| 1. |
- Bennet, Sean M. P., et al.
(författare)
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Multivariate modelling of faecal bacterial profiles of patients with IBS predicts responsiveness to a diet low in FODMAPs
- 2018
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Ingår i: Gut. - : BMJ Publishing Group Ltd. - 0017-5749 .- 1468-3288. ; 67:5, s. 872-881
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Tidskriftsartikel (refereegranskat)abstract
- Objective The effects of dietary interventions on gut bacteria are ambiguous. Following a previous intervention study, we aimed to determine how differing diets impact gut bacteria and if bacterial profiles predict intervention response. Design Sixty-seven patients with IBS were randomised to traditional IBS (n=34) or low fermentable oligosaccharides, disaccharides, monosaccharides and polyols (FODMAPs) (n=33) diets for 4 weeks. Food intake was recorded for 4 days during screening and intervention. Faecal samples and IBS Symptom Severity Score (IBS-SSS) reports were collected before (baseline) and after intervention. A faecal microbiota dysbiosis test (GA-map Dysbiosis Test) evaluated bacterial composition. Per protocol analysis was performed on 61 patients from whom microbiome data were available. Results Responders (reduced IBS-SSS by >= 50) to low FODMAP, but not traditional, dietary intervention were discriminated from non-responders before and after intervention based on faecal bacterial profiles. Bacterial abundance tended to be higher in non-responders to a low FODMAP diet compared with responders before and after intervention. A low FODMAP intervention was associated with an increase in Dysbiosis Index (DI) scores in 42% of patients; while decreased DI scores were recorded in 33% of patients following a traditional IBS diet. Non-responders to a low FODMAP diet, but not a traditional IBS diet had higher DI scores than responders at baseline. Finally, while a traditional IBS diet was not associated with significant reduction of investigated bacteria, a low FODMAP diet was associated with reduced Bifidobacterium and Actinobacteria in patients, correlating with lactose consumption. Conclusions A low FODMAP, but not a traditional IBS diet may have significant impact on faecal bacteria. Responsiveness to a low FODMAP diet intervention may be predicted by faecal bacterial profiles.
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| 2. |
- Nybacka, Sanna, et al.
(författare)
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Neither self-reported atopy nor IgE-mediated allergy are linked to gastrointestinal symptoms in patients with irritable bowel syndrome
- 2018
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Ingår i: Neurogastroenterology and Motility. - : Wiley. - 1350-1925 .- 1365-2982. ; 30:10
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Tidskriftsartikel (refereegranskat)abstract
- BackgroundAmong patients with irritable bowel syndrome (IBS), atopic disease has been proposed as a common comorbidity increasing the IBS symptom burden. We therefore assessed the prevalence of self-reported atopy among patients with IBS as compared to non-IBS controls, and whether atopy and higher serum IgE levels were associated with increased IBS symptom severity. MethodsLevels of total and specific IgE in serum were measured and questionnaires assessing the presence of atopic disease (ie, eczema, asthma, rhinoconjunctivitis, and pollen allergy), gastrointestinal symptom burden, food intolerance, somatic, and psychological symptoms were completed. Key resultsIn total, 223 patients with IBS and 47 controls participated. Presence of atopic disease was reported in 55% of patients with IBS compared to 40% of controls (P=.07). IBS patients with atopic manifestations (N=123) had higher total serum IgE levels (median 31 vs 16 kU(A)/L, P<.001) and higher prevalence of self-reported food intolerance (28% vs 9%, P=.002) than non-atopic IBS patients (N=100), respectively, but no major difference in gastrointestinal or psychological symptom burden was noted. However, severe somatic symptoms were more common among atopic than non-atopic patients with IBS (38% vs 27%, P=.028). We found no associations between self-reported atopy and IBS symptom severity using linear regression models. Conclusions & InferencesAtopic disease is common in patients with IBS, but that is also true for subjects without IBS. The presence of atopic disease in IBS is associated with self-reported food intolerance and somatic symptom severity, but unrelated to IBS symptom severity.
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| 3. |
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| 4. |
- Ahluwalia, Bani, et al.
