Nutritional therapy of Crohn's disease in childhood

Review article: diet and inflammatory bowel disease--epidemiology and treatment

BACKGROUND

Diet is thought to have an important role in the immunopathogenesis and treatment of inflammatory bowel disease (IBD).

AIM

To identify dietary constituents as risk factors for development of IBD and the therapeutic efficacy of dietary modifications or enteral nutrition in IBD.

METHODS

The Medline and the Cochrane Library were searched for clinical trials and meta-analyses in the scope of diet and nutrition in IBD.

RESULTS

There are many studies in small cohorts of patients that claim that intake of certain diet constituents like fat, refined sugar, fruits, vegetables and fibre affect the expression of IBD. These are often compromised by insufficient data or methodological limitations and do not provide unequivocal evidence to incriminate any particular dietary factor. Among various dietary interventions, none has shown striking efficacy with the possible exception of complete enteral nutrition. Enteral nutrition appears effective in both active and quiescent Crohn's disease (CD), but independent meta-analyses have shown enteral nutrition to be inferior to corticosteroids in the management of active CD, when assessed on an intention-to-treat basis.

CONCLUSIONS

The current levels of knowledge concerning dietary risk factors for IBD, and the therapeutic efficacy of dietary and nutritional interventions need to be supported by well-designed trials in large cohorts of patients.

Nutrition and Crohn's disease: an update of print and Web-based guidance

This article reviews the role of nutrition in Crohn's disease, one of the inflammatory bowel diseases. In addition to presenting a comprehensive review of the state-of-the-evidence on nutritional risks and nutritional therapies in Crohn's disease, and making specific nutrient recommendations, this article includes a list of Web-based resources, including websites, blogs, newsletters, and multimedia podcasts that can be utilized by patients and healthcare providers alike to learn more about the etiology, pathophysiology, and nutritional management of Crohn's disease.

Treatment of inflammatory bowel disease in childhood: best available evidence

The physician treating children with inflammatory bowel disease is confronted with a number of specific problems, one of them being the lack of randomized, controlled drug trials in children. In this review, the role of nutritional therapy is discussed with a focus on primary treatment, especially for children with Crohn's disease. Then, the available medical therapies are highlighted, reviewing the evidence of effectiveness and side effects in children, as compared with what is known in adults. Nutritional therapy has proven to be effective in inducing and maintaining remission in Crohn's disease while promoting linear growth. Conventional treatment consists of aminosalicylates and corticosteroids, whereas the early introduction of immunosuppressives (such as azathioprine or 6-mercaptopurine) is advocated as maintenance treatment. If these drugs are not tolerated or are ineffective, methotrexate may serve as an alternative in Crohn's disease. Cyclosporine is an effective rescue therapy in severe ulcerative colitis, but only will postpone surgery. A novel strategy to treat Crohn's disease is offered by infliximab, a monoclonal antibody to the proinflammatory cytokine tumor necrosis factor (TNF)-alpha. Based on the best-available evidence, suggested usage is provided for separate drugs with respect to dosage and monitoring of side effects in children.

Reversal of altered intestinal mucosal immunity in rats fed elemental diet by supplementation of oleic acid

We have previously demonstrated that elemental diet (ED) induces decreased lymphocyte transport in intestinal lymph and significant changes in T cell subsets and the number of IgA-containing cells in gut-associated lymphoid tissues of rats. In order to examine whether the low fat content contributes to the induction of immunological changes in gut-associated lymphoid tissues, the effects of additional fatty acid in the ED were investigated. Rats were divided into four groups: elemental diet alone, elemental diet supplemented with 5% oleic acid (OA), elemental diet with 10% OA and conventional diet as a control. These diets were given at the same daily calorie intake for 4 weeks. The flow rate of intestinal lymph showed no significant difference between the four groups. However, lymphocyte flux as well as the percentage of CD3+ and CD4+ cells were significantly greater in the control and the 10% OA groups than in the ED and 5% OA groups. Intestinal lymph showed decreased concentrations of IgG and IgA in the ED group, whereas the addition of 10% OA significantly attenuated the decrease in these levels. In mesenteric lymph nodes, the CD4+/CD8+ ratio was significantly decreased in the ED group, but 10% OA reversed this change. Immunohistochemical analysis of the ileal mucosa showed that in the ED group the population of CD4+ cells was decreased, while the number of CD8+ cells was increased. Supplementation of OA to ED produced similar stepwise attenuation of the changes in lymphocyte subpopulations in the lamina propria, while the 10% OA group reached levels that were not statistically different from controls. In the elemental diet group, there was a significant decrease in immunoglobulin-containing cells of the IgA class in the lamina propria of the intestine. Similarly, the addition of OA induced dose-dependent recovery in the number of IgA-containing cells. These results suggest that a low dietary concentration of fat may be closely related to changes in lymphocyte transport in intestinal lymph and mucosal immunity of intestinal mucosa induced by the feeding of a long-term ED.

