Publications by authors named "Ian M Johnston"

Background: Bile acid diarrhoea (BAD) is a common cause of chronic diarrhoea with a population prevalence of primary BAD around 1%. Previous studies have identified associations with low levels of the ileal hormone fibroblast growth factor 19 (FGF19), obesity and hypertriglyceridaemia. The aim of this study was to identify further associations of BAD.

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Objectives: Chronic diarrhea caused by primary bile acid diarrhea (PBAD) is a common condition. We have previously shown PBAD is associated with low fasting serum levels of the ileal hormone, fibroblast growth factor 19 (FGF19). FGF19 is a negative regulator of hepatic bile acid synthesis and is stimulated by farnesoid X receptor agonists, which produce symptomatic improvement in PBAD.

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Background: Bile acids [BA] are usually reabsorbed by the terminal ileum, but this process is frequently abnormal in Crohn’s disease [CD]. BA malabsorption occurs, and excess colonic BA cause secretory diarrhea. Furthermore, the hormone fibroblast growth factor 19 [FGF19] is synthesized in the ileum in response to BA absorption and regulates BA synthesis.

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Fibroblast growth factor 19 (FGF19) is proposed to be a negative feedback regulator of hepatic bile acid (BA) synthesis. We aimed to clarify the distribution of FGF19 expression in human intestine and to investigate induction in a novel explant system. Ileal and colonic mucosal biopsies were obtained at endoscopy and analyzed for FGF19 transcript expression.

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The role of bile acids (BA) extends far beyond lipid digestion and cholesterol metabolism. The transcriptional regulation of multiple genes within the liver and intestine are under their influence. BA exert these effects through binding and activating receptors in much the same way as endocrine hormones.

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