What Are Possible Environmental Triggers for IBD?

The root cause of inflammatory bowel disease (IBD) is still a mystery to doctors and scientists. They once thought diet and stress were the culprits. But they now know that, while these things can make IBD worse, they do not cause the condition.¹

Experts are looking at whether environmental triggers can bring on IBD. These triggers can include where you live or whether you engage in certain behaviors. The number of people with IBD has risen over the years in different parts of the world. This increase suggests to researchers that environmental factors play a role in triggering the disease.²

Researchers are also closely studying the effects of environmental factors on the gut microbiome. The gut microbiome is all the bacteria, fungi, viruses, and other microorganisms that naturally live in your gut.²

Environmental factors could affect the makeup of the gut microbiome and contribute to IBD inflammation. It is possible that having less variety, or diversity, in your microbiome puts you more at risk for an IBD, such as Crohn's disease or ulcerative colitis.²

Possible environmental risk factors for IBD

Here is a closer look at some of the environmental IBD triggers that researchers are exploring.

Antibiotics

Researchers have linked these medicines to a higher chance of forming IBD, especially in young children. Studies have shown that taking antibiotics can make the bacteria in your gut less diverse. This effect could last for many months after taking them.²

Living in an urban area

Where you live may also play a role in whether you develop IBD. Urban areas have seen higher rates of the disease, especially areas with rapid growth. This increase may be related to factors that come with city living, like pollution and diet.²

Pollution

Researchers have connected exposure to air pollution in urban areas to poorer health, including IBD. Studies of mice show that high levels of airborne pollution allow more harmful substances to pass through the digestive tract lining. This is called having gut permeability. These substances then enter the bloodstream, which can lead to inflammation and IBD.²

Other studies do not show a clear link between air pollution and IBD. So, more research is need to understand the possible link.²

Diet

Studies show that eating higher amounts of certain nutrients or food additives may contribute to IBD. While diet may not directly cause IBD, it could change the makeup of your gut microbiome and lead to the disease. Scientists think an increase in harmful bacteria and a decrease in "good" bacteria disrupt the immune system. This change could also lead to gut permeability.²

Other triggers

Researchers have also looked at other possible triggers for IBD. They include:³

• Smoking
• Appendix or tonsil removal
• Taking oral birth control
• Lack of vitamin D
• Drinking soft drinks

Environmental factors and future IBD research

Pinpointing environmental triggers and learning more about how they relate to IBD could lead to new treatments and ways to prevent the disease. But researchers need data from more, and higher quality, studies to better understand the causes of the disease.^2,3

They suggest a "multi-omic" approach. This means the study of multiple aspects of the biological system. For example, genomics studies the DNA system, and proteomics studies the proteins in a cell. By looking at these "omics" together, researchers can get a more complete picture of how biological systems work. This approach has become important in fields such as environmental science.^2,3