Effect of fish oil enriched enteral diet on inflammatory bowel disease tissues in organ culture: Differential effects on ulcerative colitis and Crohn’s disease

Inflammatory bowel disease therapeutic strategies by modulation of the microbiota: how and when to introduce pre-, pro-, syn-, or postbiotics?

Inflammatory bowel diseases (IBD), a heterogeneous group of inflammatory conditions that encompass both ulcerative colitis and Crohn's disease, represent a major public health concern. The etiology of IBD is not yet fully understood and no cure is available, with current treatments only showing long-term effectiveness in a minority of patients. A need to increase our knowledge on IBD pathophysiology is growing, to define preventive measures, to improve disease outcome, and to develop new effective and lasting treatments. IBD pathogenesis is sustained by aberrant immune responses, associated with alterations of the intestinal epithelial barrier (IEB), modifications of the enteric nervous system, and changes in microbiota composition. Currently, most of the treatments target the inflammation and the immune system, but holistic approaches targeting lifestyle and diet improvements are emerging. As dysbiosis is involved in IBD pathogenesis, pre-, pro-, syn-, and postbiotics are used/tested to reduce the inflammation or strengthen the IEB. The present review will resume these works, pointing out the stage of life, the duration, and the environmental conditions that should go along with microbiota or microbiota-derived treatments.

Habitual Fish Oil Supplementation and Risk of Incident Inflammatory Bowel Diseases: A Prospective Population-Based Study

Background

Inflammatory Bowel Diseases (IBDs) have been emerging in recent years with the advance of global industrialization and diet pattern transformation. Marine n-3 polyunsaturated fatty acids (n-3 PUFAs), enriched in fish oils, have well-known human health promotion. Evidence on the association of fish oil supplementation with the risk of developing IBDs was scarce. This study aimed to examine the association between the use of fish oil supplements and the risk of developing inflammatory bowel diseases (IBDs) among the general population.

Methods

We conducted a prospective cohort study of 447,890 participants aged 40-69 years from the UK Biobank. A touch screen questionnaire was used to get the data about fish oil intake at baseline. Incident diagnoses of IBDs were ascertained by the International Classification of Diseases (ICD-9 and ICD-10) or self-report. Cox proportional hazards model was applied to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) of developing IBDs and their subtypes.

Results

We documented 1,646 incident cases of IBDs, including 533 incident cases of Crohn's disease (CD) and 1,185 incident cases of ulcerative colitis (UC) during an average of 8 years of follow-up. After multivariate adjustment, the use of fish oil was associated with a 12% lower risk of IBDs (HR: 0.88, 95% CI: 0.78-0.99, p = 0.03) compared with non-consumers. For subtypes of IBDs, fish oil supplementation was inversely associated with a 15% lower risk of UC (HR: 0.85, 95% CI: 0.75-0.99, p = 0.02) but was not correlated with the risk of CD (p = 0.22). Besides, fish oil supplementation showed a significant inverse correlation with baseline CRP levels (β = -0.021, p < 0.001) and a positive association with baseline albumin levels (β = 0.135, p < 0.001) after adjustment for multiple variates.

Conclusion

Habitual intake of fish oil supplements was associated with a lower risk of IBDs and UC. Fish oil users tended to have lower baseline C-reactive protein levels and higher baseline albumin levels compared with non-users. It was concluded that fish oil supplement use may be recommended for the prevention and control of IBDs.

Dietary Supplementation with Vitamin D, Fish Oil or Resveratrol Modulates the Gut Microbiome in Inflammatory Bowel Disease

Gastrointestinal health is influenced by the functional genes and metabolites generated by the human microbiome. As the volume of current biomedical and translational research indicates, the importance and impact of this ecosystem of microorganisms, especially those comprising the gut microbiome on human health, has become increasingly apparent. Changes to the gut microbiome are associated with inflammatory bowel disease (IBD), which is characterized by persistent intestinal inflammation. Furthermore, the lifetime dietary choices of their host may positively or negatively affect both the gut microbiome and its impact on IBD. As such, "anti-inflammatory" dietary supplements, their impact, and mechanisms in restoring gut microbiota homeostasis during IBD is an area of intensive research. Dietary supplementation may represent an important adjuvant treatment avenue for limiting intestinal inflammation in IBD. Overall, this review addresses the development of the gut microbiome, the significance of the gut microbiome in IBD, and the use of dietary supplements such as vitamin D, fish oil, and resveratrol in the mitigation of IBD-associated gut dysbiosis and intestinal inflammation.

