Review article: the role of nutrition in the treatment of inflammatory bowel disease

Astragalus polysaccharides protect against dextran sulfate sodium-induced colitis by inhibiting NF-κВ activation

Astragalus polysaccharide (APS) is a bioactive extract of Astragalus membranaceus (AM), which possess a wide range of medicinal benefits, including anti-inflammatory, anti-oxidative, anti-tumor and anti-diabetic effects. The present work evaluated the therapeutic effect of APS and its potential mechanisms in a mouse model of dextran sulfate sodium (DSS)-induced colitis. The APS treatment led to significant improvements in colitis disease activity index (DAI) and histological scores, as well as significantly increased weight and colon length in mice as compared to the control group. Mechanically, reduced NF-κВ DNA phosphorylation activity and downregulated TNF-α, IL-1β, IL-6, IL-17 expressions and myeloperoxidase (MPO) activity were associated with improvement in colitis observed in APS-treated mice. These findings suggest that APS may represent a natural therapeutic approach for treating inflammatory bowel disease, such as ulcerative colitis.

The Importance and Challenges of Dietary Intervention Trials for Inflammatory Bowel Disease

Inflammatory bowel disease is believed to be caused by a combination of genetic and environmental stimuli such as our diet. Diets high in meat and fats and low in fruits and vegetables have been associated with new-onset inflammatory bowel disease. This has triggered interest in using dietary modification as a treatment. The 3 principle models of dietary intervention are supplementation with selected dietary components, exclusion of selected dietary components, or use of dietary formulas in place of a normal diet. Despite the high level of interest in dietary interventions as a treatment for inflammatory bowel disease, few well-designed clinical trials have been conducted to firmly establish the optimal diet to induce or maintain remission. This may be in part related to the challenges of conducting dietary intervention trials. This review examines these challenges and potential approaches to be used in dietary intervention trials.

Diet in the pathogenesis and treatment of inflammatory bowel diseases

Some of the most common symptoms of the inflammatory bowel diseases (IBD, which include ulcerative colitis and Crohn's disease) are abdominal pain, diarrhea, and weight loss. It is therefore not surprising that clinicians and patients have wondered whether dietary patterns influence the onset or course of IBD. The question of what to eat is among the most commonly asked by patients, and among the most difficult to answer for clinicians. There are substantial variations in dietary behaviors of patients and recommendations for them, although clinicians do not routinely endorse specific diets for patients with IBD. Dietary clinical trials have been limited by their inability to include a placebo control, contamination of study groups, and inclusion of patients receiving medical therapies. Additional challenges include accuracy of information on dietary intake, complex interactions between foods consumed, and differences in food metabolism among individuals. We review the roles of diet in the etiology and management of IBD based on plausible mechanisms and clinical evidence. Researchers have learned much about the effects of diet on the mucosal immune system, epithelial function, and the intestinal microbiome; these findings could have significant practical implications. Controlled studies of patients receiving enteral nutrition and observations made from patients on exclusion diets have shown that components of whole foods can have deleterious effects for patients with IBD. Additionally, studies in animal models suggested that certain nutrients can reduce intestinal inflammation. In the future, engineered diets that restrict deleterious components but supplement beneficial nutrients could be used to modify the luminal intestinal environment of patients with IBD; these might be used alone or in combination with immunosuppressive agents, or as salvage therapy for patients who do not respond or lose responsiveness to medical therapies. Stricter diets might be required to induce remission, and more sustainable exclusion diets could be used to maintain long-term remission.

High prevalence of vitamin A deficiency in Crohn's disease patients according to serum retinol levels and the relative dose-response test

AIM: To assess the vitamin A status of patients with Crohn’s disease (CD) by evaluating serum retinol levels and the relative dose response (RDR) test (liver retinol stores).

METHODS: Vitamin A nutritional status was measured by serum retinol obtained by high performance liquid chromatography and the RDR test for evaluation of the hepatic stores. Body composition was performed by densitometry by dual-energy X-ray absorptiometry. Vitamin A dietary intake was assessed from a semi-quantitative food frequency questionnaire.

