If you have chronic obstructive pulmonary disease (COPD), you might also be at risk for inflammatory bowel disease (IBD), and vice versa. A new systematic review of genetic studies suggests that these two seemingly unrelated conditions share a common genetic vulnerability.
The review looked at genome-wide association studies (GWAS) and found that genetic pleiotropy—where the same genes influence multiple traits—underpins a shared susceptibility to defects in the body's mucosal defenses. This means that problems with the protective barriers in your lungs and gut may stem from the same genetic roots.
Beyond genetics, the review also highlights how immune cells can travel between the gut and lungs, spreading inflammation. An imbalance in certain immune cells, along with changes in gut bacteria that reduce beneficial short-chain fatty acids, may worsen damage to both organs. The authors describe a "hypoxic loop" where low oxygen levels fuel a cycle of injury.
It's important to note that this is a review of existing studies, not new research. No specific treatments were tested, and the findings are based on patterns, not proven cause-and-effect. Still, the results offer a clearer picture of why lung and gut health are so closely linked.