Actors and Factors in the Resolution of Intestinal Inflammation: Lipid Mediators As a New Approach to Therapy in Inflammatory Bowel Diseases

In the last few decades, the pathogenesis of inflammatory bowel disease (IBD) in genetically predisposed subjects susceptible to specific environmental factors has been attributed to disturbance of both the immune and non-immune system and/or to the imbalanced interactions with microbes. However, increasing evidences support the idea that defects in pro-resolving pathways might strongly contribute to IBD onset. The resolution of inflammation is now recognized as a dynamic event coordinated by specialized pro-resolving lipid mediators (LMs), which dampen inflammation-sustaining events, such as angiogenesis, release of pro-inflammatory cytokines, clearance of apoptotic cells, and microorganisms. Among these pro-resolving molecules, those derived from essential polyunsaturated fatty acids (PUFAs) have been shown to induce favorable effects on a plethora of human inflammatory disorders, including IBD. Here, we offer a summary of mechanisms involving both cellular and molecular components of the immune response and underlying the anti-inflammatory and pro-resolving properties of PUFAs and their derivatives in the gut, focusing on both ω-3 and ω-6 LMs. These fatty acids may influence IBD progression by: reducing neutrophil transmigration across the intestinal vasculature and the epithelium, preventing the release of pro-inflammatory cytokines and the up-regulation of adhesion molecules, and finally by promoting the production of other pro-resolving molecules. We also discuss the numerous attempts in using pro-resolving PUFAs to ameliorate intestinal inflammation, both in patients with IBD and mouse models. Although their effects in reducing inflammation is incontestable, results from previous works describing the effects of PUFA administration to prevent or treat IBD are controversial. Therefore, more efforts are needed not only to identify and explain the physiological functions of PUFAs in the gut, but also to unveil novel biosynthetic pathways of these pro-resolving LMs that may be dysregulated in these gut-related disorders. We suppose that either PUFAs or new medications specifically promoting resolution-regulating mediators and pathways will be much better tolerated by patients with IBD, with the advantage of avoiding immune suppression.

Polyunsaturated Fatty Acids and Their Derivatives: Therapeutic Value for Inflammatory, Functional Gastrointestinal Disorders, and Colorectal Cancer

Polyunsaturated fatty acids (PUFAs) are bioactive lipids which modulate inflammation and immunity. They gained recognition in nutritional therapy and are recommended dietary supplements. There is a growing body of evidence suggesting the usefulness of PUFAs in active therapy of various gastrointestinal (GI) diseases. In this review we briefly cover the systematics of PUFAs and their metabolites, and elaborate on their possible use in inflammatory bowel disease (IBD), functional gastrointestinal disorders (FGIDs) with focus on irritable bowel syndrome (IBS), and colorectal cancer (CRC). Each section describes the latest findings from in vitro and in vivo studies, with reports of clinical interventions when available.

Nutrition in Pediatric Inflammatory Bowel Disease: From Etiology to Treatment. A Systematic Review

Nutrition is involved in several aspects of pediatric inflammatory bowel disease (IBD), ranging from disease etiology to induction and maintenance of disease. With regards to etiology, there are pediatric data, mainly from case-control studies, which suggest that some dietary habits (for example consumption of animal protein, fatty foods, high sugar intake) may predispose patients to IBD onset. As for disease treatment, exclusive enteral nutrition (EEN) is an extensively studied, well established, and valid approach to the remission of pediatric Crohn’s disease (CD). Apart from EEN, several new nutritional approaches are emerging and have proved to be successful (specific carbohydrate diet and CD exclusion diet) but the available evidence is not strong enough to recommend this kind of intervention in clinical practice and new large experimental controlled studies are needed, especially in the pediatric population. Moreover, efforts are being made to identify foods with anti-inflammatory properties such as curcumin and long-chain polyunsaturated fatty acids n-3, which can possibly be effective in maintenance of disease. The present systematic review aims at reviewing the scientific literature on all aspects of nutrition in pediatric IBD, including the most recent advances on nutritional therapy.

Oleic acid, hydroxytyrosol and n-3 fatty acids collectively modulate colitis through reduction of oxidative stress and IL-8 synthesis; in vitro and in vivo studies

Our recent study has demonstrated that medium chain triglycerides (MCT) and monounsaturated fatty acids potentiate the beneficial effects of fish oil on risk factors of cardiovascular disease. In the present study, we have investigated the influence of MCT or olive oil on the protective and mucosal healing ability of fish oil in ulcerative colitis using cell simulation and animal models. Caco-2 cells grown in medium chain fatty acids enriched medium has exaggerated t-butyl hydroperoxide induced cell damage, GSH depletion, and IL-1β induced IL-8 synthesis, compared to the cells grown in oleic acid & hydroxytyrosol (OT) enriched medium. Further, combined treatment of cells with eicosapentaenoic acid, docosahexaenoic acid, and OT has remarkably attenuated the cell damage, and IL-8 synthesis, compared to individual treatments. To evaluate the effect of these lipid formulations in vivo, adult Wistar rats were fed diet enriched with high amount of medium chain triglycerides (MCT), virgin olive oil, or their combination with fish oil. Colitis was induced in rats using dextran sulfate sodium (DSS) for 7days followed by 10-days of recovery period. Rats of MCT group exhibit severe disease activity, higher levels of inflammatory cytokines in the colon compared to the olive oil group. Furthermore, there was persistent body weight loss, loose stools, higher levels of inflammatory cytokines in the rats of MCT group, even after DSS was withdrawn from drinking water. Conversely, fish oil has remarkably attenuated the DSS induced alterations in both MCT and olive oil diet groups with significantly greater effect in the olive oil group. Thus, MCT increase the susceptibility to colitis through oxidative damage and IL-8 synthesis in intestinal epithelial cells. The beneficial effects of virgin olive oil could be partially attributed to hydroxytyrosol. Combined treatment of hydroxytyrosol, oleic acid and n-3 fatty acids exhibit huge therapeutic benefits in colitis.

