Omega 3 fatty acids (fish oil) for maintenance of remission in ulcerative colitis

Global attitudes on and the status of enteral nutrition therapy for pediatric inflammatory bowel disease

Enteral nutrition (EN) is a diet-remission therapy for inflammatory bowel disease (IBD) that plays a more important role in children than adults. EN includes exclusive enteral nutrition (EEN), partial enteral nutrition (PEN), and maintenance enteral nutrition (MEN). However, EEN remains an unstandardized treatment for pediatric IBD. The types and methods of EN differ around the world. The current study reviewed the EN literature on children with IBD. A total of 12 survey studies were identified that analyzed the current state of EN use, including clinical opinions, implementation methods, treatment course, EEN formula, IBD classification, progress, dietary reintroduction, and patient feedback. The findings revealed that EEN has a strong effect on mild to moderate Crohn's disease (CD). The usage rates of this treatment in different sites were ileum/colon (Paris classification L3) > ileum (L1) > upper digestive tract (L4) > colon (L2) > perianal disease (P) > ulcerative colitis (UC) > extraintestinal lesions. The polymeric formula was the most used EN formulation. New EN diets include a CD exclusion diet (CDED), a specific carbohydrate diet (SCD), and a CD treatment-with-eating (CD-TREAT) diet. Children with IBD responded similarly to EEN administered orally or using a feeding tube. Most guidelines recommended 6-8 weeks of EEN treatment to induce remission. Many clinicians preferred to combine drug medications during EEN and recommended that MEN accounts for at least 25-35% of daily caloric intake. EN remains an unstandardized therapy that requires teamwork across disciplines.

Reducing Disease Activity of Inflammatory Bowel Disease by Consumption of Plant-Based Foods and Nutrients

Inflammatory bowel disease is a chronic and recurring inflammatory condition of the gastrointestinal tract encompassing ulcerative colitis and Crohn's disease. Although the pathogenesis of inflammatory bowel disease remains to be fully elucidated, environmental factors such as diet are believed to play a pivotal role in the onset and management of inflammatory bowel disease. Diet is thought to play an essential role in intestinal inflammation due to its regulatory effects on the microbiota, gut immune system, and epithelial barrier function. Although the evidence remains insufficient to draw firm conclusions on the role of specific dietary components in gastrointestinal diseases, studies have suggested that a Western diet with high intakes of total fats, omega-6 fatty acids, and meat have been associated with intestinal inflammation and relapse of inflammatory bowel disease. In contrast to a Western diet, plant-based diets often result in a reduced intake of total fats and meats and an increased intake of plant fibers which may contribute to reduced intestinal inflammation. This review critically examines the influence of plant-based dietary components on the clinical disease course of inflammatory bowel disease. Furthermore, this review discusses the benefits and possible limitations of plant-derived dietary components in the treatment of inflammatory bowel disease while addressing the principal type of disease and the anatomic site of inflammation within the gastrointestinal tract. Finally, this review points out important directions for future research on the role of diet in inflammatory bowel disease. A better understanding of the role of diet and intestinal inflammation may pave the way for novel dietary interventions and specific foods- or food supplements, which can support the treatment of inflammatory bowel disease.

Efficient Attenuation of Dextran Sulfate Sodium-Induced Colitis by Oral Administration of 5,6-Dihydroxy-8Z,11Z,14Z,17Z-eicosatetraenoic Acid in Mice

