, group 2 including 24 patients with the diagnosis of RRMS who are in remission phase, group 3 including 24 patients with secondary progressive MS (SPMS) and group 4 including 20 age- and sex-matched healthy controls. Results In the RRMS group of this study, serum Zonulin varying between (12_ 93) with mean 28.692 and +\-22.894 SD. In the progressive group of this study, serum Zonulin varying between (2_ 18) with mean 8.021 and +\-3.866 SD. In the remission group of this study, serum Zonulin varying between (1.5_ 11) with mean 4.522 and +\-3.026 SD. In the control group of this study, serum Zonulin varying between (1.3_ 6) with mean 2.690 and +\-1.292 SD. P-Value was &amp;lt;0.001, which is significant in RRMS group in relation to progressive, remission and control groups. P-Value was 0.849, which is insignificant in progressive group in relation to remission group. P-Value was 0.584, which is insignificant in progressive group in relation to control group. P-Value was 0.973, which is insignificant in remission group in relation to control group. Conclusion this study included 62 patients diagnosed as multiple sclerosis that are divided into 3 groups and serum Zonulin level was assessed in each group and the results were significant in the relapse group which indicates autoimmune theory of MS and link between gut barrier and CNS also illustrated the role of gut microbiota in the MS. It also supported disintegration of intestinal barrier during the attack of MS for further work up studies regarding oral medication in the acute attack of MS.

Serum Zonulin Levels Are Higher Among Children with Autism Spectrum Disorders and Correlated with Social Impairment.

Zonulin is a protein that affects the integrity of intercellular connections in the intestines. It has been emphasized that autoimmune diseases as well as neurodevelopmental disorders, for example autism spectrum disorder (ASD), may occur through alterations in intestinal permeability and blood-brain barrier. We aimed to investigate the gastrointestinal permeability of individuals with ASD by determining serum zonulin levels and their relationship to symptom severity. Twenty-five ASD patients and 19 controls were included. Serum zonulin levels were measured by enzyme-linked immunosorbent assay kits. Clinical severity was assessed by the Childhood Autism Rating Scale (CARS), and social skills of the control group were evaluated by the Conners' Parents and Teacher's Rating Scales-Revised/Long Forms (CPRS-CTRS). Mean zonulin levels were significantly higher in the ASD group and positively correlated with CARS scores. After regression analysis, serum zonulin levels predicted CARS total scores. We could not find any significant correlation between zonulin levels and CPRS-CTRS sociability subscale scores in the control group. The positive correlation between serum zonulin levels and ASD severity may require precaution for impaired intestinal permeability in clinical practice, especially for the cases in which sociability is severely impaired. However, it is too early to state that intestinal permeability has a role in the etiology of ASD. Further studies involving specific autism subgroups, and samples with certain dietary differences are needed.

Gut integrity and duodenal enteropathogen burden in undernourished children with environmental enteric dysfunction.

Environmental enteric dysfunction (EED) is a subclinical condition of intestinal inflammation, barrier dysfunction and malabsorption associated with growth faltering in children living in poverty. This study explores association of altered duodenal permeability (lactulose, rhamnose and their ratio) with higher burden of enteropathogen in the duodenal aspirate, altered histopathological findings and higher morbidity (diarrhea) that is collectively associated with linear growth faltering in children living in EED endemic setting. In a longitudinal birth cohort, 51 controls (WHZ > 0, HAZ > −1.0) and 63 cases (WHZ< -2.0, refractory to nutritional intervention) were recruited. Anthropometry and morbidity were recorded on monthly bases up to 24 months of age. Dual sugar assay of urine collected after oral administration of lactulose and rhamnose was assessed in 96 children from both the groups. Duodenal histopathology (n = 63) and enteropathogen analysis of aspirate via Taqman array card (n = 60) was assessed in only cases. Giardia was the most frequent pathogen and was associated with raised L:R ratio (p = 0.068). Gastric microscopy was more sensitive than duodenal aspirate in H. pylori detection. Microscopically confirmed H. pylori negatively correlated with HAZ at 24 months (r = −0.313, p = 0.013). Regarding histopathological parameters, goblet cell reduction significantly correlated with decline in dual sugar excretion (p< 0.05). Between cases and controls, there were no significant differences in the median (25th, 75th percentile) of urinary concentrations (μg/ml) of lactulose [27.0 (11.50, 59.50) for cases vs. 38.0 (12.0, 61.0) for controls], rhamnose [66.0 (28.0, 178.0) vs. 86.5 (29.5, 190.5)] and L:R ratio [0.47 (0.24, 0.90) vs. 0.51 (0.31, 0.71)] respectively. In multivariable regression model, 31% of variability in HAZ at 24 months of age among cases and controls was explained by final model including dual sugars. In conclusion, enteropathogen burden is associated with altered histopathological features and intestinal permeability. In cases and controls living in settings of endemic enteropathy, intestinal permeability test may predict linear growth. However, for adoption as a screening tool for EED, further validation is required due to its complex intestinal pathophysiology.