Prospective double-blind randomized study on the efficacy and safety of an n-3 fatty acid enriched intravenous fat emulsion in postsurgical gastric and colorectal cancer patients

Background

A lipid emulsion composed of soybean oil (long-chain triglycerides, LCT), medium-chain triglycerides (MCT) and n-3 poly-unsaturated fatty acids (PUFAs) was evaluated for immune-modulation efficacy, safety, and tolerance in patients undergoing major surgery for gastric and colorectal cancer.

Methods

In a prospective, randomized, double-blind study, 99 patients with gastric and colorectal cancer receiving elective surgery were recruited and randomly assigned to either the study group, receiving the n-3 PUFAs enriched intravenous fat emulsion (IVFE), or the control group, receiving a lipid emulsion comprised of soybean oil and MCTs (0.8 – 1.5 g · kg^-1 · day^-1) as part of total parenteral nutrition (TPN) regimen from surgery (day -1) up to post-operative day 7. Safety and efficacy parameters were assessed on day -1 and post-operative visits on day 1, 3, and 7. Adverse events were documented daily and compared between the groups.

Results

Pro-inflammatory markers, laboratory parameters, and adverse events did not differ prominently between the 2 groups, with the exception of net changes (day 7 minus day -1) of free fatty acids (FFAs), triglyceride, and high-density lipoprotein (HDL). Net decrease of FFAs was remarkably higher in the study group, while the net increase of triglyceride and decrease of HDL was significantly lower.

Conclusions

The n-3 PUFA-enriched IVFE showed improvements in lipid metabolism. In respect of efficacy, safety and tolerance both IVFE were comparable. In patients with severe stress, there is an inflammation-attenuating effect of n-3 PUFAs. Further, adequately powered clinical trials will be necessary to address this question in postsurgical GI cancer patients.

Trial registration

US ClinicalTrials.gov NCT00798447.

Chemically defined diet alters the protective properties of fructo-oligosaccharides and isomalto-oligosaccharides in HLA-B27 transgenic rats

Non-digestible oligosaccharides (NDO) were shown to reduce inflammation in experimental colitis, but it remains unclear whether microbiota changes mediate their colitis-modulating effects. This study assessed intestinal microbiota and intestinal inflammation after feeding chemically defined AIN-76A or rat chow diets, with or without supplementation with 8 g/kg body weight of fructo-oligosaccharides (FOS) or isomalto-oligosaccharides (IMO). The study used HLA-B27 transgenic rats, a validated model of inflammatory bowel disease (IBD), in a factorial design with 6 treatment groups. Intestinal inflammation and intestinal microbiota were analysed after 12 weeks of treatment. FOS and IMO reduced colitis in animals fed rat chow, but exhibited no anti-inflammatory effect when added to AIN-76A diets. Both NDO induced specific but divergent microbiota changes. Bifidobacteria and Enterobacteriaceae were stimulated by FOS, whereas copy numbers of Clostridium cluster IV were decreased. In addition, higher concentrations of total short-chain fatty acids (SCFA) were observed in cecal contents of rats on rat chow compared to the chemically defined diet. AIN-76A increased the relative proportions of propionate, iso-butyrate, valerate and iso-valerate irrespective of the oligosaccharide treatment. The SCFA composition, particularly the relative concentration of iso-butyrate, valerate and iso-valerate, was associated (P ≤ 0.004 and r ≥ 0.4) with increased colitis and IL-1 β concentration of the cecal mucosa. This study demonstrated that the protective effects of fibres on colitis development depend on the diet. Although diets modified specific cecal microbiota, our study indicates that these changes were not associated with colitis reduction. Intestinal inflammation was positively correlated to protein fermentation and negatively correlated with carbohydrate fermentation in the large intestine.

Omega 3 fatty acids (fish oil) for maintenance of remission in Crohn's disease

BACKGROUND

The anti-inflammatory effects of n-3 (omega-3 fatty acids, fish oil) have been suggested to be beneficial in chronic inflammatory disorders such as inflammatory bowel disease. This review is an update of a previously published Cochrane review.

OBJECTIVES

To systematically review the efficacy and safety of n-3 for maintenance of remission in Crohn's disease (CD).

SEARCH METHODS

The following databases were searched from inception to November 2013 without language restriction: CENTRAL, MEDLINE, EMBASE, HealthSTAR, PubMed, and ACP journal club.

SELECTION CRITERIA

Randomized placebo-controlled trials (RCT) of n-3 for maintenance of remission in CD were included. Studies must have enrolled patients of any age group, who were in remission at the time of recruitment, and were followed for at least six months. The intervention must have been fish oil or n-3 given in pre-defined dosage. Co-interventions were allowed only if they were balanced between the study groups.

