The findings support the effects of BAs on satiety , lipid and cholesterol metabolism , incretins and glucose homoeostasis , energy metabolism , gut microbiota and endoplasmic reticulum stress following bariatric surgery .
Many of these metabolic effects are modulated through the BA receptors FXR and TGR5 .
We also explore a possible link between BAs and carcinogenesis following bariatric surgery .
Conclusions : Overall there is good evidence to support the role of BAs in the metabolic effects of bariatric surgery through the above mechanisms .
BAs could serve as a novel therapeutic pharmacological target for the treatment of obesity and its associated co-morbidities
Background : Bariatric surgery is currently the most efficacious treatment for obesity and its associated metabolic co-morbidities , such as diabetes .
The metabolic improvements occur through both weight-dependent and weight-independent mechanisms .
Bile acids ( BAs ) have emerged as key signalling molecules that have a central role in modulating many of the physiological effects seen after bariatric surgery .
This systematic review assesses the evidence from both human and animal studies for the role of BAs in reducing the metabolic complications of obesity following bariatric surgery .
Intestinal adaptation after ileal interposition surgery increases bile acid recycling and protects against obesity-related comorbidities.
Surgical interposition of distal ileum into the proximal jejunum is a bariatric procedure that improves the metabolic syndrome . Changes in intestinal and hepatic physiology after ileal interposition ( transposition ) surgery ( IIS )  are not well understood . Our aim was to eluci date the adaptation of the interposed ileum , which we hypothesized , would lead to early bile acid reabsorption in the interposed ileum , thus short circuiting enterohepatic bile acid recycling to more proximal bowel segments . Rats with diet-induced obesity were r and omized to IIS  , with 10 cm of ileum repositioned distal to the duodenum , or sham surgery . A subgroup of sham rats was pair-fed to IIS rats . Physiological parameters were measured until 6 wk postsurgery . IIS rats ate less and lost more weight for the first 2 wk postsurgery . At study completion , body weights were not different , but IIS rats had reversed components of the metabolic syndrome . The interposed ileal segment adapted to a more jejunum-like villi length , mucosal surface area , and GATA4/ILBP mRNA . The interposed segment retained capacity for bile acid reabsorption and anorectic hormone secretion with the presence of ASBT and glucagon-like-peptide-1-positive cells in the villi . IIS rats had reduced primary bile acid levels in the proximal intestinal tract and higher primary bile acid levels in the serum , suggesting an early and efficient reabsorption of primary bile acids . IIS rats also had increased taurine and glycine-conjugated serum bile acids and reduced fecal bile acid loss . There was decreased hepatic Cyp27A1 mRNA with no changes in hepatic FXR , SHP , or NTCP expression . IIS protects against the metabolic syndrome through short-circuiting enterohepatic bile acid recycling . There is early reabsorption of primary bile acids despite selective " jejunization " of the interposed ileal segment . Changes in serum bile acids or bile acid enterohepatic recycling may mediate the metabolic benefits seen after bariatric surgery
The findings support the effects of BAs on satiety , lipid and cholesterol metabolism , incretins and glucose homoeostasis , energy metabolism , gut microbiota and endoplasmic reticulum stress following bariatric surgery .
Many of these metabolic effects are modulated through the BA receptors FXR and TGR5 .
We also explore a possible link between BAs and carcinogenesis following bariatric surgery .
Conclusions : Overall there is good evidence to support the role of BAs in the metabolic effects of bariatric surgery through the above mechanisms .
BAs could serve as a novel therapeutic pharmacological target for the treatment of obesity and its associated co-morbidities
Background : Bariatric surgery is currently the most efficacious treatment for obesity and its associated metabolic co-morbidities , such as diabetes .
The metabolic improvements occur through both weight-dependent and weight-independent mechanisms .
Bile acids ( BAs ) have emerged as key signalling molecules that have a central role in modulating many of the physiological effects seen after bariatric surgery .
This systematic review assesses the evidence from both human and animal studies for the role of BAs in reducing the metabolic complications of obesity following bariatric surgery .