Circulating fasting total BA was not associated with obesity .
FGF19 was inversely and faecal BA excretion was positively associated with obesity .
Roux-en-Y gastric bypass ( RYGB ) and sleeve gastrectomy ( SG )  modulated BA metabolism , ie , increased BA and FGF19 .
Our results indicate that BA metabolism is altered in obesity .
Bile acid profiles over 5 years after gastric bypass and duodenal switch: results from a randomized clinical trial.
BACKGROUND Bile acids have been proposed as key mediators of the metabolic effects after bariatric surgery . Currently no reports on bile acid profiles after duodenal switch exist , and long-term data after gastric bypass are lacking . OBJECTIVE To investigate bile acid profiles up to 5 years after Roux-en-Y gastric bypass and biliopancreatic diversion with duodenal switch and to explore the relationship among bile acids and weight loss , lipid profile , and glucose metabolism . SETTING S Two Sc and inavian University Hospitals . METHODS We present data from a r and omized clinical trial of 60 patients with body mass index 50 - 60 kg/m2 operated with gastric bypass or duodenal switch .  Repeated measurements of total and individual bile acids from fasting serum during 5 years after surgery were performed . RESULTS Mean concentrations of total bile acids increased from 2.3 µmol/L ( 95 % confidence interval [ CI ] , -.1 to 4.7 ) at baseline to 5.9 µmol/L ( 3.5 - 8.3 ) 5 years after gastric bypass and from 1.0 µmol/L ( 95 % CI , -1.4 to 3.5 ) to 9.5 µmol/L ( 95 % CI , 7.1 - 11.9 ) after duodenal switch ; mean between-group difference was -4.8 µmol/L ( 95 % CI , -9.3 to -.3 ) , P = .036 . Mean concentrations of primary bile acids increased more after duodenal switch , whereas secondary bile acids increased proportionally across the groups . Higher levels of total bile acids at 5 years were associated with lower body mass index , greater weight loss , and lower total cholesterol . CONCLUSIONS Total bile acid concentrations increased substantially over 5 years after both gastric bypass and duodenal switch , with greater increases in total and primary bile acids after duodenal switch . ( Surg Obes Relat Dis 2017;0:000 - 000 . ) © 2017 American Society for Metabolic and Bariatric Surgery . All rights reserved
Circulating fasting total BA was not associated with obesity .
FGF19 was inversely and faecal BA excretion was positively associated with obesity .
Roux-en-Y gastric bypass ( RYGB ) and sleeve gastrectomy ( SG )  modulated BA metabolism , ie , increased BA and FGF19 .
Our results indicate that BA metabolism is altered in obesity .