DATA COLLECTION AND ANALYSIS

The primary outcome was the relapse rate and secondary outcomes included change in disease activity scores, time to first relapse and adverse events. Two independent investigators reviewed studies for eligibility, extracted the data and assessed study quality using the Cochrane risk of bias tool. The overall quality of the evidence supporting the primary and selected secondary outcomes was reassessed for the current update using the GRADE system. We used the RevMan software for analyses. We calculated the risk ratio (RR) and corresponding 95% confidence interval (CI) for dichotomous outcomes and the hazard ratio and 95% CI for time-to-event outcomes. Random-effects or fixed-effect models were used according to degree of heterogeneity and sensitivity analyses were performed in an attempt to explore possible sources of heterogeneity.

MAIN RESULTS

Six studies with a total of 1039 patients were eligible for inclusion. The two largest studies were rated as low risk of bias for all assessed items. Four studies were rated as unclear risk of bias for randomization and allocation concealment. Two studies were rated as high risk of bias for incomplete outcome data and selective reporting. There was a marginal significant benefit of n-3 therapy for maintenance of remission. Thirty-nine per cent of patients in the n-3 group relapsed at 12 months compared to 47% of placebo patients (6 studies, 1039 patients; RR 0.77, 95% CI 0.61 to 0.98). A GRADE analysis rated the overall quality of the evidence for the primary outcome (i.e. relapse) as very low due to unexplained heterogeneity (I2 = 58%), publication bias, and a high or unknown risk of bias in four studies in the pooled analysis. When two large studies at low risk of bias were considered the benefit was no longer statistically significant. Thirty-seven per cent of patients in the n-3 group relapsed at 12 months compared to 42% of placebo patients (2 studies, 738 patients; RR 0.88, 95% CI 0.74 to 1.05). No significant heterogeneity was identified for this pooled analysis ( I2 = 0%). A GRADE analysis indicated that the overall quality of the evidence supporting this outcome was moderate due to sparse data (294 events). No serious adverse events were recorded in any of the studies but in a pooled analyses there was a significantly higher rate of diarrhea (4 studies, 862 patients; RR 1.36 95% CI 1.01 to 1.84) and upper gastrointestinal tract symptoms (5 studies, 999 patients; RR 1.65, 95% CI 1.25 to 2.18) in the n-3 treatment group.

AUTHORS' CONCLUSIONS

Evidence from two large high quality studies suggests that omega 3 fatty acids are probably ineffective for maintenance of remission in CD. Omega 3 fatty acids appear to be safe although they may cause diarrhea and upper gastrointestinal tract symptoms.

A double-blind randomized study comparing the efficacy and safety of a composite vs a conventional intravenous fat emulsion in postsurgical gastrointestinal tumor patients

BACKGROUND

Composite intravenous fat emulsion, a fat emulsion composed of soybean oil, medium-chain triglycerides (MCT), olive oil, and fish oil, was evaluated for metabolic efficacy, immune modulation, clinical efficacy, safety, and tolerance in surgical gastrointestinal (GI) tumor patients.

METHODS

In a prospective, randomized, double-blind study, 40 patients were randomized after elective digestive surgery to receive isonitrogenous, isoenergetic parenteral nutrition for 5 days postoperatively with either composite 20% IVFE (composed of soybean, MCT, olive, and fish oils) or a conventional long-chain triglyceride (LCT)/MCT 20% IVFE (LCT/MCT IVFE); IVFE was dosed at 1-2 g/kg body weight. Safety and efficacy parameters were assessed on operation day (day 0) and at the end of study (day 6). Adverse events were documented daily and clinical outcomes were recorded and compared between the groups.

RESULTS

Metabolic parameters, laboratory parameters, proinflammatory cytokine levels, adverse events, and clinical outcomes did not differ between the 2 groups, with the exception that postoperative low-density lipoprotein levels decreased significantly in the composite IVFE group (93.2 ± 24.3 vs 110.5 ± 26.4 mg/dL, P = .038).

CONCLUSIONS

composite IVFE was comparable with conventional LCT/MCT IVFE in efficacy, safety, tolerance, and clinical outcomes in surgical GI tumor patients.

Treatment of inflammatory bowel disease (IBD)

Inflammatory bowel disease (IBD) is a chronic inflammatory disease of the gastrointestinal tract, which includes Crohn's disease (CD) and ulcerative colitis (UC). These diseases have become important health problems. Medical therapy for IBD has advanced dramatically in the last decade with the introduction of targeted biologic therapies, the optimization of older therapies, including rugs such as immunomodulators and 5-aminosalicylic acid (5-ASA), and a better understanding of the mucosal immune system and the genetics involved in the pathogenesis of IBD. The goal of IBD therapy is to induce and maintain remission. The current treatment paradigm involves a step-up approach, moving to aggressive, powerful therapies only when milder therapies with fewer potential side effects fail or when patients declare themselves to have an aggressive disease. This review focuses on the current treatments for inflammatory bowel disease.