RESULTS: This study included 38 CD patients and 33 controls. Low serum retinol concentrations were detected in 29% of CD patients vs 15% in controls (P < 0.005). The RDR test was positive in 37% of CD patients vs 12% in controls, which indicated inadequate hepatic vitamin A stores (P < 0.005). Individuals with hypovitaminosis A had lower BMI and body fat compared with those without this deficiency. There was no association between vitamin A deficiency and its dietary intake, ileal location, presence of disease activity and prior bowel resections.

CONCLUSION: Patients with CD have higher prevalence of vitamin A deficiency, as assessed by two independent methods.

Intestinal anti-inflammatory activity of apigenin K in two rat colitis models induced by trinitrobenzenesulfonic acid and dextran sulphate sodium. Br J Nutr. 2015;113:618-626. [PMID: 25654996 DOI: 10.1017/s0007114514004292]

Flavonoids are polyphenolic compounds that are widespread in nature, and consumed as part of the human diet in significant amounts. The aim of the present study was to test the intestinal anti-inflammatory activity of apigenin K, a soluble form of apigenin, in two models of rat colitis, namely the trinitrobenzenesulfonic acid (TNBS) model and the dextran sulphate sodium (DSS) model. Apigenin K (1, 3 and 10 mg/kg; by the oral route; n 4-6 per group) was administered as a pre-treatment to rats with TNBS and DSS colitis, and colonic status was checked by macroscopic and biochemical examination. Apigenin K pre-treatment resulted in the amelioration of morphological signs and biochemical markers in the TNBS model. The results demonstrated a reduction in the inflamed area, as well as lower values of score and colonic weight:length ratio compared with the TNBS group. Myeloperoxidase (MPO) activity was reduced by 30 % (P< 0·05). Moreover, apigenin K pre-treatment ameliorated morphological signs and biochemical markers in the DSS model. Thus, macroscopic damage was significantly reduced and the colonic weight:length ratio was lowered by approximately 10 %, while colonic MPO and alkaline phosphatase activities were decreased by 35 and 21 %, respectively (P< 0·05). Apigenin K pre-treatment also tended to normalise the expression of a number of colonic inflammatory markers (e.g. TNF-α, transforming growth factor-β, IL-6, intercellular adhesion molecule 1 or chemokine (C-C motif) ligand 2). In conclusion, apigenin K is found to have anti-inflammatory effects in two preclinical models of inflammatory bowel disease.

Nutritional status in patients with ulcerative colitis in Isfahan, Iran

Background:

Malnutrition is common among patients with inflammatory bowel disease. The present study aimed to investigate the nutritional status of ulcerative colitis (UC) patients in Isfahan, Iran.

Materials and Methods:

In this descriptive analytical cross-sectional study, between Dec 2011 and Jun 2012, 99 patients with UC were randomly selected and evaluated. Age, sex, duration of disease, body mass index (BMI) and laboratory parameters recorded for all patients. Nutritional risk index (NRI) was calculated and its association with patients’ variables was assessed with regard to UC disease severity.

Results:

Twelve patients out of 99 patients had mild UC and 87 patients had moderate to severe UC. Based on the NRI, 90.9% were not malnourished and 9.1% were at moderate to severe risk for malnutrition. Among laboratory parameters only, serum potassium level in patients with moderate to severe UC was significantly higher than those with mild UC (P = 0.017). Other laboratory parameters were similar between patients stratified by US status. Patients age s significantly correlate with serum vitamin D, immunoglobulin a (IgA) and potassium level (P > 0.05), also duration of disease was significantly correlate with Phosphorus (P = 0.024) among laboratory parameters.

Conclusion:

In studied UC patients, malnutrition risk was based on degree of disease severity. Patients with moderate to severe UC were more at risk for malnutrition compared to the patients with mild UC. Furthermore, among laboratory parameters only serum potassium level was higher among patients with moderate to severe UC compared to others.

Drosophila as a model for intestinal dysbiosis and chronic inflammatory diseases

The association between deregulated intestinal microbial consortia and host diseases has been recognized since the birth of microbiology over a century ago. Intestinal dysbiosis refers to a state where living metazoans harbor harmful intestinal microflora. However, there is still an issue of whether causality arises from the host or the microbe because it is unclear whether deregulation of the gut microbiota community is the consequence or cause of the host disease. Recent studies using Drosophila and its simple microbiota have provided a valuable model system for dissecting the molecular mechanisms of intestinal dysbiosis. In this review, we examine recent exciting observations in Drosophila gut-microbiota interactions, particularly the links among the host immune genotype, the microbial community structure, and the host inflammatory phenotype. Future genetic analyses using Drosophila model system will provide a valuable outcome for understanding the evolutionarily conserved mechanisms that underlie intestinal dysbiosis and chronic inflammatory diseases.