(författare)
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Effects of Aloe barbadensis Mill. extract (AVH200 (R)) on human blood T cell activity in vitro
- 2016
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Ingår i: Journal of Ethnopharmacology. - : Elsevier BV. - 0378-8741 .- 1872-7573. ; 179, s. 301-309
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Tidskriftsartikel (refereegranskat)abstract
- Ethnopharmacological relevance: Aloe barbadensis Mill. (Aloe vera) is a widely used medicinal plant well reputed for its diverse therapeutic applications. It has been used for thousands of years in folk medicine to treat various conditions and the Aloe vera gel has been reported to possess anti-inflammatory as well as immunostimulatory and immunomodulatory properties. However, the mode of action is still unclear. Aim of the study: The aim of this study was determine the effects of two well-defined A. barbadensis Mill. extracts AVH200 (R) and AVE200 on human blood T cells in vitro. Materials and methods: Peripheral blood mononuclear cells (PBMC) from healthy donors were stimulated polyclonally in the presence or absence of AVH200 (R) and AVE200. The T cell phenotype was investigated by flow cytometry, cell proliferation was determined by CFSE dye and thymidine assay, respectively and cytokine secretion was determined by MSD (R) Multi-Spot Assay system and ELISA. Results: The presence of AVH200 (R) resulted in a reduced expression of CD25 among CD3(+) T cells and suppression of T cell proliferation in a dose dependent manner. Furthermore, AVH200 (R) reduced the expression of CD28 on CD3(+) T cells. AVH200 (R) also reduced the secretion of IL-2, IFN-gamma and IL-17A in PBMC cultures. The AVH200 (R) dose dependent reduction in T cell activation and proliferation recorded in the cell cultures was not due to apoptosis or cell death. Additionally, AVH200 (R) was found to be more effective as compared to AVE200 in reducing T cell activation and proliferation. Conclusion: AVH200 (R) has the potential to reduce the activation, proliferation and cytokine secretion of healthy human blood T cells. Our study suggests that AVH200 (R) has a suppressive effect on human blood T cells in vitro.
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| 5. |
- Ahluwalia, Bani, et al.
(författare)
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Immunopathogenesis of inflammatory bowel disease and mechanisms of biological therapies
- 2018
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Ingår i: Scandinavian Journal of Gastroenterology. - : Informa UK Limited. - 0036-5521 .- 1502-7708. ; 53:4, s. 379-389
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Tidskriftsartikel (refereegranskat)abstract
- Inflammatory bowel disease (IBD) is a chronic inflammatory disorder of the gastrointestinal tract with a multifactorial pathophysiology. Full comprehension of IBD pathology is still out of reach and, therefore, treatment is far from ideal. Nevertheless, components involved in IBD pathogenesis including environmental, genetic, microbial, and immunological factors are continuously being investigated and the improved knowledge contributes to the development of new therapies. In this article we review the aspects of the immunopathogenesis of IBD, with focus on mucosal immunity, and discuss mechanisms of action for current and emerging biological therapies.
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| 6. |
- Ahluwalia, Bani, et al.
(författare)
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Mucosal immune system of the gastrointestinal tract: maintaining balance between the good and the bad
- 2017
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Ingår i: Scandinavian Journal of Gastroenterology. - : Informa UK Limited. - 0036-5521 .- 1502-7708. ; 52:11, s. 1185-1193
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Tidskriftsartikel (refereegranskat)abstract
- The gastrointestinal tract (GI tract) is a unique organ inhabited by a range of commensal microbes, while also being exposed to an overwhelming load of antigens in the form of dietary antigens on a daily basis. The GI tract has dual roles in the body, in that it performs digestion and uptake of nutrients while also carrying out the complex and important task of maintaining immune homeostasis, i.e., keeping the balance between the good and the bad. It is equally important that we protect ourselves from reacting against the good, meaning that we stay tolerant to harmless food, commensal bacteria and self-antigens, as well as react with force against the bad, meaning induction of immune responses against harmful microorganisms. This complex task is achieved through the presence of a highly efficient mucosal barrier and a specialized multifaceted immune system, made up of a large population of scattered immune cells and organized lymphoid tissues termed the gut-associated lymphoid tissue (GALT). This review provides an overview of the primary components of the human mucosal immune system and how the immune responses in the GI tract are coordinated and induced. © 2017 Informa UK Limited, trading as Taylor & Francis Group.
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| 7. |
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| 8. |
- Barbara, G., et al.
(författare)
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Rome Foundation Working Team Report on Post-Infection Irritable Bowel Syndrome
- 2019
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Ingår i: Gastroenterology. - : Elsevier BV. - 0016-5085. ; 156:1
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND & AIMS: The existence of postinfection irritable bowel syndrome (PI-IBS) has been substantiated by epidemiology studies conducted in diverse geographic and clinical settings. However, the available evidence has not been well summarized, and there is little guidance for diagnosis and treatment of PI-IBS. The ROME Foundation has produced a working team report to summarize the available evidence on the pathophysiology of PI-IBS and provide guidance for diagnosis and treatment, based on findings reported in the literature and clinical experience. METHODS: The working team conducted an evidence-based review of publication databases for articles describing the clinical features (diagnosis), pathophysiology (intestinal sensorimotor function, microbiota, immune dysregulation, barrier dysfunction, enteroendocrine pathways, and genetics), and animal models of PI-IBS. We used a Delphi-based consensus system to create guidelines for management of PI-IBS and a developed treatment algorithm based on published findings and experiences of team members. RESULTS: PI-IBS develops in about 10% of patients with infectious enteritis. Risk factors include female sex, younger age, psychological distress during or before acute gastroenteritis, and severity of the acute episode. The pathogenesis of PI-PBS appears to involve changes in the intestinal microbiome as well as epithelial, serotonergic, and immune system factors. However, these mechanisms are incompletely understood. There are no evidence-based, effective pharmacologic strategies for treatment of PI-IBS. We provide a consensus-based treatment algorithm, based on clinical presentation and potential disease mechanisms. CONCLUSIONS: Based on a systematic review of the literature and team experience, we summarize the clinical features, pathophysiology (from animal models and human studies), and progression of PI-IBS. Based on these findings, we present an algorithm for diagnosis and treatment of PI-IBS based on team consensus. We also propose areas for future investigation.
