Use of the 13C-sucrose breath test to assess chemotherapy-induced small intestinal mucositis in the rat

Abstract

Mucositis is a debilitating side-effect of chemotherapy which affects the mucosa of the gastrointestinal tract, particularly the small intestine. Currently there are no simple, non-invasive methods to detect and monitor small intestinal function and the severity of mucosal damage. Activity of the brush-border enzyme sucrase provides an indicator of small intestinal absorptive function that remains relatively constant throughout life. Measuring 13CO-2 levels in expired breath following ingestion of 13C-sucrose is a non-invasive marker of total intestinal sucrase activity. We evaluated the sucrose breath test (SBT) as an indicator of small intestinal injury and dysfunction, utilizing a rat model of chemotherapy-induced mucositis. SBT results reflected the time-course of damage and repair after methotrexate (MTX) treatment, with damage most severe 72 h after chemotherapy, and repair commencing after 96 h. SBT results correlated significantly with jejunal sucrase activity determined biochemically (r2=0.89; p