British Dietetic Association evidence-based guidelines for the dietary management of Crohn's disease in adults

BACKGROUND

Crohn's disease is a debilitating chronic inflammatory bowel disease. Appropriate use of diet and nutritional therapy is integral to the overall management strategy of Crohn's disease. The aim was to develop evidence-based guidelines on the dietary management of Crohn's disease in adults.

METHODS

Questions relating to the dietary management of Crohn's disease were developed. These included the roles of enteral nutrition to induce remission, food re-introduction diets to structure food re-introduction and maintain remission, and dietary management of stricturing disease, as well as whether probiotics or prebiotics induce or maintain remission. A comprehensive literature search was conducted and relevant studies from January 1985 to November 2009 were identified using the electronic database search engines CINAHL, Cochrane Library, EMBASE, MEDLINE, Scopus and Web of Science. Evidence statements, recommendations, practical considerations and research recommendations were developed.

RESULTS

Fifteen research papers were critically appraised and the evidence formed the basis of these guidelines. Although corticosteroids appear to be more effective, enteral nutrition (elemental or non-elemental) can be offered as an alternative option to induce disease remission. After a course of enteral nutrition, food re-introduction diets may be useful to structure food re-introduction and help maintain disease remission. Dietary fibre is contraindicated in the presence of strictures as a result of the risk of mechanical obstruction. The use of probiotics and prebiotics is not currently supported.

CONCLUSIONS

As an alternative to corticosteroids, evidence supports enteral nutrition to induce disease remission. Food re-introduction diets provide structure to food re-introduction and help maintain disease remission. These guidelines aim to reduce variation in clinical practice.

Immunomodulatory effects of heat-killed Enterococcus faecalis TH10 on murine macrophage cells

The objective of this study was to investigate the immunomodulatory effects of heat-killed Enterococcus faecalis TH10 (hk-TH10) and its signal transduction on murine macrophage RAW264 cells. RAW264 cells produced nitric oxide (NO) following hk-TH10 treatment. In order to investigate the mechanisms underlying hk-TH10-stimulated NO production, we further measured NO production in RAW264 cells treated with Toll-like receptor (TLR) 4 inhibitor peptide, NF-κB inhibitor, TLR1-siRNA, TLR2-siRNA, and TLR-6 siRNA. Furthermore, the activation of TLR2-TLR1/6 pathway molecules was analyzed by Western blotting. The result of this study showed that hk-TH10 stimulates NO in RAW264 cells through the activation of the TLR2-TLR1/6 pathway. From our findings, we can conclude that hk-TH10 isolated from a traditional side-dish fermented food (tempeh) may facilitate host immunomodulation.

The efficacy of exclusive nutritional therapy in paediatric Crohn's disease, comparing fractionated oral vs. continuous enteral feeding

BACKGROUND

Nutritional therapy has an established role as induction therapy in paediatric Crohn's disease. However, compliance is the main difficulty and may be greatly influenced by the administration route.

AIM

To analyse the efficiency of exclusive nutrition to induce remission in children with Crohn's disease comparing fractionated oral vs. continuous enteral feeding.

METHODS

The medical records of 106 patients treated by exclusive nutritional therapy [Modulen IBD (R)] by either oral or continuous enteral route were reviewed retrospectively. Comparative analyses of remission rates, changes in anthropometry, Paediatric Crohn's disease Activity Index (PCDAI), laboratory indices and compliance rates were performed.

RESULTS

On exclusive enteral nutrition, at 8 weeks, 34/45 patients achieved remission in the oral group (75% on intention-to-treat analysis) and 52/61 (85%) in the enteral nutrition group (P = 0.157). All patients showed a significant decrease in disease severity assessed by PCDAI (P < 0.0001) and significant improvements in anthropometric measures and inflammatory indices. No difference was observed whether Modulen IBD was administered orally or by continuous enteral feeding, apart from weight gain, which was greater in the enteral group (P = 0.041). In a subgroup of patients, mucosal healing was evidenced on follow-up endoscopies showing a clear correlation to remission. Compliance rates (87% and 90%) were similar. Nevertheless, noncompliant patients had lower mucosal healing and remission rates.

