In vivo Influence of Nicotine on Human Basal and NSAID-induced Gut Barrier Function

Abstract

Background: Smoking reduces the non-steroidal anti-inflammatory drug (NSAID)-induced small intestinal permeability increase in healthy people. It also affects inflammatory bowel disease that is associated with a disturbed gut barrier function. To assess the role of nicotine on barrier function, its influence on basal and NSAID-induced intestinal permeability was studied in healthy volunteers. Methods: Thirty-one healthy non-smoker subjects performed permeability tests with ⁵¹Cr-EDTA and sugar markers (sucrose, lactulose, mannitol, sucralose) before and during 2 weeks of nicotine patch application, and with and without indomethacin intake, respectively. Since smoking has been described as affecting motility, transit measurements were also done with the sodium[¹³C]-octanoate and lactose- [¹³C]-ureïde breath tests before and during nicotine exposure. Correlations between permeability markers were checked and the influence of gastrointestinal transit was assessed. Results: Nicotine did not affect barrier function in vivo, nor gastric emptying, small-bowel transit time or orocaecal transit. ⁵¹Cr-EDTA and lactulose correlated in basal 0–6 h permeability testing (r= 0.529, P < 0.0001), as did 6–24 h excretion of ⁵¹Cr-EDTA and sucralose (r= 0.474, P < 0.001); 97% and 90% of the subjects had a permeability increase after indomethacin intake for 0–6 h and 6–24 h excretion of Cr-EDTA, respectively. This population proportion is 63% for lactulose/mannitol and 83% for sucralose. Conclusions: Short-term exposure to nicotine does not alter normal basal or NSAID-induced gut barrier function or transit. ⁵¹Cr-EDTA and the respective sugar markers correlate well in in vivo permeability testing in healthy humans. The radioactive test detects more NSAID-induced permeability increase than does the lactulose/mannitol ratio permeability test.

Key words:

• ⁵¹Cr-EDTA
• gastric emptying
• lactulose
• mannitol
• nicotine
• orocaecal transit time
• permeability
• smoking
• sucralose
• sucrose