Anti-inflammatory and anti-angiogenic effect of long chain n-3 polyunsaturated fatty acids in intestinal microvascular endothelium

BACKGROUND & AIMS

The role of endothelial cells in inflammatory bowel disease has been recently emphasized. Endothelial activation and expression of adhesion molecules are critical for leukocytes recruitment into the inflammatory wall. Compelling evidence demonstrated anti-inflammatory effects of long chain n-3 PUFA in inflammatory models. We previously showed that long chain n-3 PUFA (EPA and DHA) inhibited inflammatory response in epithelial and dendritic cells. As long chain n-3 PUFA treatment led to a decreased expression of adhesion molecules in endothelial cells from other organs, we have now investigated their effect on intestinal endothelial cells in vitro and in colitic rats.

METHODS

In vitro study: Primary culture of human intestinal microvascular endothelial cells (HIMEC) were pre-treated with DHA and then incubated with IL-1β. In vivo study: Colitis was induced in 2 groups at day0 by intrarectal injection of 2-4-6-trinitrobenzen sulfonic acid (TNBS). Rats received by gavage either fish oil, rich in EPA and DHA (TNBS+n-3) or an isocaloric isolipidic oil formula for 14 days.

RESULTS

DHA led to a decreased VCAM-1, TLR4, cyclooxygenase-2 and VEGFR2 expression and a decreased production of IL-6, IL-8 and GM-CSF and a reduced production of PGE(2) and LTB(4) (p < 0.001) in IL-1β-induced HIMEC. Similarly, dietary intervention with fish oil rich in EPA and DHA significantly decreased colon production of PGE(2) and LTB(4,) endothelial VCAM-1 and VEGFR2 in rats with colitis.

CONCLUSIONS

Data obtained from in vitro and in vivo studies reveal a potential anti-angiogenic role of long chain n-3 PUFA in intestinal endothelial cells. This protective effect of long chain n-3 PUFA may partly explain the observed benefit of dietary intake of long chain n-3 PUFA in IBD development.

Maintenance of remission in inflammatory bowel disease using omega-3 fatty acids (fish oil): a systematic review and meta-analyses

The objective was to systematically review the efficacy and safety of n-3 (omega-3 fatty acids, fish oil) for maintaining remission in Crohn's disease (CD) and ulcerative colitis (UC). Electronic databases were searched systematically for randomized controlled trials of n-3 for maintenance of remission in inflammatory bowel disease (IBD). Studies of patients of any age group who were in remission at the time of recruitment and were followed for at least 6 months were included. The primary outcome was relapse rate at the end of the follow-up period. Nine studies were eligible for inclusion; six studies of CD (n = 1039) and three of UC (n = 138). There was a statistically significant benefit for n-3 in CD (relative risk [RR] 0.77; 95% confidence interval [CI] 0.61-0.98); however, the studies were heterogeneous (I(2) = 58%). The absolute risk reduction was -0.14 (95% CI: -0.25 to -0.02). Opinions may vary on whether this is a clinically significant effect. Two well-done studies with a larger sample size reported no benefit. A sensitivity analysis excluding a small pediatric study resulted in the pooled RR being no longer statistically significant. A funnel plot analysis suggested publication bias for the smaller studies. For UC, there was no difference in the relapse rate between the n-3 and control groups (RR 1.02; 95% CI: 0.51-2.03). The pooled analysis showed a higher rate of diarrhea (RR 1.36; 95% CI: 1.01-1.84) and symptoms of the upper gastrointestinal tract (RR 1.96; 95% CI: 1.37-2.80) in the n-3 treatment group. There are insufficient data to recommend the use of omega 3 fatty acids for maintenance of remission in CD and UC.

An α-linolenic acid-rich formula reduces oxidative stress and inflammation by regulating NF-κB in rats with TNBS-induced colitis

We have previously shown that α-linolenic acid (ALA), a (n-3) PUFA exerts in vitro antiinflammatory effects in the intestine. In this study, we aimed to evaluate its effect on inflammatory and oxidative stress in a colitis model. Colitis was induced in 2 groups at d 0 by intrarectal injection of 2-4-6-trinitrobenzen sulfonic acid (TNBS), whereas the control group received the vehicle. Rats we fed 450 mg . kg(-1) . d(-1) of ALA (TNBS+ALA) while the other colitic group (TNBS) and the control group were fed an isocaloric corn oil formula for 14 d (from d -7 to d 7). RBC fatty acid composition was assessed. Oxidative stress was studied by measuring urinary 8-isoprostanes (8-IP) and colon glutathione (GSH) concentration and inducible nitric oxide synthase (iNOS) expression. Colitis was assessed histologically, by production of proinflammatory mediators, including cytokines, leukotrienes B(4) (LTB(4)), and cyclooxygenase-2 (COX-2) and by nuclear factor-κB (NF-κB) activation. The ALA-rich diet significantly increased the RBC levels of ALA, eicosapentaenoic acid, and docosapentaenoic acid (n-3) compared with the TNBS group (P < 0.01 for all). The beneficial effect of ALA supplementation on oxidative stress was reflected by lower urinary 8-IP levels (P < 0.05), a normalized colon GSH concentration (P < 0.01), and reduced colon iNOS expression (P < 0.05) compared with the TNBS group. ALA also protected against colon inflammation as assessed by lower tumor necrosis factor-α secretion and mRNA level (P < 0.05), reduced NF-κB activation (P = 0.01), and lower colon lipid mediator concentrations such as LTB(4) and COX-2 (P < 0.05) compared with the TNBS group. These findings show that an ALA-rich formula is beneficial to TNBS-induced colitic rats via inhibition of oxidative and inflammatory stress.