CONCLUSIONS

These retrospective data suggest that the use of fractionated oral nutritional therapy might be as efficacious as continuous enteral administration to induce remission and mucosal healing in children with Crohn's disease. However, appropriate prospective clinical trials are needed to confirm these findings.

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.

Qingdai Granules up-regulate MUC2 mRNA expression but down-regulate iNOS mRNA expression in the colonic mucosa of rats with ulcerative colitis

AIM: To investigate the effects of Qingdai Granules (QDG) on the expression of mucin 2 (MUC2) and inducible nitric oxide synthase (iNOS) mRNAs in the colonic mucosa of rats with ulcerative colitis.

METHODS: Ulcerative colitis was induced in rats by giving an enema of trinitrobenzene sulphonic acid (TNBS) and ethanol. The experimental animals were randomly divided into six groups: normal group, model group, sulfasalazine (SASP) group (500 mg/kg), and low-, medium- and high-dose QDG groups (600, 900 and 1 200 mg/kg). Except the normal group, the other groups were given intragastrically normal saline, SASP, and different concentrations of QDG, respectively, from day 3 after model establishment for 10 d. On day 14, rats were killed to evaluate disease activity index (DAI) and colon mucosa damage index (CMDI). The expression of MUC2 and iNOS mRNAs in the colonic mucosa of rats was detected by reverse transcription-polymerase chain reaction (RT-PCR).

RESULTS: Compared with the model group, the DAI and CMDI in the medium- and high-dose QDG groups significantly decreased, the expression of MUC2 mRNA in the colon of rats in the medium- and high-dose QDG groups was significantly up-regulated (2.06 ± 0.70 vs 1.24 ± 0.47 and 2.34 ± 0.86 vs 1.24 ± 0.47; both P < 0.01), and the expression of iNOS mRNA in the high-dose QDG group was significantly down-regulated (0.35 ± 0.12 vs 0.62 ± 0.31, P < 0.05).

CONCLUSION: QDG can exert protective effects against rat ulcerative colitis perhaps by up-regulating MUC2 mRNA expression and down-regulating iNOS mRNA expression.

Enteral nutrition for the maintenance of remission in Crohn's disease: a systematic review

OBJECTIVE

This review study was designed to evaluate the efficacy of enteral nutrition (EN) for the maintenance of remission in patients with Crohn's disease (CD) who achieved medically or surgically induced remission.

METHODS

The Medline, Embase, Ovid, and Cochrane database search of literature was carried out to identify studies that reported the efficacy of EN for the maintenance of remission in CD. The main outcome measure was the occurrence of clinical or endoscopic relapse.

RESULTS

Ten studies were included: one randomized controlled trial, three prospective non-randomized trials, and six retrospective studies. Elemental, semielemental or polymeric diets were used as an oral supplement or a nocturnal tube feeding in addition to ordinary foods. Comparing outcomes between patients who received EN and those who did not, the clinical remission rate was significantly higher in those with EN in all seven studies. In two studies, EN showed suppressive effects on endoscopic disease activity. In all four studies investigating impacts of the quantity of enteral formula on clinical remission, higher amounts of enteral formula were associated with higher remission rates: > or =30 kcal/kg ideal body weight/day (vs. <30 kcal/kg ideal body weight/day), > or =1200 kcal/day (vs. <1200 kcal/day), and > or =1600 kcal/day (vs. <1600 kcal/day). Quantitative pooling of studies was not feasible because of the diversity of interventions and outcome measures among the studies.

CONCLUSION

Although the evidence level is not high, the available data suggest that EN may be useful for maintaining remission in patients with CD. Large randomized controlled trials are necessary to assess a definite efficacy of EN for the maintenance of remission.

