The urban diet and Crohn's disease: is there a relationship?

What if gastrointestinal complications in endurance athletes were gut injuries in response to a high consumption of ultra-processed foods? Please take care of your bugs if you want to improve endurance performance: a narrative review

To improve performance and recovery faster, athletes are advised to eat more often than usual and consume higher doses of simple carbohydrates, during and after exercise. Sports energetic supplements contain food additives, such as artificial sweeteners, emulsifiers, acidity regulators, preservatives, and salts, which could be harmful to the gut microbiota and impair the intestinal barrier function. The intestinal barrier plays a critical function in bidirectionally regulation of the selective transfer of nutrients, water, and electrolytes, while preventing at the same time, the entrance of harmful substances (selective permeability). The gut microbiota helps to the host to regulate intestinal homeostasis through metabolic, protective, and immune functions. Globally, the gut health is essential to maintain systemic homeostasis in athletes, and to ensure proper digestion, metabolization, and substrate absorption. Gastrointestinal complaints are an important cause of underperformance and dropout during endurance events. These complications are directly related to the loss of gut equilibrium, mainly linked to microbiota dysbiosis and leaky gut. In summary, athletes must be cautious with the elevated intake of ultra-processed foods and specifically those contained on sports nutrition supplements. This review points out the specific nutritional interventions that should be implemented and/or discontinued depending on individual gut functionality.

Olfactory Function in Patients with Inflammatory Bowel Disease (IBD) Is Associated with Their Body Mass Index and Polymorphism in the Odor Binding-Protein (OBPIIa) Gene

Smell strongly contributes to food choice and intake, influencing energy balance and body weight; its reduction or loss has been related to malnutrition problems. Some patients with inflammatory bowel disease (IBD), mainly Crohn’s disease (CD) and ulcerative colitis (UC), are underweight, while others are overweight. Some studies suggest that changes in eating habits could be linked to specific disorders of the olfactory functions. We assessed the olfactory performance in 199 subjects (healthy control (HC) n = 99, IBD n = 100), based on the olfactory Threshold, Discrimination and Identification score (TDI score), measured with the “Sniffin’ Sticks” test. Subjects were genotyped for the rs2590498 polymorphism of the OBPIIa gene. IBD patients showed both a slightly, but significantly, lower olfactory function and a higher BMI compared to HC subjects. Threshold (in both population) and Discrimination (in IBD patients) olfactory score were affected by the OBPIIa genotype. BMI was influenced by both health status and OBPIIa genotype. A lower olfactory function may delay the satiety sensation and thus increase meal duration and body weight in IBD patients. However, the AA genotype of the OBPIIa seems to “protect” IBD patients from more severe olfactory dysfunction.

Development and Validation of Surveys to Estimate Food Additive Intake

(1) Background: The Food Agricultural Organization/World Health Organization (FAO/WHO) International Food Standards Codex Alimentarius CXS 192e International Food Standards (hereafter, CODEX) declares additives non-toxic, but they have been associated with changes to the microbiota changes and thinning of the mucus layer of the gut. Their widespread use has occurred in parallel with increased inflammatory bowel disease (IBD) incidence. This paper reports on the development and validation of surveys to estimate additive intake. (2) Methods: Dietitians created a food-additive database, with a focus on additives that have been associated with IBD. For each additive, information on the CODEX food-category they are permitted in and the associated maximum permissible levels (mg/kg) was recorded. Based on the database, questions to assess early life (part 1) and recent (part 2) additive intake were written. Forward–backward translation from English to Chinese was undertaken. Thirty-one individuals were evaluated to assess understandability. A further fifty-seven individuals completed the tool on two occasions, a fortnight apart; agreement was assessed using Cohen’s kappa coefficient or the intra-class correlation coefficient (ICC). (3) Results: The participants reported that it was difficult to remember food intake and estimate portion sizes. The participants also noted confusion around the term ‘home-grown’. Instructions and definitions were added; after this, respondents judged the questionnaires as clear. The average kappa coefficient for part 1 and part 2 questions were 0.61 and 0.67, respectively. The average ICC ranged from 0.30 to 0.94; three food lists were removed due to low reliability. (4) Conclusions: Two tools have been created and validated, in two languages, that reliably assess remote and recent food additive intake.

Analysis of the Nutrients and Food Products Intake of Polish Males with Ulcerative Colitis in Remission

In spite of the lack of evidence of diet therapy efficacy to sustain remission of ulcerative colitis (UC), the dietary counseling may be beneficial, as a number of patients restrict intake of some products with no medical consultation. The aim of the present study was to analyze the nutrients and food products intake of Polish males with UC in remission in comparison with a control group. The UC group of 44 male patients with the confirmed remission, as well as the pair-matched group of 44 male controls, matched by their age and concurrent diseases, was recruited for the study. Their dietary intake was assessed based on three-day dietary records (to analyze the nutrients and food products intake) and information about food products excluded from their diet, and compared between respondents. It was observed that the intake of food products did not differ between the compared groups, except for the intake of potatoes and sugar, which was higher (p = 0.0033, p = 0.0092, respectively) in UC patients (median of 209 g and 11 g, respectively) than the control males (median of 100 g and 1 g, respectively). However, it did not influence differences of energy value and nutrients intake between groups, except for the intake of lactose and vitamin B₂ per 1000 kcal, which was lower (p = 0.0425, p = 0.0444, respectively) in UC patients (median of 1.8 g and 0.7 g/1000 kcal) than the control males (median of 3.6 g and 0.8 g/1000 kcal). It was observed that the differences in food products intake between the UC individuals in remission and healthy controls were only minor and did not contribute to any significant differences in their nutrients intake. It was concluded that UC patients should be educated not only about the potential influence of food products on their well-being but also about healthy diet recommendations.

