European Crohn's and Colitis Organisation Topical Review on Environmental Factors in IBD

Dynamic changes in the gut microbiota composition during adalimumab therapy in patients with ulcerative colitis: implications for treatment response prediction and therapeutic targets

BACKGROUND

While significant research exists on gut microbiota changes after anti-tumor necrosis factor-alpha (anti TNF-α) therapy for ulcerative colitis, little is known about the longitudinal changes related to the effects of anti TNF-α. This study aimed to investigate the dynamics of gut microbiome changes during anti TNF-α (adalimumab) therapy in patients with ulcerative colitis (UC).

RESULTS

The microbiota composition was affected by the disease severity and extent in patients with UC. Regardless of clinical remission status at each time point, patients with UC exhibited microbial community distinctions from healthy controls. Distinct amplicon sequence variants (ASVs) differences were identified throughout the course of Adalimumab (ADA) treatment at each time point. A notable reduction in gut microbiome dissimilarity was observed only in remitters. Remitters demonstrated a decrease in the relative abundances of Burkholderia-Caballeronia-Paraburkholderia and Staphylococcus as the treatment progressed. Additionally, there was an observed increase in the relative abundances of Bifidobacterium and Dorea. Given the distribution of the 48 ASVs with high or low relative abundances in the pre-treatment samples according to clinical remission at week 8, a clinical remission at week 8 with a sensitivity and specificity of 72.4% and 84.3%, respectively, was predicted on the receiver operating characteristic curve (area under the curve, 0.851).

CONCLUSIONS

The gut microbiota undergoes diverse changes according to the treatment response during ADA treatment. These changes provide insights into predicting treatment responses to ADA and offer new therapeutic targets for UC.

Potential of algae-derived alginate oligosaccharides and β-glucan to counter inflammation in adult zebrafish intestine

Alginate oligosaccharides (AOS) are natural bioactive compounds with anti-inflammatory properties. We performed a feeding trial employing a zebrafish (Danio rerio) model of soybean-induced intestinal inflammation. Five groups of fish were fed different diets: a control (CT) diet, a soybean meal (SBM) diet, a soybean meal+β-glucan (BG) diet and 2 soybean meal+AOS diets (alginate products differing in the content of low molecular weight fractions - AL, with 31% < 3kDa and AH, with 3% < 3kDa). We analyzed the intestinal transcriptomic and plasma metabolomic profiles of the study groups. In addition, we assessed the expression of inflammatory marker genes and histological alterations in the intestine. Dietary algal β-(1, 3)-glucan and AOS were able to bring the expression of certain inflammatory genes altered by dietary SBM to a level similar to that in the control group. Intestinal transcriptomic analysis indicated that dietary SBM changed the expression of genes linked to inflammation, endoplasmic reticulum, reproduction and cell motility. The AL diet suppressed the expression of genes related to complement activation, inflammatory and humoral response, which can likely have an inflammation alleviation effect. On the other hand, the AH diet reduced the expression of genes, causing an enrichment of negative regulation of immune system process. The BG diet suppressed several immune genes linked to the endopeptidase activity and proteolysis. The plasma metabolomic profile further revealed that dietary SBM can alter inflammation-linked metabolites such as itaconic acid, taurochenodeoxycholic acid and enriched the arginine biosynthesis pathway. The diet AL helped in elevating one of the short chain fatty acids, namely 2-hydroxybutyric acid while the BG diet increased the abundance of a vitamin, pantothenic acid. Histological evaluation revealed the advantage of the AL diet: it increased the goblet cell number and length of villi of the intestinal mucosa. Overall, our results indicate that dietary AOS with an appropriate amount of < 3kDa can stall the inflammatory responses in zebrafish.