[Management of ileal stenosis in patients with Crohn's disease]

Stenosis is the most frequent complication during Crohn's disease. The lesion can be inflammatory, or due to a fibrosing or neoplastic process. The medical treatment with anti-inflammatory drugs is usually sufficient as first line treatment; fibrous lesions require endoscopic or surgical procedures while neoplastic lesions require surgery. A multidisciplinary approach (radiologic, medical, surgical and endoscopic) is needed. In a first part, we discuss the definition of stenosis and the modalities of imaging (particularly MRI) and of treatment (particularly with TNFalpha antagonists). Then we expose the strategy for the management of the most frequent clinical situations: occlusion, ileal inflammatory stenosis, stenosis of an ileocolonic anastomosis and chronic fibrous stenosis. The treatment decision takes into account the results of radiological assessment, CRP level and the effects of the previous treatments.

Importance of nutrition in inflammatory bowel disease

Inflammatory bowel disease (IBD) results from the interaction between an individual's immune response and precipitant environmental factors, which generate an anomalous chronic inflammatory response in those who are genetically predisposed. Various feeding practices have been implicated in the origin of IBD based on epidemiological observations in developed countries, but we do not have solid evidence for the etiological role played by specific food types. IBD is associated with frequent nutritional deficiencies, the pattern and severity of which depends on the extent, duration and activity of the inflammation. Nutritional support allows these deficiencies in calories, macro- and micro-nutrients to be rectified. Enteral nutrition is also a primary therapy for IBD, especially for Crohn's disease, as it allows the inflammatory activity to be controlled, kept in remission, and prevents or delays the need for surgery. Nutritional support is especially important in childhood IBD as an alternative to pharmacological treatment. This report discusses the complex relationship between diet and IBD.

Importance of nutrition in inflammatory bowel disease

Inflammatory bowel disease (IBD) results from the interaction between an individual’s immune response and precipitant environmental factors, which generate an anomalous chronic inflammatory response in those who are genetically predisposed. Various feeding practices have been implicated in the origin of IBD based on epidemiological observations in developed countries, but we do not have solid evidence for the etiological role played by specific food types. IBD is associated with frequent nutritional deficiencies, the pattern and severity of which depends on the extent, duration and activity of the inflammation. Nutritional support allows these deficiencies in calories, macro- and micro-nutrients to be rectified. Enteral nutrition is also a primary therapy for IBD, especially for Crohn’s disease, as it allows the inflammatory activity to be controlled, kept in remission, and prevents or delays the need for surgery. Nutritional support is especially important in childhood IBD as an alternative to pharmacological treatment. This report discusses the complex relationship between diet and IBD.

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. Proc Nutr Soc. 2009;68:127-134. [PMID: 19208269 DOI: 10.1017/s0029665109001025]

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.

Estado actual del tratamiento de la enfermedad inflamatoria intestinal

Treatment of inflammatory bowel disease should take some general considerations into account, standing out among them the importance of nutrition, antithrombotic prophylaxis in certain situations, prevention of osteoporosis and prevention of colorectal cancer by endoscopic screening in extensive ulcerous colitis or Crohn's colitis. Ulcerous colitis is still effectively treated with salicylates and steroids in its mild and moderate forms. Severe forms require parenteral steroids, cyclosporine or infliximab, and these are successfully used with immunosuppressants (azathioprine or mercaptopurine) in steroid dependence. Maintenance with salicylates, that should be adequately complied with, is an important point. Crohn's disease is treated with steroids in its mild and moderate forms, and again in corticodependent ones with immunosuppressants, which we are using increasingly sooner. Refractory forms or fistulous forms benefit from the use of biological treatments (infliximab) generally accompanied by immunosuppressants.

Enteral nutritional therapy for induction of remission in Crohn's disease

BACKGROUND

The role of enteral nutrition in Crohn's disease is controversial. Increasing research on the mechanisms by which nutritional therapy improves the clinical well being of patients with Crohn's disease has led to novel formula design and trials comparing two different forms of enteral nutrition. This meta-analysis aims to provide an update on the existing effectiveness data for both corticosteroids versus enteral nutrition and for one form of enteral nutrition versus another for inducing remission of active Crohn's disease.

OBJECTIVES

To evaluate the effectiveness of exclusive enteral nutrition (EN) as primary therapy to induce remission in Crohn's disease and to examine the importance of formula composition on effectiveness.