Influence of environmental factors on the onset and course of inflammatory bowel disease

Numerous environmental factors have been linked with inflammatory bowel disease. These include smoking, diet, hygiene, drugs, geographical and psychosocial factors. These factors may either increase the risk of or protect against developing this condition and can also affect the course of illness in a positive or negative manner. A number of studies have examined the influence of environmental factors on inflammatory bowel diseases as a whole as well as on ulcerative colitis and Crohn’s disease separately. As there are differences in the pathogenesis of ulcerative colitis and Crohn’s disease, the effect of environmental factors on their onset and course is not always similar. Some factors have shown a consistent association, while reports on others have been conflicting. In this article we discuss the current evidence on the roles of these factors on inflammatory bowel disease, both as causative/protective agents and as modifiers of disease course.

Association between genetic polymorphisms in interferon regulatory factor 5 (IRF5) gene and Malaysian patients with Crohn's disease

OBJECTIVE

The study aimed to investigate the association between the interferon regulatory factor 5 (IRF5) gene polymorphisms and the onset of Crohn's disease (CD) in a Malaysian cohort.

METHODS

Genomic DNA was extracted from blood samples collected from 91 CD patients and 100 healthy individuals via a conventional phenol-chloroform extraction method. Screening of the four target single nucleotide polymorphisms (SNPs), including rs3807306, rs4728142, rs10954213 and rs11770589 was carried out in a real-time polymerase chain reaction (PCR) thermal cycler using TaqMan genotyping assay. The genetic data obtained was subsequently subjected to statistical analysis to relate the SNPs to the onset of CD in the Malaysian population. The genotyping assay and data were further validated selectively by conventional PCR amplification of the SNP sites and DNA sequencing.

RESULTS

The rs3807306 G allele was a risk factor for CD (OR 2.3630, P = 0.00004), whereas the homozygous T genotype was protective against the disease (OR 0.2038, P = 0.00004). The heterozygous A/G genotype of rs10954213 was significantly associated with CD (OR 4.319, P = 0.0377). On the other hand, the homozygous A and heterozygous A/G genotypes of the rs11770589 were significant in the controls (OR 0.4242, P = 0.0166) and patients (OR 2.000, P = 0.0179), respectively. In the ethnic-stratification analysis, the rs11770589 homozygous A genotype was protective in Indians (OR 0.1551, P = 0.0112).

CONCLUSION

IRF5 gene polymorphisms may play a role in the development of CD in the Malaysian population.

A 3D co-culture of three human cell lines to model the inflamed intestinal mucosa for safety testing of nanomaterials

Oral exposure to nanomaterials is a current concern, asking for innovative biological test systems to assess their safety, especially also in conditions of inflammatory disorders. Aim of this study was to develop a 3D intestinal model, consisting of Caco-2 cells and two human immune cell lines, suitable to assess nanomaterial toxicity, in either healthy or diseased conditions. Human macrophages (THP-1) and human dendritic cells (MUTZ-3) were embedded in a collagen scaffold and seeded on the apical side of transwell inserts. Caco-2 cells were seeded on top of this layer, forming a 3D model of the intestinal mucosa. Toxicity of engineered nanoparticles (NM101 TiO2, NM300 Ag, Au) was evaluated in non-inflamed and inflamed co-cultures, and also compared to non-inflamed Caco-2 monocultures. Inflammation was elicited by IL-1β, and interactions with engineered NPs were addressed by different endpoints. The 3D co-culture showed well preserved ultrastructure and significant barrier properties. Ag NPs were found to be more toxic than TiO2 or Au NPs. But once inflamed with IL-1β, the co-cultures released higher amounts of IL-8 compared to Caco-2 monocultures. However, the cytotoxicity of Ag NPs was higher in Caco-2 monocultures than in 3D co-cultures. The naturally higher IL-8 production in the co-cultures was enhanced even further by the Ag NPs. This study shows that it is possible to mimic inflamed conditions in a 3D co-culture model of the intestinal mucosa. The fact that it is based on three easily available human cell lines makes this model valuable to study the safety of nanomaterials in the context of inflammation.

Long-term clinical outcomes of urban versus rural environment in Korean patients with Crohn's disease: results from the CONNECT study

BACKGROUND AIMS

Environmental factors and genetic predisposition are thought to play important roles in the pathogenesis of Crohn's disease [CD]. Although numerous studies have reported the positive association between urban environment and CD development, few studies have compared the clinical outcomes between urban and rural environments. Therefore, this study aimed to compare the clinical characteristics and long-term prognosis between urban and rural populations of patients with CD.

METHODS

This retrospective multicenter cohort study included 1002 Korean patients diagnosed with CD [743 urban residents and 259 rural residents] between 1982 and 2008 from 32 medical centers. The clinical outcomes of urban versus rural populations were compared using the KaplanMeier method and log-rank test.