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| 9. |
- Bashashati, M, et al.
(författare)
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Colonic immune cells in irritable bowel syndrome: A systematic review and meta-analysis.
- 2018
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Ingår i: Neurogastroenterology and motility : the official journal of the European Gastrointestinal Motility Society. - : Wiley. - 1365-2982. ; 30:1
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Tidskriftsartikel (refereegranskat)abstract
- Increases in mucosal immune cells have frequently been observed in irritable bowel syndrome (IBS) patients. However, this finding is not completely consistent between studies, possibly due to a combination of methodological variability, population differences and small sample sizes. We performed a meta-analysis of case-control studies that compared immune cell counts in colonic biopsies of IBS patients and controls.PubMed and Embase were searched in February 2017. Results were pooled using standardized mean difference (SMD) and were considered significant when zero was not within the 95% confidence interval (CI). Heterogeneity was assessed based on I2 statistics where I2 ≤50% and I2 >50% indicated fixed and random effect models, respectively.Twenty-two studies on 706 IBS patients and 401 controls were included. Mast cells were increased in the rectosigmoid (SMD: 0.38 [95% CI: 0.06-0.71]; P=.02) and descending colon (SMD: 1.69 [95% CI: 0.65-2.73]; P=.001) of IBS patients. Increased mast cells were observed in both constipation (IBS-C) and diarrhea predominant IBS (IBS-D). CD3+ T cells were increased in the rectosigmoid (SMD: 0.53 [95% CI: 0.21-0.85]; P=.001) and the descending colon of the IBS patients (SMD: 0.79, 95% CI [0.28-1.30]; P=.002). This was possibly in relation to higher CD4+ T cells in IBS (SMD: 0.33 [95% CI: 0.01-0.65]; P=.04) as there were no differences in CD8+ T cells.Mast cells and CD3+ T cells are increased in colonic biopsies of patients with IBS vs non-inflamed controls. These changes are segmental and sometimes IBS-subtype dependent. The diagnostic value of the quantification of colonic mucosal cells in IBS requires further investigation.
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| 10. |
- Bennet, Sean, et al.
(författare)
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Altered intestinal antibacterial gene expression response profile in irritable bowel syndrome is linked to bacterial composition and immune activation
- 2018
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Ingår i: Neurogastroenterology and Motility. - : Wiley. - 1350-1925. ; 30:12
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Tidskriftsartikel (refereegranskat)abstract
- Background Immune activity and gut microbiota may impact the pathophysiology of irritable bowel syndrome (IBS). We aimed to determine whether antibacterial gene expression of immune activity-defined IBS patients differed compared to healthy subjects (HS) and ulcerative colitis (UC) patients and whether antibacterial profiles reflected gut microbiota composition and IBS symptoms. Methods Key Results Expression of 84 antibacterial genes in biopsies from HS, IBS patients (clustered according to immune activity (systemic and intestinal cytokines): immunonormal or immunoactive), and UC patients was assessed by Human Antibacterial Response RT2 Profiler PCR Array. In IBS patients, 16S rRNA gene sequencing of fecal and mucosal bacteria was performed and symptom pattern and severity were assessed. Intestinal antibacterial gene expression profiles differed between IBS patients (n = 31) and HS (n = 16), but did not differ between IBS subgroups based on bowel habit predominance or symptom severity. Based on previously identified IBS clusters, IBS patients with normal (n = 15) and enhanced immune activity (n = 16) had clearly separate antibacterial gene expression profiles from active UC patients (n = 12) and differed compared to each other and to HS. The differences in antibacterial gene expression profiles between immunonormal and immunoactive IBS patients were also reflected in distinct fecal and mucosal microbiota composition profiles, but not in symptom pattern or severity. Conclusions & Inferences This study demonstrates an altered antibacterial gene expression profile in IBS patients compared to HS and UC patients. While not linked to symptoms, immune activity-defined IBS clusters showed different intestinal antibacterial gene expression and distinct fecal and mucosal bacterial profiles.
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