1. Fat malabsorption caused by bile-salt deficiency is not easily corrected by standard therapy. It has been shown in rats with bile-salt deficiency that non-ionic detergents can replace bile salts and improve fat absorption. A careful assessment of the place of synthetic detergents such as Tween in human therapy has not been reported.
2. The effects of Tween were studied in 13 patients with bile-salt-deficient steatorrhoea, eight of whom received Tween 80 and five Tween 20.
3. Tween therapy reduced steatorrhoea in 10/13 patients; a mean decrease in faecal fat of 33% was achieved with best effect seen in patients with severe steatorrhoea.
4. In the five patients given Tween 20, duodenal/jejunal intubation was conducted using meals with or without added Tween. Jejunal bile salt concentrations were low in all subjects and Tween had no effect on bile-salt output.
5. With Tween addition micellar free fatty acids and phospholipids were increased in four out of the five patients (mean increases 100% and 260% respectively). The mean ratio of fatty acid to bile salt increased from 1·26 to 3·53 and of phospholipid to bile salt from 0·09 to 0·21 in the presence of Tween.
6. The results suggest that in steatorrhoea due to bile-salt deficiency Tween causes increased micellization of ingested fat and improvement in fat absorption.
7. Tween and other non-ionic detergents may, therefore, find a place in therapy of bile-salt deficiency.