Effect of rapid colonic transit on stool microbiome and short-chain fatty acids in diarrhoea-predominant irritable bowel syndrome

In a recent article in GUT,1 we showed that, among 194 patients with diarrhoea-predominant irritable bowel syndrome (IBS-D), 43 had altered bile acid (BA) metabolism (ABAM) (serum 7αC4>52 ng/mL). Patients with ABAM, had faster colonic transit (CT), lower α diversity and a different microbial compositional profile based on β diversity compared with IBS-D without ABAM. There were no significant differences in the stool short-chain fatty acid (SCFA) concentrations between the two groups.1 There is evidence that transit impacts gut microbiome composition and diversity.2