Allergic and Immunologic Perspectives of Inflammatory Bowel Disease

Abstract

Inflammatory bowel disease (IBD) is a chronic immune-mediated inflammatory condition primarily involving the gastrointestinal tract. It includes Crohn's disease (CD), ulcerative colitis (UC), and a less common phenotype-indeterminate colitis. It is thought to result from a complex interplay of environmental, microbial, and host factors including genetic factors, although the exact mechanism is not known. Dietary factors have been shown to play a role in the pathogenesis of IBD and can potentially alter the intestinal microbiota as well as disrupt the immune function in the gut. CD is characterized by transmural inflammation, sometimes associated with granulomatous lesions, and involves the entire gastrointestinal tract but often spares the rectum. UC is characterized by mucosal inflammation typically confined to the colon and rectum. Although IBD is mostly seen in western world, recent data suggests that the incidence and prevalence are increasing worldwide. Enteral nutrition has been shown to be effective in inducing remission in pediatric population with CD; however, there is mixed data in adult population. Nutritional deficiencies such as vitamin D and zinc deficiency are often noted in IBD patients. Several extraintestinal manifestations are noted in patients with IBD. Some of them parallel with the disease activity and others are independent of the disease course. Assessment of IBD disease activity clinically, radiologically, if indicated, biochemically and endoscopically is important to guide therapy in IBD. To ensure comprehensive care, it is important to assess associated conditions such as nutritional and psychological well-being, as well as age appropriate health maintenance status prior to starting treatment for IBD. Several biologic agents including anti-tumor necrosis factor alpha (anti-TNF-α) drugs, anti-integrins, and antibodies to the p40 subunit of IL12/23 are approved for induction and maintenance of remission of IBD. Steroids are also often used for induction. Anti-metabolites and thiopurines are also useful either as monotherapy or in combination regimens. Potential side effects of anti-TNF-α drugs such as serious infections, malignancy, worsening of heart failure, and infusion-related reactions should be considered prior to starting these drugs. Anti-TNF-α drugs with or without immunomodulators (azathioprine, 6-mercaptopurine, methotrexate) are often used for the induction and maintenance of remission. Treating to target of endoscopic and clinical remission provides the best long-term outcomes. Our knowledge and understanding of IBD has grown significantly. However, there are several unanswered questions on pathogenesis, disease behavior, and drivers of inflammation in various patient subgroups which require further research.

The effects of fermentation products of prebiotic fibres on gut barrier and immune functions in vitro

“…Oat β-glucan 94% fermentation products led to a higher increase of cytokines and chemokines compared to oat β-glucan 28% fermentation products, suggesting that metabolites from oat β-glucan fermentation play an important role in modulating cytokine and chemokine productions. It is widely accepted that pro- and anti-inflammatory signals are both important for a balanced immune response ( Buckley & Rast, 2017 ; Clarke & Chintanaboina, 2018 ; Koboziev et al, 2015 ; Kotredes, Thomas & Gamero, 2017 ; Martin-Subero et al, 2016 ; Pott & Stockinger, 2017 ; Sarrabayrouse et al, 2015 ; Webb & Tait Wojno, 2017 ). Even if the modulated cytokines may exert both pro- and anti-inflammatory properties, our results clearly show that their expression is highly regulated by the fermentation supernatant of oat β-glucan 28% and oat β-glucan 94% in two of three donors.…”

Effect of Quercetin Monoglycosides on Oxidative Stress and Gut Microbiota Diversity in Mice with Dextran Sodium Sulphate-Induced Colitis

“…Inflammatory bowel disease (IBD) is a chronic immune system-mediated inflammatory disorder that comprises a range of conditions predominantly affecting the gastrointestinal tract [ 1 ]. These conditions include Crohn's disease, ulcerative colitis, and indeterminate colitis, a rare condition.…”

Farrerol Ameliorates TNBS-Induced Colonic Inflammation by Inhibiting ERK1/2, JNK1/2, and NF-κB Signaling Pathway

“…In this study, we found that Farrerol significantly improved the expression of claudin-1, occludin, and ZO-1 in colonic tissue from TNBS-induced mice. The mucus layer is mostly composed of mucin, defensin, and lecithin that is abundant in the colon and covers the outer epithelial surface to protect the mucosa [ 41 ]. The mucus layer contains an outer loose permeable layer that contacts commensal bacterial and an inner firm mucus layer that contacts the intestinal epithelium cells [ 42 ].…”