Protective Effects of Phoenixin-14 Peptide in the Indomethacin-Induced Duodenal Ulcer: An Experimental Study

Phoenixin-14‎ (PNX‎-14‎) is a newly identified neuropeptide with potential anti-inflammatory effects in the gastrointestinal tract. In this study, we evaluated the protective effect of PNX-14 against the formation of experimental indomethacin (IND)-induced duodenal ulcer. Thirty-two‎ male Sprague-Dawley rats were randomly assigned to the four following study groups: (1) negative control (2) IND (7.5 mg/kg subcutaneous IND), (3) famotidine (FA) (7.5 mg/kg subcutaneous IND followed by 40 mg/kg intraperitoneal‎ FA), and (4) PNX-14 (7.5 mg/kg subcutaneous IND followed by 50 µ/kg intraperitoneal‎ PNX-14). Outcome measures included macroscopic evaluation of duodenal lesion, serum levels of IL-1ß, TNF-α, IL-6, and IL-12, and tissue biochemical parameters of oxidative stress, including malondialdehyde (MDA)‎‏,‏‎ myeloperoxidase ‎‎(MPO) activity, superoxide dismutase (SOD) ‎activity, and catalase activity. Results The macroscopic grade of duodenal lesions were significantly smaller in the PNX-14 group than in the IND group (p < 0.001). Serum inflammatory cytokines were significantly increased in the IND group. PNX-14 treatment significantly decreased the serum levels of inflammatory cytokines (p < 0.0001). Oxidative contents (MDA and MPO activity) were significantly smaller in the PNX-14 group compared with the IND group (p < 0.0001), while anti-oxidative contents (SOD and catalase activity) were significantly more (p < 0.0001). PNX-14 was superior to FA in several anti-inflammatory properties, such as inhibiting the release of inflammatory cytokines and increasing the catalase activity. PNX-14 showed significant protective effects against the formation of IND-induced duodenal ulcers. These results suggest a promising therapeutic implication for PNX-14 in the treatment of gastrointestinal inflammatory disorders.

[What is confirmed in the treatment of chronic inflammatory bowel diseases]

The prevalence of the chronic inflammatory bowel diseases (CIBD) Crohn's disease (CD) and ulcerative colitis (UC) is on the rise worldwide. In Germany CIBDs are also a significant healthcare problem. The pathogenesis is complex and involves genetic factors, environmental aspects and changes in the immunological constitution. Furthermore, the gut microbiota plays a role in the maintenance of intestinal inflammation. Fortunately, several new drugs, in particular biologicals, have been approved for the treatment of CIBDs. The treatment of UC is mainly based on 5‑aminosalicylic acid formulations, preferably as a topical form for distal colitis and proctitis as well as local budesonide formulations. In the case of extensive spread, high disease activity and refractory disease antibodies (biologicals) are successfully used, similar to CD. In addition to anti-tumor necrosis factor antibodies (infliximab, adalimumab, golimumab), vedolizumab, an anti-integrin antibody and the interleukin 12/23 antibody ustekinumab can be successfully used. The intravenous and also subcutaneous administration of antibodies are increasing in importance and are now available for all forms. Furthermore, the Janus kinase inhibitor tofacitinib is an orally administered option for UC. Clinical scores, endoscopy, ultrasound, laboratory parameters and calprotectin determination in stool are employed to evaluate treatment response (treat to target approach). Ultimately, the long-term goal is mucosal healing. Despite advances in the pharmaceutical treatment, a significant number of patients with CIBD still suffer from treatment refractory courses and need surgery at some time during the disease.

Factors Affecting Ulcerative Colitis Flare-Ups: Associations With Smoking Habits and Other Patient Characteristics

Background and study aims

Currently, there are no studies conducted in the Kingdom of Saudi Arabia (KSA) that have assessed the relationship between ulcerative colitis (UC) flare-ups and smoking. The present study aims to assess the risk of UC flare-ups and evaluate the relationship between UC flare-ups and smoking in adult patients following up at King Abdulaziz University Hospital in Jeddah, KSA.

Patients and methods

This was a retrospective study involving patients with confirmed UC between January 2015 and December 2020. Various information was examined, including demographic, clinical, endoscopic, radiologic, and laboratory data. Descriptive statistics were used for summarizing findings and a logistic regression analysis was applied to test for possible associations.