RESULTS

Disease distribution and behavior of the urban population did not differ from those of the rural population. There were no significant differences in the cumulative probabilities of perianal fistula [P = 0.086] and intestinal complications such as stricture [P = 0.109], fistula [P = 0.952], abscess [P = 0.227], and perforation [P = 0.382] between the two groups. In addition, no significant differences were observed between the two groups with regard to the cumulative probabilities of immunosuppressant use [P = 0.527] and biologic agent use [P = 0.731]. Although the cumulative probability of surgery in the urban population was significantly higher than that in the rural population [P = 0.040], this difference was mainly established within the first year from diagnosis [19.1% vs 13.5%, P = 0.042] and observed only among patients diagnosed in 2005-2008 [P = 0.033].

CONCLUSIONS

There were no differences in terms of disease presentation and natural history between urban and rural populations, except for a higher rate of surgery in the urban population who were recently diagnosed with CD.

Changes in intestinal tight junction permeability associated with industrial food additives explain the rising incidence of autoimmune disease

The incidence of autoimmune diseases is increasing along with the expansion of industrial food processing and food additive consumption. The intestinal epithelial barrier, with its intercellular tight junction, controls the equilibrium between tolerance and immunity to non-self-antigens. As a result, particular attention is being placed on the role of tight junction dysfunction in the pathogenesis of AD. Tight junction leakage is enhanced by many luminal components, commonly used industrial food additives being some of them. Glucose, salt, emulsifiers, organic solvents, gluten, microbial transglutaminase, and nanoparticles are extensively and increasingly used by the food industry, claim the manufacturers, to improve the qualities of food. However, all of the aforementioned additives increase intestinal permeability by breaching the integrity of tight junction paracellular transfer. In fact, tight junction dysfunction is common in multiple autoimmune diseases and the central part played by the tight junction in autoimmune diseases pathogenesis is extensively described. It is hypothesized that commonly used industrial food additives abrogate human epithelial barrier function, thus, increasing intestinal permeability through the opened tight junction, resulting in entry of foreign immunogenic antigens and activation of the autoimmune cascade. Future research on food additives exposure-intestinal permeability-autoimmunity interplay will enhance our knowledge of the common mechanisms associated with autoimmune progression.

Analysis of Gut Microbiome and Diet Modification in Patients with Crohn's Disease

OBJECTIVE

The human intestine harbors trillions of commensal microbes that live in homeostasis with the host immune system. Changes in the composition and complexity of gut microbial communities are seen in inflammatory bowel disease (IBD), indicating disruption in host-microbe interactions. Multiple factors including diet and inflammatory conditions alter the microbial complexity. The goal of this study was to develop an optimized methodology for fecal sample processing and to detect changes in the gut microbiota of patients with Crohn's disease receiving specialized diets.

DESIGN

Fecal samples were obtained from patients with Crohn's disease in a pilot diet crossover trial comparing the effects of a specific carbohydrate diet (SCD) versus a low residue diet (LRD) on the composition and complexity of the gut microbiota and resolution of IBD symptoms. The gut microbiota composition was assessed using a high-density DNA microarray PhyloChip.

RESULTS

DNA extraction from fecal samples using a column based method provided consistent results. The complexity of the gut microbiome was lower in IBD patients compared to healthy controls. An increased abundance of Bacteroides fragilis (B. fragilis) was observed in fecal samples from IBD positive patients. The temporal response of gut microbiome to the SCD resulted in an increased microbial diversity while the LRD diet was associated with reduced diversity of the microbial communities.

CONCLUSION

Changes in the composition and complexity of the gut microbiome were identified in response to specialized carbohydrate diet. The SCD was associated with restructuring of the gut microbial communities.

Place of upbringing in early childhood as related to inflammatory bowel diseases in adulthood: a population-based cohort study in Northern Europe

Background The two inflammatory bowel diseases (IBD), ulcerative colitis and Crohn's disease, has increased rapidly during the twentieth century, but the aetiology is still poorly understood. Impaired immunological competence due to decreasing biodiversity and altered microbial stimulation is a suggested explanation. Objective Place of upbringing was used as a proxy for the level and diversity of microbial stimulation to investigate the effects on the prevalence of IBD in adulthood. Methods Respiratory Health in Northern Europe (RHINE) III is a postal follow-up questionnaire of the European Community Respiratory Health Survey (ECRHS) cohorts established in 1989–1992. The study population was 10,864 subjects born 1945–1971 in Denmark, Norway, Sweden, Iceland and Estonia, who responded to questionnaires in 2000–2002 and 2010–2012. Data were analysed in logistic and Cox regression models taking age, sex, smoking and body mass index into consideration. Results Being born and raised on a livestock farm the first 5 years of life was associated with a lower risk of IBD compared to city living in logistic (OR 0.54, 95 % CI 0.31; 0.94) and Cox regression models (HR 0.55, 95 % CI 0.31; 0.98). Random-effect meta-analysis did not identify geographical difference in this association. Furthermore, there was a significant trend comparing livestock farm living, village and city living (p < 0.01). Sub-analyses showed that the protective effect was only present among subjects born after 1952 (OR 0.25, 95 % CI 0.11; 0.61). Conclusion This study suggests a protective effect from livestock farm living in early childhood on the occurrence of IBD in adulthood, however only among subjects born after 1952. We speculate that lower microbial diversity is an explanation for the findings.

