Objective: The mechanism of nutrient sensing in the upper small intestine (USI) and ileum that regulates glucose homeostasis remains elusive. Short-term high-fat (HF) feeding increases taurochenodeoxycholic acid (TCDCA; an agonist of farnesoid X receptor (FXR)) in the USI and ileum of rats, and the increase of TCDCA is prevented by transplantation of microbiota obtained from the USI of healthy donors into the USI of HF rats. However, whether changes of TCDCA-FXR axis in the USI and ileum alter nutrient sensing remains unknown.
Methods: Intravenous glucose tolerance test was performed in rats that received USI or ileal infusion of nutrients (i.e., oleic acids or glucose) via catheters placed toward the lumen of USI and/or ileum, while mechanistic gain- and loss-of-function studies targeting the TCDCA-FXR axis or bile salt hydrolase activity in USI and ileum were performed.
Results: USI or ileum infusion of nutrients increased glucose tolerance in healthy but not HF rats. Transplantation of healthy microbiome obtained from USI into the USI of HF rats restored nutrient sensing and inhibited FXR via a reduction of TCDCA in the USI and ileum. Further, inhibition of USI and ileal FXR enhanced nutrient sensing in HF rats, while inhibiting USI (but not ileal) bile salt hydrolase of HF rats transplanted with healthy microbiome activated FXR and disrupted nutrient sensing in the USI and ileum.
Conclusions: We reveal a TCDCA-FXR axis in both the USI and ileum that is necessary for the upper small intestinal microbiome to govern local nutrient-sensing glucoregulatory pathways in rats.
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http://dx.doi.org/10.1016/j.molmet.2020.101132 | DOI Listing |
Mol Metab
February 2021
Toronto General Hospital Research Institute, UHN, Toronto, Canada; Department of Physiology, University of Toronto, Toronto, Canada; Department of Medicine, University of Toronto, Toronto, Canada; Banting and Best Diabetes Center, University of Toronto, Toronto, Canada. Electronic address:
Objective: The mechanism of nutrient sensing in the upper small intestine (USI) and ileum that regulates glucose homeostasis remains elusive. Short-term high-fat (HF) feeding increases taurochenodeoxycholic acid (TCDCA; an agonist of farnesoid X receptor (FXR)) in the USI and ileum of rats, and the increase of TCDCA is prevented by transplantation of microbiota obtained from the USI of healthy donors into the USI of HF rats. However, whether changes of TCDCA-FXR axis in the USI and ileum alter nutrient sensing remains unknown.
View Article and Find Full Text PDFNat Commun
January 2019
Institute for Research in Biomedicine, Università della Svizzera Italiana, Via Vincenzo Vela 6, 6500, Bellinzona, Switzerland.
T cell dependent secretory IgA (SIgA) generated in the Peyer's patches (PPs) of the small intestine shapes a broadly diverse microbiota that is crucial for host physiology. The mutualistic co-evolution of host and microbes led to the relative tolerance of host's immune system towards commensal microorganisms. The ATP-gated ionotropic P2X7 receptor limits T follicular helper (Tfh) cells expansion and germinal center (GC) reaction in the PPs.
View Article and Find Full Text PDFScand J Gastroenterol
May 2009
Division of Operative Endoscopy and Gastroenterology, Fabio Di Giovambattista - USI, Rome, Italy.
Objective: Less severe histological changes have sometimes been reported in the terminal ileum (TI) of coeliac patients. The aim of this work was to assess whether magnified ileoscopy and the corresponding biopsy could be used when diagnosing coeliac disease (CD). This would be of clinical value in coeliac patients who show predominant abdominal symptoms and who undergo colonoscopy with ileoscopy as first clinical examination.
View Article and Find Full Text PDFInt Urol Nephrol
November 2007
Department of Urology, All India Institute of Medical Sciences, New Delhi 110029, India.
Objective: A national survey was conducted among the urologists in India to find the preference for urinary diversion after radical cystectomy for muscle invasive carcinoma of the urinary bladder, percentage of neobladder reconstruction, segment of the bowel used, complication rate, need for self-intermittent catherisation on follow up and the survival.
Material And Methods: A detailed questionnaire was mailed to all members of the urological society of India (USI) to find out their preference for urinary diversion following radical cystectomy for muscle invasive carcinoma urinary bladder. For the neobladder reconstruction, they were asked for the type of bowel segment used, complication rate, reoperation rate, need for intermittent clean catheterisation on follow up and 5-year survival.
Pharm Res
March 2000
Department of Pharmaceutics, College of Pharmacy, Rutgers-The State University of New Jersey, Piscataway 08854, USA.
Purpose: To investigate the regional influence of intestinal spreading and pH recovery on the performance of drug and excipient delivery systems and their impact on the oral absorption of a model peptide drug, salmon calcitonin (sCT), in conscious beagle dogs.
Methods: Male beagle dogs were surgically prepared with subdermal Intestinal Access Ports (IAP). The catheter from one port was placed in the duodenum and the other in the ileum.
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