Results

Eighty-nine patients with UC were included in the study. Almost half (48.3%) had recurrent UC flare-ups during follow-up. A non-significant relationship was found between recurrent UC flares and all types of smoking habits (cigarette smoking, P = 0.15; shisha smoking, P = 0.88; and vape smoking, P = 0.09). Participants who were underweight (P = 0.041), had family history of UC (P = 0.013), depression (P = 0.033), fecal incontinence (P = 0.003), iron deficiency anemia (P = 0.009), or a malignancy (P = 0.039) had a significantly higher probability of experiencing recurrent flares. Binary logistic regressions revealed that family history of UC (OR = 5.3, P = 0.007) and fecal incontinence (OR = 4.7, P = 0.006) were associated significantly with recurrent flares.

Conclusion

There was no clear association between smoking and recurrent UC flares identified in this cohort. Of the variables considered, UC patients with fecal incontinence or family history of UC were at the highest risk of developing recurrent flares.

Diet as an environmental trigger in inflammatory bowel disease: a retrospective comparative study in two European cohorts

BACKGROUND AND AIMS

inflammatory bowel disease development has been associated with several environmental factors, among which, diet can play a key role, probably due to a westernized lifestyle. However, its involvement in the pathogenesis of inflammatory bowel disease (IBD) is difficult to demonstrate. The aim of this study was to analyze dietary composition in a Romanian and Belgian population with IBD.

METHODS

an observational retrospective comparative study was performed using two European cohorts (Romanian and Belgian). The IBD group included 76 Romanian and 53 Belgian patients with an IBD diagnosis, while the control group included a total of 56 healthy people (35 Romanians and 21 Belgians). All subjects were interviewed and asked to fill in a questionnaire regarding diet.

RESULTS

in the entire IBD cohort (Romanian + Belgian), a significantly increased consumption of sweets (OR 3.36 [95 % CI 1.6,7]), processed and high fat meat (OR 2.5 [95 % CI 1.4, 4.7], fried food (OR 9.5 [3.8, 23.6]), salt (OR 2.8 [1.5, 5.3]), ice cream (OR 3.25 [1.1, 9.8]), mayonnaise (OR 3.49 [1.1, 10.3]), margarine (OR 5.63 [1.64, 19.33]) and chips/nachos/other snacks (OR 2.3 [0.97, 5.73]) were found compared to the healthy control group. The intake of seeds, nuts (OR 0.26 [0.14, 0.52]) and yoghurt consumption (OR 0.44 [0.23, 0.83]) was lower in the IBD group compared to the control group.

CONCLUSION

a westernized diet with increased consumption of sweets, processed food, high fat meat, fried food, salt, margarine, snacks, ice cream and mayonnaise seems to be a risk factor for IBD in Romanian and Belgian IBD patients. Intake of seeds, nuts and yoghurt may be a protective factor.

Impact of Cigarette Smoking on the Risk of Osteoporosis in Inflammatory Bowel Diseases

Cigarette smoking constitutes one of the most important modifiable factors of osteoporosis, as well as contributes to an early death, tumors, and numerous chronic diseases. The group with an increased risk of a lower bone mineral density are patients suffering from inflammatory bowel diseases. In fact, tobacco smoke, which contains more than 7000 chemical compounds, affects bone mineral density (BMD) both directly and indirectly, as it has an impact on the RANK-RANKL-OPG pathway, intestinal microbiota composition, and calcium-phosphate balance. Constant cigarette use interferes with the production of protective mucus and inhibits the repair processes in the intestinal mucus. Nicotine as well as the other compounds of the cigarette smoke are important risk factors of the inflammatory bowel disease and osteoporosis. Additionally, cigarette smoking may decrease BMD in the IBD patients. Interestingly, it affects patients with Crohn's disease and ulcerative colitis in different ways-on the one hand it protects against ulcerative colitis, whereas on the other it increases the risk of Crohn's disease development. Nevertheless, all patients should be encouraged to cease smoking in order to decrease the risk of developing other disorders.