Transcriptional Changes after Enniatins A, A1, B and B1 Ingestion in Rat Stomach, Liver, Kidney and Lower Intestine

Enniatins (ENs) are depsipeptide mycotoxins produced by Fusarium fungi. They are known for their capacity to modulate cell membrane permeability and disruption of ionic gradients, affecting cell homeostasis and initiating oxidative stress mechanisms. The effect of the acute toxicity of ENs A, A1, B and B1 at two different concentrations after 8 h of exposure was analysed in Wistar rats by a transcriptional approach. The following key mitochondrial and nuclear codified genes related to the electron transport chain were considered for gene expression analysis in stomach, liver, kidney and lower intestine by quantitative Real-Time PCR: mitochondrially encoded NADH dehydrogenase 1 (MT-ND1), mitochondrially encoded cytochrome c oxidase 1 (MT-COX1), succinate dehydrogenase flavoprotein subunit A and ATP synthase F1 subunit alpha, respectively. Moreover, the expression of markers involved in oxidative stresssuperoxide dismutase 1 (SOD1), glutathione peroxidase 1 (Gpx1), heme oxygenase 1, apoptosis B-cell lymphoma 2, Bcl2 Associated protein X (Bax), tumor suppressor protein (p53), inhibition of apoptosis nuclear factor kappa of activated B cells, immune system interleukin 1β and intestinal tight junction Occludin merely in lower intestine tissues have been investigated. For mitochondrial genes, the main differences were observed for MT-ND1 and MT-COX1, showing its deficiency in all selected organs. With regard to the intestinal barrier’s cellular response to oxidative stress, the activity of the antioxidant gene SOD1 was decreased in a dose-dependent manner. Similarly, the catalytic enzyme GPx1 was also downregulated though merely at medium dose employed. On the contrary, the pro-apoptotic Bax and p53 regulators were activated after ENs exposure, reporting a significant increase in their expression. Furthermore, the alteration of intestinal permeability was assessed by the abnormal activity of the tight junction protein occludin. In summary, ENs may generate mitochondrial disorders and induce oxidative stress in intestinal barrier function.

The Effect of a Novel Serine Protease Inhibitor on Inflammation and Intestinal Permeability in a Murine Colitis Transfer Model.