Smell and taste in inflammatory bowel disease

Objective

To investigate the olfactory/gustatory functions of patients with inflammatory bowel disease (IBD) by smell/taste tests, and to determine if disease activity or medication might influence the olfactory/gustatory functions of patients.

Patients and Methods

In total, 59 IBD patients (37 Crohn's disease (CD) and 22 ulcerative colitis (UC) patients) were studied using “Sniffin' sticks” and “taste strips” for olfactory and gustatory tests, respectively, and compared to healthy controls and published normative data.

Results

Among IBD (CD and UC) patients, the values for odor threshold, but not for odor identification or discrimination, were significantly lower than that of the normative data. Further, these patients showed lower values than the normative taste values and the control group for all tastes, except sour; 57.6% of the IBD patients were hyposmic, while 30.5% were hypogeusic. Subjective self-assessments showed that the patients were not aware of their reduced olfactory/gustatory functions. There were no relevant differences in taste and smell abilities between the CD and UC patients. Disease activity and treatment did not influence the olfactory/gustatory functions.

Conclusion

IBD (CD and UC) patients exhibited significant reductions in the olfactory and gustatory functions. Therefore, patients should be tested by smell/taste tests, in order to be adequately informed of their olfactory/gustatory functions and provided an understanding of how to overcome their limitations, and thus improve their quality of life.

Aluminum as an adjuvant in Crohn's disease induction

Alum (AlK(SO(4))(2)) is an adjuvant commonly utilized in vaccines, and is a ubiquitous element used extensively in contemporary life. Food, air, water, waste, the earth's surface, and pharmaceuticals all represent pathways of aluminum (Al) exposure. Crohn's disease (CD) is a chronic relapsing intestinal inflammation in genetically susceptible individuals and is caused by yet unidentified environmental factors. Al is a potential factor for the induction of inflammation in CD, and its immune activities share many characteristics with the immune pathology of CD: many luminal bacterial or dietary compounds can be adsorbed to the metal surface and induce Th1 profile cytokines, shared cytokines/chemokines, co-stimulatory molecules, and intracellular pathways and stress-related molecular expression enhancement, affecting intestinal macrobiota, trans-mural granuloma formation, and colitis induction in an animal CD model. The inflammasome plays a central role in Al mode of action and in CD pathophysiology. It is suggested that Al adjuvant activity can fit between the aberrations of innate and adaptive immune responses occurring in CD. The CD mucosa is confronted with numerous inappropriate bacterial components adsorbed on the Al compound surface, constituting a pro-inflammatory supra-adjuvant. Al fits the diagnostic criteria of the newly described autoimmune/inflammatory syndrome induced by adjuvants. If a cause and effect relationship can be established, the consequences will greatly impact public health and CD prevention and management.

Carbohydrate Elimination or Adaptation Diet for Symptoms of Intestinal Discomfort in IBD: Rationales for "Gibsons' Conundrum"

Therapeutic use of carbohydrates in inflammatory bowel diseases (IBDs) is discussed from two theoretical, apparent diametrically opposite perspectives: regular ingestion of prebiotics or withdrawal of virtually all carbohydrate components. Pathogenesis of IBD is discussed connecting microbial flora, host immunity, and genetic interactions. The best studied genetic example, NOD2 in Crohn's disease, is highlighted as a model which encompasses these interactions and has been shown to depend on butyrate for normal function. The role of these opposing concepts in management of irritable bowel syndrome (IBS) is contrasted with what is known in IBD. The conclusion reached is that, while both approaches may alleviate symptoms in both IBS and IBD, there is insufficient data yet to determine whether both approaches lead to equivalent bacterial effects in mollifying the immune system. This is particularly relevant in IBD. As such, caution is urged to use long-term carbohydrate withdrawal in IBD in remission to control IBS-like symptoms.

Does evidence exist to include dietary therapy in the treatment of Crohn's disease?

Prescription drugs and surgery are two common medical therapies for Crohn's disease (CD), an inflammatory bowel disease that affects the GI tract. Unfortunately, certain drugs can cause serious side effects, and surgeries must often be repeated. No diet has been established to alleviate the pain and suffering of CD patients. This is curious given the fact that a higher prevalence of food sensitivities exist in this population of patients, and enteral nutrition is not only the first-line of therapy in Japan, but a known research method used to place the majority of CD patients into remission. Although not all patients respond equally to diet, many simply remove symptom-provoking foods, such as dairy, wheat, corn and certain fruits and vegetables. We suggest assisting these patients in their self-assessment of irritating and symptom-provoking foods by educating them in the use of a food-symptom diary followed by a customized elimination diet trialed for 2-4 weeks to determine if there is any benefit to the individual patient.

