High animal‐fat intake changes the bile‐acid composition of bile juice and enhances the development of Barrett's esophagus and esophageal adenocarcinoma in a rat duodenal‐contents reflux model

The dietary components responsible for the development of Barrett's esophagus (BE) and esophageal adenocarcinoma (EAC) remain unclear. Wistar rats were divided into four groups based on their diet: a low soybean-oil diet, a low cow-fat diet, a high soybean-oil diet, and a high cow-fat diet. First, we evaluated the bile acid composition of the bile juice in each group without operation, using high-performance liquid chromatography. Because only high cow-fat intake induced changes in the composition of bile acids in bile juice, we then selected animals fed with a low soybean-oil diet and those with a high cow-fat diet to carry out esophago-jejunostomy for reflux of the duodenal contents, and compared sequential morphological changes between these groups up to 30 weeks after surgery. At 30 weeks after surgery, the reflux animals in the high cow-fat group showed a significantly higher incidence of BE and Barrett's dysplasia than those in the low soybean-oil group, and the incidence of EAC in the high cow-fat group was also slightly higher than that in the low soybean-oil group. High dietary animal fat changed the bile-acid composition and increased the concentration of taurine conjugates in the bile juice. These increased bile acids promoted the development of BE and Barrett's dysplasia leading to EAC. (Cancer Sci 2007; 98: 1683–1688)