5,6-dihydroxy-8Z,11Z,14Z,17Z-eicosatetraenoic acid (5,6-DiHETE) is an eicosapentaenoic acid-derived newly discovered bioactive anti-inflammatory lipid mediator having diverse functions. Here, we assessed the potential of orally administered 5,6-DiHETE in promoting healing of dextran sulfate sodium (DSS)-induced colitis in mice. We measured the plasma concentrations of 5,6-DiHETE in untreated mice before and 0.5, 1, 3, and 6 h after its oral administration (150 or 600 μg/kg) in mice. Mice developed colitis by DSS (2% in drinking water for 4 days), and 5,6-DiHETE (150 or 600 μg/kg/day) was orally administered from day 9 to 14. Next, the faecal hardness and bleeding were assessed, and the dissected colons on day 14 via H&E staining. The plasma concentration of 5,6-DiHETE reached 25.05 or 44.79 ng/mL 0.5 h after the administration of 150 or 600 μg/kg, respectively, followed by a gradual decrease. The half-life of 5,6-DiHETE was estimated to be 1.25-1.63 h. Diarrhoea deteriorated after day 3 and peaked on day 5, followed by a gradual recovery. Histological assessment on day 14 showed DSS-mediated granulocyte infiltration, mucosal erosion, submucosal edema, and cryptal abscesses in mice. Oral administration of 150 or 600 μg/kg/day of 5,6-DiHETE accelerated the recovery from the DSS-induced diarrhoea and significantly ameliorated colon inflammation. The therapeutic effect of 600 μg/kg/day 5,6-DiHETE was slightly stronger than that by 150 μg/kg/day. Our study reveals attenuation of DSS-induced colitis in mice by the oral administration of 5,6-DiHETE dose-dependently, thereby suggesting a therapeutic potential of 5,6-DiHETE for inflammatory bowel disease.

ω-3 Polyunsaturated Fatty Acids on Colonic Inflammation and Colon Cancer: Roles of Lipid-Metabolizing Enzymes Involved

Substantial human and animal studies support the beneficial effects of ω-3 polyunsaturated fatty acids (PUFAs) on colonic inflammation and colorectal cancer (CRC). However, there are inconsistent results, which have shown that ω-3 PUFAs have no effect or even detrimental effects, making it difficult to effectively implement ω-3 PUFAs for disease prevention. A better understanding of the molecular mechanisms for the anti-inflammatory and anticancer effects of ω-3 PUFAs will help to clarify their potential health-promoting effects, provide a scientific base for cautions for their use, and establish dietary recommendations. In this review, we summarize recent studies of ω-3 PUFAs on colonic inflammation and CRC and discuss the potential roles of ω-3 PUFA-metabolizing enzymes, notably the cytochrome P450 monooxygenases, in mediating the actions of ω-3 PUFAs.

Nutrition and the Immune System: A Complicated Tango

Enthusiasm exists for the potential of diet to impact the immune system, prevent disease and its therapeutic potential. Herein, we describe the challenge to nutrition scientists in defining this relationship through case studies of diets and nutrients in the context of allergic and autoimmune diseases. Moderate-quality evidence exists from both human intervention and observational studies to suggest that diet and individual nutrients can influence systemic markers of immune function and inflammation; numerous challenges exist for demonstrating the impact of defined diets and nutrient interventions on clearly influencing immune-mediated-clinical disease endpoints. A growing body of evidence suggests that further consideration of dietary patterns, immune system and gut microbiome composition and function, and subsequent epigenetic modifications are needed to improve our understanding of diet-immune system interactions.

Nutritional approach as therapeutic manipulation in inflammatory bowel disease

Malnutrition is observed more frequently in patients with inflammatory bowel disease (IBD) than in the general population and associated with adverse clinical outcomes. This study aimed to review the current knowledge regarding the efficacy of dietary and nutritional intervention in IBD patients. Exclusive enteral nutrition might be inferior to corticosteroid treatment in adults with active Crohn’s disease (CD) but might even be superior considering the adverse effects of corticosteroid treatment in children. Total parenteral nutrition has no advantage over enteral nutrition, which is considered a more physiologic modality in organ function. Current guidelines do not yet recommend ω3-polyunsaturated fatty acid supplementation for the prevention and maintenance of remission in IBD patients. Dietary fiber supplementation could be effective in the relief of symptoms and maintenance of remission in ulcerative colitis (UC). Although vitamin D may be favorable to clinical course of IBD and bone density. Probiotic supplementation has proven to be effective in preventing and treating pouchitis for UC but is less effective in treating CD. Nutritional interventions not only correct nutritional deficiencies but also improve symptoms and clinical courses of the disease. Hence, nutritional approaches need to be developed to significantly evaluate the effectiveness of dietary interventions used to treat IBD.