Regional variations in the use of complementary and alternative medicines (CAM) for inflammatory bowel disease patients in Italy: an IG-IBD study

BACKGROUND AND AIM

Complementary and alternative medicines (CAM) are being used increasingly by patients with Crohn's disease (CD) and ulcerative colitis (UC). We aimed to assess the prevalence and usage of CAM in different geographical areas of Italy and possible predictors of their use.

METHODS AND MATERIALS

A structured questionnaire, administered to outpatients, attending 8 general hospitals and 9 tertiary referral centres, was completed by 2011 patients (909 CD, 1087 UC and 15 indeterminate colitis). 583 patients lived in the North, 659 in Central Italy and 769 in the South.

RESULTS

CAM users were 475 (23.6%) with no regional differences in their distribution. Usage correlated significantly with female gender (p=0.030), higher education (p=0.021), hospitalization rates (p=0.000), extra-intestinal complications (p=0.000), non-adherence to conventional treatments (p=0.054), adverse reactions to conventional treatments (p=0.000), and active disease (p=0.007); 5-ASA usage was associated with a more limited use of CAM (p=0.005). Dietary changes or supplements and prayer were significantly more frequently reported in South, while Northern Italian patients more frequently used homeopathy, herbal medicines and physical exercises. Patients in Central Italy adopted an intermediate behavior. CAM use ameliorated the patient's general well-being according to two thirds of the users. Costs were higher for Northern patients than in Central or Southern Italy.

CONCLUSION

One in four IBD patients in Italy use CAM. More money is spent on CAM in Northern Italy. Regional differences emerged as regards the type of CAM but not in terms of disease features, frequency of and reasons for CAM use, or perceived effects.

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.

Change in the fatty acid pattern of erythrocyte membrane phospholipids after oral supplementation of specific fatty acids in patients with gastrointestinal diseases

BACKGROUND/OBJECTIVES

The fatty acid pattern of membrane phospholipids is suggested to affect membrane fluidity and epithelial barrier function as a result of membrane fatty acid unsaturation. The incorporation of n-3 polyunsaturated fatty acids (PUFAs) into membrane phospholipids may diminish inflammatory potential in patients with gastrointestinal diseases. The aim of this study was to improve the fatty acid profile of erythrocyte membrane phospholipids after oral supplementation of specific fatty acids in patients with maldigestion and/or malabsorption.

SUBJECTS/METHODS

We conducted a randomized, double-blind, controlled trial. A total of 48 patients with gastrointestinal diseases received either fat-soluble vitamins A,D,E,K (ADEK) or ADEK plus fatty acids alpha-linolenic acid (ALA), docosahexaenoic acid (DHA) and medium-chain triglycerides (FA-ADEK) for 12 weeks. The fatty acid profile of erythrocyte membrane phospholipids, dietary intake, plasma antioxidant vitamins and serum gamma-glutamyl transferase (GGT) were evaluated at baseline, 8 and 12 weeks after supplementation.

RESULTS

Supplementation with FA-ADEK increased ALA, DHA and eicosapentaenoic acid (EPA) concentrations of erythrocyte membrane phospholipids by 0.040, 1.419 and 0.159%, respectively, compared with ADEK supplementation (-0.007, 0.151 and 0.002%, respectively) after 12 weeks (all P<or=0.001). Serum GGT activity decreased in patients receiving FA-ADEK compared with those receiving ADEK with a significant difference after 8 weeks.

CONCLUSIONS

The significant change in erythrocyte membrane fatty acid pattern demonstrates the incorporation of orally administered n-3 PUFA in patients with maldigestion and malabsorption. The increase in ALA and DHA, as well as the conversion of ALA to EPA is attributed to the supplementation of sufficient amounts of ALA and DHA, respectively. Serum GGT activity decreased in response to decreased oxidative stress.

Omega 3 fatty acids (fish oil) for maintenance of remission in Crohn's disease

BACKGROUND

The anti-inflammatory effects of n-3 (omega-3 fatty acids, fish oil) have been suggested to be beneficial in chronic inflammatory disorders such as inflammatory bowel disease.

OBJECTIVES

To systematically review the efficacy and safety of n-3 for maintenance of remission in Crohn's disease (CD).

SEARCH STRATEGY

The following databases were searched from their inception without language restriction: Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE, Healthstar, PubMed, and ACP journal club. Experts were contacted for unpublished data.

SELECTION CRITERIA

Randomized placebo-controlled trials (RCT) of n-3 for maintenance of remission in CD were included. Studies must have enrolled patients of any age group, who were in remission at the time of recruitment, and were followed for at least six months. The intervention must have been fish oil or n-3 given in pre-defined dosage. Co-interventions were allowed only if they were balanced between the study groups. The primary outcome was the relapse rate and secondary outcomes included change in disease activity scores, time to first relapse and adverse events.

