Mucosal Plasma Cell Activation and Proximity to Nerve Fibres Are Associated with Glycocalyx Reduction in Diarrhoea-Predominant Irritable Bowel Syndrome: Jejunal Barrier Alterations Underlying Clinical Manifestations

Intestinal barrier dysfunction; Intestinal glycocalyx; Mucosal nerve fibresDisfunción de la barrera intestinal; Glicocálix intestinal; Fibras nerviosas de la mucosaDisfunció de la barrera intestinal; Glicocàlix intestinal; Fibres nervioses de la mucosaIrritable bowel syndrome (IBS) is a disorder of brain-gut interaction characterised by abdominal pain and changes in bowel habits. In the diarrhoea subtype (IBS-D), altered epithelial barrier and mucosal immune activation are associated with clinical manifestations. We aimed to further evaluate plasma cells and epithelial integrity to gain understanding of IBS-D pathophysiology. One mucosal jejunal biopsy and one stool sample were obtained from healthy controls and IBS-D patients. Gastrointestinal symptoms, stress, and depression scores were recorded. In the jejunal mucosa, RNAseq and gene set enrichment analyses were performed. A morphometric analysis by electron microscopy quantified plasma cell activation and proximity to enteric nerves and glycocalyx thickness. Immunoglobulins concentration was assessed in the stool. IBS-D patients showed differential expression of humoral pathways compared to controls. Activation and proximity of plasma cells to nerves and IgG concentration were also higher in IBS-D. Glycocalyx thickness was lower in IBS-D compared to controls, and this reduction correlated with plasma cell activation, proximity to nerves, and clinical symptoms. These results support humoral activity and loss of epithelial integrity as important contributors to gut dysfunction and clinical manifestations in IBS-D. Additional studies are needed to identify the triggers of these alterations to better define IBS-D pathophysiology.This study was funded in part by Fondo Europeo de Desarrollo Regional (FEDER), Fondo de Investigación Sanitaria and Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBEREHD), Instituto de Salud Carlos III, Subdirección General de Investigación Sanitaria, Ministerio de Economía y Competitividad: CP18/00116 (C.M.), PI19/01643 (B.L.); PI17/01443 (D.G.); PI15/00301 (C.A.-C.), PI17/0190 (J.S.), PI19/01643 & CPII16/00031, (M.V.); CIBEREHD CB06/04/0021 (F.A., C.A.-C., J.S., M.V.); Ministerio de Educación, Dirección General de Investigación: SAF 2016-76648-R (F.A.); Agència de Gestió d’Ajuts Universitaris i de Recerca, de la Generalitat de Catalunya: 2014 SGR 1285 (F.A.); Vall d’Hebron Institut de Recerca, Programa de becas predoctorales Amics de Vall d’Hebron: PRED-VHIR-2016-34 (C.P.-C.), PRED-VHIR-2014-018 (M.F.), the Swedish Research Council dnr 2019-00653 (J.-P.G.M.), and the European Union’s Horizon research and innovation programme 2020, grant no. 848228 (E.E., A.R.-U., B.L., C.A.-C., J.S.)

Non-digestible Polysaccharides and Intestinal Barrier Function : specific focus on its efficacy in elderly and patients with Crohn’s disease

A large number of elderly suffer from gastrointestinal (GI) symptoms such as constipation and diarrhoea. The underlying mechanisms of age-acquired GI symptoms are not well studied but are necessary to clarify in order to recommend the right treatment. Non-digestible polysaccharides (NPS) are dietary fibres that could have beneficial effects on the intestinal immune system and barrier function, although their efficacy needs to be evaluated. Paper I showed that elderly with GI symptoms have significantly higher small intestinal permeability than a general elderly population, along with a stronger association to psychological distress. In Paper II we performed a randomised controlled trial with a general population of elderly that consumed either placebo, the NPS’s arabinoxylan or oat β-glucan for a period of 6 weeks. No protective effects were observed related to indomethacin-induced intestinal hyperpermeability, inflammatory markers, or self-reported health if compared to placebo. Paper III showed that stimulation with a yeast-derived β-glucan significantly attenuated Compound (C) 48/80-induced hyperpermeability in colonic biopsies from elderly with GI symptoms mounted in Ussing chambers, but not in young healthy adults. Arabinoxylan attenuated only C48/80-induced transcellular permeability in elderly but both paracellular and transcellular permeability in young healthy adults. Paper IV showed that the same yeast-derived β-glucan from paper III could cross the epithelium of ileal tissues from patients with Crohn’s disease (CD) and non-CD controls, mounted in Ussing chambers, and attenuate C48/80-induced hyperpermeability. In conclusion, we found that elderly with GI symptoms display a deteriorated barrier function and that administration of selective NPS can have beneficial effect on intestinal permeability in selective populations

Are self-reported gastrointestinal symptoms among older adults associated with increased intestinal permeability and psychological distress?