Omega Fatty Acids and Inflammatory Bowel Diseases: An Overview

Inflammatory bowel diseases (IBD) are chronic, inflammatory processes that affect the gastrointestinal tract and are mainly represented by ulcerative colitis (UC) and Crohn’s disease (CD). Omega 3 (ω3) fatty acids (eicosapentanoic acid and docosahexaenoic acid) show an indispensable role in the inflammatory processes and, for these reasons, we aimed to review the effects of these acids on UC and CD. Databases such as PUMED and EMBASE were searched, and the final selection included fifteen studies that fulfilled the inclusion criteria. The results showed that ω3 fatty acids reduce intestinal inflammation, induce and maintain clinical remission in UC patients, and are related with the reduction of proinflammatory cytokines, decrease disease activity and increase the quality of life of CD patients. Furthermore, the consumption of these fatty acids may be related to a reduced risk of developing IBD. Many studies have shown the beneficial effects of ω3 as adjunctive in the treatment or prevention of UC or CD. Nevertheless, most were performed with a small number of patients and there are many variations in the mode of consumption, the type of food or the type of formulation used. All these factors substantially interfere with the results and do not allow reliable comparisons.

Fish, Shellfish, and Children's Health: An Assessment of Benefits, Risks, and Sustainability

American children eat relatively little fish and shellfish in comparison with other sources of animal protein, despite the health benefits that eating fish and shellfish may confer. At the same time, fish and shellfish may be sources of toxicants. This report serves to inform pediatricians about available research that elucidates health risks and benefits associated with fish and shellfish consumption in childhood as well as the sustainability of fish and shellfish harvests.

Dietary intake of fish, n-3 polyunsaturated fatty acids, and risk of inflammatory bowel disease: a systematic review and meta-analysis of observational studies

PURPOSE

Fish consumption and dietary intake of n-3 polyunsaturated acids (PUFAs) may be associated with inflammatory bowel disease (IBD). We aimed to conduct a systematic review and summarize published articles on the association between fish consumption and dietary intake of n-3 PUFAs with the risk of IBD.

METHODS

PubMed, Scopus, and Web of Science databases were used to conduct a comprehensive search and identify eligible literature published prior to January 2019. Fixed-effects model or random-effects models (DerSimonian-Laird method) were applied to pool the effect sizes. Cochrane Q test was used to trace the potential source of heterogeneity across studies.

RESULTS

12 studies (5 prospective and 7 case-control) were included in the systematic review, which ten of them were eligible for inclusion in the meta-analysis. Studies were included a total sample size of 282610 participants which 2002 of them were cases of IBD [1061 Crohn's disease (CD) and 937 ulcerative colitis (UC)]. A negative association was found between fish consumption and the incidence of CD (pooled effect size: 0.54, 95%CI: 0.31-0.96, P = 0.03). There was no relationship between total dietary n-3 PUFAs intake and IBD (pooled effect size: 1.17, 95%CI: 0.80-1.72, P = 0.41). A significant inverse association was observed between dietary long-chain n-3 PUFAs and the risk of UC (pooled effect size: 0.75, 95%CI: 0.57-0.98, P = 0.03). Moreover, no association was found between α-Linolenic acid (ALA) and IBD (pooled effect size: 1.17, 95%CI: 0.63-2.17, P = 0.62).

CONCLUSIONS

Findings showed a negative association between fish consumption and the risk of CD. Moreover, there was a significant inverse association between dietary long-chain n-3 PUFAs and the risk of UC.

The Imbalance between n-6/n-3 Polyunsaturated Fatty Acids and Inflammatory Bowel Disease: A Comprehensive Review and Future Therapeutic Perspectives