Is Psoriasis Treatment a Risk Factor for Inflammatory Bowel Disease?

Inflammatory bowel diseases—ulcerative colitis and Crohn’s disease—are linked with several environmental and genetic risk factors. There are also known drugs able to induce de novo disease or to exacerbate its course. Several autoimmune disorders are more frequent in patients with inflammatory bowel diseases, including psoriasis. The aim of the presented review was to summarise current knowledge on the links between psoriasis therapy and inflammatory bowel diseases. The interleukin-17 inhibitors (secukinumab, brodalumab and ixekizumab) and tumour necrosis factor inhibitor (etanercept), have the potential to induce ulcerative colitis and Crohn’s disease de novo or exacerbate existing but silent diseases. There is no evidence that other biologic agents used in psoriasis are lined with such risk. The biologic drugs for psoriasis differ in their potential to induce or worsen inflammatory bowel diseases. Currently, there are no recommendations in European guidelines to screen patients with psoriasis for inflammatory bowel diseases. However, based on available evidence, inflammatory bowel diseases should not be forgotten on in-depth diagnostics in patients with psoriasis.

Phages and Their Role in Gastrointestinal Disease: Focus on Inflammatory Bowel Disease

Inflammatory bowel diseases (IBDs) are a group of chronic autoinflammatory diseases including Crohn's disease and ulcerative colitis. Although the molecular mechanisms governing the pathogenesis of gastrointestinal inflammation are not completely clear, the main factors are presumed to be genetic predisposition, environmental exposure, and the intestinal microbiome. Hitherto, most of the studies focusing on the role of the microbiome studied the action and effect of bacteria. However, the intestinal microbiome comprises other members of the microbial community as well, namely, fungi, protozoa, and viruses. We believe that bacteriophages are among the main orchestrators of the effect of microbiota on the gut mucosa. Therefore, this review aims to summarize the knowledge of the role of intestinal phageome in IBD and to discuss the concept of phage therapy and its future applications.

Dietary Composition and Effects in Inflammatory Bowel Disease

Dramatic changes in the environment and human lifestyle have been associated with the rise of various chronic complex diseases, such as inflammatory bowel disease (IBD). A dysbiotic gut microbiota has been proposed as a crucial pathogenic element, contributing to immune imbalances and fostering a proinflammatory milieu, which may be associated with disease relapses or even the initiation of IBD. In addition to representing important regulators of the mucosal immunity and the composition of the gut microbiota, food components have been shown to be potential environmental triggers of epigenetic modifications. In the context of chronic intestinal inflammation, dietary habits and specific food components have been implicated as important modulators of epigenetic mechanisms, including DNA methylation, which may predispose a person to the increased risk of the initiation and evolution of IBD. This review provides novel insights about how dietary factors may interact with the intestinal mucosa and modulate immune homeostasis by shaping the intestinal ecosystem, as well as the potential influence of diet in the etiopathogenesis and management of IBD.

Westernized Diet is the Most Ubiquitous Environmental Factor in Inflammatory Bowel Disease

Inflammatory bowel disease (IBD), a collective term for Crohn disease and ulcerative colitis, is a polygenic disease thought to be triggered by environmental factors. A Western or westernized lifestyle may be a major driver of the growing incidence of IBD. IBD may represent dysregulated mucosal inflammation to gut microbiota. Despite many review articles on environmental factors in IBD, no consensus exists regarding which factor contributes most to trigger the onset of IBD. Identification and recognition of major environmental factors are prerequisite for effective disease treatment and prevention. Representative environmental factors such as smoking, breastfeeding, nonsteroidal anti-inflammatory drugs, antibiotic use in childhood, oral contraceptives, and appendectomy do not correlate with disease onset in most patients with IBD. In contrast, diet appears to be important in most cases of IBD. Diets rich in animal protein (risk factor) and deficient in dietary fiber (preventive factor) are characteristic of westernized diets in affluent societies. Recent research shows that westernized diets are associated with a reduced gut microbial diversity (dysbiosis), which may result in increased susceptibility to IBD and other common chronic diseases. Plant-based diets rich in dietary fiber are associated with increased microbial diversity. Recent reports on IBD therapy that replaced westernized diets with plant-based diets achieved far better outcomes than those previously reported in the literature. We believe that westernized diet-associated gut dysbiosis is the most ubiquitous environmental factor in IBD. Adoption of this concept may have the potential to provide a better quality of life for patients with IBD.

