LAUSR

INTRODUCTION Duodenal Mucosal Resurfacing (DMR) is a new endoscopic ablation technique aimed at improving glycemia and metabolic control in patients with type 2 diabetes mellitus (T2DM). DMR appears to improve insulin resistance, which is the root cause of T2DM, but its mechanism of action is largely unknown. Bile acids function as intestinal signalling molecules in glucose and energy metabolism via the activation of farnesoid X receptor and secondary signalling (e.g. via fibroblast growth factor 19[FGF19]), and are linked to metabolic health. METHODS We investigated the effect of DMR and GLP-1 on postprandial bile acid responses in 16 patients with insulin-dependent T2DM, using mixed meal tests performed at baseline and six months after the DMR procedure. RESULTS The combination treatment allowed discontinuation of insulin treatment in 11/16 (69%) of patients while improving glycaemic and metabolic health. We found increased postprandial unconjugated bile acid responses (all p<0.05), an overall increased secondary bile acid response (p=0.036) and a higher 12α-hydroxylated:non12α-hydroxylated ratio (p<0.001). Total bile acid concentrations were unaffected by the intervention. Postprandial FGF19 and 7-alpha-hydroxy-4-cholesten-3-one (C4) concentrations decreased post-intervention (both p<0.01). CONCLUSION AND DISCUSSION Our study demonstrates that DMR with GLP-1 modulates the postprandial bile acid response. The alterations in postprandial bile acid responses may be the result of changes in the microbiome, ileal bile acid uptake and improved insulin sensitivity. Controlled studies are needed to elucidate the mechanism linking the combination treatment to metabolic health and bile acids.