Eating habits have changed dramatically over the years, leading to an imbalance in the ratio of n-6/n-3 polyunsaturated fatty acids (PUFAs) in favour of n-6 PUFAs, particularly in the Western diet. Meanwhile, the incidence of inflammatory bowel disease (IBD) is increasing worldwide. Recent epidemiological data indicate the potential beneficial effect of n-3 PUFAs in ulcerative colitis (UC) prevention, whereas consumption of a higher ratio of n-6 PUFAs versus n-3 PUFAs has been associated with an increased UC incidence. The long-chain dietary n-3 PUFAs are the major components of n-3 fish oil and have been shown to have anti-inflammatory properties in several chronic inflammatory disorders, being involved in the regulation of immunological and inflammatory responses. Despite experimental evidence implying biological plausibility, clinical data are still controversial, especially in Crohn’s disease. Clinical trials of fish-oil derivatives in IBD have produced mixed results, showing beneficial effects, but failing to demonstrate a clear protective effect in preventing clinical relapse. Such data are insufficient to make a recommendation for the use of n-3 PUFAs in clinical practice. Here, we present the findings of a comprehensive literature search on the role of n-3 PUFAs in IBD development and treatment, and highlight new therapeutic perspectives.

Biosynthesis of proresolving lipid mediators by vascular cells and tissues

Recent evidence suggests that specialized proresolving lipid mediators (SPMs) generated from docosahexaenoic acid (DHA) can modulate the vascular injury response. However, cellular sources for these autacoids within the vessel wall remain unclear. Here, we investigated whether isolated vascular cells and tissues can produce SPMs and assessed expression and subcellular localization of the key SPM biosynthetic enzyme 5-lipoxygenase (LOX) in vascular cells. Intact human arteries incubated with DHA ex vivo produced 17-hydroxy DHA (17-HDHA) and D-series resolvins, as assessed by liquid chromatography-tandem mass spectrometry. Addition of 17-HDHA to human arteries similarly increased resolvin production. Primary cultures of human saphenous vein endothelial cells (ECs) and vascular smooth muscle cells (VSMCs) converted 17-HDHA to SPMs, including resolvin D1 (RvD1) and other D-series resolvins and protectins. This was accompanied by a rapid translocation of 5-LOX from nucleus to cytoplasm in both ECs and VSMCs, potentially facilitating SPM biosynthesis. Conditioned medium from cells exposed to 17-HDHA inhibited monocyte adhesion to TNF-α-stimulated EC monolayers. These downstream effects were partially reversed by antibodies against the RvD1 receptors ALX/FPR2 and GPR32. These results suggest that autocrine and/or paracrine signaling via locally generated SPMs in the vasculature may represent a novel homeostatic mechanism of relevance to vascular health and disease.-Chatterjee, A., Komshian, S., Sansbury, B. E., Wu, B., Mottola, G., Chen, M., Spite, M., Conte, M. S. Biosynthesis of proresolving lipid mediators by vascular cells and tissues.

A Review of Recruitment, Adherence and Drop-Out Rates in Omega-3 Polyunsaturated Fatty Acid Supplementation Trials in Children and Adolescents

INTRODUCTION

The influence of n-3 long-chain polyunsaturated fatty acids (n-3 LCPUFA) supplementation on health outcomes has been studied extensively with randomized controlled trials (RCT). In many research fields, difficulties with recruitment, adherence and high drop-out rates have been reported. However, what is unknown is how common these problems are in n-3 LCPUFA supplementation studies in children and adolescents. Therefore, this paper will review n-3 LCPUFA supplementation studies in children and adolescents with regard to recruitment, adherence and drop-out rates.

METHODS

The Web of Science, PubMed and Ovid databases were searched for papers reporting on RCT supplementing children and adolescents (2-18 years) with a form of n-3 LCPUFA (or placebo) for at least four weeks. As a proxy for abiding to CONSORT guidelines, we noted whether manuscripts provided a flow-chart and provided dates defining the period of recruitment and follow-up.

RESULTS

Ninety manuscripts (reporting on 75 studies) met the inclusion criteria. The majority of the studies did not abide by the CONSORT guidelines: 55% did not provide a flow-chart, while 70% did not provide dates. The majority of studies provided minimal details about the recruitment process. Only 25 of the 75 studies reported an adherence rate which was on average 85%. Sixty-five of the 75 studies included drop-out rates which were on average 17%.