Dietary risk factors for inflammatory bowel diseases in a high-risk population: Results from the Faroese IBD study

Background

The Faroe Islands currently have the highest recorded inflammatory bowel disease (IBD) incidence in the world.

Objective

This study investigated environmental risk factors for IBD in the Faroese population.

Methods

Environmental exposure data including lifestyle risk factors and neurotoxicants collected for over 30 years were retrieved from the Children's Health and the Environment in the Faroes (CHEF) cohorts including mainly mother–child pairs, with exposure data collected from pregnant mothers. For lifestyle risk factors, the incidence of IBD and ulcerative colitis (UC) was calculated as the rate ratio (RR) with 95% confidence intervals (CI) in exposed versus non-exposed persons. For neurotoxicants RR was calculated for persons with high versus low exposure.

Results

Six cohorts included 5698 persons with complete follow-up data and at least one exposure, and 37 were diagnosed with IBD. For pilot whale/blubber, the RR was 1.02 (95% CI, 0.48–2.18); RR of 1.01 for fish (95% CI, 0.35–2.91); and of the pollutants studied, a statistical significantly increased risk was found for 1,1,1,-trichloro-2,2-bis-(p-chlorophenyl) ethane (p,p'-DDT); RR 3.04 (95% CI, 1.12–8.30). RRs were 1.96 (95% CI, 1.03–3.73) for smoking and 1.10 (95% CI, 0.55–2.19) for alcohol intake.

Conclusion

The high IBD incidence is unlikely to be caused by special dietary habits or by environmental pollutants.

Breath Analysis Using eNose and Ion Mobility Technology to Diagnose Inflammatory Bowel Disease-A Pilot Study

Early diagnosis of inflammatory bowel disease (IBD), including Crohn's disease (CD) and ulcerative colitis (UC), remains a clinical challenge with current tests being invasive and costly. The analysis of volatile organic compounds (VOCs) in exhaled breath and biomarkers in stool (faecal calprotectin (FCP)) show increasing potential as non-invasive diagnostic tools. The aim of this pilot study is to evaluate the efficacy of breath analysis and determine if FCP can be used as an additional non-invasive parameter to supplement breath results, for the diagnosis of IBD. Thirty-nine subjects were recruited (14 CD, 16 UC, 9 controls). Breath samples were analysed using an in-house built electronic nose (Wolf eNose) and commercial gas chromatograph-ion mobility spectrometer (G.A.S. BreathSpec GC-IMS). Both technologies could consistently separate IBD and controls [AUC ± 95%, sensitivity, specificity], eNose: [0.81, 0.67, 0.89]; GC-IMS: [0.93, 0.87, 0.89]. Furthermore, we could separate CD from UC, eNose: [0.88, 0.71, 0.88]; GC-IMS: [0.71, 0.86, 0.62]. Including FCP did not improve distinction between CD vs UC; eNose: [0.74, 1.00, 0.56], but rather, improved separation of CD vs controls and UC vs controls; eNose: [0.77, 0.55, 1.00] and [0.72, 0.89, 0.67] without FCP, [0.81, 0.73, 0.78] and [0.90, 1.00, 0.78] with FCP, respectively. These results confirm the utility of breath analysis to distinguish between IBD-related diagnostic groups. FCP does not add significant diagnostic value to breath analysis within this study.