Background: A protease/antiprotease disbalance is observed in inflammatory bowel diseases (IBD). We therefore studied the effect of the novel serine protease inhibitor UAMC-00050 on intestinal inflammation and permeability in a chronic colitis T cell transfer mouse model to get further insight into the regulation of T cell-mediated immunopathology. Methods: Colitis was induced in severe combined immunodeficient (SCID) mice, by the adoptive transfer of CD4+CD25−CD62L+ T cells. Animals were treated intraperitoneally (i.p.) 2x/day with vehicle or UAMC-00050 (5 mg/kg) from week 2 onwards. Colonic inflammation was assessed by clinical parameters, colonoscopy, macroscopy, microscopy, myeloperoxidase activity and cytokine expression levels. At week 4, 4 kDa FITC-dextran intestinal permeability was evaluated and T helper transcription factors, protease-activated receptors and junctional proteins were quantified by RT-qPCR. Results: Adoptive transfer of CD4+CD25−CD62L+ T cells resulted in colonic inflammation and an altered intestinal permeability. The serine protease inhibitor UAMC-00050 ameliorated both the inflammatory parameters and the intestinal barrier function. Furthermore, a decrease in colonic mRNA expression of Tbet and PAR4 was observed in colitis mice after UAMC-00050 treatment. Conclusion: The beneficial effect of UAMC-00050 on inflammation was apparent via a reduction of Tbet, IFN-γ, TNF-α, IL-1β and IL-6. Based on these results, we hypothesize a pivotal effect of serine protease inhibition on the Th1 inflammatory profile potentially mediated via PAR4.

Food Contaminants Effects on an In Vitro Model of Human Intestinal Epithelium.

Pesticide residues represent an important category of food contaminants. Furthermore, during food processing, some advanced glycation end-products resulting from the Maillard reaction can be formed. They may have adverse health effects, in particular on the digestive tract function, alone and combined. We sought to validate an in vitro model of the human intestinal barrier to mimic the effects of these food contaminants on the epithelium. A co-culture of Caco-2/TC7 cells and HT29-MTX was stimulated for 6 h with chlorpyrifos (300 μM), acrylamide (5 mM), Nε-Carboxymethyllysine (300 μM) alone or in cocktail with a mix of pro-inflammatory cytokines. The effects of those contaminants on the integrity of the gut barrier and the inflammatory response were analyzed. Since the co-culture responded to inflammatory stimulation, we investigated whether this model could be used to evaluate the effects of food contaminants on the human intestinal epithelium. CPF alone affected tight junctions’ gene expression, without inducing any inflammation or alteration of intestinal permeability. CML and acrylamide decreased mucins gene expression in the intestinal mucosa, but did not affect paracellular intestinal permeability. CML exposure activated the gene expression of MAPK pathways. The co-culture response was stable over time. This cocktail of food contaminants may thus alter the gut barrier function.

Treating the Metabolic Syndrome by Fecal Transplantation-Current Status.

Simple SummaryThe term “gut microbiome” refers to the microbial inhabitants whuch populate the intestine, including their number and diversity. In this review, we elaborate on how the microbiome affects the balance of pro- and anti-inflammatory responses in the gut. This ecosystem also influences systemic immunity. An imbalance of the microbiome is implicated in a number of inflammatory conditions, ranging from diabetes and metabolic disorders to non-alcoholic liver disease, cirrhosis, and liver cancer. A high dietary intake of animal-based processed foods and sugar is linked to a gut microbiome containing a higher volume of ‘opportunistic’ bacterial species, including the Firmicutes sp. and Ruminococcus sp., which are involved in pro-inflammatory activity. A diet rich in plant- and fish-based foods is linked to gut microbes that have the opposite effect by enhancing species such as the Faecalibacterium sp., which produce short-chain fatty acids that help control inflammation and protect the cells lining the gut. We also discuss fecal microbiome transplant as a modality to modify intestinal inflammatory processes via the changes in the gut microbiome.The intestinal microbiome (IM) is important for normal gastrointestinal (GI) and other organ systems’ functioning. An alteration in the normal IM, dysbiosis, and changes in intestinal motility result in microorganisms’ overgrowth and an alteration in intestinal permeability. The gut–brain axis is also of importance in the irritable bowel syndrome (IBS) and associated bowel overgrowth. Secondary to the epidemic of obesity, the metabolic syndrome has become a major health problem. Disturbances in the fecal microbiome are associated with the metabolic syndrome. Metabolic-associated fatty liver disease (MAFLD) is now the current terminology for non-alcoholic fatty liver disease. IM alteration by fecal transplantation is an approved treatment method for recurrent Clostridioides difficile infection. Initially performed by either duodenal infusion or colonoscopy, it is now easily performed by the administration of capsules containing stools. We discuss the intestinal microbiome—its composition, as well as the qualitative changes of microbiome composition leading to inflammation. In addition, we discuss the evidence of the effect of fecal transplantation on the metabolic syndrome and MAFLD, as well as its clinical indications.

