Page 109 - Human Bile Acid Metabolism: a Postprandial Perspective

Introduction
Bile acids have gained attention as hormone-like factors in metabolism exerting effects via the transmembrane receptor Takeda G-coupled protein receptor 5 (TGR5) [1–4]. The feedback repression of hepatic bile acid synthesis is managed through the nuclear farnesoid X receptor (FXR) and involves ileal Fibroblast Growth Factor 19 (FGF19) [4,5]. Intestinal L-cell secretion of glucagon-like peptide 1 (GLP-1) is one of the best-described ways of in-vivo stimulation of TGR5 by bile acids [6].
Bile acids have been implicated in the deranged glucose metabolism of patients with obesity and type 2 diabetes mellitus (DM2) [7,8]. Obesity is characterized by decreased postprandial bile acid concentrations [9] and increased bile acid synthesis [10]. DM2 patients have increased postprandial plasma concentrations of the bile acids cholate (CA), deoxycholate (DCA) and chenodeoxycholic acid (CDCA) [11].
Bariatric surgery, and the Roux-en-Y gastric bypass procedure (RYGB) in 6 particular, increases fasting and postprandial bile acid levels and results in 45%
of patients not needing medication after 5 years [12,13]. The Duodenal-Jejunal
Bypass Liner (DJBL, GI Dynamics, Lexington, MA) is a 60 cm long impermeable
liner, which is delivered and retrieved endoscopically. Its placement results in weight loss and improvement of DM2 with lowering of the use of antidiabetic medication such as sulfonylurea derivatives, metformin and insulin [14–16].
Given the proposed role of bile acids in DM2 and RYGB, we examined the effects of DJBL placement on the postprandial bile acid response at different time points after the procedure.
Material and methods
Subjects
Seventeen subjects with obesity and DM2 were included in the Maastricht University Medical Center, Maastricht, and the Atrium Medical Center Parkstad, Heerlen, the Netherlands between February and July 2010 as reported previously
Duodenal-jejunal bypass liner
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