Thomas and colleagues,¹ in this issue of Gut, extend previous work from the laboratory of R Hermon Dowling by showing that acromegalic patients treated with octreotide have an increase in faecal anaerobic bacteria that convert cholic acid, the major primary bile acid in humans, to deoxycholic acid, the major secondary bile acid (see page 630). The paper also confirms previous reports from the Dowling laboratory^2,3 that octreotide treatment increases colonic transit time in acromegalic patients. In addition, the paper of Thomas et al shows that octreotide treatment results in enrichment of deoxycholic acid in fasting state plasma bile acids.

The present paper is the 11th and could well be the last in a series of papers spanning more than a decade from the Dowling laboratory that have dealt with the pathogenesis of gall stones in acromegalic patients treated with octreotide, a potent somatostatin agonist. Octreotide is a synthetic peptide whose amide bonds are resistant to hydrolysis by plasma peptidases, thus resulting in its having a much longer duration of action than that of somatostatin.⁴ In acromegalic patients, octreotide administration suppresses the release of growth hormone and insulin growth factor by the pituitary and results in clinical improvement.⁵

The initial paper in this series showed that such patients have an increased prevalence of gall stones.⁶ The gall stones were shown to be rich in cholesterol⁷ and, as would be expected, bile was found to be supersaturated in cholesterol⁸ and to …