Just as we've known all along: gluten sensitivity is real. That's the word from the University of Maryland Center for Celiac Research, where researchers said yesterday that gluten sensitivity represents a separate and distinct condition from celiac disease.
The researchers, led by Dr. Alessio Fasano, found differences between gluten sensitivity and celiac disease at the molecular level, and also in responses from the immune system.
Dr. Fasano estimates that 6% of the population has gluten sensitivity, compared to 1% with celiac disease.
In order to be diagnosed with celiac disease, you need to have an endoscopy that shows villous atrophy, or significant damage to your small intestines.
However, many people with the symptoms of celiac disease have little or no damage to their small intestines. Previously, physicians would have told them that gluten was not causing their symptoms, but many of them improved significantly on a gluten-free diet.
This led Dr. Fasano and his team to conclude that there might be another condition, "gluten sensitivity," in play. In this current study, published online March 9 in BMC Medicine, they investigated differences between diagnosed celiacs with Marsh 3 or Marsh 4 damage to their intestines, and people whose intestines showed no signs of celiac-related damage, but who still reacted to gluten in their diets.
The study enrolled 26 gluten-sensitive patients who underwent a four-month gluten challenge. Those classified as gluten-sensitive met these criteria: negative EMA-IgA and tTG-IgA blood tests, intestinal mucosa at Marsh stage 0 or Marsh stage 1, and improvement in symptoms within days of starting the gluten-free diet.
In addition, the study recruited 42 patients with active celiac disease, plus 39 control subjects with dyspepsia (upset stomach or acid indigestion) but no underlying inflammation.
For each subject, the researchers determined the level of intestinal permeability (in celiac disease, your intestines become more permeable, allowing proteins to escape into the blood stream). They also looked at genetics, along with the expression of genes in the small intestines.
They found differences in intestinal permeability, plus differences in the expression of the genes that regulate the immune response, between all the study subjects, indicating that gluten-sensitive individuals have different responses to gluten than celiacs.
The research may allow new tests to be developed that will detect gluten sensitivity specifically, the study concluded.
A. Fasano et al. Divergence of gut permeability and mucosal immune gene expression in two gluten-associated conditions: celiac disease and gluten sensitivity. BMC Medicine 2011, 9:23. doi:10.1186/1741-7015-9-23.