POS0329 GASTROINTESTINAL INVOLVEMENT IN SYSTEMIC SCLEROSIS: PATHOGENETIC ROLE OF GUT MICROBIOME, CYTOKINES AND ADIPOKINES

Background:Gastrointestinal (GI) involvement is very common in patients with Systemic Sclerosis (SSc). The pathophysiology of GI manifestations has not yet been defined. Cell-mediated immunological reactions appear to lead to endothelial damage resulting in fibrosis. The risk of developing malnutrition reinforces the need to better understand GI pathophysiology in these patients.Objectives:The study aimed to evaluate GI symptoms (GIT 2.0) and malnutrition status (MUST) and to determine specific bacterial changes in gut microbiome by investigating the possible presence of positive hot spots in bacterial species in SSc patients and their potential role in the disease progression. We also evaluated serum levels of adipokines and cytokines involved in the pathogenesis of SSc and their role, in addition to gut microbiome, in predicting the onset of GI involvement and malnutrition in SSc patients.Methods:We enrolled 25 scleroderma patients (EULAR/ACR 2013 criteria). UCLA-SCTC GIT 2.0 questionnaire to evaluate GI symptoms and MUST to investigate the risk of malnutrition were used. Gut microbiome was analyzed and the samples were subjected to extraction for the 16S rRNA gene (Earth Microbiome Project and the NIH-Human Microbiome Project). The microbiome was investigated at phenotypic and genotypic level. Serum levels of cytokines and adipokines (adiponectin and leptin) were evaluated by ELISA.Results:79.9% of patients had GERD and 63.5% abdominal distension at GIT 2.0 questionnaires. 48% of patients had moderate risk of malnutrition (MUST=2) and 12% had high risk (MUST=3). Gut microbioma: 19 patients (76%) had low similarity and 11 (44%) low diversity compared to the healthy population. The prevailing enterotypes of gut microbiome was Bacteroides (80%) and Prevotella (20%). The genotypic evaluation showed a reduced concentration of: gluten-digesting (Lactobacillus); lactose-digesting (Faecalibacterium); vitamin K-producing (Enterococcus, Desulfovibrio and Veillonella); acetaldehyde-degrading bacteria. 24 patients (96%) showed a reduction in bacteria devoted to maintaining weight control (Bifidobacterium and Ruminococcus). The patients had an altered intestinal permeability with less mucolytic bacteria (Bacteroides) and reduced production of LPS (Enterobacter and Escherichia). Low levels of butyrate (Eubacterium and Clostridium), acetate and propionate were found for SCFA-producing bacteria. Potentially pathogenic bacteria were also investigated: Salmonella was found in 14 (56%), Klebsiella in 9 (36%) and Enterococcus Faecalis in 3 (12%) patients. 11 (44%) patients had elevated serum levels of IL10 and IL12; 4 (16%) had high value of leptin. Correlation was found in patients who had a reduced concentration of gluten-digesting bacteria and MUST. Elevated MUST was correlated with serological increase in IL17A and IFN-α. Serum levels of IL12 and IL10 were found to correlate with specific bacteria alterations: high concentration of acetaldehyde-producing bacteria and low levels of acetaldehyde-degrade bacteria (also correlated with high serum levels of IL6), mucolytic bacteria and producers of hydrogen sulphide, acetate and propionate. Finally, reduced levels of mucolytic bacteria and acetate producing bacteria correlated with high serum leptin levels.Conclusion:The relationship between the gut microbiome and SSc seems to be multifactorial. In our study genotypic changes of gut microbioma might play a role in damaging the permeability of the mucosa and increasing risk of malnutrition. The evaluation of gut microbiome and cytokine profile is probably going to be of value in the follow-up of SSc. However, further studies are needed to clarify the impact of GI dysbiosis on the immune system in SSc.