Role of diet in the management of inflammatory bowel disease

Many studies have looked at connections between diet, etiology, signs and symptoms associated with inflammatory bowel disease (IBD). Although these connections are apparent to clinicians, they are difficult to prove qualitatively or quantitatively. Enteral feeding and polymeric diets are equally effective at bringing about remission in Crohn’s disease (CD). Parenteral feeding is also effective, although none of these methods is as effective as corticosteroid therapy. However, enteral feeding is preferred in the pediatric population because linear growth is more adequately maintained via this route. Exclusion diets in patients brought into remission using an elemental diet have been shown to maintain remission for longer periods. Studies that aim to isolate culpable food groups have shown that individuals react differently on exposure to or exclusion of various foods. The commonly identified food sensitivities are cereals, milk, eggs, vegetables and citrus fruits. Studies that have looked at gut mucosal antigen behavior have shown higher rectal blood flow, in response to specific food antigens, in those with CD over healthy subjects. Exclusion of sugar shows little evidence of amelioration in CD. Omega 3 fatty acids show promise in the treatment of IBD but await larger randomized controlled trials. Patients frequently notice that specific foods cause aggravation of their symptoms. Whilst it has been difficult to pinpoint specific foods, with advances in the laboratory tests and food supplements available, the aim is to prolong remission in these patients using dietary measures, and reduce the need for pharmacotherapy and surgical intervention.

Inflammatory bowel disease: review from the aspect of genetics

Regardless of how inflammatory bowel disease (IBD) is defined, the term "genetic susceptibility" is always included. Due to substantial progress in the characterization of susceptible genes that interact with environmental influences, a number of review articles offering the latest insights continue to be presented. To date, more than 30 novel IBD susceptible loci have been found, while several promising associations between IBD and gene variants have also been identified and replicated effectively. The present review highlights recent insights regarding linkage analysis and genome-wide association presented in studies of IBD susceptible genes, which provide additional evidence supporting their involvement in disease pathogenesis, based on linking to innate immune systems as a result of interactions with intestinal microbial flora. An improved understanding of IBD genetics will promote the identification of novel therapeutic agents, making it possible to identify environmental factors related to intestinal inflammation.

Rising incidence of inflammatory bowel disease among children: a 12-year study

OBJECTIVE

Data suggest an increase in the incidence of pediatric inflammatory bowel disease (IBD). We examined the trend of the incidence of IBD in children.

PATIENTS AND METHODS

A retrospective investigation was conducted on a cohort of children diagnosed with IBD between 1991 and 2002 who were registered in the IBD center at Texas Children's Hospital. The diagnosis of IBD was based on clinical, radiological, endoscopic, and histological examinations.

RESULTS

There were 272 children eligible for the analysis; 56% diagnosed with Crohn disease (CD), 22% with ulcerative colitis (UC), and 22% with indeterminate colitis. The male-to-female ratio was 1.2:1 in CD, 0.6:1 in UC, and 0.8:1 in indeterminate colitis. From 1991 to 2002, the incidence rate has doubled from 1.1/100,000/year (95% confidence interval [CI] 0.85-1.36) to 2.4/1001,000/year (95% CI 2.10-2.77). This trend was valid for CD but not for UC. Whites had higher incidence rate of IBD than African Americans or Hispanics: 4.15/100,000/year (95% CI 3.48-4.82) versus 1.83/100,000/year (95% CI 1.14-2.51), and 0.61/100,000/year (95% CI 0.33-0.89), respectively. African Americans were predominantly diagnosed with CD.

CONCLUSIONS

The results demonstrate the rising incidence of IBD among children with evidence of more CD than UC. Recognition of these results will have important implications for diagnosis and management of IBD in children.

Childhood Inflammatory Bowel Disease in Libya: Epidemiological and Clinical features

Background & Aims: Inflammatory bowel disease is thought to be rare in Libya. The aim is to determine the prevalence of juvenile onset inflammatory bowel disease in Libya. Setting: Al-Fateh childrens' hospital, Benghazi, Libya. Methods: This is a retrospective study of all cases diagnosed over 10 years (1997–2006) with either ulcerative colitis, Crohn's disease or indeterminate colitis. Inclusion criteria were age <15 years at time of presentation who were resident in the eastern part of the country and who diagnosed with inflammatory bowel disease. Clinical features were outlined using a proforma. Results: Sixteen cases were diagnosed with inflammatory bowel disease, of whom 11 were males (M:F ratio of 1.5:1). The prevalence and incidence rates in the year 2006 were 3.6 and 0.9 per 100,000 children, respectively. The incidence rate increased from 0.2 in 2002 to 0.9 in 2006 (Z score of 39.87, p= 0.00). The age at presentation ranged from 5 months to 14 years. Nine had Crohn's disease (6 males) and 6 had ulcerative colitis (4 males). One patient had indeterminate colitis. The most common clinical features were diarrhea in 10 (62.5%), abdominal pain, anorexia and weight loss in 9 (56.2%), anemia in 7 (43.75%) and vomiting in 6 (37%). Ileopancolitis was found in 3 patients whereas 6 patients had ileocecal disease. Conclusions: Childhood inflammatory bowel disease in this population is not so rare and it is increasing. The clinical pattern is similar to that reported by others.

