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Gut 2015;64:84-92 doi:10.1136/gutjnl-2013-305965
Increased colonic bile acid exposure: a relevant factor for symptoms and treatment in IBS
+ Author Affiliations
1Department of Internal Medicine and Clinical Nutrition, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
2University of Gothenburg Centre for Person-Centred Care (GPCC), Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
3Department of Medicine, Metabolism Unit, Center for Endocrinology, Metabolism, and Diabetes, Karolinska Institutet, Karolinska University Hospital Huddinge, Stockholm, Sweden
4Molecular Nutrition Unit, Department of Biosciences and Nutrition, Karolinska Institutet, Karolinska University Hospital Huddinge, Stockholm, Sweden
5Department of Internal Medicine, Medicine and R&D Unit, Skaraborgs Hospital, Skövde, Sweden
Correspondence to Professor Magnus Simrén, Department of Internal Medicine & Clinical Nutrition, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, 41345 Gothenburg, Sweden; firstname.lastname@example.org
Received 26 August 2013
Revised 18 March 2014
Accepted 21 March 2014
Published Online First 12 April 2014
Objective Bile acids may play a role in the pathogenesis of IBS. We investigated the potential effects of bile acids entering the colon and its role in the symptom pattern in IBS.
Design We measured 75Se-labelled homocholic acid-taurine (75SeHCAT) retention, and serum levels of 7α-hydroxy-4-cholesten-3-one (C4) and fibroblast growth factor (FGF) 19 in patients with IBS (n=141) and control subjects (75SeHCAT n=29; C4 and FGF19 n=435). In patients with IBS stool frequency and form, as well as GI symptom severity were registered, and in a proportion of patients colonic transit time and rectal sensitivity were measured (n=66). An 8-week open-label treatment with colestipol was offered to patients with 75SeHCAT <20%, and the effect of treatment was evaluated with IBS severity scoring system and adequate relief of IBS symptoms.
Results Compared with controls, patients with IBS had lower 75SeHCAT values (p=0.005), higher C4c levels (C4 corrected for cholesterol) (p<0.001), but similar FGF19 levels. Abnormal 75SeHCAT retention (<10%) was seen in 18% of patients, whereas 23% had elevated C4c levels. Patients with IBS with 75SeHCAT retention <10% had more frequent stools, accelerated colonic transit time, rectal hyposensitivity, a higher body mass index, higher C4c and lower FGF19 levels. Colestipol treatment improved IBS symptoms (IBS severity scoring system 220±109 vs 277±106; p<0.01), and 15/27 patients fulfilled criteria for treatment response (adequate relief ≥50% of weeks 5–8).
Conclusions Increased colonic bile acid exposure influences bowel habit and colonic transit time in patients with IBS. A high response rate to open label treatment with colestipol supports this, but placebo-controlled studies are warranted.
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