Current management of inflammatory bowel disease

The aetiology of ulcerative colitis and Crohn's disease remains unknown. While this remains so, treatment must be directed towards pathogenetic mechanisms. Corticosteroids, sulphasalazine and the new salicylates, the immunosuppressants azathioprine, 6-MP and, more recently, cyclosporin and metronidazole have become the accepted and standard forms of treatment. The importance of maintaining nutritional status is often overlooked but must be considered in every patient. Recognition of the occurrence of disease in all age groups, and in particular in children and adolescents, is also important, as is an appreciation of the special problems involved. The possibility of surgery at some stage of the disease should be raised with the patient. As the pathogenetic mechanisms of inflammatory bowel disease are further elucidated, new forms of treatment will be developed. This is already happening, with studies looking at such agents as immunoglobulin G, eicosapentaenoic acid and a new specific inhibitor of 5-lipoxygenase. These offer hope of more potent drugs with low side-effect profiles that may complement or replace the currently available agents used in the management of inflammatory bowel disease.

Serum concentrations of tumour necrosis factor alpha in childhood chronic inflammatory bowel disease

Serum tumour necrosis factor alpha (TNF alpha) concentrations were measured by enzyme linked immunoadsorbent assay in 31 normal children and during 65 episodes of clinical remission and 54 episodes of relapse in 92 children with chronic inflammatory bowel disease. An appreciable rise in TNF alpha was found only in children in relapse of ulcerative colitis and colonic Crohn's disease. The group of children with small bowel Crohn's disease in relapse did not show increases of TNF alpha above control concentrations, despite an equivalent rise in disease indices. Height velocity was depressed in children with relapse of large bowel Crohn's disease and ulcerative colitis compared with the equivalent condition in remission. The impairment of growth velocity was significantly greater in relapse of large bowel Crohn's disease and ulcerative colitis than in small bowel Crohn's disease alone, although for the subgroups in stage 1 puberty (prepubertal) the differences were not significant. Inadequate growth in chronic inflammatory bowel disease is currently ascribed to inadequate nutrition and TNF alpha may contribute to this through its cachexia inducing effects. It may, in addition, diminish pituitary growth hormone release. These results suggest that production of TNF alpha may be associated with growth failure in relapse of colonic inflammatory bowel disease.

The effect of elemental diet on intestinal permeability and inflammation in Crohn's disease

This study examines whether treatment of acute Crohn's disease with an elemental diet improves intestinal integrity and inflammation as assessed by a 51Cr-labeled ethylenediaminetetraacetatic acid (EDTA) permeability test and the fecal excretion of 111In-labeled autologous leukocytes, respectively. Thirty-four patients with active Crohn's disease completed a 4-week treatment course with an elemental diet. Active disease was characterized by increased intestinal permeability [24-hour urine excretion of orally administered 51Cr-EDTA, 6.4% +/- 0.6% (mean +/- SE); normal, less than 3.0%] and by high fecal excretion of 111In-labeled leukocytes (14.2% +/- 1.1%; normal, less than 1.0%). Twenty-seven (80%) went into clinical remission, usually within a week of starting treatment. After 4 weeks of treatment, there was a significant decrease in both the urine excretion of 51Cr-EDTA (to 3.4% +/- 0.5%; P less than 0.01) and the fecal excretion of 111In (to 5.7% +/- 1.0%; P less than 0.001), indicating that such treatment is not just symptomatic. A framework for the mechanism by which elemental diet works, centering around the importance of the integrity of the intestinal barrier function, is proposed, and also appears to provide a logical explanation for some relapses of the disease.

Nutritional management of inflammatory bowel disease

The etiology and specific treatment of Crohn's disease and ulcerative colitis are unknown, and the treatment strategy for patients with inflammatory bowel disease is essentially symptomatic and supportive. The malnutrition that frequently accompanies inflammatory bowel disease is a manifestation of intestinal failure and should be vigorously corrected with total parenteral nutrition, elemental diets, or both. Evidence exists for the value of total parenteral nutrition and elemental diets as primary therapy for inflammatory bowel disease in selected patients. Judicious nutritional therapy remains a cornerstone in the adjunctive management of these patients.

Management of children and adolescents with inflammatory bowel disease

The management of children and adolescents with inflammatory bowel disease requires all the skills offered by the health care team. This article reviews the principles of therapy, the specifics of therapy, and the attitudes of the authors relating to long-term management of these patients. Specific recommendations relating to nutritional support for patients are also made. A pertinent updated bibliography is also given.