Symposium on 'The challenge of translating nutrition research into public health nutrition'. Session 3: Joint Nutrition Society and Irish Nutrition and Dietetic Institute Symposium on 'Nutrition and autoimmune disease'. Nutrition in Crohn's disease

The exact aetiology of Crohn's disease remains unknown. The consensus is that the disease results from a complex interaction between genes, immunity and environmental factors. Diet is attractive, in theory, as an environmental risk factor in the aetiology of the disease. The epidemiological data, often impeded by methodological issues, have failed to confirm a direct link between pre-diet illness and the development of Crohn's disease. Once diagnosed, however, nutrition has an important role in disease management. Among the nutritional issues are malnutrition, weight loss and suboptimal nutritional status; these outcomes may be present at any stage of the disease but are likely to be overt during acute illness and hospitalisation. Malnutrition has been identified in approximately 40% of hospital admissions with Crohn's disease and is associated with higher mortality, longer hospital stays and higher healthcare costs. Patients in remission may indeed be overweight and appear to be influenced by the general population trends toward overweight and obesity. Irrespective of BMI, patients are at risk of micronutrient deficiencies. Vitamin D deficiency, for example, is common in Crohn's disease and has important implications for bone health. Moreover, newer evidence suggests that vitamin D has potential anti-inflammatory effects. Dietary approaches, in the form of enteral nutrition, have previously been shown to reduce inflammation and treat the active disease. Current guidelines now recommend that corticosteroids are more effective than enteral nutrition for treating adults. Enteral nutrition has important growth and developmental benefits and continues to be a recommended therapy for children with Crohn's disease.

Ingested matter affects intestinal lesions in Crohn's disease

BACKGROUND

Environmental factors of the modern Western lifestyle may trigger Crohn's disease (CD) in susceptible individuals. Because such factors could be part of ingested matter, we intended to improve intestinal Crohn's lesions by exclusion thereof.

METHODS

At first we tested a highly restricted diet (based on spelt bread and red meat, both derived from intensively monitored organic farming) in 5 pilot cases. In a subsequent controlled trial, 18 patients with mild-to-moderate CD were randomly assigned to receive either this active diet or a control diet (low-fiber, low-fat, and high-carbohydrate). Mucosal improvement was assessed by magnetic resonance imaging (MRI) and endoscopy. Secondary endpoints included sonography, the Crohn's Disease Activity Index (CDAI), and the Inflammatory Bowel Disease Questionnaire (IBDQ).

RESULTS

Four of 5 pilot patients showed significant improvement within 4 weeks. From 18 patients in the controlled trial, 8 were randomized to the active and 10 to the control group; 4 decided to quit immediately after dietary counseling, 3 in the active and 1 in the control group (P = 0.183). At 6 weeks MRI and endoscopy showed improvement of intestinal lesions in 3 of 4 assessable patients of the active group and 1 of 9 patients of the control group (P = 0.027). Sonography showed improvement in 4 of 5 patients of the active group and in 1 of 8 assessable patients of the control group (P = 0.016). CDAI and IBDQ improved in both groups to a similar extent.

CONCLUSIONS

Ingested matter as part of the modern Western lifestyle may cause persistence of intestinal Crohn's lesions.

Hygiene hypothesis in inflammatory bowel disease: A critical review of the literature

The hygiene hypothesis is thought to be a significant contributor to the growing incidence of inflammatory bowel disease (IBD) around the world, although the evidence for specific factors that underlie the hygiene hypothesis in IBD is unclear. We aimed to systematically review the literature to determine which hygiene-related factors are associated with the development of IBD. Publications identified from a broad based MEDLINE and Current Contents search between 1966 and 2007 on key terms relevant to the 'hygiene hypothesis' and IBD including H pylori exposure, helminths, cold chain hypothesis, measles infection and vaccination, antibiotic use, breastfeeding, family size, sibship, urban upbringing, day care attendance and domestic hygiene were reviewed. The literature suggests that the hygiene hypothesis and its association with decreased microbial exposure in childhood probably plays an important role in the development of IBD, although the strength of the supporting data for each of the factors varies considerably. The most promising factors that may potentially be associated with development of IBD include H pylori exposure, helminths, breastfeeding and sibship. However, the vast majority of studies in this area are plagued by serious methodological shortcomings, particularly the reliance on retrospective recall of information making it difficult to truly ascertain the importance of a 'hygiene hypothesis' in IBD. The 'hygiene hypothesis' in IBD is an important area of research that may give clues to the aetiology of this disease. Directions for future research are recommended.

Adequacy of nutritional intake in a Canadian population of patients with Crohn's disease

Crohn's disease is frequently associated with nutritional deficiencies, often a result of disease activity and poor oral intake. This study investigated the adequacy of dietary intake, based on the Canadian Dietary Reference Intake, in ambulatory patients with Crohn's disease and a normal body mass index (BMI; calculated as kg/m(2)). This was a cross-sectional study of 74 patients with mean age of 35.7+/-1.4 years and BMI of 23.05+/-0.45. All patients completed a 7-day food record and a diary for the Crohn's Disease Activity Index. Mean Crohn's Disease Activity Index was 138.99+/-11.38. Energy and protein intakes were within the recommended levels of intake, but total carbohydrates, fat, and saturated fat intake exceeded the recommended levels of <55%, <35%, and <10% in 39.2%, 27%, and 59.5% of the patients, respectively. Micronutrient intakes were suboptimal most notably for folate, vitamins C, E, and calcium. There were no substantial differences between patients with active and inactive disease in terms of failure to meet the Dietary Reference Intake. In conclusion, in this population sample, a large number of ambulatory patients with Crohn's disease have suboptimal dietary patterns despite a normal BMI and inactive disease. Dietary counseling and supplementation may be warranted in this patient population.

