New Research Finally Connects Inflammatory Bowel Disease and Celiac Disease

Maria Ines Pinto-Sanchez, MD

Patients with either inflammatory bowel disease (IBD) or celiac disease are at an increased risk of contracting the other disorder, according to new research.

A team, led by Maria Ines Pinto-Sanchez, MD, Department of Medicine, Farncombe Family Digestive Research Institute, McMaster University, performed a systematic review and meta-analyses to assess the evidence for an association between celiac disease and inflammatory bowel disease.

Researchers were previously split on any association between celiac disease and inflammatory bowel disease.

The investigators searcher various databases for studies assessing the risk of celiac disease in patients with inflammatory bowel disease, as well as the risk of IBD in patients with celiac disease, compared with controls of any type.

The team used the Newcastle-Ottawa Scale to evaluate the risk of bias. They also used GRADE to assess the certainty of evidence.

Overall, the investigators identified 9791 studies conducted between 1978-2019 that met their criteria, 65 of which were included in the final analysis.

Of the final 65 studies, 30 studies included control groups with a total of 13.6 million participants—43,000 with celiac patients, 166,000 IBD patients (39,000 Crohn’s disease, 56,000 ulcerative colitis, and 3000 indeterminate colitis patients), and 13.4 million controls.

They found with moderate certainty an increased risk of celiac disease in patients with IBD when compared to controls (RR, 3.96; 95% CI, 2.23-7.02). There was also an increased risk of inflammatory bowel disease in patients with celiac disease when compared to controls (RR, 9.88; 95% CI, 4.03-24.21).

On the other hand, there were low-certainty evidence for the risk of anti-Saccharomyces antibodies, a serologic marker of IBD, in patients with celiac disease compared to controls (RR, 6.22; 95% CI, 2.44—15.84).

There was low certainty evidence for no difference in risk of HLA-DQ2 or DQ8 in patients with IBD when compared to controls (RR, 1.04; 95% CI, 0.42—2.56), as well as very low certainty evidence for an increased risk of anti-tissue transglutaminase in patients with IBD compared to controls (RR, 1.52; 95% CI, 0.52-4.40).

Patients with inflammatory bowel disease also had a slight decrease in the risk of anti-endomysial antibodies compared to controls (RR, 0.70; 95% CI, 0.18-2.74). However, these results are not certain.

“In a systematic review and meta-analysis, we found an increased risk of IBD in patients with celiac disease and increased risk of celiac disease in patients with IBD, compared with other patient populations,” the authors wrote. “High-quality prospective cohort studies are needed to assess the risk of celiac disease-specific and IBD-specific biomarkers in patients with IBD and celiac disease.”

Both inflammatory bowel disease and celiac disease are chronic and disabling intestinal conditions that share similar risk factors. In recent years, the prevalence of both diseases has increased.

The exact cause of IBD is not currently known, but it is believed that infections, genes, and other environmental factors are involved. For celiac disease, the main environmental trigger is dietary gluten, but specific genes are needed for individuals to develop the disorder.

The study, “Association Between Inflammatory Bowel Diseases and Celiac Disease: A Systematic Review and Meta-Analysis,” was published online in Gastroenterology.