CONCLUSION

Less than half of the included studies abided by the CONSORT guidelines (45% included a flow chart, while 30% reported dates). Problems with recruitment and drop-out seem to be common in n-3 LCPUFA supplementation trials in children and adolescents. However, reporting about recruitment, adherence and dropout rates was very heterogeneous and minimal in the included studies. Some techniques to improve recruitment, adherence and dropout rates were identified from the literature, however these techniques may need to be tailored to n-3 LCPUFA supplementation studies in children and adolescents.

An Examination of Diet for the Maintenance of Remission in Inflammatory Bowel Disease

Diet has been speculated to be a factor in the pathogenesis of inflammatory bowel disease and may be an important factor in managing disease symptoms. Patients manipulate their diet in attempt to control symptoms, often leading to the adoption of inappropriately restrictive diets, which places them at risk for nutritional complications. Health professionals struggle to provide evidence-based nutrition guidance to patients due to an overall lack of uniformity or clarity amongst research studies. Well-designed diet studies are urgently needed to create an enhanced understanding of the role diet plays in the management of inflammatory bowel disease. The aim of this review is to summarize the current data available on dietary management of inflammatory bowel disease and to demonstrate that dietary modulation may be an important consideration in managing disease. By addressing the relevance of diet in inflammatory bowel disease, health professionals are able to better support patients and collaborate with dietitians to improve nutrition therapy.

Environmental risk factors for inflammatory bowel diseases: Evidence based literature review

AIM: Advances in genetics and immunology have contributed to the current understanding of the pathogenesis of inflammatory bowel diseases (IBD).

METHODS: The current opinion on the pathogenesis of IBD suggests that genetically susceptible individuals develop intolerance to dysregulated gut microflora (dysbiosis) and chronic inflammation develops as a result of environmental insults. Environmental exposures are innumerable with varying effects during the life course of individuals with IBD. Studying the relationship between environmental factors and IBD may provide the missing link to increasing our understanding of the etiology and increased incidence of IBD in recent years with implications for prevention, diagnosis, and treatment. Environmental factors are heterogeneous and genetic predisposition, immune dysregulation, or dysbiosis do not lead to the development of IBD in isolation.

RESULTS: Current challenges in the study of environmental factors and IBD are how to effectively translate promising results from experimental studies to humans in order to develop models that incorporate the complex interactions between the environment, genetics, immunology, and gut microbiota, and limited high quality interventional studies assessing the effect of modifying environmental factors on the natural history and patient outcomes in IBD.

CONCLUSION: This article critically reviews the current evidence on environmental risk factors for IBD and proposes directions for future research.

Epidemiology and risk factors for IBD

IBD, comprising Crohn's disease and ulcerative colitis, is a chronic immunologically mediated disease at the intersection of complex interactions between genetics, environment and gut microbiota. Established high-prevalence populations of IBD in North America and Europe experienced the steepest increase in incidence towards the second half of the twentieth century. Furthermore, populations previously considered 'low risk' (such as in Japan and India) are witnessing an increase in incidence. Potentially relevant environmental influences span the spectrum of life from mode of childbirth and early-life exposures (including breastfeeding and antibiotic exposure in infancy) to exposures later on in adulthood (including smoking, major life stressors, diet and lifestyle). Data support an association between smoking and Crohn's disease whereas smoking cessation, but not current smoking, is associated with an increased risk of ulcerative colitis. Dietary fibre (particularly fruits and vegetables), saturated fats, depression and impaired sleep, and low vitamin D levels have all been associated with incident IBD. Interventional studies assessing the effects of modifying these risk factors on natural history and patient outcomes are an important unmet need. In this Review, the changing epidemiology of IBD, mechanisms behind various environmental associations and interventional studies to modify risk factors and disease course are discussed.

Is the omega-3 index a valid marker of intestinal membrane phospholipid EPA+DHA content?

