Analysis of Oral Microbiota in Herpetiform Aphthous Ulcers Patients

To examine the microbiota in the oral mucosa and saliva of patients with herpetiform aphthous ulcers (HAU) and compare it with healthy individuals.

16S rRNA sequencing was employed to analyze the oral mucosal bacterial communities of healthy individuals (healthy controls) and HAU patients (ulcerated sites, healthy sites, and healed ulcer sites).

Species richness in patients with HAU was statistically significantly lower than in healthy individuals. At the phylum level, the abundance of Firmicutes in the healthy sites of HAU patients was lower, while that of Proteobacteria was higher compared to healthy controls. In the ulcerated sites, the abundance of Firmicutes diminished, and the abundance of Proteobacteria increased relative to the healthy sites. In the healed ulcer sites, the abundance of these two phyla had partially recovered but had not yet reached the level of healthy sites in the ulcer phase. At the genus level, the abundance of Streptococcus in the healthy sites of HAU patients was lower than that in healthy controls, whereas Haemophilus_D was higher. In the ulcerated sites, the abundance of Streptococcus decreased, while the abundances of Neisseria and Haemophilus_D increased compared to the healthy sites. In the healed ulcer sites, the abundance of these three bacterial genera recovered to levels close to those in healthy sites during the ulcer phase. LEfSe analysis indicated that o_Enterobacterales_A, f_Pasteurellaceae, f_Erysipelotrichaceae, g_Bulleidia, f_Peptoniphilaceae, and g_Parvimonas were identified as biomarkers in the ulcerated sites.

These findings highlight the distinct microbial signatures associated with HAU and suggest that microbial community changes may play a role in disease progression and healing.