SEARCH STRATEGY

Studies were selected using a computer-assisted search of the on-line bibliographic databases MEDLINE (1966-2006) and EMBASE (1984-2006), as well as the Science Citation Index on Web of Science. Additional citations were sought by manual search of references of articles retrieved from the computerized search, abstracts submitted to major gastroenterologic meetings and published in the journals: American Journal of Gastroenterology, Gut, Gastroenterology, Journal of Pediatric Gastroenterology and Nutrition, and Journal of Parenteral and Enteral Nutrition, and from the reviewers' personal files or contact with leaders in the field.

SELECTION CRITERIA

All randomized and quasi-randomized controlled trials involving patients with active Crohn's disease defined by a clinical disease activity index were considered for review. Studies evaluating the administration of one type of enteral nutrition to one group of patients and another type of enteral nutrition or conventional corticosteroids to the other group were selected for review.

DATA COLLECTION AND ANALYSIS

Data were extracted independently by two authors and any discrepancies were resolved by rereading and discussion. For the dichotomous variable, achievement of remission, individual and pooled trial statistics were calculated as odds ratios (OR) with 95% confidence intervals (CI); both fixed and random effect models were used. The results for each analysis were tested for heterogeneity using the chi square statistic. The studies were separated into two groups: A. one form of enteral nutrition compared with another form of enteral nutrition and B. one form of enteral nutrition compared with corticosteroids. Subgroup analyses were conducted on the basis of clinical or disease criteria and formula composition. Sensitivity analyses were conducted on the basis of the inclusion of abstract publications, methodologic quality and by random or fixed effects models.

MAIN RESULTS

In part A, of the 15 included eligible trials (one abstract) comparing different formulations of EN for the treatment of active CD, 11 compared one (or more) elemental formula to a non-elemental one, three compared enteral diets of similar protein composition but different fat composition, and one compared non-elemental diets differing only in glutamine enrichment. Meta-analysis of ten trials comprising 334 patients demonstrated no difference in the efficacy of elemental versus non-elemental formulas (OR 1.10; 95% CI 0.69 to 1.75). Subgroup analyses performed to evaluate the different types of elemental and non-elemental diets (elemental, semi-elemental and polymeric) showed no statistically significant differences. Further analysis of seven trials including 209 patients treated with EN formulas of differing fat content (low fat: < 20 g/1000 kCal versus high fat: > 20 g/1000 kCal) demonstrated no statistically significant difference in efficacy (OR 1.13; 95% CI 0.63 to 2.01). Similarly, the effect of very low fat content (< 3 g/1000 kCal) or type of fat (long chain triglycerides) were investigated, but did not demonstrate a difference in efficacy in the treatment of active CD, although a non significant trend was demonstrated favoring very low fat and very low long chain triglyceride content. This result should be interpreted with caution due to statistically significant heterogeneity and small sample size. Sensitivity analyses had no significant effects on the results. The role of specific fatty acids or disease characteristics on response to therapy could not be evaluated. In part B, eight trials (including two abstracts) comparing enteral nutrition to steroid therapy met the inclusion criteria for review. Meta-analysis of six trials that included 192 patients treated with enteral nutrition and 160 treated with steroids yielded a pooled OR of 0.33 favouring steroid therapy (95% CI 0.21 to 0.53). A sensitivity analysis including the abstracts resulted in an increase in the number of participants to 212 in the enteral nutrition group and 179 in the steroid group but the meta-analysis yielded a similar result (OR 0.36; 95% CI 0.23 to 0.56). There were inadequate data from full publications to perform further subgroup analyses by age, disease duration and disease location.

AUTHORS' CONCLUSIONS

Corticosteroid therapy is more effective than enteral nutrition for inducing remission of active Crohn's disease as was found in previous systematic reviews. Protein composition does not influence the effectiveness of EN in the treatment of active CD. A non significant trend favouring very low fat and/or very low long chain triglyceride content exists but larger trials are required to explore the significance of this finding.

