A single faecal bile acid stool test demonstrates potential efficacy in replacing SeHCAT testing for bile acid diarrhoea in selected patients.

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Authors
Kumar, Aditi
Jain, Manushri
Ford, Clare
Gama, Rousseau
Steed, Helen
Brookes, Matthew James
Hughes, Lauren Elizabeth
Issue Date
2022-05-18
Journal
Type
Cohort Study
Multicentre Study
Observational Study
Peer-Reviewed Publication
Keywords
Bile acid diarrhoea
Bile acid
Bile salts
Diarrhoea
Stool sample
Ileal diseases
Selenium
Taurocholic acid
23-seleno-25-homotaurocholic acid
SeHCAT scan
selenium-homotaurocholic acid (SeHCAT) scan
Post-cholecystectomy
Crohn's disease
Sensitivity
Specificity
Journal Title
Scientific Reports
Volume
12
Issue
1
Begin page
8313
End page
DOI
Abstract
This study examines the validity of measuring faecal bile acids (FBA) in a single stool sample as a diagnostic tool for bile acid diarrhoea (BAD) by direct comparison to the 75selenium-homotaurocholic acid (SeHCAT) scan. A prospective observational study was undertaken. Patients with chronic diarrhoea (> 6 weeks) being investigated for potential BAD with SeHCAT scan provided stool samples for measurement of FBA, using an enzyme-linked immunosorbent assay. Patients were characterised into four groups: SeHCAT negative control group, post-cholecystectomy, idiopathic BAD and post-operative terminal ileal resected Crohn's disease. Stool samples were collected at baseline and 8-weeks post treatment to determine whether FBA measurement could be used to monitor therapeutic response. 113 patients had a stool sample to directly compare with their SeHCAT result. FBA concentrations (μmol/g) and interquartile ranges in patients in the control group (2.8; 1.6-4.2), BAD (3.6; 1.9-7.2) and post-cholecystectomy cohort 3.8 (2.3-6.8) were similar, but all were significantly lower (p < 0.001) compared to the Crohn's disease cohort (11.8; 10.1-16.2). FBA concentrations in patients with SeHCAT retention of < 15% (4.95; 2.6-10.5) and < 5% (9.9; 4.8-15.4) were significantly higher than those with a SeHCAT retention > 15% (2.6; 1.6-4.2); (p < 0.001 and p < 0.0001, respectively). The sensitivity and specificity using FBA cut-off of 1.6 μmol/g (using ≤ 15% SeHCAT retention as diagnostic of BAD) were 90% and 25% respectively. A single random stool sample may have potential use in diagnosing severe BAD or BAD in Crohn's patients. Larger studies are now needed to confirm the potential efficacy of this test to accurately diagnose BAD in the absence of SeHCAT testing.
Citation
Kumar A, Al-Hassi HO, Jain M, Phipps O, Ford C, Gama R, Steed H, Butterworth J, McLaughlin J, Galbraith N, Brookes MJ, Hughes LE. A single faecal bile acid stool test demonstrates potential efficacy in replacing SeHCAT testing for bile acid diarrhoea in selected patients. Sci Rep. 2022 May 18;12(1):8313. doi: 10.1038/s41598-022-12003-z. PMID: 35585139; PMCID: PMC9117305.