Despite numerous studies investigating n-3 long chain polyunsaturated fatty acid (LCPUFA) supplementation and inflammatory bowel diseases (IBD), the extent to which dietary n-3 LCPUFAs incorporate in gastrointestinal (GI) tissues and correlate with red blood cell (RBC) n-3 LCPUFA content is unknown. In this study, mice were fed three diets with increasing percent of energy (%en) derived from eicosapentaenoic acid (EPA)+docosahexaenoic acid (DHA). Dietary levels reflected recommended intakes of fish/fish oil by the American Heart Association. We analyzed the FA composition of phospholipids extracted from RBCs, plasma, and GI tissues. We observed that the 0.1%en EPA+DHA diet was sufficient to significantly increase the omega-3 index (RBC EPA+DHA) after 5 week feeding. The baseline EPA levels were 0.2-0.6% across all tissues increasing to 1.6-4.3% in the highest EPA+DHA diet; these changes resulted in absolute increases of 1.4-3.9% EPA across tissues. The baseline DHA levels were 2.2-5.9% across all tissues increasing to 5.8-10.5% in the highest EPA+DHA diet; these changes resulted in absolute increases of 3.2-5.7% DHA across tissues. These increases in EPA and DHA across all tissues resulted in strong (r>0.91) and significant (P<0.001) linear correlations between the omega-3 index and plasma/GI tissue EPA+DHA content, suggesting that the omega-3 index reflects the relative amounts of EPA+DHA in GI tissues. These data demonstrate that the GI tissues are highly responsive to dietary LCPUFA supplementation and that the omega-3 index can serve as a valid biomarker for assessing dietary EPA+DHA incorporation into GI tissues.

Altered colonic mucosal Polyunsaturated Fatty Acid (PUFA) derived lipid mediators in ulcerative colitis: new insight into relationship with disease activity and pathophysiology

Objectives

Ulcerative colitis (UC) is a relapsing inflammatory disorder of unconfirmed aetiology, variable severity and clinical course, characterised by progressive histological inflammation and with elevation of eicosanoids which have a known pathophysiological role in inflammation. Therapeutic interventions targetting eicosanoids (5-aminosalicylates (ASA)) are effective first line and adjunctive treatments in mild-moderate UC for achieving and sustaining clinical remission. However, the variable clinical response to 5-ASA and frequent deterioration in response to cyclo-oxygenase (COX) inhibitors, has prompted an in depth simultaneous evaluation of multiple lipid mediators (including eicosanoids) within the inflammatory milieu in UC. We hypothesised that severity of inflammation is associated with alteration of lipid mediators, in relapsing UC.

Design

Study was case-control design. Mucosal lipid mediators were determined by LC-MS/MS lipidomics analysis on mucosal biopsies taken from patients attending outpatients with relapsing UC. Univariate and multivariate statistical analyses were used to investigate the association of mucosal lipid mediators, with the disease state and severity graded histologically.

Results

Levels of PGE₂, PGD₂, TXB₂, 5-HETE, 11-HETE, 12-HETE and 15-HETE are significantly elevated in inflamed mucosa and correlate with severity of inflammation, determined using validated histological scoring systems.

Conclusions

Our approach of capturing inflammatory mediator signature at different stages of UC by combining comprehensive lipidomics analysis and computational modelling could be used to classify and predict mild-moderate inflammation; however, predictive index is diminished in severe inflammation. This new technical approach could be developed to tailor drug treatments to patients with active UC, based on the mucosal lipid mediator profile.

Docosahexaenoic acid, inflammation, and bacterial dysbiosis in relation to periodontal disease, inflammatory bowel disease, and the metabolic syndrome

Docosahexaenoic acid (DHA), a long-chain omega-3 polyunsaturated fatty acid, has been used to treat a range of different conditions, including periodontal disease (PD) and inflammatory bowel disease (IBD). That DHA helps with these oral and gastrointestinal diseases in which inflammation and bacterial dysbiosis play key roles, raises the question of whether DHA may assist in the prevention or treatment of other inflammatory conditions, such as the metabolic syndrome, which have also been linked with inflammation and alterations in normal host microbial populations. Here we review established and investigated associations between DHA, PD, and IBD. We conclude that by beneficially altering cytokine production and macrophage recruitment, the composition of intestinal microbiota and intestinal integrity, lipopolysaccharide- and adipose-induced inflammation, and insulin signaling, DHA may be a key tool in the prevention of metabolic syndrome.

