# Associations between oral health problems and inflammatory bowel disease: evidence from prospective cohort study

## TL;DR

Poor oral health is linked to a higher risk of inflammatory bowel disease, with more oral health issues increasing the risk, possibly through inflammation.

## Contribution

This study is the first to explore the cumulative effect of multiple oral health problems and their inflammatory mediation in relation to IBD.

## Key findings

- Mouth ulcers, painful gums, and dentures are associated with increased risk of Crohn’s disease and ulcerative colitis.
- Having more oral health problems correlates with higher Crohn’s disease risk in a dose-dependent manner.
- Low-grade inflammation partially mediates the link between painful gums and dentures with Crohn’s disease.

## Abstract

An association exists between oral health problems and inflammatory bowel disease (IBD). However, few studies have considered comprehensive oral health problems and the concurrent presence of multiple oral health problems in relation to IBD. Additionally, the role of inflammatory responses as a mediator in this relationship remains unexplored. This study aimed to investigate association between oral health problems and IBD utilizing data from the UK Biobank.

Oral health were assessed via self-reported. IBD was defined by disease classification codes from the International Classification of Diseases-10. Cox regression models were employed to analyze the relationships between oral health problems and IBD, using mediation analysis to investigate the role and effect size of inflammatory indicators in this association.

Among 412,134 participants, mouth ulcers (HR: 1.25, 95% CI: 1.02-1.53), painful gums (HR: 1.50, 95% CI: 1.12-2.03), and dentures (HR: 1.30, 95% CI: 1.10-1.53) linked to Crohn’s disease (CD) risk. Mouth ulcers (HR: 1.16, 95% CI: 1.01-1.34) and dentures (HR: 1.18, 95% CI: 1.05-1.33) linked to ulcerative Colitis (UC) risk. Having two (HR: 1.29, 95% CI: 1.02-1.63)/three (HR: 1.69, 95% CI: 1.14-2.49)/more than three (HR: 2.13, 95% CI: 1.20-3.78) oral health problems correlated with CD risk, with more oral health problems correlating with higher CD risk (P for trend < 0.001). Low-grade inflammation index (INFLA-score) positively mediated the association between painful gums (proportion mediated=3.09%)/dentures (proportion mediated=5.40%) and CD.

Mouth ulcers and dentures may increase the risk of CD and UC, while painful gums associates with CD. More oral health problems link to higher CD risk. Inflammatory responses partially mediating the association between painful gums/dentures and CD.