Gluten sensitivity may be caused by immune response, study finds

Individuals who are suffering from gluten sensitivity, but do not have celiac disease, may finally have an explanation for their condition, according to a new study from Columbia University Medical Center (CUMC).

The team, in collaboration with the University of Bologna in Italy, found that patients who experience various gastrointestinal symptoms in response to wheat ingestion may be suffering from a body-wide inflammatory immune reaction not seen in patients with celiac disease.

The inflammation, researchers said, is due to a weakened gut, and the condition is referred to as non-celiac gluten or wheat sensitivity (NCWS). Symptoms of NCWS include intestinal problems, as well as fatigue, cognitive difficulties, or mood disturbances.

"Our study shows that the symptoms reported by individuals with this condition are not imagined, as some people have suggested," study co-author Dr. Peter H. Green, Phyllis and Ivan Seidenberg Professor of Medicine at CUMC and director of the Celiac Disease Center, said in the news release. "It demonstrates that there is a biological basis for these symptoms in a significant number of these patients."

In people with celiac disease, the immune system attacks the lining of the small intestine after gluten from wheat, rye, or barley is eaten. This leads to various gastrointestinal symptoms, such as stomach pain, diarrhea, and bloating. Individuals with celiac disease show intestinal damage, but unlike patients with NCWS, do not demonstrate a large-scale systematic immune response.

In a study published in Gut, researchers examined 160 participants: 80 with NCWS, 40 with celiac disease, and 40 with neither condition. They found that NCWS is linked to a weakened intestinal barrier that allows the movement of microbial and dietary molecules from the intestines into the rest of the body. This, researchers suggest, ultimately results in the body-wide immune response that patients saw in response to gluten.

"A systemic immune activation model would be consistent with the generally rapid onset of the reported symptoms in people with non-celiac wheat sensitivity," study leader Armin Alaedini, PhD, an assistant professor of medicine at CUMC, said in the press release.

Study authors estimate that approximately 3 million Americans suffer from NCWS. However, they also found that NCWS patients who excluded wheat and gluten from their diet for six months reported significant improvements in both intestinal and non-intestinal symptoms.

Researchers hope that future studies will allow them to better understand the mechanisms responsible for both NCWS and celiac disease.

"These results shift the paradigm in our recognition and understanding of non-celiac wheat sensitivity, and will likely have important implications for diagnosis and treatment," co-author Dr. Umberto Volta, a professor of internal medicine at the University of Bologna, said in the press release. "Considering the large number of people affected by the condition and its significant negative health impact on patients, this is an important area of research that deserves much more attention and funding."