Effects of increase in fish oil intake on intestinal eicosanoids and inflammation in a mouse model of colitis

BACKGROUND

Inflammatory bowel diseases (IBD) are chronic intestinal inflammatory diseases affecting about 1% of western populations. New eating behaviors might contribute to the global emergence of IBD. Although the immunoregulatory effects of omega-3 fatty acids have been well characterized in vitro, their role in IBD is controversial.

METHODS

The aim of this study was to assess the impact of increased fish oil intake on colonic gene expression, eicosanoid metabolism and development of colitis in a mouse model of IBD. Rag-2 deficient mice were fed fish oil (FO) enriched in omega-3 fatty acids i.e. EPA and DHA or control diet for 4 weeks before colitis induction by adoptive transfer of naïve T cells and maintained in the same diet for 4 additional weeks. Onset of colitis was monitored by colonoscopy and further confirmed by immunological examinations. Whole genome expression profiling was made and eicosanoids were measured by HPLC-MS/MS in colonic samples.

RESULTS

A significant reduction of colonic proinflammatory eicosanoids in FO fed mice compared to control was observed. However, neither alteration of colonic gene expression signature nor reduction in IBD scores was observed under FO diet.

CONCLUSION

Thus, increased intake of dietary FO did not prevent experimental colitis.

Experimental evidence of ω-3 polyunsaturated fatty acid modulation of inflammatory cytokines and bioactive lipid mediators: their potential role in inflammatory, neurodegenerative, and neoplastic diseases

A large body of evidence has emerged over the past years to show the critical role played by inflammation in the pathogenesis of several diseases including some cardiovascular, neoplastic, and neurodegenerative diseases, previously not considered inflammation-related. The anti-inflammatory action of ω-3 polyunsaturated fatty acids (PUFAs), as well as their potential healthy effects against the development and progression of the same diseases, has been widely studied by our and others' laboratories. As a result, a rethinking is taking place on the possible mechanisms underlying the beneficial effects of ω-3 PUFAs against these disorders, and, in particular, on the influence that they may exert on the molecular pathways involved in inflammatory process, including the production of inflammatory cytokines and lipid mediators active in the resolving phase of inflammation. In the present review we will summarize and discuss the current knowledge regarding the modulating effects of ω-3 PUFAs on the production of inflammatory cytokines and proresolving or protective lipid mediators in the context of inflammatory, metabolic, neurodegenerative, and neoplastic diseases.

Omega-3 polyunsaturated fatty acids and inflammatory processes: nutrition or pharmacology?

Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are n-3 fatty acids found in oily fish and fish oil supplements. These fatty acids are able to inhibit partly a number of aspects of inflammation including leucocyte chemotaxis, adhesion molecule expression and leucocyte-endothelial adhesive interactions, production of eicosanoids like prostaglandins and leukotrienes from the n-6 fatty acid arachidonic acid, production of inflammatory cytokines and T cell reactivity. In parallel, EPA gives rise to eicosanoids that often have lower biological potency than those produced from arachidonioc acid and EPA and DHA give rise to anti-inflammatory and inflammation resolving resolvins and protectins. Mechanisms underlying the anti-inflammatory actions of n-3 fatty acids include altered cell membrane phospholipid fatty acid composition, disruption of lipid rafts, inhibition of activation of the pro-inflammatory transcription factor nuclear factor kappa B so reducing expression of inflammatory genes, activation of the anti-inflammatory transcription factor NR1C3 (i.e. peroxisome proliferator activated receptor γ) and binding to the G protein coupled receptor GPR120. These mechanisms are interlinked. In adult humans, an EPA plus DHA intake greater than 2 g day⁻¹ seems to be required to elicit anti-inflammatory actions, but few dose finding studies have been performed. Animal models demonstrate benefit from n-3 fatty acids in rheumatoid arthritis (RA), inflammatory bowel disease (IBD) and asthma. Clinical trials of fish oil in patients with RA demonstrate benefit supported by meta-analyses of the data. Clinical trails of fish oil in patients with IBD and asthma are inconsistent with no overall clear evidence of efficacy.

