Farnesoid X receptor - a molecular predictor of weight loss after vertical sleeve gastrectomy?

Abstract

Objective: To determine the expression of the bile acid receptor, farnesoid X (FXR), in human gastric mucosa and investigate correlations between expression and body-mass index (BMI) and in patients with obesity, with changes in weight and BMI following vertical sleeve gastrectomy (VSG). Methods: Human gastric mucosa was obtained from normal/overweight individuals (macroscopically-normal tissue following surgery for malignancy) or from patients with obesity (VSG). The expression of FXR and its isoforms (FXRα, FXRβ) were examined by quantitative PCR and compared with the G protein-coupled bile acid receptor, GPBA. In patients with obesity, changes in BMI and weight loss were determined following VSG. Results: FXRα was the predominant isoform in normal/overweight individuals. FXR expression was higher in patients with obesity but GPBA receptor expression was unchanged. For those with obesity (n = 19), no correlation was found between FXR expression and change in Body-Mass Index (BMI)/month or weight loss/month, taken 3 ± 1 months after surgery, or in BMI or weight at surgery. Conclusions: Obesity is associated with increased FXR expression in the gastric mucosa. The findings are preliminary but suggest that this increase in FXR expression is a consequence of obesity, rather than its cause.