Gut-brain axis dysfunction underlies FODMAP-induced symptom generation in irritable bowel syndrome.

Background: FODMAPs produce similar small bowel water and colonic gas in patients with irritable bowel syndrome (IBS) and healthy controls (HCs), despite IBS patients reporting increased gastrointestinal (GI) symptoms.

Aim: To unravel the mechanisms underlying FODMAP-induced symptom reporting, we investigated gut and brain responses to fructan administration in IBS patients and HC.

Methods: This randomised, double-blind, cross-over study consisted of three visits where fructans (40 g/500 mL saline), glucose (40 g/500 mL saline) or saline (500 mL) were infused intragastrically during 1 h MR brain scanning; abdominal MRI was performed before, 1 h, and 2 h post-infusion.