Nutritional management of adults with inflammatory bowel disease: practical lessons from the available evidence

Inflammatory bowel disease (IBD) is associated with impairment of nutritional status both anthropometrically and biochemically, which results from both qualitative and quantitative changes in dietary intake alongside disease activity. Dietary intervention to replace deficiency is essential and may also be used to treat active disease and to reduce symptoms. The evidence for dietary interventions in this area is reviewed and the following recommendations made: ■Assessment of nutritional status is an essential part of the investigation of all patients with IBD and deficiency should be actively sought.■Any patient with macro- or micronutrient deficiency should be referred for dietetic assessment.■Micronutrient deficiency (most frequently iron, vitamin B12, folate and magnesium) should be replaced aggressively, parenterally if necessary.■Significant improvement in gastrointestinal symptoms can be achieved by low-residue diets (for stricturing disease) and (always under dietetic supervision) management of lactose and other intolerances.■Irritable bowel syndrome symptoms in patients with IBD can respond to low fermentable oligo-, di-, monosaccharide and polyol (FODMAP) diets, again this must be done under dietetic supervision.■Active Crohn's disease can be treated by exclusive enteral nutrition (elemental/polymeric/altered fat formulations all have equivalent efficacy).■Enteral nutrition can maintain remission in Crohn's disease and in this context can be given alongside normal oral intake.■Nutritional support does not have an established role in the treatment of active ulcerative colitis, other than in the management of malnutrition.■Total parenteral nutrition should not be used unless intestinal failure occurs.■There is insufficient evidence to support the routine use of Ω3 fish oil, prebiotics and glutamine in the treatment of active IBD.

Current treatment of ulcerative colitis

Ulcerative colitis (UC) is a chronic disease featuring recurrent inflammation of the colonic mucosa. The goal of medical treatment is to rapidly induce a steroid-free remission while at the same time preventing complications of the disease itself and its treatment. The choice of treatment depends on severity, localization and the course of the disease. For proctitis, topical therapy with 5-aminosalicylic acid (5-ASA) compounds is used. More extensive or severe disease should be treated with oral and local 5-ASA compounds and corticosteroids to induce remission. Patients who do not respond to this treatment require hospitalization. Intravenous steroids or, when refractory, calcineurin inhibitors (cyclosporine, tacrolimus), tumor necrosis factor-α antibodies (infliximab) or immunomodulators (azathioprine, 6-mercaptopurine) are then called for. Indications for emergency surgery include refractory toxic megacolon, perforation, and continuous severe colorectal bleeding. Close collaboration between gastroenterologist and surgeon is mandatory in order not to delay surgical therapy when needed. This article is intended to give a general, practice-orientated overview of the key issues in ulcerative colitis treatment. Recommendations are based on published consensus guidelines derived from national and international guidelines on the treatment of ulcerative colitis.

Dietary docosahexaenoic and eicosapentaenoic acid: emerging mediators of inflammation

The inflammatory response is designed to help fight and clear infection, remove harmful chemicals, and repair damaged tissue and organ systems. Although this process, in general, is protective, the failure to resolve the inflammation and return the target tissue to homeostasis can result in disease, including the promotion of cancer. A plethora of published literature supports the contention that dietary n-3 polyunsaturated fatty acids (PUFA), and eicosapentaenoic (EPA, 20:5n-3) and docosahexaenoic acid (DHA, 22:6n-3) in particular, are important modulators of a host's inflammatory/immune responses. The following review describes a mechanistic model that may explain, in part, the pleiotropic anti-inflammatory and immunosuppressive properties of EPA and DHA. In this review, we focus on salient studies that address three overarching mechanisms of n-3 PUFA action: (i) modulation of nuclear receptor activation, i.e., nuclear factor-kappaB (NF-kappaB) suppression; (ii) suppression of arachidonic acid-cyclooxygenase-derived eicosanoids, primarily prostaglandin E(2)-dependent signaling; and (iii) alteration of the plasma membrane micro-organization (lipid rafts), particularly as it relates to the function of Toll-like receptors (TLRs), and T-lymphocyte signaling molecule recruitment to the immunological synapse (IS). We propose that lipid rafts may be targets for the development of n-3 PUFA-containing dietary bioactive agents to down-modulate inflammatory and immune responses and for the treatment of autoimmune and chronic inflammatory diseases.

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.