675: Salivary Microbiota and Network Changes in Oral Lichen Planus with Candida vs. Healthy Controls

Topic: Experimental (Non-clinical) Human Studies
Subtopic: Non -specific to any diagnosis, Omics (Proteomics/Metabolomics/Transcriptomics/Genomics), Pain mechanisms (e.g. descending inhibitory control, placebo, inflammation)

Background and Aims: Oral lichen planus (OLP) is a chronic immune-mediated mucosal disorder frequently accompanied by Candida colonization. However, the polymicrobial interactions and network alterations underlying this association remain poorly understood. This study aimed to characterize bacterial-fungal community changes and interkingdom network dynamics in OLP patients with confirmed Candida detection compared to healthy controls.

Methods: Unstimulated saliva samples were collected from 27 OLP patients and 30 healthy controls. Bacterial 16S rRNA (V1-V2) and fungal ITS2 regions were simultaneously sequenced using Illumina NovaSeq. Taxonomic profiling, diversity analyses, differential analysis, and intermicrobial correlations were analyzed.

Results: Beta diversity analysis revealed distinct community separation (p=0.001). OLP showed increased Bacteroidetes and decreased Firmicutes. Health-associated commensals (Streptococcus salivarius, Rothia mucilaginosa, Haemophilus parainfluenzae, Veillonella dispar) were depleted, while pro-inflammatory anaerobes (Prevotella, Fusobacterium, Leptotrichia, Selenomonas) were enriched. Candida abundance was similar between groups (0.31% vs. 0.29%), though Candida albicans predominated in OLP. Network analysis showed Candida occupied a central position with expanded connectivity to disease-associated genera. The disease network exhibited increased negative correlations and dispersed topology, indicating reduced ecological stability versus the healthy network.

Conclusions: OLP is characterized by compositional dysbiosis and disrupted bacterial-fungal interaction networks. Candida acts as a keystone species driving interkingdom dysbiosis that perpetuates mucosal inflammation. These findings support microbiome-targeted adjunctive therapies—including antifungals, selective antimicrobials, and probiotics—for managing Candida-associated OLP.

References: 1. Wang K, Lu W, Tu Q, et al. Salivary mycobiome dysbiosis and its potential impact on bacteriome shifts and host immunity in oral lichen planus. Int J Oral Sci. 2019;11:13.
2. Du M, Jiang L, Wei F, et al. Dysbiosis of saliva microbiome in patients with oral lichen planus. BMC Microbiol. 2020;20:75.
3. Sims KJ, Zhu J, Chandra J, et al. Dysbiosis and interactions of the mycobiome and bacteriome in mucosal lesions of oral lichen planus patients. J Oral Microbiol. 2024;16:2374639.
4. Hajishengallis G, Lamont RJ. Beyond the red complex: the polymicrobial synergy and dysbiosis model. Mol Oral Microbiol. 2012;27:409-419.

Presenting Author: Hye-Min Ju
Submitting Author: Hyemin Ju

Senior Author: Hye-Min Ju

IASP 2026 Global Year theme of Neuropathic Pain: No

• Jee-Won Jang: DDS - Pusan National University Dental Hospital
• Sung-Hee Jeong: DMD, PhD - Pusan National University, School of Dentistry/Pusan National University Dental Hospital
• Soo-Min Ok: DDS,PhD - Pusan National University, School of Dentistry/Pusan National University Dental Hospital
• Yong-Woo Ahn: DDS,PhD - Pusan National University, School of Dentistry/Pusan National University Dental Hospital
• Hee-Sam Na: PhD - Pusan National University, School of Dentistry