Background: Despite the substantial number of older adults suffering from gastrointestinal (GI) symptoms little is known regarding the character of these complaints and whether they are associated with an altered intestinal barrier function and psychological distress. Our aim was to explore the relationship between self-reported gut health, intestinal permeability and psychological distress among older adults. Methods: Three study populations were included: 1) older adults with GI symptoms (n = 24), 2) a group of older adults representing the general elderly population in Sweden (n = 22) and 3) senior orienteering athletes as a potential model of healthy ageing (n = 27). Questionnaire data on gut-health, psychological distress and level of physical activity were collected. Intestinal permeability was measured by quantifying zonulin in plasma. The level of systemic and local inflammation was monitored by measuring C-reactive protein (CRP), hydrogen peroxide in plasma and calprotectin in stool samples. The relationship between biomarkers and questionnaire data in the different study populations was illustrated using a Principal Component Analysis (PCA). Results: Older adults with GI symptoms displayed significantly higher levels of both zonulin and psychological distress than both general older adults and senior orienteering athletes. The PCA analysis revealed a separation between senior orienteering athletes and older adults with GI symptoms and showed an association between GI symptoms, psychological distress and zonulin. Conclusions: Older adults with GI symptoms express increased plasma levels of zonulin, which might reflect an augmented intestinal permeability. In addition, this group suffer from higher psychological distress compared to general older adults and senior orienteering athletes. This relationship was further confirmed by a PCA plot, which illustrated an association between GI symptoms, psychological distress and intestinal permeability.Funding Agencies|Bo Rydins stiftelse [F0514]; Knowledge Foundation [20110225]; Faculty of Medicine and Health at Orebro University; Diarrheal Disease Research Centre, Linkoping University</p

Effects of Dietary Fibres on Acute Indomethacin-Induced Intestinal Hyperpermeability in the Elderly: A Randomised Placebo Controlled Parallel Clinical Trial

The effect of dietary fibres on intestinal barrier function has not been well studied, especially in the elderly. We aimed to investigate the potential of the dietary fibres oat beta-glucan and wheat arabinoxylan to strengthen the intestinal barrier function and counteract acute non-steroid anti-inflammatory drug (indomethacin)-induced hyperpermeability in the elderly. A general population of elderly subjects (&amp;gt;= 65 years,n= 49) was randomised to a daily supplementation (12g/day) of oat beta-glucan, arabinoxylan or placebo (maltodextrin) for six weeks. The primary outcome was change in acute indomethacin-induced intestinal permeability from baseline, assessed by an in vivo multi-sugar permeability test. Secondary outcomes were changes from baseline in: gut microbiota composition, systemic inflammatory status and self-reported health. Despite a majority of the study population (85%) showing a habitual fibre intake below the recommendation, no significant effects on acute indomethacin-induced intestinal hyperpermeability in vivo or gut microbiota composition were observed after six weeks intervention with either dietary fibre, compared to placebo.Funding Agencies|European UnionEuropean Union (EU) [289517]; Bo Rydin foundation [F0514]</p

Present and Future Therapeutic Approaches to Barrier Dysfunction

There is converging and increasing evidence, but also uncertainty, for the role of abnormal intestinal epithelial barrier function in the origin and development of a growing number of human gastrointestinal and extraintestinal inflammatory disorders, and their related complaints. Despite a vast literature addressing factors and mechanisms underlying changes in intestinal permeability in humans, and its connection to the appearance and severity of clinical symptoms, the ultimate link remains to be established in many cases. Accordingly, there are no directives or clinical guidelines related to the therapeutic management of intestinal permeability disorders that allow health professionals involved in the management of these patients to carry out a consensus treatment based on clinical evidence. Instead, there are multiple pseudoscientific approaches and commercial propaganda scattered on the internet that confuse those affected and health professionals and that often lack scientific rigor. Therefore, in this review we aim to shed light on the different therapeutic options, which include, among others, dietary management, nutraceuticals and medical devices, microbiota and drugs, and epigenetic and exosomes-manipulation, through an objective evaluation of the scientific publications in this field. Advances in the knowledge and management of intestinal permeability will sure enable better options of dealing with this group of common disorders to enhance quality of life of those affected.Funding Agencies|Fondo Europeo de Desarrollo Regional (FEDER)European Commission; Fondo de Investigacion SanitariaInstituto de Salud Carlos III; Instituto de Salud Carlos III, Subdireccion General de Investigacion Sanitaria, Ministerio de Economia y Competitividad, Ajuts per a la contractacio de personal investigador FI-Agencia de Gestio dAjuts Universitaris i de Recerca (AGAUR); Generalitat de CatalunyaGeneralitat de CatalunyaGeneral Electric; Swedish Research CouncilSwedish Research CouncilEuropean Commission; European Commision [PI19/0164, FI20/00256, 2020FI_B1 00127, 2019FI_B 00817, PI17/0190, CIBERehd CB06/04/0021, 2019-00653, :848228]; FWO (Fonds Wetenschappelijk Onderzoek)FWO [G.093818]; KU LeuvenKU Leuven; Centro de Investigacion Biomedica en Red de Enfermedades Hepaticas y Digestivas (CIBEREHD)</p