Exploring possible mechanisms for primary bile acid malabsorption: evidence for different regulation of ileal bile acid transporter transcripts in chronic diarrhoea.

Objectives: Chronic diarrhoea resulting from primary idiopathic bile acid malabsorption (IBAM) is common, but its aetiology is largely unknown. We investigated possible mechanisms, first looking for common sequence variations in the cytoplasmic ileal bile acid-binding protein (IBABP, gene symbol FABP6), and secondly, determining the expression of ileal mucosal transcripts for the apical sodium-linked bile acid transporter (ASBT), IBABP, the putative basolateral transporters, OSTalpha and OSTbeta, and regulatory factors.

Methods: Genomic DNA was prepared from two cohorts of patients and two control groups; the promoter and exonic regions of FABP6 were sequenced.