DATA COLLECTION AND ANALYSIS

Two independent investigators reviewed studies for eligibility, extracted the data and assessed study quality using Jadad's criteria. Meta-analyses were performed using RevMan 4.2 software weighted by the Mantel-Haenszel method. Random or fixed effect models were used according to degree of heterogeneity and subgroup analyses were performed in an attempt to explore possible sources of heterogeneity.

MAIN RESULTS

Six studies were eligible for inclusion. There was a marginal significant benefit of n-3 therapy for maintaining remission (RR 0.77 0.; 95%CI 0.61 to 0.98; P = 0.03). However, the studies were both clinically and statistically heterogeneous (P = 0.03, I(2) = 58%). Two large studies showed negative results. When considering the estimated rather than the observed 1-year relapse rate of these two studies, the benefit was no longer statistically significant (RR 0.59; 95% CI 0.34 to 1.03; P=0.06). A funnel plot suggested publication bias. No serious adverse events were recorded in any of the studies but in a pooled analyses there was a significantly higher rate of diarrhea (RR 1.36 95% CI 1.01 to 1.84) and symptoms of the upper gastrointestinal tract (RR 1.98 95% CI 1.38 to 2.85) in the n-3 treatment group.

AUTHORS' CONCLUSIONS

Omega 3 fatty acids are safe but probably ineffective for maintenance of remission in CD. The existing data do not support routine maintenance treatment of Crohn's disease with omega 3 fatty acids.

Comparison of cytokine modulation by natural peroxisome proliferator-activated receptor gamma ligands with synthetic ligands in intestinal-like Caco-2 cells and human dendritic cells--potential for dietary modulation of peroxisome proliferator-activated receptor gamma in intestinal inflammation

BACKGROUND

Peroxisome proliferator-activated receptor gamma (PPARgamma) plays a role in the regulation of intestinal inflammation and is activated by both natural (polyunsaturated fatty acid; PUFAs) and synthetic (troglitazone) ligands. The fatty acid content of defined formula diets may play a role in mediating the antiinflammatory effect, but the mechanism is unclear.

OBJECTIVE

We evaluated to what extent the effect of PUFAs on intestinal inflammation is mediated via PPARgamma.

DESIGN

The human enterocyte-like cell line Caco-2 and human dendritic cells were stimulated by interleukin (IL) 1beta and lipoprotein polysaccharide, respectively, in the presence of PPARgamma agonists (troglitazone or PUFAs) or antagonist (GW9662). Five PUFAs were tested: alpha-linolenic acid (ALA), conjugated linoleic acid (CLA), docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA), and gamma-linolenic acid (GLA). Cytokine production was measured by enzyme-linked immunosorbent assay and PPARgamma, I-kappaB, and inducible nitric oxide synthase (iNOS) expression by Western blot.

RESULTS

In Caco-2 cells, IL-6 secretion was significantly decreased by troglitazone, DHA, EPA, and GLA. IL-8 production was significantly decreased by troglitazone, ALA, DHA, EPA, and GLA. PPARgamma expression was significantly increased by troglitazone, DHA, and EPA. iNOS expression was significantly decreased by troglitazone, DHA, and EPA. Troglitazone and PUFAs at 0.1 mumol/L tended to increase the expression of I-kappaB. Addition of GW9662 reversed the effect of troglitazone and PUFAs at 0.1 mumol/L on IL-8 production and decreased the expression of PPARgamma. EPA and DHA also modulated the dendritic cell response to lipoprotein polysaccharide.

CONCLUSIONS

The tested PUFAs exerted an antiinflammatory effect in vitro in both models. This effect of PUFAs in Caco-2 cells is similar to that of troglitazone on intestinal inflammation mediated by PPARgamma, and the potency of the antiinflammatory effect is linked to the number of double bonds.

Diet and ulcerative colitis

Dietary factors have been considered as a possible risk factor for ulcerative colitis (UC). Red meat, high fat intake and high protein intake are associated with development and relapse in UC. On the other hand, probiotics, fish oil and dietary fiber have shown good efficacy in the treatment of UC. This paper reviews the updated data on the role of dietary factors in the pathogenesis and treatment of UC.

Detection of inflammatory bowel disease by proton magnetic resonance spectroscopy (1H MRS) using an animal model

BACKGROUND

The aim of this study was to analyze the potential of proton magnetic resonance spectroscopy (1H MRS) in diagnosing early inflammatory bowel disease (IBD).

METHODS

Thirty male Sprague Dawley rats were fed 2% carrageenan in their diet for either 1 or 2 weeks. 1H MRS was performed ex-vivo on colonic mucosal samples (n = 123) and the spectra were analyzed by a multivariate method of analysis. The results of the multivariate analysis were correlated with histological analysis performed using H & E stain for the presence of inflammation in the samples from each group.

