Salivary Biomarkers in Crohn’s Disease and Ulcerative Colitis: A Scoping Review and Evidence Map

Abstract

Salivary biomarkers have been explored as potential non-invasive tools for the diagnosis and monitoring of inflammatory bowel diseases (IBD), including Crohn's Disease (CD) and Ulcerative Colitis (UC). This study presents a scoping review and evidence mapping on the use of saliva as a matrix in which biomarkers can be identified for these conditions. A systematic search of multiple databases and studies was conducted until 28 January 2025, resulting in the selection of 12 relevant articles. The quantified evidence synthesis identified eight molecular and microbial categories. Of these, four classes, including cytokines, microRNAs, calprotectin, and the microbiome, have demonstrated the most consistent potential. Alterations in these biomarkers, such as an increase in the <i>Prevotella</i> genus within the microbiome, and elevated PSMA7 levels, may reflect disruptions in intestinal barrier integrity and immune response. However, factors such as oral health status, hygiene habits, and medication must be carefully considered. Therefore, further clinical research is essential to validate specific biomarkers.