Bile acid metabolism after jejunoileal bypass operation for obesity

Bile acid metabolism and duodenal bacterial flora were studied in 12 obese patients before and 1-2 months after jejunoileal bypass operation, either including 37.5 cm jejunum and 12.5 cm ileum (Type I) or 12.5 cm jejunum and 37.5 cm ileum (Type III). The cholic acid pool size was unchanged after type I, but decreased after type III, bypass. The daily fractional turn-over of cholic acid increased about five times after both types of operation. The synthesis rate of cholic acid increased after both types of bypass, but more after type I than after type III. In duodenal bile the ratios of cholic to taurine conjugates increased after type I, but were unchanged after type III bypass, whereas the ratio of cholic to chenodeoxycholic acid was unchanged after both types of bypass. The bacterial flora and the occurrence of free bile acids in the fasting duodenal contents did not change after either of the two types of bypass operation. It is concluded that jejunoileal bypass results in marked disturbances in the bile acid metabolism. Surprisingly, these are most severe after bypass including the longest ileum, possibly because of insufficient stimulation of the bile acid synthesis in this type of operation.