Radical scavenging and anti-inflammatory properties of STW 5 (Iberogast) and its components

A combination of ethanolic extracts from nine medicinal plants is successfully used in STW 5 (Iberogast((R))) for treatment of gastrointestinal disorders. To elucidate possible modes of action, the focus of this study is on antioxidant properties of the phytomedicine STW 5. In fact, functional gastrointestinal diseases, such as non-ulcer dyspepsia (NUD) and irritable bowel syndrome, are often initiated by or correlated to inflammatory processes, where oxidants such as reactive oxygen species (ROS) play a crucial role. Prominent in vivo sources of ROS generation are represented by the enzymes xanthine oxidase (XOD) or myeloperoxidase (MPO). Applying these enzymes in models in vitro, we show that STW 5 and its components possess strong antioxidant activities. Depending on the model investigated, even pro-oxidant activities of single components of STW 5 could be observed. Interestingly, these effects were absent in STW 5, indicating cooperation between the components. Moreover, if one of the component extracts of STW 5 is omitted, the antioxidant activity is reduced. Thus we conclude that all the single extracts combined in STW 5 are of importance for the therapeutic effect, working in concert. The component of STW 5 performing best in vitro differed with the model investigated, respectively, with ROS and ROS generators. In the XOD system, the extracts of lemon balm leaf and peppermint leaf showed the best antioxidant result, whereas concerning MPO driven chlorination reactions, bitter candy tuft extract was the most efficient antioxidant. Best protection against peroxynitrite induced oxidation of methionine like sulfur-compounds exhibited the STW 5 components lemon balm leaf, Matricaria flower and peppermint leaf.

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.

Effects of olsalazine sodium on expression of nitric oxide synthase in patients with ulcerative colitis: an analysis of 36 cases

AIM: To explore the effects of olsalazine sodium on the expression of nitric oxide synthase (NOS) in patients with ulcerative colitis (UC).

METHODS: The colonic mucosa specimens were collected from 36 patients with active ulcerative colitis. The expression of inducible NOS (iNOS), epithelial NOS(eNOS), and nitrotyrosine were detected by immunohistochemistry before and after the patients were treated with olsalazine sodium.

RESULTS: eNOS was expressed in the mucosal epithelial cells of the inflammatory area in 4 patients, but not expressed in the inflammatory cells. iNOS was expressed in the mucosal epithelial cells of all the 36 (100%) samples (13 strong positive and 23 light positive) taken from inflammatory area. iNOS light positive staining in acinar cells of colonic epithelium was detected in 1 patient only. Inflammatory cells in the lamina propria expressed iNOS in 18 (50%) cases. After the treatment of olsalazine sodium, iNOS was lightly and positively expressed in the mucosal epithelial cells of only 5 patients, and no iNOS was expressed in non-inflammatory areas. Nitrotyrosine was detected in the mucosal epithelial cells of inflammatory areas in 5 patients, of which only 1 was accompanied by light and positive expression of nitrotyrosine in the acinar epithelial cells. No nitrotyrosine expression was found in the inflammatory cells of the lamina propria and non-inflammatory areas.

CONCLUSION: Olsalazine sodium can inhibit the expression of iNOS, alleviate the inflammation, and promote the healing of the ulcer.

Long-term outcome of nutritional therapy in paediatric Crohn's disease

BACKGROUND AND AIMS

Long-term effects of using enteral feed therapy to induce remission in paediatric Crohn's disease are poorly documented. The aim of this study is to examine the short and long-term impact of enteral nutrition as primary therapy for children with newly diagnosed Crohn's disease.

METHODS

Since 1994, a data base was set up in Bristol for all children with inflammatory bowel diseases. The data of newly diagnosed patients with Crohn's disease in whom enteral nutrition was used as the primary therapy (44 children) was analysed, with particular reference to time to remission, to first and subsequent relapse, and to first steroid usage.

RESULTS

Forty out of 44 patients (90%) responded to enteral nutrition, with a median time to remission of 6 weeks. 25 of these 40 (62%) relapsed, with a median duration of remission of 54.5 weeks (range 4-312). 15 (38%) have not relapsed. 21 of the 44 (47%) have not received steroids. In those who eventually required steroids, their use was postponed for a median 68 weeks (range 6-190). Site of disease activity had no impact on response to enteral nutrition, but there was a trend towards earlier relapse in those with isolated colonic involvement.

CONCLUSIONS

This data suggests that there are long-term benefits to the use of enteral nutrition to induce remission in children with Crohn's disease Steroids may be avoided in nearly half the cases and, in others, their use postponed by 68 weeks.