Objective:

To review the molecular and immunological mechanisms driving the comorbidity between COPD and IBD, with a focus on the critical role of the gut-lung axis in these interactions.

Key Findings:

• Significant bidirectional comorbidity risk exists between COPD and IBD, with specific prevalence rates.
• Shared genetic susceptibility and immune mechanisms underlie the gut-lung axis, supported by recent GWAS findings.
• Gut dysbiosis and systemic hypoxia contribute to inflammation in both conditions, with implications for treatment.
• Pharmacological interventions targeting the gut-lung axis may improve treatment outcomes, as evidenced by recent clinical trials.

Interpretation:

The gut-lung axis represents a complex network of interactions that can exacerbate both COPD and IBD, necessitating integrated diagnostic and therapeutic approaches that consider these interconnections.

Limitations:

• Current understanding of the gut-lung axis is still evolving and may not encompass all relevant mechanisms, particularly emerging factors.
• Existing studies may have confounding factors, such as patient demographics and comorbidities, that complicate the interpretation of comorbidity risks.

Conclusion:

A deeper understanding of the gut-lung axis can lead to novel therapeutic strategies for managing COPD and IBD as interconnected diseases, including potential microbiota-targeted therapies.