Nutrition in inflammatory bowel disease

Nutrition has an important role in the management of inflammatory bowel disease. This role includes the prevention and correction of malnutrition, the prevention of osteoporosis and in children the promotion of optimal growth and development. In active Crohn's disease nutritional therapy (in the form of enteral feeding) is an effective primary therapy for many patients. Corticosteroids, however, are more effective than enteral diet therapy in adults. Enteral diets should be considered as primary therapy in pediatric Crohn's disease, especially in children with poor nutritional status or growth impairment. Enteral nutrition does not have a proven primary therapeutic role in ulcerative colitis. There are many theories that suggest that diet may be implicated in the aetiology of inflammatory bowel disease, however, there are, as yet, no dietary approaches proven to reduce the risk of developing IBD.

Haplotype of prostaglandin synthase 2/cyclooxygenase 2 is involved in the susceptibility to inflammatory bowel disease

AIM: Prostaglandin G/H synthase 2 (PTGS2 or COX2) is one of the key factors in the cellular response to inflammation. PTGS2 is expressed in the affected intestinal segments of patients with inflammatory bowel diseases (IBD). In IBD patients, non-steroidal anti-inflammatory drugs, which have been shown to reduce both the production and activity of PTGS2, may activate IBD and aggravate the symptoms. We aimed at examining genetic variants of PTGS2 that may be risk factors for IBD.

METHODS: We genotyped 291 individuals diagnosed with IBD and 367 controls from the Dutch population for the five most frequent polymorphisms of the PTGS2 gene. Clinical data were collected on all patients. DNA was extracted via normal laboratory methods. Genotyping was carried out using multiplex PCR followed by the Invader Assay and the 5 exonuclease assay (TaqMan). New polymorphism screening was performed by pre-screening with denaturing high-performance liquid chromatography, followed by fluorescent sequencing.

RESULTS: Allele 5209G was weakly associated with Crohn's disease (odds ratio [OR] 1.63, 95% confidence interval [CI] 1.03-2.57), and allele 8473T with ulcerative colitis (OR 1.50, 95%CI 1.00-2.27). The haplotype including both alleles showed a strong association with IBD (OR 13.15, 95%CI 3.17-116.15). This haplotype, while rare (-0.3%) in the general population, is found more frequently in patients (3.5%).

CONCLUSION: Our data suggest that this haplotype of PTGS2 contributes to the susceptibility of IBD.

Dietary risk factors for inflammatory bowel disease: a multicenter case-control study in Japan

To evaluate the role of dietary factors in the etiology of inflammatory bowel disease (IBD), we conducted a multicenter hospital-based case-control study in a Japanese population. Cases were IBD patients aged 15 to 34 years [ulcerative colitis (UC) 111 patients; Crohn's disease (CD) 128 patients] within 3 years after diagnosis in 13 hospitals. One control subject was recruited for each case who was matched for sex, age, and hospital. A semiquantitative food frequency questionnaire was used to estimate preillness intakes of food groups and nutrients. All the available control subjects (n = 219) were pooled, and unconditional logistic models were applied to calculate odds ratios (ORs). In the food groups, a higher consumption of sweets was positively associated with UC risk [OR for the highest versus lowest quartile, 2.86; 95% confidence interval (CI), 1.24 to 6.57], whereas the consumption of sugars and sweeteners (OR, 2.12; 95% CI, 1.08 to 4.17), sweets (OR, 2.83; 95% CI, 1.38 to 5.83), fats and oils (OR, 2.64; 95% CI, 1.29 to 5.39), and fish and shellfish (OR, 2.41; 95% CI, 1.18-4.89) were positively associated with CD risk. In respect to nutrients, the intake of vitamin C (OR, 0.45; 95% CI, 0.21 to 0.99) was negatively related to UC risk, while the intake of total fat (OR, 2.86; 95% CI, 1.39 to 5.90), monounsaturated fatty acids (OR, 2.49; 95% CI, 1.23 to 5.03) and polyunsaturated fatty acids (OR, 2.31; 95% CI, 1.12 to 4.79), vitamin E (OR, 3.23; 95% CI, 1.45 to 7.17), and n-3 (OR, 3.24; 95% CI, 1.52 to 6.88) and n-6 fatty acids (OR, 2.57; 95% CI, 1.24 to 5.32) was positively associated with CD risk. Although this study suffers from the shortcoming of recall bias, which is inherent in most retrospective studies (prospective studies are warranted to confirm the associations between diet and IBD risk), the present findings suggest the importance of dietary factors for IBD prevention.

Children with early-onset inflammatory bowel disease (IBD): analysis of a pediatric IBD consortium registry

OBJECTIVE

To determine the characteristics of inflammatory bowel disease (IBD) in young patients.

STUDY DESIGN

Uniform data were collected from a cohort of patients with IBD who were enrolled from January 2000 to November 2002 at six pediatric centers (Pediatric IBD Consortium).

RESULTS

Of 1370 children in the registry, the mean age at IBD diagnosis was 10.3 +/- 4.4 years; 54% were male, and 86% were white. Diagnosis was confirmed in 87 (6.1%) under 3 years of age, 211 (15.4%) before 6 years, 654 (47.7%) at 6 to 12 years, and 505 (36.9%) at 13 to 17 years. More than 63% of children younger than 8 years of age had isolated colonic disease, whether Crohn disease, ulcerative colitis (UC), or indeterminate colitis. Conversely, only 35% of those 8 years of age or older had isolated colonic disease ( P < .0001). Overall, 29% had one or more family members with IBD. The subgroup of children younger than 3 years of age with UC had the highest prevalence of first-degree relatives with IBD (44%).