RESULTS

Multivariate analysis classified the samples in their respective groups with an accuracy of 82%. Our region selection algorithm identified four regions in the spectra as being discriminatory. The metabolites assigned to these regions include creatine, phosphatidylcholine, the -CH2HC= group in fatty acyl chain, and the glycerol backbone of lipids. The differences in concentration of these metabolites in each group offer insight into the biochemical changes occurring during IBD and confer diagnostic potential to 1H MRS as a tool to study colonic inflammation in conjunction with biopsy.

CONCLUSION

1H MRS is a sensitive tool to detect early colonic inflammation in an animal model of IBD.

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

BACKGROUND

Omega-3 fatty acids (n-3, fish oil) have been shown to have anti-inflammatory properties. Therefore, n-3 therapy may be beneficial in chronic inflammatory disorders such as ulcerative colitis.

OBJECTIVES

To systematically review the efficacy and safety of n-3 for maintaining remission in ulcerative colitis (UC).

SEARCH STRATEGY

The following databases were searched from their inception without language restriction: Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE, Healthstar, PubMed, and ACP journal club. Experts were contacted for unpublished data.

SELECTION CRITERIA

Randomized placebo-controlled trials (RCT) of fish oil for maintenance of remission in UC were included. Studies must have enrolled patients (of any age group) who were in remission at the time of recruitment, and were followed for at least six months. The intervention must have been fish oil given in pre-defined dosage. Co-interventions were allowed only if they were balanced between the study groups. The primary outcome was relapse rate and the secondary outcome was frequency of adverse events. Other outcomes to assess efficacy were change in disease activity scores and time to first relapse.

DATA COLLECTION AND ANALYSIS

Two independent investigators reviewed studies for eligibility, extracted the data and assessed study quality. Meta-analysis weighted by the Mantel-Haenszel method was performed using RevMan 4.2.8 software. Random or fixed effect models were used according to degree of heterogeneity and subgroup analyses were performed to explore heterogeneity. A sensitivity analysis was performed excluding a study of questionable quality .

MAIN RESULTS

The three studies that were included used different formulation and dosing of n-3 but none used enteric coated capsules. The pooled analysis showed a similar relapse rate in the n-3 treated patients and controls (RR 1.02; 95% CI 0.51 to 2.03; P = 0.96). Combining the studies resulted in virtually no statistical heterogeneity (P = 0.93, I(2) = 0%). Various subgroup and sensitivity analyses showed similar results. However, the total number of patients enrolled in these studies was small (n = 138). No significant adverse events were recorded in any of the studies and not enough data were available to pool the other secondary outcomes for meta-analysis.

AUTHORS' CONCLUSIONS

No evidence was found that supports the use of omega 3 fatty acids for maintenance of remission in UC. Further studies using enteric coated capsules may be justified.

Omega 3 fatty acids (fish oil) for maintenance of remission in Crohn's disease

BACKGROUND

The anti-inflammatory effects of n-3 (omega-3 fatty acids, fish oil) have been suggested to be beneficial in chronic inflammatory disorders such as inflammatory bowel disease.

OBJECTIVES

To systematically review the efficacy and safety of n-3 for maintaining remission in Crohn's disease (CD).

SEARCH STRATEGY

The following databases were searched from their inception without language restriction: Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE, Healthstar, PubMed, and ACP journal club. Experts were contacted for unpublished data.

SELECTION CRITERIA

Randomized placebo-controlled trials (RCT) of n-3 for maintenance of remission in CD were included. Studies must have enrolled patients of any age group, who were in remission at the time of recruitment, and were followed for at least six months. The intervention must have been fish oil or n-3 given in pre-defined dosage. Co-interventions were allowed only if they were balanced between the study groups. The primary outcome was relapse rate and secondary outcomes were change in disease activity scores, time to first relapse and adverse events.

DATA COLLECTION AND ANALYSIS

Two independent investigators reviewed studies for eligibility, extracted the data and assessed study quality using Jadad's criteria. Meta-analysis was performed using RevMan 4.2 software, weighted by the Mantel-Haenszel method. Random or fixed effect models were used according to degree of heterogeneity and subgroup analyses were performed to address heterogeneity.

MAIN RESULTS

Four studies were eligible for inclusion. There was a non statistically significant benefit of n-3 therapy for maintaining remission (RR 0.64; 95%CI 0.4 to 1.03; P = 0.07). However, the studies were both clinically and statistically heterogeneous (P = 0.01, I(2) = 72%). Three studies used enteric coated capsules (positive effects) and one ordinary gelatin capsules (no advantage). Subgroup analyses of studies which used enteric coated capsules revealed a statistically significant benefit for maintenance of remission (RR 0.49; 95% CI 0.35 to 0.69; RD 0.31; 95% CI 0.19 to 0.43); number needed to treat to prevent relapse in 1 year was 3 (95% CI 2 to 5; I(2) = 19%). However, the total number of patients enrolled in these studies was small (n = 166). No significant adverse events were recorded in any of the studies and not enough data were available to analyze the other secondary outcomes.

AUTHORS' CONCLUSIONS

Omega 3 fatty acids are safe and may be effective for maintenance of remission in CD when used in enteric coated capsules. However, there are not sufficient data to recommend the routine use of n-3 for maintenance of remission in CD. The small number of patients in the included studies warrants further larger RCTs.