Medical doctors typically only recognize the people who have gluten sensitivity are those with celiac disease, a chronic inflammation of the bowel that is aggravated by the protein found in breads.  But a growing number of people with irritable-bowel symptoms tell their doctors that eliminating gluten seems to help them out.  An Australian study evaluated patients who tested negative for celiac (by looking for a specific immune system protein in the gut) and gave them all of them 2 slices of bread and a muffin to eat every day.  Half of the group was given the bread with gluten, and the other half was gluten-free.

68% of the gluten group reported symptoms like pain, loose stool, and being tired compared to 40% of the gluten-free group.  Six of the people in the gluten group dropped out of the study because they couldn't tolerate the symptoms after an average of 7 days, while 3 people in the gluten free group dropped after an average of 16. 

While the study doesn't uncover the reason for the increased pain, bloating, stool inconsistency and fatigue associated with the gluten group, it does show that the protein may aggravate the problem for some people who have irritable bowel syndrome.  While not a landmark finding for those who have been advocating gluten awareness for more than a decade, this study should encourage both doctors and patients to experiment with gluten free alternatives, even if they haven't been diagnosed with celiac.

Biesiekierski JR, Newnham ED, Irving PM, Barrett JS, Haines M, Doecke JD, Shepherd SJ, Muir JG, Gibson PR. (2011). "Gluten causes gastrointestinal symptoms in subjects without celiac disease: a double-blind randomized placebo-controlled trial."  Am J Gastroenterol. 106(3):508-14.