CONCLUSIONS

This demographically diverse pediatric IBD cohort revealed age-related variation in the distribution of IBD phenotype, with a high prevalence of isolated colonic disease in young children. Positive family history was especially common in young patients with UC.

Incidence of juvenile-onset Crohn's disease in Scotland: association with northern latitude and affluence

BACKGROUND & AIMS

The incidence of Crohn's disease in Scottish children has increased steadily over 30 years. Many studies have investigated genetic influence or possible links with childhood events. We aimed to study sociodemographic and/or geographic distribution of juvenile=onset Crohn's disease in Scotland.

METHODS

Using a previously established and validated database covering the entire Scottish population, 580 Scottish children (<16 years of age at symptom onset) with inflammatory bowel disease incident between 1981 and 1995 were identified. Postcodes of incident cases were classed for geographic location and material deprivation. Incidence rates (/100,000/year) were sex standardized to the 1991 census population. The effects of sex, geographic location, time, and deprivation category were estimated from a multifactorial Poisson regression model.

RESULTS

The incidence of juvenile-onset Crohn's disease was 2.3 (95% CI: 2.0-2.5) for the time period 1981 to 1995 and was significantly higher in northern (3.1, 95% CI: 2.6-3.8) than in southern Scotland (2.1, 95% CI: 1.9-2.4, P < 0.001). The incidence of juvenile-onset ulcerative colitis did not show north/south variation ( P = 0.677). The relative risks of developing CD were significantly lower in postcode areas with deprivation categories 2-7 as compared with deprivation score 1 (most affluent, P = 0.033). This pattern was not seen for UC.

CONCLUSIONS

There was an increased incidence of juvenile-onset Crohn's disease in northern compared with southern Scotland. Children from more affluent areas had a higher relative risk of developing Crohn's disease. Juvenile onset ulcerative colitis did not show north/south variation in incidence or association with affluence.

Environmental risk factors (excluding tobacco and microorganisms): critical analysis of old and new hypotheses

The increase in incidence in both ulcerative colitis and Crohn's disease during the 20th century has led to an abundance of different hypotheses on what sort of exposures are responsible. There has been a special focus on dietary factors, as well as on other exposures introduced on a population-based level, including fast food, cola drinks, toothpaste, antibiotics and oral contraceptives. The aim of this review is to critically assess the results from the different observational studies that have investigated these hypotheses, and also to propose research agendas that should be pursued in the future. The conclusion is that infectious exposures and early bacterial colonization, which are associated with better hygiene early in life and that influence immune function, and possibly oral contraceptives, remain the only exposures of interest for future research into the aetiology of ulcerative colitis and Crohn's disease.

Nutritional therapy in inflammatory bowel diseas

Nutritional intervention is an important adjunctive therapy for patients with inflammatory bowel disease (IBD). The correction and maintenance of nutritional status, achieved by careful nutritional monitoring and intervention, should be an integral part of the multidisciplinary management of IBD throughout all stages of the disease. In acute Crohn's disease, enteral nutrition (polymeric and elemental) is an effective and safe primary therapy for many patients. Enteral diets should be considered as primary therapy in pediatric Crohn's disease patients, especially in children with poor nutritional status or growth impairment and in patients with severe drug-induced side effects. Total parenteral nutrition does not have a primary therapeutic role in IBD.

Standard therapy of Crohn's disease

Therapy of Crohn's disease is either counteracting the underlying mechanisms of bowel inflammation or specifically targeting certain complications of disease, e.g. strictures, fistulae, bacterial overgrowth, or anemia. The therapeutic arsenal is well defined and has been tested for safety and efficacy. There is need and opportunity to adapt therapies to individual situations. This is made on the basis of scientific facts that have been collected from randomized controlled trials and on the basis of reasoned thinking that weighs the potential effect against potential side effects in individual cases. In clinical practice, the potency of lifestyle changes such as smoking cessation is still underestimated and not extensively exploited. As the understanding of genetic mutations, their gene function and phenotypic expression grows, we anticipate that future treatment can be tailored to certain genotypes or phenotypes of Crohn's disease.

Nutritional Treatments in Inflammatory Bowel Disease

The role of nutritional intervention in inflammatory bowel disease (IBD) is twofold: first, as primary therapy for patients with acute Crohn's disease; second, as an invaluable adjunctive therapy for the correction and maintenance of nutritional status for both patients with Crohn's disease and those with ulcerative colitis. Careful nutritional monitoring and appropriate nutritional intervention throughout all stages of disease should be an integral part of the multidisciplinary management approach to IBD. In terms of primary therapy, polymeric and elemental enteral diets are an effective therapy for patients with acute Crohn's disease, offering an unrivaled safety profile and significant nutritional benefits. Enteral diets should be considered as primary therapy in children with Crohn's disease, especially in those with poor nutritional status or growth impairment, and in patients with severe drug-induced side effects. Total parenteral nutrition (TPN) does not have a primary therapeutic role in patients with IBD.