Is there a link between genetics and Inflammatory Bowel Disease (IBD)?

September 3, 2024

Swedish Digestive Health Team

[3 MIN READ]

Researchers have found that genetics may play a role in Inflammatory Bowel Disease (IBD), but the cause of IBD remains unknown.
The risk of IBD can be reduced with lifestyle changes that focus on a healthy diet, physical exercise and other habits and activities that support overall wellbeing.
If you are concerned that you or a family member have IBD, the first step is to talk to your primary care provider.

Is there a link between genetics and Inflammatory Bowel Disease (IBD)?

Researchers at London's Francis Crick Institute made news in 2024 when they published a study pinpointing a genetic abnormality as a cornerstone for the development of IBD and other immune disorders. The British press picked up the study and touted it as identifying a "major cause" of IBD with the potential to open more treatment pathways.

To learn more about how this study may impact IBD treatment, we spoke with Michael Chiorean, M.D., director of the IBD Center at Swedish Medical Center.

What is IBD?

IBD is a term that refers to immune-mediated conditions that inflame the digestive tract over a long time. There are two main types of IBD:

Ulcerative colitis, which affects the large intestine (colon), causing inflammation and sores.
Crohn's disease, which can cause inflammation anywhere in the digestive tract but most often affects the small intestine and colon. It can also spread deep into the layers of the digestive tract.
IBD is classified as a disease, and both ulcerative colitis and Crohn's disease may cause symptoms like diarrhea, rectal bleeding, stomach pain, fatigue and weight loss. Some people have mild symptoms, while others have severe issues that could become life-threatening. Both conditions increase the risk of colon cancer.

"Some naturopathic providers offer to test for IBD, but there is no laboratory test that tells you that you have it," says Dr. Chiorean. "People who experience unusual GI symptoms such as bleeding, chronic diarrhea or unexpected weight loss should talk to their primary care provider who can refer them to a gastroenterologist for further evaluation."

Is there a difference between IBS and IBD?

While the terms used to describe them sound similar, IBD and irritable bowel syndrome (IBS) are two very distinct gastrointestinal disorders. People with IBS may experience symptoms like those of IBD, but they do not have intestinal damage. Rather, it is caused by overactivity of the gut nervous system. IBS does not cause inflammation, does not require hospitalization or surgery and does not increase a person's cancer risk.

DNA doesn’t explain what causes IBD

The researchers who published the study linking DNA to IBD found a section of DNA that is only active in some immune cells known to cause inflammation in the bowels.

"The greatest news from this study is the application of functional genomics to IBD," says Dr. Chiorean. "It clarifies some questions about the function of an important immune subset called macrophages that are specifically related to immune-mediated disorders, including IBD. But the genetic associations published in the study were well known before."

"However, the study does not answer why people get IBD, nor does it give great clues about treatment or a cure," he adds. "And the only treatments mentioned in the BBC article as possible applications of this discovery are chemotherapies used for aggressive cancers called sarcomas. So, at this time, we still do not have a direct application for diagnosis or treatment of IBD."

What to do if you are concerned about IBD

While there is evidence of a genetic link to IBD, Dr. Chiorean emphasizes that parents should not worry too much about passing IBD on to their offspring.

"There is a 4% to 8% risk of transmitting IBD to an offspring," he says. "Breastfeeding, a healthy diet, exposure to pets and farm animals, regular physical exercise and avoiding obesity, smoking and excessive antibiotics can all reduce the risk of IBD."

For patients who are concerned that IBD might run in their family, Dr. Chiorean encourages them to discuss those concerns with a gastroenterologist or an IBD expert in an IBD center such as the IBD Center at Swedish Medical Center.

Treatment

Swedish has a large and growing number of treatment options for IBD. Each patient's care is tailored to the disease type (i.e., Crohn's or ulcerative colitis), severity, other non-GI manifestations and the patient's prior therapies.

"The Swedish IBD Center is engaged in several clinical trials with cutting-edge therapies that may provide additional breakthroughs in treatment," says Dr. Chiorean. "And we offer some diets that work for a select group of patients."

"IBD conditions can have a profound effect on a person's life — they are chronic, life-long and often start at an early age. However, in my over 20-year career, we have never had such a rich treatment toolbox and a promising pipeline for new strategies and therapeutics."

Learn more and find a physician or advanced practice clinician (APC)

Whether you require an in-person visit or want to consult a doctor virtually, you have options. Contact Swedish Primary Care to schedule an appointment with a primary care provider. You can also connect virtually with your provider to review your symptoms, provide instruction and follow up as needed. And with Swedish ExpressCare Virtual, you can receive treatment in minutes for common conditions such as colds, flu, urinary tract infections and more. You can use our provider directory to find a specialist or primary care physician near you.

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