[What is the role of nutrition in ulcerative colitis? A contribution to the current status of diet therapy in treatment of inflammatory bowel diseases].

Nutritional therapy for ulcerative colitis (UC) is controversial. Studies are usually designed to investigate total parenteral (TPN) or total enteral nutrition (TEN), and before these can be compared it is necessary to differentiate between the different therapeutic aims. The aims of artificial nutritional support in patients with UC are the readjustment of the nutritional status, possible remission of disease activity, and decrease in the incidence of surgical intervention or postoperative complication. Owing to the heterogeneity of the results published so far, it is still difficult to compare studies. Nevertheless, they indicate that the extent and severity of the colitis and the patient selection are of paramount importance in the implementation of nutritional therapy. Positive effects of TPN reported from non-controlled studies were not confirmed by controlled trials. Moreover, TPN was no more effective than an oral diet. Regarding remission rates or operative interventions needed, TPN had more side effects than and no defined advantages over TEN. TEN seems to be useful for certain patients. In some patients with UC, it seems to be accompanied by fewer postoperative complications. However, a definitive conclusion on the effects of TEN or TPN is not yet possible. In this context, certain fatty acids may have an important role in the treatment of UC. In prospective, randomized and controlled studies omega-3 fatty acids were found to be therapeutically useful. A reduction of the steroid doses needed is particularly important. Another therapeutic approach in distal UC is seen in the rectal administration of short chain fatty acids.