How Does Excess Fat Contribute to Inflammatory Bowel Disease?

Intra-abdominal fat cells associated with the progression of Crohn’s disease and ulcerative colitis.

The role of excess fat across a wide variety of health-related problems is well known, but this effect may stretch further than previously thought.

A recent study published in Cellular and Molecular Gastroenterology and Hepatology found excess intra-abdominal fat cells may contribute to the development and progression of inflammatory bowel disease (IBD).

"A well-appreciated feature of IBD, especially longstanding Crohn's disease, is intra-abdominal fat, also known as creeping fat, which wraps around the intestine. However, it's not clear whether this fat is protective or harmful," study author Charalabos Pothoulakis, MD, said in a press release. "Our study offers insight into this phenomenon. We found that intra-abdominal fat cells may normally be programmed to dampen inflammation but, in fact, have acquired a tendency to promote inflammation in IBD."

Determining the role of creeping fat in IBD is difficult because it generally is not found in healthy patients, rendering controlled studies a challenge, according to the current study. To overcome this issue, researchers isolated and cultured pre-intra-abdominal fat cells from healthy subjects and from patients suffering from IBD, including Crohn's disease and ulcerative colitis.

Researchers found signaling mediators generated by the intra-abdominal fat cells of healthy subjects are significantly different from mediators produced by intra-abdominal fat cells from IBD patients. These findings indicate that intra-abdominal fat plays an active role in gut immunity and inflammation.

Unexpectedly, researchers found the fat cell responses were different among patients with ulcerative colitis and Crohn's disease. Prior research indicated a potential role for creeping fat in the pathophysiology of just Crohn's disease, however, the current study provided the first evidence implicating intra-abdominal fat tissue in the development of ulcerative colitis, as well.

The researchers concluded that additional studies are needed to improve the understanding of how inflammation promotes the production of creeping fat, and how fat cells may offer a therapeutic target.

"This research provides new insight that may lead to future targeting of intra-abdominal fat cells for therapeutic benefit," said study co-author Jerrold R. Turner, MD, PhD, AGAF.