Exploring the Link between Green Spaces and Digestive System Diseases: Observational and Genetic Perspectives

Abstract

Purpose: To explore the epidemiological and genetic link between green spaces and digestive system diseases.

Methods: The current study includes two main parts. The first part is a comprehensive meta-analysis of epidemiological findings, subsequently, two-sample epigenetic Mendelian randomization (MR) analysis is conducted to explore the genetic associations between green spaces and digestive system diseases.

Results: The meta-analysis part included seven studies, with six cohort studies and one ecological study. After pooling up all the data, we found that green space was not significantly associated with the overall risk of digestive system diseases (OR=0.97, 95% CI=0.92 to 1.01, P=0.17, I²=90.09%). Subgroup analysis showed that green space was associated with reduced risk of liver diseases (OR=0.93, 95% CI=0.88 to 0.99, P=0.02, I²=79.76%). In the MR analysis, genetic evidence suggested significant causal effects between green spaces-associated DNA methylation and digestive system diseases. Specifically, the PRSS23 gene and CpG site cg10916494 were strongly associated with ulcerative colitis, indicating potential biological pathways linking green spaces and digestive system diseases.

Conclusion: Our findings suggested that while epidemiological evidence did not strongly indicate that green spaces were associated with digestive system diseases. However, MR analysis indicated that significant causal effects between green spaces-associated DNA methylation and digestive system diseases existed.